Gravity Well Of A DarkStar

JoshK · « **Reply #580 on:** 15 May 2006, 01:55 am »

Lin,

Yes I do need to hear them for myself. But, I am a believer in Hoffman's Iron law. I don't know of anyone who has claimed the B200 to have real output below 300hz, which isn't near low enough for myself. That isn't to say I wouldn't love the B200 in a project, but I personally probably wouldn't run them full range, but that is me. To each his own.

I am not here to start fights. I understand at least as well as anyone that it is preference that matters most in this hobby. I just like to correlate facts with my own preference, so I understand my own likes with real physical explanation.

opnly bafld · « **Reply #581 on:** 15 May 2006, 02:15 am »

JoshK,
Not sure what the fight remark was about.
I certainly did not take it that way.

I was just stating my experience with the B200s and other drivers reinforcing the lower freq. to 40hz with the Augies, 20hz with my sub.
Have plenty of speakers around that are rated to above 20k and don't feel like anything is missing when listening to the B200s.
I don't know all the answers, just what I and others have heard.
Thanks,
Lin

Wind Chaser · « **Reply #582 on:** 15 May 2006, 02:28 am »

Jiffy Boob,

With 4X15" woofs, you is serious about the bass!

There is a guy on the Decware forums called Mr Content who has made a good study of the B200 in OB. Over the past few years he has experimented and tweaked at least 12 different implementations. Talk about serious, he has (at last count) 20 pairs of the B200...

Having dialogued with him and seen pictures of his latest creation, I find it interesting that he is able to crossover a single pair of B200's at 40Hz at 18 db per octave with no hole in between! Of course that is in his room with his system.

John

lonewolfny42 · « **Reply #583 on:** 15 May 2006, 02:29 am »

Lin....What's the size of the room your using your speakers in ?

Chris[/list:u]

opnly bafld · « **Reply #584 on:** 15 May 2006, 02:38 am »

Hi Chris,
Right now they are in the living room, @14'x24' , open on the front right to a dining room and kitchen. They will be going back into a spare room, @ 14'x12' after I do some rearranging.
Lin

opnly bafld · « **Reply #585 on:** 15 May 2006, 02:50 am »

Hello Windchaser,
I just checked the Decware forum and Mr. Content says he has his subs crossed at 60hz, even so still pretty amazing

I tried the Augies crossed lower, but I kept having this feeling I was listening to Bose sub-sats.

Lin

JiffyBoob · « **Reply #586 on:** 15 May 2006, 09:01 am »

Opnly Bafld

Does mr Content state how he arrives at 60hz for a crossover point? This seems low.

Windchaser

The 4 X 15 inch dipole woofer system doesnt produce overwhelming bass at all. Dipole doesnt do this. It does move a fair amount of air, and balances well with the output of the B200. According to Dmason, the DarkStar is basically a distillation of Dr Linkwitz' findings and design. He didnt see any point in reinventing the wheel invented by a physicist, so it was a workable distillation of that Orion design, in a more elegant solution. It works very well. The added B200 OB idea also works very well in allowing one to forego the dipole bass implementation, which apparently was a real bitch to build and particularly to mount the drivers, if I remember correctly. Again, the idea of adding more B200's ie four pairs, is simply to SEE WHAT HAPPENS. And we already know it will not be bad. Bi amped and EQ'd it should be dynamic, lovely and LARGE, with the point source retained thru the upper driver. We will also get to hear Vinnie's new Signature amplifier with this high output rig
==See how much I've learned?

konut · « **Reply #587 on:** 15 May 2006, 12:58 pm »

FWIW, I chose a 70hz, 24db per octave high pass point for my A8s to cross to a sealed sub. A couple of reasons. Its said that 80hz is where sound starts to get directional, so I wanted a 10hz 'buffer'. Its also said that to present a benign load to the amp, cross at 1 octave above the -3db point, in the case of the A8s 43hz, avoiding the impedance rise toward the tuning frequency. I felt that using the 24db per octave slope would reduce the level enough for this as well as avoid any bass hump a shallower slope might present. This has worked out well for me with a seemless transition using the low pass filter in the sub at at about 60hz.

mcgsxr · « **Reply #588 on:** 15 May 2006, 02:06 pm »

Josh, I will claim real output below 300Hz for the b200 on OB, in my room. I have reviewed the Law that you state, and I know that your math and tech skills dwarf my own, but my ears don't lie to me.

I will do my best to get some test tones, and report back with some objective information around what level they can achieve, at what Hz, but I am certain that below 100Hz is regularly reproduced using my JVC, and with the amps that markC brought over, we (4 of us) were sure that we were hitting below 60Hz, run full range, balanced from top to bottom.

I respect that you are test driven, and will try to back my subjective claims as best I can, etc.

