AudioCircle
Audio/Video Gear and Systems => Enclosures => Topic started by: Bob in St. Louis on 7 May 2011, 02:57 pm
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I'm building a double Ripole for a forum buddy, "New Praetorian" (Jeff) with two prototype 18" Hawthorne Audio drivers. I have not gotten very far yet, but have taken a few pictures. It took me quite a while to get over the shear size of these monsters, and I wanted Jeff to get a feel for their size.
As a result, most of my pictures are of the bare drivers. :oops: :lol:
I bought three sheets of voidless Baltic Birch. The dimensions are 5'x5'x 3/4, 13 ply.
In all, there will be twelve "layers" of plywood. So far, I've managed to get twelve perfect 21" x 21" pieces of plywood.
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Notice the knife for size reference. :shock:
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/1.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/2.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/3.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/4.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/5.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/DSC_0648.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/7.jpg)
more soon.......... :thumb:
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By the way....for Windows users, if you hold the [Ctrl] button and tap the "-" key, the image will fit your screen better.
For Mac users, um.....give your unit a swift kick. Maybe that will help. :dunno: :wink:
Bob
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Hey Bob, don't be a hater. :lol:
By the way, it comes up full size on my Mac......no clicking involved. Love ya, man!!!!
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Well Mark, my first post was too dry, too serious. I had to get some humor in there somewhere.
It's generally a safe bet to pick on the Mac users. :wink:
But I'll let you know when I get the Ripole fired up. You can come over for a listen.
Bob
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Can't wait to hear them. They will be monsters :icon_twisted:
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God I love big woofers. I am such a sad child!
Those look very good, and knowing what I do about Hawthorne, they will be well designed.
Looking forward to hearing about what the final product turns out like, I have been fascinated by ripoles for years, but have never built up a set.
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Hi Bob,
Are those basically 18" Super Augies? :o
They look like really impressive drivers. Looking forward to learning more about them.
Hawthorne Audio is a great company run by great people!
-Nick
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Sorry for the delayed reply....Mother's Day and all that goes with it........I'm sure you understand. :wink:
Mark (St. Louis) - I'd LOVE for the GAS guys to come over and see the new toy, once it's operational.
Mark (Canada) - Thanks man. Yes, I have high hopes for these as well.
With the history of their "lineage" and all, I have every confidence they'll blow the dust off my carpet in a most violent way. :lol:
Nick - Sure, you could call them "Super Augies". That sounds good to me! :thumb:
The measured weight on the UPS shipping sticker was 45 pounds. There's not much weight to the cardboard and styrofoam. So yea, they're "Super" alright. ha ha
There was another post, but it's now gone. The poster was asking for a definition of Ripole, and strangely enough I'm not able to find one. :dunno:
I can find build threads (including a recent one > HERE < (http://www.audiocircle.com/index.php?topic=90175.0)). Several in fact. But a true definition eludes me. In this particular build, I'm no more than the sawdust maker. The dimentions have been provided for me. I basically don't have to use much brain power, just the fellow that guides the tools across the wood.
Tomorrow I have the day off. Sawdust will fly again. :thumb:
Bob
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http://www.lautsprechershop.de/hifi/ridtahler_en.htm
http://www.lautsprechershop.de/hifi/ripol_en.htm
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Nice! :D
Thank you very much Lin.
I assume the "Ri" in RiPole is a combination of the word Dipole and the inventors name, "Ridtahler" combining to form "RiPole"?
Bob
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When two are bolted together like this:
(http://www.lautsprechershop.de/hifi/images/dipol_ridtahler.gif)
it looks rather like the Linkwitz W-frame:
(http://linkwitzlab.com/images/graphics/d_woof1.gif)
My understanding is that the "ripole" is intended to provide (more) mass loading of the driver with the lower area of the openings and thus reduce Fs. I'm curious as to how beneficial this all is. A narrower profile would certainly be a plus in many situations.
How's the sawdust coming along Bob? ;)
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Very cool project!
I've wanted to hear the Augies for a while now.
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Sorry Bob, that was me asking what a Ripole was, but I found answers so I deleted the post. As I read they behave differently from most subs.
Didn't know Hawthorne did 18 inchers.
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John - Yes. The Ripole is pretty close to the Linkwitz. The main difference is that he's got the "front" of the enclosure open to the rear wave of one driver, and front wave of another.
The Ripole is the front wave of both.
...And to answer your question...the sawdust, by the way, was going fine until the (brand new) Craftsman router I have let it's smoke out. :evil:
Note the one picture of the workshop that's foggy? That's not a photographic effect, that's smoke in my house. Sure did smell bad.
jtwrace - Come on by. I'll give you a listen. :wink:
JLM - Yes, I wasn't going to name names, but yea, it was your post I saw. :lol:
The one Lin linked us to is the best I've seen yet.
Hawthorne doesn't "really" have 18 inchers yet. This is just a little something to see what they're capable of.
By the way.... In the interest of full disclosure, I suppose I should say that if anybody is curious if I'm a Hawthorne Audio fanboy, you'd be correct.
Ok... On to the pictures:
As I mentioned, my (damn) Craftsman router crapped itself, so I didn't get much done today.
I bought it quite some time ago, and no longer have the receipt. This should be fun. :roll:
But here's what I've got done.
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/9.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/8.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/10.jpg)
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Decades ago it was a standing joke in our office that Craftsman routers would burn up while under warrantee (the warrantee "reset" each time we traded the burnt out ones). So we started "sharing" one between all of us and let Sears replace it 4 or 5 times before we all got our projects done.
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Sunshine... haven't I tought you that porter cable is the only way to router :green:
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OMG.. two 18's in a Ripole is gonna be INSANE :thumb:
I think Axel Ridtahler would call your configuration (woofers face-to-face) a "BMC" (blow motion control) Ripole. Nice work, BTW... I see you're a fellow woodworker too.
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JLM - Yea..... :duh: ..... I had a negative attitude towards Craftsman routers for many years, but they caught me in a moment of weakness when I saw the shiny aluminium machine on the store shelf. They also got me to buy one of their circle jigs. :oops: :roll:
Horrible piece of equiment. The Jasper circle jig is MUCH better.
