Ripole build - dual 18" Hawthorne Audio drivers

Bob in St. Louis · « **on:** 7 May 2011, 02:57 pm »

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.

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.

============

Notice the knife for size reference.

more soon..........

Bob in St. Louis · « **Reply #1 on:** 7 May 2011, 02:59 pm »

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.

Bob

Blackmore · « **Reply #2 on:** 7 May 2011, 04:15 pm »

Hey Bob, don't be a hater.

By the way, it comes up full size on my Mac......no clicking involved. Love ya, man!!!!

Bob in St. Louis · « **Reply #3 on:** 7 May 2011, 04:24 pm »

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.

But I'll let you know when I get the Ripole fired up. You can come over for a listen.

Bob

Blackmore · « **Reply #4 on:** 7 May 2011, 06:06 pm »

Can't wait to hear them. They will be monsters

mcgsxr · « **Reply #5 on:** 7 May 2011, 09:09 pm »

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.

nicksgem10s · « **Reply #6 on:** 7 May 2011, 10:27 pm »

Hi Bob,

Are those basically 18" Super Augies?

They look like really impressive drivers. Looking forward to learning more about them.

Hawthorne Audio is a great company run by great people!

-Nick

Bob in St. Louis · « **Reply #7 on:** 8 May 2011, 11:33 pm »

Sorry for the delayed reply....Mother's Day and all that goes with it........I'm sure you understand.

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.

Nick - Sure, you could call them "Super Augies". That sounds good to me!

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.

I can find build threads (including a recent one > HERE <). 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.

Bob

opnly bafld · « **Reply #8 on:** 9 May 2011, 12:12 am »

http://www.lautsprechershop.de/hifi/ridtahler_en.htm

http://www.lautsprechershop.de/hifi/ripol_en.htm

Bob in St. Louis · « **Reply #9 on:** 9 May 2011, 12:30 am »

Nice!

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

JohnR · « **Reply #10 on:** 9 May 2011, 01:47 am »

When two are bolted together like this:

it looks rather like the Linkwitz W-frame:

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?

jtwrace · « **Reply #11 on:** 9 May 2011, 11:46 am »

Very cool project!

I've wanted to hear the Augies for a while now.

JLM · « **Reply #12 on:** 9 May 2011, 01:20 pm »

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.

Bob in St. Louis · « **Reply #13 on:** 9 May 2011, 10:33 pm »

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.

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.

JLM - Yes, I wasn't going to name names, but yea, it was your post I saw.

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.

But here's what I've got done.

JLM · « **Reply #14 on:** 9 May 2011, 11:21 pm »

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.

Hebrew Hammer · « **Reply #15 on:** 9 May 2011, 11:25 pm »

Sunshine... haven't I tought you that porter cable is the only way to router

Jazzman53 · « **Reply #16 on:** 9 May 2011, 11:45 pm »

OMG.. two 18's in a Ripole is gonna be INSANE

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.

Bob in St. Louis · « **Reply #17 on:** 10 May 2011, 12:43 am »

JLM - Yea.....

..... 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.

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.

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.

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

Jazzman53 · « **Reply #18 on:** 10 May 2011, 02:22 am »

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.

Letitroll98 · « **Reply #19 on:** 11 May 2011, 01:03 am »

Quote from: Hebrew Hammer on 9 May 2011, 11:25 pm

Sunshine... haven't I tought you that porter cable is the only way to router

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.