No fight by any means, just good banter, in my books! I don't shy from objective means, I just don't have as much access to test gear, as I do my subjective gear... my ears!

In any case, it looks like a number of folks are striking off on new tangents, each with vigor, and passion - just the sort of thing that makes this place, and thread, so much fun!

Vinnie R. · « **Reply #589 on:** 15 May 2006, 02:39 pm »

Quote from: mcgsxr

Josh, I will claim real output below 300Hz for the b200 on OB, in my room. I have reviewed the Law that you state, and I know that your math and tech skills dwarf my own, but my ears don't lie to me.
...

All,

I am certainly getting very good bass in my room down to the 80Hz range (I'm using test tones) and believe it or not, I can actually hear bass down to 32Hz in my room. Sure, it is very attenuated down there, but it is there and can be heard. The bass roll off that I get below 80Hz is also a slow roll off, meaning there is still bass in the 50Hz and 60Hz range, just not as solid as the 80 to 100 Hz range.

I didn't get such good results a few months ago in my condo. Now in my new listening room (approx a 13.5' square, with a trapezoidal ceiling that peaks at 9' tall and the imaginary base of the trapezoid being 5' from the floor) I have a very lifelike center image, and plenty of depth beyond that. Perhaps this has to do with the fact that my baffles are now 4 feet from the rear wall AND the edge of the baffle is also touching the side wall, so this probably explains the impressive bass I am getting. The floor, side wall, and back wall 4' back are kind of forming a box, but the top and opposite side are open. I need to draw my room and OB placement on paper and scan it to show you what I am describing. I have the drivers aiming at my listening chair and am engulfed in a very spacious presentation!

I am driving them with the new Signature 30 and the source is the modded Olive's analog output into the amp. If there is one word that I can think of to describe what I am hearing with these B200 OBs, it would be "tangible." The sound has a very real, very open quality that sounds so free of constraint. While playing in darkness, I feel like I can take a few steps on over to the stage and reach out and touch the performers and their instruments. There is so much space to the sound.

I am not itching to make the baffle something like this:
http://www.visaton.com/english/artikel/art_829_6_20_2.html

If I were to add a second driver (be it another B200 or the BGS 40 show in the link above), I would still run the top B200 full range, and use a simple low pass filter for the bottom driver. The fact that the bass rolloff of the B200 is a slow rolloff suggests to me that I want to find a low cutoff freq. for the bass driver and have it slowly roll off the bass frequencies in such a way that it fills in the slow roll off of the B200 bass....to flatten things out.

The other topic that I want to bring up (and I apologize if this has been beat to death in the past) is the baffle material. I am using 1/2" clear acrylic (24" wide x 42" tall), but I wonder if the sound would be much different if MFD or plywood were to be used? Maybe even 3/4" thick? And using a baffle like the link above with its attached sides, I would think that this would be very solid.

After listening all weekend to my B200 OBs, I am now driven to take their performance to the next level...

The funny thing is that my B200s are barely even broken in and they sound so good!

And the best part is that I have a dedicated listening room, so my wife isn't giving me any grief about these big baffles looking strange in our living room. Heck, I made them clear so she wouldn't really see them, but it turns out that she saw right through them (and my evil scheme!).

Anyway, life is very good now!

nodiak · « **Reply #590 on:** 15 May 2006, 03:44 pm »

Here's the numbers from my in room measurements of B200. 11.5'w x 26.5'L x 7.5'h room. 19" x 33" flat OB panel. Panels 66" out from front wall, 26" to driver center from side walls. Mic was 10.5' from speaker plane.

HZ: 32 63 125 250 500 1K 2K 4K 8K 16K

SPL: -8.5 -6 -5 -2.5 0 0 0 -2.5 -2 -5

That's: 32/-8.5, 63/-6, 125/-5, 250/-2.5, 500/0, 1K/0, 2K/0, 4K/-2.5, 8K/-2, 16K/-5 .

Perfect for blending in a bass driver imo. I'm not a super tweeter type, but some may like that addition. BSC would work for some folks senses too.

Don

-Richard- · « **Reply #591 on:** 15 May 2006, 05:16 pm »

There is another factor that may have some value to look at regarding the
bass performance of the B200's in OB...

Until Vinnie's new Signature 30 arrives, I am using an integrated amp with
tone controls. The bass tone control seems to move the B200's into a
slightly greater range of excursion which translates into bass well down
to 40Hz...Yes.,.simple EQ from the Pleistocene era...but it works...

Does anyone out there have an oldtimey tone control preamp and B200's in OB?

If so, try using your bass tone control to see if that will augment the bass
performance...you may find that you can get away without a subwoofer for a while...

Another thought: I am currently folding-in the sound of my Omega Bipoles with the
sound of the B200's using 2 different amps and Y splitters coming from my CD
player. The sound I am getting is very impressive.