Randy - Thanks for the advice hun. I'll be available next Saturday. I'll supply the beer. You supply the router. 8)
Lesson learned.
Although I'm sure the best I can hope for would be an even exchange where I get another unit of the same quality. :|
Charlie - I hope to make Axel proud. I do believe this unit will cause some property damage, given the proper amp. Unfortunately, I do not have such a unit, but the fellow that has bought these is contemplating a 4,000 watt amp to power them. :o
Thank you for the complement. I'd love to consider myself a woodworker, but those fellas that are truly "workers of wood" are in another league. I'm simply able to cut two pieces of wood the same size and glue them together. I am humbled too often with craftsmen of wood.
Bob
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I have a pair of Ripoles with two 12" Peerless SLS (parallel 4 ohm) in each one and I'm driving both with a single Carver TFM-25 amp (225W/ch into 8 ohms). The SLS driver doesn't have the X-max of its XLS brother but it has less moving mass so I figure it's faster and cleaner, within it's limits of travel. Anyway, what I've found is that the Carver can push the cones to X-max with plenty of power left so I there would be no advantage to a huge amp, in my case. I'm glad I went ahead and built a pair of them because you need a lot of cone area with Ripoles.
I like my DeWalt router but I sure wish I had that circle jig. :)
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Sunshine... haven't I tought you that porter cable is the only way to router :green:
Good pick, my dad ran Porter Cable and Delta Machinery when they were both under Rockwell, before the new parent company split off Porter Cable. Great tools.
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Good pick, my dad ran Porter Cable and Delta Machinery when they were both under Rockwell, before the new parent company split off Porter Cable. Great tools.
if you ever seen pics of my builds, you would understand that my routers hate me and hate their life... but keep asking for more :green:
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Turns out the warranty for a Craftsman router is 12 months. Mine is older then that. There is no more warranty, or mercy on the part of Sears.
It's done.
Also, to clarify....I mentioned I bought this a while back but this is the first real project I've used it for.
My wife has since corrected me.
I used it for the kitchen remodel. If you recall the thread, there was extensive router work done.
So...I suppose I feel better about the thing dying, but not much. It's probably got an eight mile of "use" in it's life.
Home Depot doesn't sell a plunge router of any quality higher then the $69 Ryobi unit.
I've burnt through more Ryobi hand tools then I care to mention.
I bought a DeWalt #DW618PK at Lowes for $200. Also bought a 1/4" upspiral bit and a 1/4" downspiral bit. Never used either one before.
The Craftsman circle jig I bought at Sears that I was going to take back is a perfect match for the unit sold at Lowes by some brand I've never heard of.
Although I'm not very fond of the unit, I'll keep it. The Jasper jig is much more stable, simply because there's less crap going on.
This thing tries to be fancy, and only makes for an unstable tool.
I still need to figure out how to make the 7" holes for the layers of plywood that surround the magnet. The circle jig only goes down to 10". :roll:
I've seen adjustable hole saws, but Depot and Lowes don't have them.
But....sawdust will fly today. :thumb:
Bob
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Quick break time. Pictures now, words later. ;)
Notice the new shiny Dewalt router on the shelf? Love it!!
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/11.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/12.jpg)
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(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/13.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/14.jpg)
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(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/15.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/16.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/17.jpg)
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So THAT'S what you said was going in the back of the Suburban!! :lol: :lol: :lol:
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:lol: Hmmmm..... now that you mention it.............. :icon_twisted:
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Looking good :thumb: Does the panel with the hole actually push up against the frame?
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Thanks John! :thumb:
Good eye by the way.
The top driver isn't bolted down and the gasket is holding everything up a bit. That's why there's a visible gap around the top "lid".
There's more to be done than appears. The top third is just sitting there for effect.
Bob
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That oughta bust up some drywall for ya!
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Thanks Charlie. Yea, it should make itself known pretty well. :icon_twisted:
One one photo for today.
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/18.jpg)
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Another day of sanding and staining. The saw dust is finished.
One more test fit to see how things are coming along.
Being the novice photographer that I am, I couldn't decide which looked best, using a flash or not.
in the end, I thought they both looked neat.
The first two pics are the front of the unit, the last are the rear. No drivers are installed.
More sanding and staining before it's finished......
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/22.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/23.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/24.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/25.jpg)
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Beautiful build Bob, really first class :thumb:.
Best,
Ed
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:o First class built....sexy.
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Thanks guys! :D
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Way cool Bob, way Cool!!!! :thumb: :thumb:
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I can't wait to listen to this beast :D
Great work as usual Bob :thumb:
Thanks!
Jeff
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I can't wait to listen to this beast :D
Great work as usual Bob :thumb:
Thanks!
Jeff
Hi Jeff,
I didn't realize you posted on this site. I think I may be able to hear/feel that beast playing up here in Southern Indiana!!
Congrats on a really nice sub.
Best,
Ed
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I'm building a double Ripole for a forum buddy, "New Praetorian" (Jeff) with two prototype 18" Hawthorne Audio drivers.
I see this is for the guy you helped construct those cherry Trios -there were already quite a few auggies. What is the overall plan here? Just curious.
Nice work, btw.
-Tony
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Thanks guys! :D
{Especially Jeff} :wink:
Tony, I think his overall plan is to crack drywall, much like mine is. :icon_twisted: :lol:
Actually, he's not only got a two channel rig (Niteshade stuff), but also a home theater. The Augies do *almost* everything he needs, this will take it the rest of the way...and beyond.
Bob
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Hello Ed. I kind of lurk here on the circle from time to time. Especially if someone is building something for me :wink:
Tony, can you ever really have enough bass? :icon_twisted: Seriously, I needed a new subwoofer to replace my SVS PC Ultra. With my current room setup, I have to put the sub in a corner behind the right speaker. Not only is this not ideal for bass in my room, it kind of detracts from two channel listening.
Thanks,
Jeff
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There's been a lot of boring stuff going on lately, sanding mainly, so as a result there's not much worthy of photographing which is why I've been quiet.
I'm nearing the point where these several pieces will become "one" with each other.
It occured to me to make a quick time lapse of one of my test fit sessions so y'all (mainly Jeff) could see what I've been up to.
