Gravity Well Of A DarkStar

Dmason · « **Reply #180 on:** 10 Jun 2005, 02:00 am »

I think the ancient Wharfedale config is worth paying attention to. It is interesting to note that the current ESL form is almost identical in dimension.

Everything Old Is New Again

I think as long as the configuration doesnt resemble a floorstanding speaker, you are well ahead. Noel is right. Speakers are too high now. The older, squat cabinets like the Altecs, RCA's and JBL's I personally remember sounded better in part because of their shape, overall. Want more proof: look at the Tannoy Prestige Line. Unchanged for centuries. Short and squat, and the Westminster is the King of All Speakers.

Stage monitors rip chiefly because of the angle of incidence, using the stage floor as a waveguide, same idea as loading the OB around corners. High quality stage monitors sound amazing in this placement, and proper mixing can make performances a real pleasure. This is verrrry similar to what we are talking about.

I also think you could get away with narrower, shorter baffles loaded ~into the corner, as long as you combined this with the lowrider driver placement. I really like that idea, AND, I plan on trying it. I also like the idea of veneer "shutters" and maybe a grille, breaking up the lines reduces the apparent width of the whole thing. Ergo, there will be a magic width and height, where, if using a grille or some other aesthetic device to divide the lines, the WAF rises in direct proportion to apparent width X height

Mark, perhaps you could give us a Nano Review of your Dark Lite set up and what you are hearing and your impressions of the Visaton in your crib.

JiffyBoob · « **Reply #181 on:** 10 Jun 2005, 04:39 am »

I just finished reading this entire thread and it is amazing. You guys are truly all over this new (old) stuff.

This is my first post, I am a friend of Dmason, and have heard his Dark star set up three times now, as recently as this evening. Let me tell you all that it is the most open, honest sounding and easy to listen to sound system I have ever had the pleasure of experiencing. With the battery power amp there is no detectable noise, just beautiful, organic sound that makes you want to listen for a long time.

I had become interested in this method of design, and am having Dan build me a pair for my own home, which I am really looking forward to. I figured I had to check out what he had going on up in his place after I had heard the horns he built, but was using the entire garage as a horn and MAN could those plywood puppies get down. So, I look forward to watching where all this goes and am excited to be a part of the Dark side of the force! ---Brett

barfind · « **Reply #182 on:** 10 Jun 2005, 08:01 am »

So JiffyBoob, (I like the sound of that!!), welcome to the "DARK SIDE" That really is a conridition in terms, as these drivers in OB are anything but dark. Anyway I hope you can get to live with this amazing sound in your home soon. You will never regret the move.

Richard, get that ship off the pad NOW

Nigel

JLM · « **Reply #183 on:** 10 Jun 2005, 10:19 am »

Richard/powerbench,

You guys should really get your hands on a CD of test tones (like Stereophile CDs 1 and 2) so that you can know what depth of bass fits your place and taste. Until you determine how deep you want to go, no one, no computer program, and no chart can tell you how to size the open baffle.

A very handy friend recently started messing around with OBs and has built a Quad looking design with a 97 dB/w/m center mounted 12 inch coaxial driver. He has it mounted on short legs and its covered with vinyl over yellow foam padding to look like padded furniture. Eventually he wants to sell them for around $700/pair.

I recently built a headboard and was left with a 34 inch by 48 inch piece of scrap. Just seeing it and smelling the fresh sawdust, the proportions seems so right, it was calling to me. OB, OB, OB....

A good place to start with an open baffle design that has wings uses an entire 4 ft by 8 ft sheet of material. Cut two 12 inch wide strips, two 16 inch strips, and two 20 inch strips all 48 inches long. Use the 12 or 16 inch strips to mount the driver and piano hinge the others together in matching pairs. These could be finished in silk over absorbent material to resemble an oriental screen. In that light the screen should be made even taller to look right. (This would help compensate for loss of bass if you wanted to put short legs on the baffle/screen.) Another advantage of the hinged baffles is to break up the reflections of one speaker off the baffle of the other speaker.

BTW the Mapleshade site sells low speaker stands (some only a couple of inches off the floor) and also suggests sitting very low to the floor (another slide towards an oriental theme).

