[stevenkelby]

An OB sub would need to be place more out into the room (away from the wall). The purpose of the subs in the rear corner is to take away the loading effects or the accumulation of bass in those rear corners. So a seal sub lets you stick it right in the corner.

Makes good sense to me now, thanks Danny!

[Guy 13]

Hi Danny and all Audio Circle members.

I thought of what might be an easy solution to the problem of vibrations from the double woofers transmitting to the top driver (Coaxial or full range).
See the left sketch below and tell me what you think.

At the same time, what do you think of the right sketch?
If there is no horizontal separation between the top and bottom sub drivers,
do you see a problem with that?
The whole constrution is double 3/4" MDF everywhere. 

Guy 13




 

[DS-21]

Not a great idea. Spikes don't have any give, so how would they stop the main panel shaking from the bass cabinet vibrations?

If you want something easy, buy some sorbothane feet off of Amazon, stick 'em on the bottom, and done.

If you really want isolation, look at Siegfried Linkwitz's new dipole. LX521 or something like that. He uses the best possible decoupler: empty space, by means of a "bridge"  that leaves a gap between woofer box and the upper panel.

[Danny Richie]

Guy,

Whether you use spikes to anchor it to the cabinet below or glue it to it makes little difference. The outside edges of the cabinet below are going to have very little resonance issue at all, especially being 1.5" thick.

And the resonance frequency of each of the panels on the H frame are higher than those woofers will be playing. They are subject to flex from pressure but making them 1.5" thick controls that very well. A front panel for the upper driver mounted across the front upper panel of the H frame further strengthens it and keeps it from flexing. Lining the panels with No Rez or any good damping layer will also help.

I lot of people tend to think that using floor spikes on a speaker is de-couple it from the floor or whatever it is setting on. That is really not the case. You are really coupling it to the floor or cabinet below. And that is really what you are looking for. It needs to be solidly anchored down or with the full weight isolated to small points (spikes) to further keep it from moving.

And DS-21,

In regards to the LX521. He basically separated the upper drivers from the lower ones in a separate box. That's a good idea. However, the lower box is still very lightly constructed and subject to a lot of flexing and panel resonances just like the Orion. The buzzing of that box is still going to cause coloration up into the mid-range. And the way that the upper drivers are supported is also very light. That is not much support for a mid-bass driver. That could also cause some issues.

I am really glad to see him get away from the wide baffles though. The sound of all the surface reflections from around the mid-bass and tweeter of the Orion always bugged me, and had a negative effect on the imaging. He also got away from that metal cone woofer. The sound of that woofer always bugged me as well. 

Too bad that thing is all actively controlled though. It needs 8 channels of amplification!    Using good quality amps how much will that cost?

[DS-21]

In regards to the LX521. He basically separated the upper drivers from the lower ones in a separate box.

The common definition of the word "box" does not cover what Mr. Linkwitz did. After all, his bridge has three open sides!

That's a good idea. However, the lower box is still very lightly constructed and subject to a lot of flexing and panel resonances just like the Orion. The buzzing of that box is still going to cause coloration up into the mid-range. And the way that the upper drivers are supported is also very light. That is not much support for a mid-bass driver. That could also cause some issues.

Maybe, maybe not.

Too bad that thing is all actively controlled though. It needs 8 channels of amplification!    Using good quality amps how much will that cost?

If one goes by reality and not the kind of audiophool idiot delusion that makes people bloviate about the "sound" of wire connectors, not too much. The common 12-channel ATI amp is better than anything you would offer, relatively inexpensive, and provides sufficient power for such a speaker in most rooms. For a smaller package, the Crown CT8150/Lexicon DD-8 amp is only 1RU and provides 8 relatively high-powered (100W) channels without requiring noisy fans. It is expensive but considering the technology involved and the space savings, not unduly so.

That said, I wasn't endorsing Mr. Linkwitz's speaker - open baffle speakers require room placement that I find unacceptable - but rather just using it as an example to show best practices for separating bass bins from mid/treble.

[Early B.]

The common 12-channel ATI amp is better than anything you would offer, relatively inexpensive, and provides sufficient power for such a speaker in most rooms.

I used to own an ATI amp, and while they're decent for home theater use, they are certainly not "audiophile quality" by any stretch of the imagination.

[Danny Richie]

If one goes by reality and not the kind of audiophool idiot delusion that makes people bloviate about the "sound" of wire connectors, not too much. The common 12-channel ATI amp is better than anything you would offer, relatively inexpensive, and provides sufficient power for such a speaker in most rooms.

Well, I don't offer amps. I have heard the ATI. It is a decent amp for home theater applications but it is FAR from the quality level I am used to and not at all an audiophile level product. I also think it was quite the bottle neck several years again when I listened to the Orion's at RMAF.

And if you have yet to experience the performance difference from higher quality wires and connectors then there is a whole new world ahead of you. Welcome to high end audio.

[Danny Richie]

We now return to our regularly scheduled programming of setting speakers on subs. 

[WireNut]

I have owned 4 box / bi-amped speaker systems since the late 80's. As i get older and my ears and or system changes,
I really like being able to move the top cabinets forward or backward to help me time aline the system to my ears.

[srb]

Although I could see the adjustment of a few inches affecting the time alignment between the tweeter and midrange drivers, I would think that the longer wavelengths coming from the bass bins would would be minimally affected by a few inches of adjustment.
 
Steve

[MarvinTheMartian]

A better bridge ? Interesting stylish two piece.
Gershman Acoustics
Black Swan
$30K circa 2005

[Danny Richie]

A better bridge ? Interesting stylish two piece.
Gershman Acoustics
Black Swan
$30K circa 2005

Those do look good, and should be very effective.