By the way, when it's in one piece, I can't lift it off my workbench. The final assembly will be on the ground. :o :lol:
>> Here's the video << (http://vimeo.com/25941468).
Bob
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Glued those 12 "pillar things" today. Also a little more sanding, a little more painting, and a bit more staining.
This is the end result of a weekends work, and the way my workshop will look until next weekend.
(the cans and jugs are my clamps)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/37.jpg)
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That sure looks like everything is just balancing on that little portable saw... :o
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Yes, as a matter of fact, it is. I've put in a bit more air in the tires to accomodate. :weights:
Bob :wink:
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The parts count is slowly diminishing. I'm down to four pieces of wood and a couple drivers.
From left to right is the bottom piece with the legs and wires attached, then the center sections, and to the far right are the drivers.
Today I've spent my time planning on where to run the wires internally, drilling holes, and routing the wires.
The last thing I want to see are crappy looking wires hanging out of the thing.
My plan by the end of the day is to have the unit in a "test fit" situation and playing music. (http://www.hawthorneaudio.com/forums/images/smilies/Bob_yes.gif)
After that, all that remains is several coats of poly, some glue, a couple loose ends, and that's about it.
Bob
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/38.jpg)
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Wrapping speaker fabric around the magnet to keep debris out of the vent, then reinstalling the rubber surround:
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/39.jpg)
In place:
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/40.jpg)
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!!!
Very nice work Bob! :thumb: Are you going to try them in your system? Will they need EQ?
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Thanks John. I've actually got it wired up and am using it now.
I'm feeding it through a Behringer DCX2496, and am adjusting XO points and slopes. No "real" EQing though.
Bob
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Hi Bob, would you mind running me through your set up, i.e. crossover points and driver types and what they are doing frequency wise. Is the ripole to cover just very low down and what does it sound like at the upper end of its use. I am planning a three way set up with a tractrix horn from 1500Hz up, an Audax PR170MO preferably from 150-200Hz up to 1500Hz and some kind of encloure with a 15" woofer, would a ripole work for me?
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They can't be on right now. I don't feel my house shakin' :lol: :lol: :lol: :lol: :lol: :lol:
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Srsly Bob,
How do these compare to your 16 other subwoofers?? :D
Just going off the finished pics, the footprint of the beast isn't as imposing as I thought it would be.
How many neighbors are required to lift it?
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Lookin good Bob! Your enclosure fashion style is developing nicely! Soon you'll be on Stereophile cover!
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Hi Bob, would you mind running me through your set up, i.e. crossover points and driver types and what they are doing frequency wise. Is the ripole to cover just very low down and what does it sound like at the upper end of its use. I am planning a three way set up with a tractrix horn from 1500Hz up, an Audax PR170MO preferably from 150-200Hz up to 1500Hz and some kind of encloure with a 15" woofer, would a ripole work for me?
You should consult with somebody about that 150Hz x-over for the Audax. It seems too close to it's resonant freq for comfort. Madisound sells the driver. You can call them for advise.
Sorry to go off topic. Those 18" cabinets are beautiful.
neo
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wisfull thinking on my part 200Hz may be better. I may have been thinking about the AP170MO fs of 60Hz but lower sensitivity
You should consult with somebody about that 150Hz x-over for the Audax. It seems too close to it's resonant freq for comfort. Madisound sells the driver. You can call them for advise.
Sorry to go off topic. Those 18" cabinets are beautiful.
neo
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Very nice job Bob! It is not as large as I thought it would be. I'll bet the ratio of bass output to enclosure size is through the roof!!
Best,
Ed
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Versus Rider - Do you still need the specs, or did you determine otherwise?
Mark - You're right. They're not on. See "why" below. :?
Matt - My wife and I can lift it as a team, but she's not very dammed happy about it. :nono:
I'll be minimizing her assistance in lifting it. It isn't fun. :lol:
Rich and Neo, thank you both for the complements!
Ed - My photography skills didn't quite capture the mass of the device. It is 21"x21"x24" tall.
When all is said and done, I'll weigh it. Just for grins. :wink:
But here's the meat of why I'm posting today, and what I posted on the Hawthorne Audio forum......
Thanks to all for the kind words, and my apologies for the lack of communication. The project stalled a bit due to either, "A", the drivers are not suited for use in RiPole alignment, or "B", these handmade, prototype drivers have been electrically damaged in a previous life (I'm not the first user). Their sound quality was nothing short of amazing, but it had almost no output before it ran out of steam.
Regardless, Darrel Hawthorne has provided a pair of >> THESE << (http://www.eminence.com/speakers/speaker-detail/?model=Kilomax_Pro_15A) as replacement.
The physical dimensions of the rear basket area and magnet area are considerably different, so much modification will be necessary to the existing enclosure. My goal is to NOT have $150 worth of materials and dozens of hours go into the burn pile. I've got a four day weekend coming up and should be making progress then. Won't be much worthy of pictures, but trust me, I'll be in the workshop figuring things out.
The new 18" drivers arrived safe and sound today, and are very impressive with regard to heft and build quality. Their shipping weight alone was 65 pounds. :shock:
They've got an accordion suspension in the center front of the cone as opposed to the normal convex dustcap. Someone else may be able to tell you what the (solid as a rock) plate in the center of the cone is. I shot a couple pics, one with my hand and one with a marker for scale. These are serious drivers. Very serious.
More later....
Bob
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/46.jpg)
(http://i85.photobucket.com/albums/k60/BobinStLouis/Stuff%20I%20built%20for%20other%20people/RiPole%20Jeff%202011/47.jpg)
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That cap would be a cool guard for my shower drain, or maybe a belt buckle. :lol:
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They've got an accordion suspension in the center front of the cone as opposed to the normal convex dustcap. Someone else may be able to tell you what the (solid as a rock) plate in the center of the cone is.
Dust Cap Composition Porous cloth top spider/ heatsink
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That cap would be a cool guard for my shower drain, or maybe a belt buckle. :lol:
One of the guys on teh Hawthorne forum said it would be great as a BBQ grate to "brand" the burgers. :lol:
Thanks for the words of wisdom Lin, much appreciated. :thumb:
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That's a great idea!!!
