Gravity Well Of A DarkStar

mcgsxr · « **Reply #600 on:** 16 May 2006, 01:34 pm »

The JVC EX A1 that I often use with my OB b200's has tone controls built into it - they are only usable via the remote, and try as I might, I cannot find any information around what frequencies they affect (I am in the same boat for the sub out - when you use the sub out feature, it cuts the bass to the mains, but even the JVC techs that I emailed could not tell me at what frequencies... time to borrow some test gear I guess!).

I find that I can use +1 or +2 to flesh out the bass nicely, if using the OB without a sub, and it makes the music right. I often run it flat, for most music that works too.

With a sub, I find that the tone controls don't help, it is easier to adjust the plate amp volume, to blend the sound.

On a different note, I remain completely convinced, that an older Yamaha integrated/receiver with the variable loudness, would absolutely be the way to go with the OB b200's.

That way, you can roll in the boost variably, rather than with a simple loudness button.

Wish I had one of those amps, sold mine back in the mid 90's...

Dmason · « **Reply #601 on:** 16 May 2006, 01:34 pm »

If it weren't for flashbacks, I wouldn't have any memories at all!

I am going to be interested in hearing about the combination of sealed and open baffle B200 together. There is no reason why this couldn't yield a very smooth-transition effect, a really workable solution, something to shape into a very room friendly form. The baffle size required for 200-300Hz flat is pretty small, something like <14 inches. This would be easy to live with, and still include all of the critical midrange and up, issuing from the OB driver. The A8 is known to measure F3=46Hz. With a larger cabinet, this could be pushed further down, perhaps approaching 40Hz...I have heard the Bastanis, with its combination of drivers, very smooth and tight, with its disparate array of drivers/materials used. Very close to the same idea here, not as much air being moved, but using two smaller and identical drivers. No one has done this. It cannot help but be a successful design in my view. That, and the line array idea are killer design ideas.

I am also looking forward to hearing from Dave D about his thoughts on the phase plugs installed in the B200's. ...These Vancouver Island guys are on the cutting edge of DIY speaker stuff. Shout outs to Planet 10/Chrisby/Russell D, and all the others i cannot think of because, except for flashbacks, I have no memories.

I also think it is very cool, the number of people who have been smacked over the head when hearing the B200, in having had the same initial reaction I had, and of all the worldwide tinkering and invention going on re OB use. From Oz come Nigel and Reverend Alf with his Quasar-esques, to John down in Costa Rica [cheeky bastard] to the very talented man with the lathe up in Campbell River, the forward thinkers Chris and Dave in Victoria, to the cosmetic surgeon in shi shi LaJolla, now hooked on his own ideas, to MN, ON, CT, GA, CA, all these different people from all over, yet groovin to the same thing. Tuned right in to the same vibe, with some Close Encounters like inclination toward experimental "travels." Such is the almost gravitation-like pull of these very dark stars.

Vinnie R. · « **Reply #602 on:** 16 May 2006, 05:06 pm »

All,

I just spoke with Louis. He is working on a floor standing version of the Aperiod 8 and SuperHemp , and mentioned that he is going to build a prototype version of this cabinet without the back for me so I can try it out with my B200s and compare it to my OBs.

I should be able to pick them up next week and I'll report on the sound once I try them.

In the meantime, I am still thinking about other OB ideas for my B200s. The fire has been lit and things are starting to COOK!

Dmason · « **Reply #603 on:** 16 May 2006, 05:18 pm »

Vinnie

Tell Louis he could make two open back cabs by cutting one cabinet in half, on the axial, yielding two cabs with 6 inch sides, for 27 inches, perfect. Also, twould be an idea to go out and get some nice half inch felt to line the backs with. 12 inch sides will offer strong resonance, and possible pipe action.