Richard, you probably have little opportunity to gain ceiling height in a 1970s vintage mobile home without extensive work.

ooheadsoo, the gaps needed to have the baffle perform in an open baffle versus infinite baffle mode is hard to say, but I guess is it should be measured in feet, not inches. Pressure from bass should be unconstrained in either case (otherwise you'd be simulating a sealed or pressure relief cabinet). The mid/high frequency backwaves wouldn't be able to contribute to imaging or frequency response balance.

mcgsxr · « **Reply #184 on:** 10 Jun 2005, 01:12 pm »

Before I live up to offering up a review for what I am hearing in my place, I wanted to try something - I rotated the baffles onto what used to be their side, so I could try this lower loading idea.

Here are the pics.

After all that hard work (OK, 30 seconds to flip the baffles, and 5 whole minutes to play with toe in...) I find it different.

If we can all agree to take the following comments as 1 guy, in 1 room, trying something different with a setup that I never intended to try this way, then read on - ie do not take my impressions to heart, and for heaven's sake try it for yourself!

In comparison to having the baffles upright (as I designed them to be...) putting them sideways does a couple of things. Mostly a lift in bass somewhere, but NOT the lowest bass, more like around the 100-150Hz mark or so (by my ears, not a test cd or anything). Next up I find that the midrange is less exquisite. I chose both "less" and "exquisite" carefully - ie the sound is still remarkably good, but for me, I find the sound in the midrange is more magical, when the baffles are upright.

I will guess that much of the issue with putting my baffles on their side is that they are TOO wide, and TOO tall this way - the dipole effect is largely blocked by the enormous baffles.

I am considering tracing out a better shape for a low install, as I can envision how it would look cool, be less visually impactful, and can still sound good.

My thoughts on how the Visatons ultimately sound, will have to wait until after today - I want to put a couple of hours in tonight, and I promise I will do my best to explain why I like this sound so much.

Oh, and as a parting gift - I am alarmed at how well these play LOUD - and I don't mean rock concert loud - I mean that they seem to be immune to distortion, and it is the amp that clips when I turn the JVC to 50 out of 50. It is perfectly clear at 40-45 depending on the source material, but truly loud loud loud at that point. I mention this, as in my experience with open baffles, they usually poop out when you crank them up. Not so with these.

mcgsxr · « **Reply #185 on:** 10 Jun 2005, 01:20 pm »

As a quick (hey, who wants to WORK at work?) follup - in putting both configurations in xlbaffle, it would seem that the lowboy vs the highboy is basically this - from 200Hz down, there is a 2-3db boost in bass for the lowboy. At 200Hz, there is a +3db vs the highboy.

Still not enough, in my room, to alleviate the use of the loudness button on the JVC, but a little more bass anyway.

Also, from 300-500Hz, there is a dip of -2db. I wonder if that relates to the midrange comments I made earlier, or not.

I will model a few more versions, and think about getting out the radial saw tomorrow...

Dmason · « **Reply #186 on:** 10 Jun 2005, 02:04 pm »

Not worth it if you sacrifice midrange. The word "exquisite" tells me you would agree.

I believe this is where digital EQ is the future for home audio.

Panelhead · « **Reply #187 on:** 10 Jun 2005, 02:30 pm »

I am sure the boxless drivers are great. I have heard the same with electrostatics, planers, and dipole drivers without the baffles.
But how are you getting your old ladies to go for the sheets of plywood propped up against the wall? The ones I have seen with plastic baffles might go at my house, but the wood and mdf would be a battle that I would lose.

George

lonewolfny42 · « **Reply #188 on:** 10 Jun 2005, 02:37 pm »

Quote from: Panelhead

I am sure the boxless drivers are great. I have heard the same with electrostatics, planers, and dipole drivers without the baffles.
But how are you getting your old ladies to go for the sheets of plywood propped up against the wall? The ones I have seen with plastic baffles might go at my house, but the wood and mdf would be a battle that I would lose.