Lets brand Darrel H when he visits. :o
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Matt, I think he's got some martial arts in his history. I ain't brandin' shit. :nono:
Bob :lol:
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True, Darrell is a bad-ass.
the bbq brand is still the best idea.
Are the new drivers gonna work??
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Why don't you come over here and find out. 8)
Not sure yet Matt. I'm an hour or so away from heading into the workshop to do some measuring and test fitting. I'm sure I can get them to work, it's just more a matter of whether I'll be adding material or removing it. At first glance, the new ones look shorter and fatter. The magnets are much larger in diameter. :?
But seriously, I'll be home for the next four days piddling around the house, so if you're free, come on over. Send me a PM and I'll give you my address.
Bob
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Hm, that sucks. Nobody tested the drivers first?
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Hm, that sucks. Nobody tested the drivers first?
Yea...well....umm..... :oops:
As it turns out, these drivers have the ability to rattle the entire house when mounted in open baffle.
Put them back in RiPole, and it all goes to Hell.
As I was disassembling the unit in my room, I was placing the "layers" off to the side. When I had it in apart I noticed the drivers were looking pretty majestic sitting on the carpet standing upright, like that was their intent.
Seemed like a good idea at the time to wire them up and see what they sound like. Why not?
As it turns out, the sound GREAT and can get VERY loud without distortion.
But put back in RiPole, I have to turn them up so loud to get any output, that they're bottoming out. With all volume/gain/setting untouched, the output from them is considerably more in OB than RiPole.
Bob :?
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Bob, did you check the polarity of the original drivers with a battery to make sure all is correct there?
I guess you know that you can touch an AA battery (for example) to the terminals to ensure the cone moves the same direction on each, with the + applied to the positive speaker terminal.
The bottoming makes it sound like the drivers were wired in opposite polarity and cancelling each other when mounted.
I say this because you mentioned they were handmade prototypes.
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Thanks for posting Russell. :D
Good point, I did not check the polarity of the drivers.
I did, however reverse the polarity to the top driver and played the track again (same results).
Next, I put the top driver 'back' electrically, then reversed polarity to the bottom driver (same results) and finally, put the bottom 'back', and reverse polarity to the entire enclosure thereby making them "pull against each other" so to speak.
The results were the same every time, using very low volume and nothing below (iirc) 40Hz.
So in essence, by process of elimination, I ruled out the driver being built incorrectly....best I can tell.
Bob
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I've been saying Ripoles suck for a while now, on diyaudio, having failed twice at getting reasonable sound from them :) . They went low in my experiments, but at atrocious efficiency and were accordingly easy to bottom out. More power to you if you prove me wrong. Otherwise, live and learn.
I'm not sure of the T/S specs for the drivers you chose, but if they are high Qts, I vaguely recall that the drivers originally suggested for ripoles were of moderately low Qts. Didn't make a difference either way in my experiments with various drivers, though (one experiment with Pyle PPA15 drivers with Qts of 0.7, IIRC and the other experiment with a conventional subwoofer driver i.e adire shiva 12").
If the drivers are high Qts and you want another idea for these (4 ? ) units, try a pair of dual OB, or dual driver W-style baffles (a-la Linkwitz).
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I've been saying Ripoles suck for a while now, on diyaudio, having failed twice at getting reasonable sound from them :) . They went low in my experiments, but at atrocious efficiency and were accordingly easy to bottom out. More power to you if you prove me wrong. Otherwise, live and learn.
I've never tried a ripole, but I'm surprised Nelson Pass's experiment works so well, since it looks like a ripole with a baffle. Maybe the baffle makes all the difference?
http://www.enjoythemusic.com/diy/0911/slot_loaded_open_baffle_speaker.htm
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I've never tried a ripole, but I'm surprised Nelson Pass's experiment works so well, since it looks like a ripole with a baffle. Maybe the baffle makes all the difference?
http://www.enjoythemusic.com/diy/0911/slot_loaded_open_baffle_speaker.htm
Close, but not quite :) Let's consider the BMC (blow motion concept) arrangement where drivers face each other and move towards and away from each other in unison and compare the equivalent dipole , ripole and "pass" slot loaded open baffle.
1. In the case of the dipole, the cavity dimensions are significantly larger compared to the woofer surface area and don't offer any mass loading to the driver motion. Bass is generated via front/rear path differences due to the baffle.
2. In the case of the ripole, the cavity dimensions are smaller compared to the woofer surface area (I think about 1/3 of Sd, or thereabouts) thereby loading the woofers on both the front and the rear). Additionally, since ripoles are so small, they fail to fully utilize front/rear path differences to generate bass via the baffle effect.
3. The "pass" slot mass loads the front of the driver (like a ripole) and also acts as a diffraction slot at higher frequencies . However, there isn't any load on the rear of the driver. At least, that's how I understand it. I can't comment any further on performance since I've never built one before.
Once again, I'm hoping I'm wrong and the OP manages to succeed with this project.
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This is very mysterious and confusing. Bob - wouldn't take long to do the battery check would it?
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I'm surprised that no one mentioned isobaric loading. All these configurations look like variations or evolutions. The isobaric gives you lower fs and cabinet volume is effectively doubled, or you need half the cabinet size. You sacrifice 3dB efficiency in a traditional sealed or reflex cabinet. I'm guessing that you need just the right driver for these more open type of loading schemes.
http://en.wikipedia.org/wiki/Isobaric_speakers
If you look at the link on page 1 of this thread, you'll see the efficiency is 80dB.
http://www.lautsprechershop.de/hifi/ripol_en.htm
I have no experience with them but it looks like a Ripole is appropriate only with a separate amp. Obviously being able to play below fs won't always work out. Professional drivers tend to be very efficient at the expense of deep bass response. If you get a fairly efficient sub driver with low fs it might be awesome.
neo
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Bob, nice work. I love a good challenge but never had the cajones to try something like this.
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I have built many isobaric subs, and unless space is a concern, I would go with a standard sealed or ported box. As noted, isobaric 1/2's the space, but also adjusts efficiency down...
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It's not isobaric and has no resemblance to one at all...