I like the idea of an Omega "Boffle" like the old Hartley Symphony... Louis knows of this design as well. He could have Boffle on top and sealed on the bottom. Good to 40Hz, and killer.

ohenry · « **Reply #604 on:** 16 May 2006, 07:06 pm »

Quote from: Dmason

...Also noticed the DarkStar thread hit 40,000 hits very recently. Dr Linkwitz referred to it as The Best Street Level de facto primer on Open Baffle he had seen on the Net. Congrats to Vinnie for having The Jumbo Thread on his circle.
...

Once again, a very, very cool read. Congrats on the "billions and billions served". Dmason, you are the OB Mickey-D of AC.

Dmason · « **Reply #605 on:** 16 May 2006, 08:05 pm »

Thanks Henry. I was hoping more for a sort of Carl Sagan vibe, but Micky D will have to do. ...How bout jus' 'billions and billions' --a sort of middleground between Cornell with Astrophysics, and Cheeseburger with Fries

opnly bafld · « **Reply #606 on:** 16 May 2006, 09:34 pm »

I agree with Dmason on the depth of an open back box.
I made a box 49"h x 14"w x 10.75"d, tried it for about a week with the back on and off.
With the back off it had about a 75% box sound and only about a 25% OB sound. But with less depth, especially near and above the driver, it should sound very open, more OB like.
The top of the box was fixed, so I am not sure how that affects the sound.
I have seen where a few have used a "top"(board) that was angled up to good effect.
Lin

Vinnie R. · « **Reply #607 on:** 17 May 2006, 03:08 am »

Quote from: opnly bafld

With the back off it had about a 75% box sound and only about a 25% OB sound. But with less depth, especially near and above the driver, it should sound very open, more OB like.
Lin

Hi Lin,

Hmmmmm....good input. Maybe the baffle is the better way to go instead of the "boffle."

I can't get this design out of my head:
http://www.visaton.com/english/artikel/art_829_6_20_2.html

I really attracted to something like this... I would slightly tilt the baffle back and the sides and bass would support everything and add rigidity. Maybe make it all out of 3/4" MDF.

I want to do something like that, but with the B200 on the top running in full range (no crossover componets here, please..). As for the bottom driver to augment the bass, the BGS 40 seems like a decent choice.... at 98dB. I can parallel this with the B200 driver, and simply put a coil in front of the BGS 40 to roll it off slowly at freq.'s higher then say in the 60 to 80Hz range. This will boost up the slow roll off of the bass of the B200 by itself in the OB....flattening things out. Based on listening in my room, my current B200 OBs only need some boost in the less than 80Hz range. There is still bass down there, but just attenuated.

I also looked into the Augie, but it is much less efficient at 88.7dB (not much of an issue if a separate amp was used for it, but I prefer to not have to go this way). The BGS 40 also has twice the max cone displacement than the Augie, but this tells me nothing about the bass quality.

Something has to happen!

opnly bafld · « **Reply #608 on:** 17 May 2006, 03:45 am »

Hey Vinnie,
Did you order from e-speakers and if so did you get the Visaton catalog in....... German?
You not only get good sounding speakers you get to learn a new language.

I am leaning toward the no box or something similar with another B200( thanks Dmason) down low and my Augies working as just subs, dipole of course.
I at first had the Augies on the same mdf baffle as my B200s, but the 15"ers shook the baffle too much, so I put them in open back boxes.
I have plenty of SS amps laying around and a x-over for Augie duty.

Also, I really like your Signature 30 amp, but since I just spent a lot of money(for me) on some new tube-mosfet amps I better wait awhile.
Thanks,
Lin

Russell Dawkins · « **Reply #609 on:** 17 May 2006, 04:24 am »

I like this comment on hearing the NoBox:

Extract from Klang & Ton 03/2004
"What a surprise! These NoBox speakers are devilishly good. The treat we were offered in our editorial offices left even the most hardened professional testers open-jawed. Although the test results promised us a treat, none of us had really expected to hear such deep, clearly defined and crisp bass. Not once did we feel there was anything missing in the bass department."

"But it is not just the bass that makes this construction stand out - it is more the phenomenal B 200 wide-range speaker which, freed from the restraints of a cabinet, excels beyond compare."