George

How about some nice wallpaper over that plywood.....[/list:u]

Dmason · « **Reply #189 on:** 10 Jun 2005, 02:44 pm »

Panelhead,

The question is valid, and the issue represents an opportunity for one's S.O. to demonstrate true love, and the selfless satisfaction in one other's joy, in life. My girlfriend is moving out in two weeks.

I think in the right room, the Lexan baffle can look very fine, Art Moderne, if the room's motif can use it. Go to the Gallery and scroll down to see a shot of Toby's Phy-HP open baffles on a slab of Lexan... Folding wings and good wood to me personally, seems the best overall solution. A 33" wide baffle can fold up into a very innocuous bundle. Here, veneering and piano hinge are your best friend. Go back in this thread for more on this. Personally, I have found that 3/4 birch ply once again lives up to its reputation as a highly musical substrate for baffles and enclosures.

My keeper DarkStars have folding baffles and veneered 3/4 ply, 5' tilt, and a high performance TQW 60" pipe for bass using an 8" metal cone driver, and trapezoidal cabinet, placed horizontally along the backwall. F3=28Hz.

mcgsxr · « **Reply #190 on:** 10 Jun 2005, 03:06 pm »

Panelhead - you raise a good point about social acceptability of broad mdf panels in the home, but...with a name like that....

Ahem.

Please understand that in my case, I am sharing the "skunkworks" versions of my speakers, AS I design them - they are not the end product of design, a revised release etc - these are the functional mules that will evolve into a form that I can get in the house permanently.

But, as I am a form follows function guy (especially with stuff I build), it will be some time before the "beauty" overshadows the "beast"!

I am interested in any way to make a large panel more appealing to all - I like the silk screen idea - could have any theme you like applied to silk, and then apply that to the screen...

miklorsmith · « **Reply #191 on:** 10 Jun 2005, 03:24 pm »

mmmm. . .Disappearing matter you need, yes. . .Have this we do. . .Given it will be when ready you are. . .yes. . .

Or, how about this. . .

Sudan here. What you're asking is utterly impossible. Nobody's been able to implement cloaking technology in under two days and you're giving me two hours. All to appease the WAFbeast. If not for the slavering jaws and incessant nagging, I'd flip you the snork and be outta here. The WAFbeast is insidious though and wants to exterminate our kind. We must approach each battle as if it were our last.

Spewie - grab the ionizers, we've got work to do. Viva la Confederation!

Panelhead · « **Reply #192 on:** 10 Jun 2005, 03:28 pm »

Quote from: mcgsxr

Panelhead - you raise a good point about social acceptability of broad mdf panels in the home, but...with a name like that....

10 years of having either Accoustat III's or a set of Apogee Stages and stands in my living room give me the right to use this moniker. My SO at the time liked the looks of the stages over the electrostatics. She shared the living room with me.
I did rebuild the III's and covered them with new grey acoustical cloth and new bases built with walnut veneer. In the end the rebuilt III's stayed and the Stages left.
My current SO does not like any speaker larger than a loaf of bread. The 5' tall folded TQWT's in my listening room look real nice; routered edges, cherry veneer, flush mounted drivers. But she still does not like them. At least they reside upstairs in a dedicated room. Out of sight, out of mind.

George

powerbench · « **Reply #193 on:** 10 Jun 2005, 03:30 pm »

Ifd I start with an adequate size baffle is there a cheapo DIG EQ out there which would work.Hey ther other Canadian Mark ill arrange to come down when I get my ClariT back(getting a few upgrades he he

)

nodiak · « **Reply #194 on:** 10 Jun 2005, 05:58 pm »

mcgsxr, you going to try it on the other side? looks like in the photo the center of the driver is ~ 13"? Laying on the other side would be ~ 19"? Would be cool to hear comments about midrange as you raise the driver in increments....4",6"? I'm at 25" driver center ht now, (dual 4" Fostex in small OB to ~125 hz), but I'm coming from the other direction. I can feel lowering the OB a little more (4-6"?) could still work as well as these in keeping the midrange, with the right tilt and dialed in baffle size. And I think I hear you suggesting that you are carefully trimming the baffle size to a minimum.
Working things out...
Don

mcgsxr · « **Reply #195 on:** 10 Jun 2005, 06:05 pm »

As far as I know, the cheaper alternative for DEQ is the Behringer (at around US$300 or so, plus shipping). I have seen them on sale in Canada, but they run around CAN$600-750 or so.