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Do you have the T&S parameters from either driver?
Did you take any measurements?
From what I've read, Ripoles need a large x-max, Qts @ .5, and a FS of around 30hz or higher.
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Face - >> THESE << (http://www.eminence.com/speakers/speaker-detail/?model=Kilomax_Pro_18A) are the replacement drivers, the spec sheet is there. I've got the T/S specs on the original driver written down at home, and don't have them with me. Since they're prototype drivers, that information may be a secret anyway, not sure.
Bob
Edited link....
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The drivers in that link look like they *should work*, maybe there's an issue with design of the enclosure or the T&S parameters aren't accurate.
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The drivers I linked to are the new replacement drivers purchased due to the prototype drivers being "blown". I've not mounted or hooked up the Eminence drivers since there's a remote chance they'll get sent back.
Bob
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Geez.
I hope you're getting something for this. (Apart from aggravation, I mean)
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Geez.
I hope you're getting something for this. (Apart from aggravation, I mean)
me too; the cabinet looks beautiful... :?
doug s,
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These are the recommended drivers:
http://www.lautsprechershop.de/hifi/ripol_en.htm
Click on further details about the driver, near the bottom.
neo
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Geez.
I hope you're getting something for this. (Apart from aggravation, I mean)
Nope. I offered to do this at no labor charge, just for the opportunity to be the "trailblazer".
I guess I got what I asked for. :duh: :lol:
Bob
p.s. Although, if the project fails entirely, I'll have one helluva real nice end table for my troubles. :thumb:
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Bob,
Your link is to the 15" driver.
18" driver page: http://www.eminence.com/speakers/speaker-detail/?model=Kilomax_Pro_18A
Lin
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:o Oh crap. Thanks Lin. :thumb:
Bob
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Would attempting the prototype described on this page help any ? http://www.diyaudio.com/forums/multi-way/195734-nelson-pass-slot-loaded-open-baffle-project-28.html
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So Bob - what happened??
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I have read the original article on ETM with great interest.
I found out yesterday morning that the problem with this project wasn't the alignment, nor was it the drivers.
Seems it's my amp. Sometimes it works, sometimes it doesn't. :duh:
Yesterday I caught it in the act "as it happened".
I've already sent my apologies to Darrel Hawthorne for "making" him buy those two Eminence KILO drivers. :oops:
He's a very forgiving man.
more later.....(when I recover from the humility)
Bob
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Oh. Well that sucks but on the bright side you don't have to rework the baffles..... or did you already do that.....
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John, I had taken the layers of the RiPole apart (a simple process) and set the two layers that contained the drivers upright, much like you'd have a OB bass driver sitting in your room.
This morning I reassembled the RiPole back to it's "normal" state. Fortunatley, I had not cut the piece up, or modified it in any way.
Bob
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I got to hear the ripole today - i want one!
It would be an amazing foundation to a full ob system, to provide the bottom octaves. Didn't sound boxy to me. Even though it wasn't optimized today, i have high hopes for the design & hope the owner has fun with this monster.
Bob's cave is so cool, with a click of his mouse we can hear the IB system alone, IB + a pair of auggies on his duet baffles, or the auggies + ripole, or probably any combo therein.
Bob will have to be the judge, but to me, the ripole's had proper tone & were accurate to low, low depths. In comparison, bob's IB system has more output for sure but isn't as musical.
thanks again for a good day today bob!!
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So did you run it with the K2?
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So did you run it with the K2?
Yip. Thank you. :wink:
Thanks for the review Matt. :thumb:
Now....to optimize things..... :duh:
Bob
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Bob's got plenty of power now, even for bob!!
How much does the K2 put out?
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Bob's got plenty of power now, even for bob!!
How much does the K2 put out?
2.5 kilowatts
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Yea, we had a change of plans regarding the boy getting the amp. The storm we had the other day took out his receiver. I was going to give him the one I use in the workshop, but that one is smoked as well. Don't have much need for an amp to power his subs without a receiver. So basically he's got nothing right now. That's why the Crown is running the RiPole.
In all, I've got five bad amps right now. :duh:
Bob
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Bad amps need to be put into the naughty corner.
(http://www.audiocircle.com/image.php?id=51521)
But seriously... any chance of some measurements? I'm DYING to know... :D
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That's a pretty nice "naughty corner". :o :lol:
I'll do some measurements pretty soon. What kind would you like? Any requests? :D
Bob
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......EDIT: Nothing fancy, all I have is a Rat Shack Digital meter.
I can't do the fancy graph stuff. :oops:
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I can't do the fancy graph stuff. :oops:
Why? You have MS Excel right?
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Not sure, I've never used it. :dunno:
I can look tonight when I get home. But what will excel do for me?
You talking about manually plotting tones?
Bob
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Not sure, I've never used it. :dunno:
I can look tonight when I get home. But what will excel do for me?
You talking about manually plotting tones?
Bob
Yes, set your "X" axis to freq and your "Y" to dB. Plot them and you'll get a nice FR graph.
I would imagine that you're using a test tone Cd like the one that Ethan has posted on his site?
EDIT: Set your "Y" scaling for 5dB.
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Ok, gotcha. That's almost like the old fashion way. :lol:
Regarding the tones, I've got a bunch of old "Bass Mechanik[sp]" test tones.
Bob
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Ok, gotcha. That's almost like the old fashion way. :lol:
Regarding the tones, I've got a bunch of old "Bass Mechanik[sp]" test tones.
Bob
Try this: http://www.realtraps.com/test-cd.htm
Noooo. The old fashion way would be with some graph paper and a ruler. :D
Doing it with MS Excel takes literally 30 seconds.
And I'd love to hear these too! :green:
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Hey Bob-o,
Download REW and you can borrow my USB mic preamp, mic and cables. Then you can do all those fancy graphs. I don't need this stuff right now, so you can keep it for a couple of months.
Heck, I'll even deliver it if that helps.
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Jtwrace, Thanks man. I'd take you up on that, but it seems Mark has trumped your offer. :lol:
Mark, that would certainly make life easy. Wifey has this weekend planned for me, so I wouldn't be able to make it out to pick up the equipment for a couple weeks. I appreciate the offer for delivery, but that's a long haul just to drop off loaner stuff, unless you're in the area anyway.