"The impression the sound makes is one of freedom and independence with a bass quality which is so good that the lack of sub-double bass is not perceived as a detraction. What really made us sit up and take notice is the unique combination of spatial separation and the phenomenal clarity of the sound picture. The overall impression these NoBox speakers make is less an overbearing, special-effects one than one of unbelievable coolness. The music is simply there, unpretentious and unobtrusive with sufficient objectivity and yet straight to the heart. Brilliant, this has given us a completely new set of impressions from the field of music."

I think I would have hours of fun with the NoBox design and 4 small amps and, in place of a crossover, a Behringer DCX 2496 crossover for $309. Once a good sounding configuration was achieved with the Behringer, then it could be replaced by nice sounding parts in a simple analog active crossover.

Dmason · « **Reply #610 on:** 17 May 2006, 05:46 am »

Before anyone goes and orders expensive Visaton BG40 woofers, there are plenty of choices available right here, which are easily better qualified and less dough.

For what it is worth, one other driver roller and open baffle-naut, Kurt Chang and I have concluded that the Parts Express Dayton IB-385-15 is THE ideal 15 inch bass driver for OB. Designed for infinite baffle, it has the right Vas, Q, bags of Xmax, everything about it, including its $120 pricetag are spot on perfect for open baffle. Kurt is using four pairs of 18 inchers + a Bohlender Graebner 50 inch ribbon dipole set up that routinely makes auditioners in Chicago obsolesce their box speakers. Have a look at the Dayton IB 385 for a No Box solution, and save money, take advantage of our efforts.

Another thing Kurt and I agree on based on experience, is the better and grander bass implementation you have, over which the open baffle wideband driver can sing like a bird out over, the better.

You can send assigned Fs to the B200 without crossover components by using a simple shunt capacitor at the amplifier. That is not considered illegal. Passive is magic-robbing crap between amp and driver. Works.

-Richard- · « **Reply #611 on:** 17 May 2006, 05:56 am »

The spec's for the Dayton IB 385-8 15" IB Subwoofer are below:

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-455&CFID=116892&CFTOKEN=77426284

The Dayton Loudspeaker IB series subwoofers are designed to produce extremely low, clean, uncolored bass in infinite baffle situations. Ideally, the subwoofers are situated between the listening room and an attic, basement, or garage using the floor, ceiling, or walls to separate the front and rear sound waves. Benefits of the infinite baffle approach include extreme low-frequency output, very clean and distortion-free sound, lack of large enclosures within the room, and amazingly loud bass with modest power amplifiers. Combining high sensitivity, good mechanical damping, and excellent excursion capabilities, the IB series subwoofers are the only drivers on the market designed specifically for infinite baffle situations. Made in the U.S.A. 5 year Limited Warranty.
Specifications: * Power handling: 350 watts RMS/600 watts max * VCdia: 2" * Le: 3.08 mH * Znom: 8 ohm * Re: 5.2 ohms * Frequency range: 20-500 Hz * Magnet weight: 90 oz. * Fs: 20.8 Hz * SPL: 88.2 dB 1W/1m, 90.0 dB 2.83V/1m * Vas: 11.11 cu. ft. * Qms: 12.08 * Qes: .69 * Qts: .65 * Xmax: 14.3 mm * Dimensions: Overall Diameter: 15-1/8", Cutout Diameter: 13-7/8", Mounting Depth: 7-3/8", Magnet Diameter: 6-1/2".
Long Excursion Design
Heavy Gauge Stamped Steel Frame
Extremely Rigid Kevlar Impregnated Paper Cone
Heavy Duty Treated Foam Surround
Single 8 ohm Voice Coil on Kapton Former
Bumped Back Plate
Vented Pole Piece

Note the frequency range above: Frequency range: 20-500 Hz

Hope this helps -Richard-

Russell Dawkins · « **Reply #612 on:** 17 May 2006, 07:15 am »

I'm curious to know which 18 incher Kurt is using, if it's not proprietary.
4 pairs!!!