Well worth seeking on eBay, or on the used market.

Behringer DEQ2496 is the one I see most often quoted as being appropriate, and somewhat affordable.

I am still exploring the non eq side of things, but I think I will try my analog EQ this weekend, and see if I survive...

JiffyBoob · « **Reply #196 on:** 10 Jun 2005, 06:09 pm »

Nodiak

What Fostex drivers are you using, and what size baffle might be a good choice for a pair of bedroom baffles? And maybe a tiny sub? Like a scaled down "acceptably compromised" version of the B200, but powered by something like that little JVC....thoughts for OB scaled to smaller rooms, secondary music systems.

JLM · « **Reply #197 on:** 10 Jun 2005, 07:11 pm »

jiffyboob,

Fostex FE127E is a nice driver (about 4 inch diameter, $37 USD, 70 - 20,000 Hz, Qts = 0.4). The E. J. Jordan 92S is about that same size and performance numbers, but cost about 3 times as much and is less efficient (86 dB/w/m versus 92 dB/w/m for the Fostex). Note that the 92S design is based on a sophisticated aluminum foil concept where the inner regions produce the higher frequencies (this is rather controversial). Both work well in open baffle.

Another plus - you can reduce baffle size to match the rated driver bass output to get an all around smaller speaker.

nodiak · « **Reply #198 on:** 10 Jun 2005, 08:59 pm »

JiffyBoob , where do speakers need to be placed in your bedroom? On floor or only up high on furniture? You know, will determine closeness of bass, so limit of xo frequency to sound cohesive. Here's my experience:

I'm using FE107E's 2 per channel in parallel in an OB 10" x 16" with 4" sides, drivers stacked long way centered on baffle. Btw, used them vertically and horizontally, like h better lately. Wanted to try ob in a traditional bookshelf size. But needs a cutoff of ~ 150hz to survive loud playing. Juuuust escaping cabinet resonance 90% of the time with that side depth to width ratio.
...and (single) FE167E's in 16"w x 22.5" tall, driver center at 14". Panels are 3 piece, 9" front with 3.5" sides at 30 degree angle, glued no hinge. They can't handle below 150 hz cutoff either.
Now, either is being driven by stock Teac al700p.

I have to play them each sitting on a stereo sub (12" sealed) to get cohesion. But I much prefer mains (OB's hopefully) that go to 70 hz so I can use a single sub for it's clarity, and physical distance. I'm learning that the B200 must be the OB driver to make that happen. Fostex won't play that low in ob.
So a 2.1 set up won't work with these Fostex imo. Even with a seperate powered sub because Fostex won't go low enough. Unless you put both ob's within say 3' of centered sub maybe, like everything in one area - console style.

I've got them to work with stereo bass using a seperate amp (Adcom 555). For passive xo a 10 mH coil on the woofers has been a good blend to Fostex ob's running wild, no cap (the 100uf I had didn't make noticeable difference, didn't have anything else on hand). I dial in frequency levels via mains amp, and a little preamp help if need.
I use them for homegrown ht too, audio out on tv and turn up the bass, all i need (in terms of "if I had to I could easily live with these"

, and i do now). Without some xo protection on these Fostex in my big room can't crank the ob's that last 10% tho.
I take it you're saying ultimate imaging and fr isn't expected in bedroom? Because might be hard to get rid of bass boom in small room using subs, as well as blending mains to sub/s if distanced.
If you have bass drivers of the same efficiency as mains then passive xo and one amp can work. Probably take 2 parelled woofers per side tho in this Fostex (93-94 db) example.
Don

JiffyBoob · « **Reply #199 on:** 10 Jun 2005, 09:51 pm »

Thanks for that.

To get speakers which go lower, it sounds like it is the B200 over again. Is anyone else using the b200 with Redwine amps, or the same type of chipset? Their thoughts.

All I know is that open baffle is the type of sound I want. My speakers today leave me wanting.