Thanks guys! :thumb:
Bob
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I work in Washington so I could drop it by the house or your work. I don't mind doing it at all. Let me know if that sounds good.
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Jtwrace, Thanks man. I'd take you up on that, but it seems Mark has trumped your offer. :lol:
That's the better way to do it....it's just a lot more in depth and takes a bit of time. Hopefully he'll lend a hand to get you going. :wink:
Good Luck and post the results.
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jtw, I assume I'd be storing the images on a server like Photobucket like where I store my photos?
Mark, I work til 5:00 during the week, and get home at 6:00.
Of course, whatever is best for you I'll be as accommodating as I can be.
Thank you. :D
Bob
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PM sent
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Geez.
I hope you're getting something for this. (Apart from aggravation, I mean)
Bob is a real good guy and is the reason my system looks and sounds as good as it does. When I get this beast home, it will go into the system with the PSI Trios and PSI center channel that he has already made for me. Without his help, my system would not be as nice as it is now. Thanks Bob!
Jeff
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Jeff, do you live in a football stadium or what?? :lol:
That's a lot of Sterling goodness! Having that many Radian CD's in the room must be fun, i still dig mine at any volume.
I think you'll enjoy the ripole. :wink:
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Jeff, do you live in a football stadium or what?? :lol:
That's a lot of Sterling goodness! Having that many Radian CD's in the room must be fun, i still dig mine at any volume.
I think you'll enjoy the ripole. :wink:
Thanks :D I can't wait to hear the Ripole :icon_twisted:
Unfortunately I only have the Silver Iris drivers in Trios. I do have upgraded crossovers with Obligato caps that Darrel made for me. I am very satisfied with them. I can't wait to hear Bob's Sterlings. I have not had a chance to hear a pair yet.
Jeff
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Your room must rock regardless! That's a lot of big woofers in multichannel.
I have most of the parts of a killer home theatre for down the road, all hawthorne 15's with my PSI's as rear channels.
Once the ripole is dialed in, you'll be louder than a KISS concert :lol:
Will you use an amp like the Crown K2? The ripole seemed more than happy w/that amp.
If you are heading to town at some point, feel free to take a detour downtown st louis to hear my Sterlings...they are difft than Bob's. Less earth-quake-ish, but fun nontheless.
matt
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Mark - way to go :thumb:
Bob - whatever you have time for mate. And if you're interested. I'm curious to know how it performs in-room. 'Course, I could make one, but... since you did... :green:
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Congrats !! While I'm not sure ripoles are my cup of tea, I'm really glad you got the issues sorted out.
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Your room must rock regardless! That's a lot of big woofers in multichannel.
I have most of the parts of a killer home theatre for down the road, all hawthorne 15's with my PSI's as rear channels.
Once the ripole is dialed in, you'll be louder than a KISS concert :lol:
Will you use an amp like the Crown K2? The ripole seemed more than happy w/that amp.
If you are heading to town at some point, feel free to take a detour downtown st louis to hear my Sterlings...they are difft than Bob's. Less earth-quake-ish, but fun nontheless.
matt
Thanks Matt. If I find myself out that way, I might have to take you up on that offer.
Jeff
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DISCLAIMER:
I've been using REW, a Behringer mic, and an M-AUDIO Fast Track Pro for about 30 minutes now. :lol:
Using that equipment I came up with this graph. Look close, you'll see six sweeps and one average.
The volume is *way* too low, but I think that's a software thing, and not an actual "real life" volume thing.
The mic was placed at the listening position.
The amazing thing to me is the difference in dB between the graphs. Especially at 32dB, there's an 11dB difference.
I changed absolutely nothing. Notice the time stamps.
But overall, this looks pretty good to a "graph noob" such as myself.
{this is my first tip-toe into measuring and should probably start another thread}
(http://i85.photobucket.com/albums/k60/BobinStLouis/Graphs/Ripole9232.png)
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Hi Bob and Matt (since you heard them also),
Very cool project you have going on.
How would you say the bass differs from the Augies?
By the way the Augies are some of my favorite bass drivers on the market and if I go back to an open baffle speaker system I am getting 4 next time :thumb:
-Nick
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Bob, cool. Nothing changed at all? Did you try the Levels button on the REW measuring page? Wondering if perhaps you can increase the mic gain on the fasttrack.
[Edit: the Check Levels button - that will tell you if REW thinks you are getting enough signal]
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Nick - Not sure about the difference between the RiPole and the dual 15" Augies. Too early to tell.
Although, the RiPole sound quality is VERY good. None of the boomy stuff you'd expect from a sealed/ported sub. Very clean, very sharp.
But like I said, I'm still in the settings/tweakings so it's too early to make serious judgements.
John - I changed nothing. In fact, I was probably leaning slightly to the left in my chair during each test. I don't think I sat up straight on any of them.
Ok....that's a bit of a stretch, but not by much. I never touched a setting, I never touched the mic position. Ever. Not once.
Interestingly, one channel of the audio is about 30dB higher than the other. Not sure why as it should be a mono signal.
"REW" had bitched every time that it's not loud enough, although I'm higher than the 65dB shown. :scratch:
Bob
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p.s. The mic levels on the Fast Track are cranked.
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What level does the Level Check report?
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Hmm....I've since unhooked, but if memory serves it was wanting -56dB and I was "only" -10.
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I'm guessing that you saw this screen then?
(http://www.audiocircle.com/image.php?id=51601)
If so, the levels are way too low - something is not configured right. You should get very close results from sweep to sweep.
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Yip, that's the one I'm seeing, although my numbers are even further apart than those. :?
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Bob,
When you get the volume problem fixed you ought to go to REW download section and get the calibration file for the Behringer 8000 mic. Then under "preferences" you click "mic/meter" and then browse for that calibration file. Then you'll be as accurate as that mic can be.
Hope you have some time tonight to get that level up.
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Great advice Mark, thank you.
The problem I'm having this morning is it won't run the tone. I'm getting an error message, "signal generator audio output not available". :scratch:
Been sifting through the pages of REW on the Home Theater Shack forum searching.