I'd also like to see a picture of Kurt's set up.

Dmason · « **Reply #613 on:** 17 May 2006, 02:22 pm »

Russell

I believe there are pix at Audio-Salem in the Gallery. If not, I will ask Kurt to perhaps post a couple shots of the system, and also his Home Theater OB system using the new Fostex 206esr and JBL Pro Bass bins. The Orchid Baffles are worth a look too.

I have asked Kurt to show us some pix here. Thank you Kurt.

opnly bafld · « **Reply #614 on:** 17 May 2006, 11:45 pm »

WOW

All I can say is the only thing better than a pair of B200s is 2 pair

Details to follow shortly.
Lin

opnly bafld · « **Reply #615 on:** 18 May 2006, 12:59 am »

I now have 2 B200s on each 45"hx20"w baffle, no wings.
The bottom driver is @ 5" off the floor and x-o is at 170hz, 24db/oct.
Top driver is running full range.
Bass is strong down to 40hz, with good output at 35hz.
I just tested with a CD, (did not have my meter handy) so I don't know the -db points.
Crossover is Rane electronic 2 way, so I will try other x-over frequencies to see how it sounds.
Right now I just want to listen to some more music.

Lin

JiffyBoob · « **Reply #616 on:** 18 May 2006, 01:14 am »

Openly Baffled

So, ... the good Doc was right again. Sounds like your reaction mirrors my own. Those who hear, know. This verifies my inclination to the bass-augmentation free zone. It is a

WHOLE NEW GAME

Please keep us informed. We will be especially interested in the results of your crossover frequencies, and their effects on sound. Very cool things are happening now.

I have "mine"

playing right now, and yes, same sonic. 1+1=4. The lower driver is mounted about half of five inches.

opnly bafld · « **Reply #617 on:** 18 May 2006, 02:00 am »

JiffyBoob,
My question is, if as you rightly note 1+1=4, does 2+2=8 or 16?

I guess you will find out soon enough.

leads to

=

Lin

JiffyBoob · « **Reply #618 on:** 18 May 2006, 03:28 am »

Openly Baffled

I suspect, -based on nothing other than excitement, that the mojo with these things is exponentially increased, based on what you and I are sharing in our experience. + and you know what I am talking about. Now there is this ultra enhanced presence factor, and a single is no slouch either, but just MORE. More presence, detail, the upper driver is relieved of any low frequencies, and the lower one is relieved of everything but those frequencies under 250Hz or so. Not a "woofer" mind you, Mark of Canada, but an extension of the mojo you hear. OB's suggestion of powerful output to 40Hz I concure with because I tried it with bass guitar, and the entire Low E fundamental is present and accounted for, with plenty of lower harmonics, (using 1974 Rickenbacker 4001 bass.) So in other words, not much is left out at all. I think four B200 will be just more goodness, more dynamics, more sound, less distortion, all good. Very cost effective.

I have no wish to plug the sub back in because the sound is so inclusive and brilliant. The added mojo makes the Art Audio PX25 which is designed with the tube in mind, really truly shine. This is very, very good stuff folks.

-Richard- · « **Reply #619 on:** 18 May 2006, 04:35 am »

ALRIGHT...ALRIGHT...Jim is busy so I borrowed an electric saber saw and will
cut a crude hole in the lower area of my simplistic OB slabs of 3/4" maple plywood...

I CAN'T STAND IT AN LONGER!!!!!

I must hear what Dmason, Jiffyboob and opnly bafld are hearing...

I will give some kind of feedback soon...

Ahhhhhhhh...the fun of it all...

Tonight listening to classical Latin American guitar: David Russell...Aire Latino...
on the Telarc label...a Scottish master of the guitar!!! (hear that Dan) but would
you believe he is the best I have ever heard...better than Segovia? Well...maybe...

Deb is thrilled with the sound...and that makes it all worthwhile...

Warm Regards -Richard-