For one thing the Bipoles have terrific bass which belies the small size of the drivers.
And just as importantly, the Bipoles introduce textural information impossible to create
with the B200's alone...

The B200's have incredible tone...which creates a life-like sound...there is stunning
resolution throughout its entire frequency gamut, especially on top, which renders
a silky effervescence with stringed instruments that few speakers can equal,
spatial depth and air is a revelation as Vinnie points out, and there is a coherent
all-over musical picture that is entirely convincing...

What I am discovering is that these characteristics create a sonic "field" that
is particularly susceptible to additions from other speakers that can further its
"textural" pallet...that is what the Bipoles are doing and the effect is quite
extraordinary...if subtle in absolute terms...

Allow me to suggest that those of you with Omega speakers that use small
Fostex drivers...or the equivalent...try splitting your CD signal to separate amps
and driving your B200's in OB and your Omegas together...dialing-in each one
until you hear a seamless blend...try playing different music and experiment with
the combinations...you may find you are getting a similar effect that I am...

We are speaking of extending the textural pallet here as an addition to all the superb
attributes of the B200 in OB...just another area one can experiment with...

Warm Regards -Richard-

opnly bafld · « **Reply #592 on:** 15 May 2006, 05:42 pm »

Hello Richard,
I have tried tone contols and while the extra bass was nice, myself along with 2 others listening felt the tradeoffs were not good.
At least with my NAD integrated, the B200s lost some of their rightness in tone at the frequencies above 100hz.
Some older equipment had the bass boost centered at 50hz, I imagine this could have a very pleasing effect.

Very good and informative posts this morning

Keep them coming.

Vinnie how did you get your B200s so fast? I ordered mine last Monday(FedEx ground) and will not recieve them until Tuesday afternoon.

Thanks,
Lin

Vinnie R. · « **Reply #593 on:** 15 May 2006, 05:57 pm »

Quote from: opnly bafld

Vinnie how did you get your B200s so fast? I ordered mine last Monday(FedEx ground) and will not recieve them until Tuesday afternoon.
...

Hi Lin,

I had them shipped 2nd day Air and had them on Friday

Russell Dawkins · « **Reply #594 on:** 15 May 2006, 06:46 pm »

Most tone controls on consumer equipment had a corner frequency of 1000 Hz for the bass control. That means the effect starts at 1000 Hz, which is quite a bit higher than what seems to be needed, insofaras the mids will also be affected.
It sounds like what is needed for a single B200 is for boost to start coming in around 150 - 200 Hz.

I like Vinnie's idea of full range on the B200 and passive one pole crossover on the bass driver. Seems to me with a little judicious tweaking you could still be operating at close to 96 dB efficiency with that 15" driver by Visaton (BGS 40 - 98dB in isolation), rather than the 90 dB quoted for the NoBox, where the crossover is quite elaborate and the bass driver is compensated for dipole cancellation to get the 32 Hz LF extension figure.

Dmason · « **Reply #595 on:** 15 May 2006, 06:47 pm »

thanks for those measurements. They make bass augmentation very easy, and effective. Keep em coming. I agree with Russell.

Brad · « **Reply #596 on:** 15 May 2006, 08:12 pm »

I don't use the B200s in OB, but I have had very good results using my A8's with a small bump in the bass tone control on my Scott amp.

It fleshed out the drum sound without appearing to affect the rest of the range.

I wonder about combining the A8's with another pair of B200s in OB.....hmmm

opnly bafld · « **Reply #597 on:** 15 May 2006, 09:31 pm »

Hi Brad,
That might (probably would) sound very good.
Louis O. was planning such a beast, but I have not heard any details lately.
Lin

-Richard- · « **Reply #598 on:** 16 May 2006, 04:07 am »

Hi Brad,

Glad to hear that your amplifier's bass tone control can help to flesh out some
of the lower end information on your A8's...nice to have that kind of simple EQ
available to us...

I think you would find it very instructive to build a simple pair of OB's for
the B200's...you will find the sound quite different from the A8's...which I
auditioned in my home thanks to Chris (god I hope my memory is right about
that...these days things in the not to distant past seem somewhat blurred)...

And yes...as long as you have 2 different amps to regulate the volume of
each pair of speakers I think they would have a wonderful synergy together...

In any case it would give you a vivid insight into what OB's are doing that has
so many of us so excited with the results...please do share your findings with
us if you decide to join the openly baffled...

Warm Regards -Richard-

lonewolfny42 · « **Reply #599 on:** 16 May 2006, 05:51 am »

Quote

...you will find the sound quite different from the A8's...which I
auditioned in my home thanks to Chris (god I hope my memory is right about
that...these days things in the not to distant past seem somewhat blurred)...

Chris[/list:u]