Bob
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Wish I knew more about Windows 7. Are you sure that your computer is talking to the M Audio pre?
(I knew I shouldn't have brought all that gear over in an Apple bag. :lol: :lol:) I know, I will burn in hell for that last comment.
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No worries Mark, I won't tell the MAC guys what you did. :icon_twisted:
"Am I sure" the PC is talking to the M Audio?
No....I'm not sure of very much at all right now. :rotflmao: :rotflmao:
Suprisingly, the Shack website hasn't been very helpful. I think I'll dig around in Windows to see what kind of button there are.
Bob
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Bob,
REW is a bit buggy/finicky in my experience. Of course, I'm using it with a Mac and couldn't get it to work until I loaded Windows XP via Parallel (virtual machine). THEN it worked fine on my Mac....no kidding! A couple of little things seem to make a difference to REW. One is to make sure all your interfaces are updated to the latest versions. I couldn't get things going until I updated my version of Java. Another is to make sure all other audio inputs/outputs are removed besides the USB to the M-audio pre. I had to remove the optical out that I used to use for my DAC and reboot with the USB to the pre attached. It seems there are lots of these little things that have to be just right.
Once you get past the frustrations of getting REW up and running consistently, you will find it is quite capable and simple to use. I enjoy it quite a bit, actually.
John
P.S. What is this Windows 7 thing you guys are speaking of? I thought the "upgrade" to Windows XP was OSX Snow Leopard (which has since been upgraded to OSX Lion). :scratch: :lol: :lol: :lol:
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Yea, it does seem to be finnicky. I "fixed" the last problem I had by unplugging the M-Audio, and plugging it back in. :roll:
Now I'm back to the original problem of the signal being too low. Interestingly, I can turn the M-Audio's volume of the sweep down to zero, and it still generates a graph almost identical to the one I posted above.
What's it hearing? :scratch:
Bob
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http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-790
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http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-790
That's pretty cool, but for $300, I think I'll stick with the (borrowed/free) Behringer mic and M-Audio piece that I have. I've actually started a thread on "The Shack", and the fellow that designed the REW software is helping to troubleshoot. It's a very powerful piece of software and Mark was kind enough to lend my some quality tools to go along with it. Once I get past the learning curve I should be in good shape.
Hell, I was able to figure out the DCX2496 remote computer interface..... I should be able to get REW. :lol:
Bob
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Hi Bob - thanks for persevering :thumb:
Interestingly, I can turn the M-Audio's volume of the sweep down to zero, and it still generates a graph almost identical to the one I posted above.
What's it hearing? :scratch:
Perhaps the noise of your computer's own soundcard. REW is not getting the mic signal.
I don't know how it's configured in Windows (yes I also am one of "those" :lol: ) but you may need to configure the Windows default input device to be the M-Audio. Then select the default device in REW. Or perhaps the other way around. In each case, restart REW after each configuration change. This is just to be sure - once you've figured out the settings it should be easy each time.
Another thing to just check is you have REW set to read the correct input channel. I understand the Fasttrack is a single channel device but you may still have to tell REW whether the signal is on the left or right channel.
(http://www.audiocircle.com/image.php?id=51660)
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These buggy issues are why I switched to HolmImpulse. REW is a great program but I have found it to be very frustrating to use. I purchased a new computer and was not able to get it to work after spending way to many hours trying to get it working. I was able to load Holm and instantly start using it.
Just a thought.
http://www.holmacoustics.com/holmimpulse.php
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jtrace, thank you for the link. I'll keep that in mind if REW decides to continue on it's present course. :lol:
I've also got another fellow willing to loan my yet another piece of equipment and software if needed.
Just for grins, I downloaded the free version of TrueRTA, and am able to get a working spectrum analyzer with seemingly accurate SPL levels. Although, it's like one bar per octave, so it's fairly useless. But at least tells me "that" end of things are working.
John....Good advice, thank you for sticking with me.
There are two RCA cables running from the M-Audio to my receiver. It does have a right and left output, although, there is a mono button. I suppose that's to "combine" the two channels? I did, however try to change the default channel to the other side with no change in things.
I'm running the M-Audio through a USB. Doesn't that mean I'm not going through a sound card? :scratch:
I do have my PC recognizing the fact there's an outside piece of equipment installed. It even calls it by name, so I know they're "talking". I did manage to get the green checkmark on the M-Audio icon, so it "should be" enabled. In fact, I've made so many changes to my PC, that I don't even have any audio from it's speakers anymore. :duh:
The fellow that designed REW hasn't replied in a while, but I'm still playing around pushing buttons. I'm hoping I'll stumble on the right combination of things, but there's a LOT of settings.
Bob
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Bob, last night your neighbor Ryan mentioned that he has the gear to get you measured quickly. That may be the easiest solution.
Sorry about dropping the ball on the XTZ analyzer, it was late & dewy in your valley, didn't want it sitting out in the humidity until morning. I'll try to make it out your way in the next few nights if you don't get this straight before then.
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I'm running the M-Audio through a USB. Doesn't that mean I'm not going through a sound card? :scratch:
Yes, I meant that it sounds like you have REW configured to get input from your internal soundcard rather than the M-audio.
Perhaps post a screenshot of your Preferences window?
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Bob,
Would you make sure that the M Audio is getting signal? On the left front panel should be a signal light and will show if the M Audio is getting anything from the mic. If not, separate the two mic cables and try just one at a time. I want to eliminate the simplest problems first. No sense going any further if you can't get signal from the mic. You could also just plug in a headphone and see if you can hear yourself talk.
Mark
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Bob,
That M Audio preamp, in this instance, has to be selected as the soundcard for your pc...an external soundcard.
Both John R & blackmore are spot on, i'd bet.
The proper Settings to get REW working are the same as you'll need with my analyzer system.
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Mmm...interesting. "External sound card". I'll see what I've got for preferences, and post a screen shot if I can't get something going on.
Mark, The green input signal light does blink with the beat, when I've got it turned up.
So the mic and the M-Audio are "hearing" what going on.
Thanks guys!
Bob
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Alright. Call me an idiot, but I don't know where to tell Windows 7 how to make the sound card external. I ran though everything that I can find, to no avail. I did take a screen shot of some sound setting tabs I had open.
Notice that M-Audio is listed on every one of the five tabs.
Also, another very interesting thing I discovered while uploading my photo, is that the Photobucket advertisement video was playing its audio through my PC, into the M-Audio, into my system and out of my main speakers.
That should be a clue?
Anyway, here's a screenshot:
(http://i85.photobucket.com/albums/k60/BobinStLouis/Graphs/Untitled.png)
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How does the REW preferences screen look?
-
(http://i85.photobucket.com/albums/k60/BobinStLouis/Graphs/1.png)
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How's that ^......
I did try right and left channels, to no avail.
Also, it is confirmed, I can watch YouTube video on my PC, with audio through the M-Audio, into the AVR. Kinda neat.
But the sweeps are still not loud enough by REWs definition.
Bob
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Bob,
This is probably not much help but here is the setup guide I followed to get REW going. It was still fussy but all the main parts are covered here, I think. It may have a clue or two...
http://www.whatsbestforum.com/showthread.php?1373-Room-Measurement-and-Acoustic-Treatment-series-Part-4-using-REW (http://www.whatsbestforum.com/showthread.php?1373-Room-Measurement-and-Acoustic-Treatment-series-Part-4-using-REW)
John
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Does the M-Audio show up in the "Input Device and Input" dropdown?
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John (Inferno) - Thank you, I'll check it out tomorrow at work.
JohnR - Yes it does, on both dropdowns. I'll revisit that again tomorrow night (wrapping things up tonight). If memory serves, I got no audio through the speakers when playing the sweep when those were selected. But like I said, I think I may play with those again.
Bob
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Nick - Not sure about the difference between the RiPole and the dual 15" Augies. Too early to tell.
Although, the RiPole sound quality is VERY good. None of the boomy stuff you'd expect from a sealed/ported sub. Very clean, very sharp.
But like I said, I'm still in the settings/tweakings so it's too early to make serious judgements.
John - I changed nothing. In fact, I was probably leaning slightly to the left in my chair during each test. I don't think I sat up straight on any of them.
Ok....that's a bit of a stretch, but not by much. I never touched a setting, I never touched the mic position. Ever. Not once.
Interestingly, one channel of the audio is about 30dB higher than the other. Not sure why as it should be a mono signal.
"REW" had bitched every time that it's not loud enough, although I'm higher than the 65dB shown. :scratch:
Bob
try ARTA (the free version doesn't let you save graphs, but other than that, it's functional)
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John (Inferno) - Thank you, I'll check it out tomorrow at work.
JohnR - Yes it does, on both dropdowns. I'll revisit that again tomorrow night (wrapping things up tonight). If memory serves, I got no audio through the speakers when playing the sweep when those were selected. But like I said, I think I may play with those again.
Bob
Any final results, charts, etc.? How did the project finally turn out ???
Thanks,
Tim
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Hey Tim,
It didn't work out. The Ripole didn't have as much output as those of us involved thought it should have had. The sound quality was great, much like an open baffle sub, but for home theater subwoofer output (SPL and Hz) it just didn't have the "umph" required.
It's a shame, we had high hopes. I've only ever seen one example of a successful ripole, and the drivers used we designed for that alignment specifically, if memory serves.
Although, I've seen the Nelson Pass Slot Load alignment, and it seems pretty similar to a ripole. I can't recall the specifics of his design, but it's pretty close.
Hope that helps Tim,
Bob
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Hey Tim,
It didn't work out. The Ripole didn't have as much output as those of us involved thought it should have had. The sound quality was great, much like an open baffle sub, but for home theater subwoofer output (SPL and Hz) it just didn't have the "umph" required.
It's a shame, we had high hopes. I've only ever seen one example of a successful ripole, and the drivers used we designed for that alignment specifically, if memory serves.
Although, I've seen the Nelson Pass Slot Load alignment, and it seems pretty similar to a ripole. I can't recall the specifics of his design, but it's pretty close.
Hope that helps Tim,
Bob
Thanks for the quick response.
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I'm not sure why someone would want to use a ripole sub for HT, you'd need quite a few around the room. As for music and only two channels, that's a different story.
Here's my result with a pair of cheap JBL 15" car subs, taken at 1m.
(http://i.imgur.com/VO25qmb.jpg)
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Well...as far as "quite a few around the room"......MORE isn't going to make them do anything that a single unit can't do.
They don't go low enough. More scattered around the room won't make them go any lower.
The goal of these Infinite Baffle specific drivers (or the "why someone would want to use ........") was to have an audiophile grade driver for home theater use.
It's a goal we have to provide quality sound through the entire spectrum was all.
I didn't graph these, so I can't speak there, but the ones you show are down 13 from 30 to 10.
So if they can handle the EQ to bring them up, then great, but if not then I'd say those aren't ready for home theater duty either.
Bottom line was that a guy who wanted his HT to sound as good as his two channel rig.
Having quality, great sounding drivers in his HT room was at the forefront of his thought process.
Cracking drywall would be nice, but it wasn't the main goal. Obviously HT needs to have a certain level of "umph", and these (in this alignment) couldn't do it.
Bob
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The purpose of ripole, or OB subs are for smoother bass response than a traditional "box" sub, not tooth rattling LF extension. Their smoothness and lack of a steep rise at the bottom are why many find them so natural sounding. The graph posted is for the bass section of a pair of stereo speakers I'm working on. No bass boost can be added, but in their final placement, some boundary gain will add to their bottom end.
There are plenty of "audiophile grade" subs suitable for HT. But when it comes to HT and fidelity, IMO, multiple sealed subs is the best approach. http://www.harman.com/EN-US/OurCompany/Innovation/Documents/White%20Papers/multsubs.pdf
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I've got OB and IB subs for my HT, so when the fellow came to me and asked if I'd build him a Ripole for his, it was like somebody asking Betty Crocker if she'd build them a never before seen caserole. :wink:
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I follow.
Not criticizing you, just sharing information. :thumb:
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It's all good. I'm cool. :thumb:
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Insane build Bob. I missed it till now and read all 8 pages in one sitting.
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Thanks Navin. :thumb: