[Jonathon Janusz]

Yep, the stack of circles is how mine was done.  A lot of waste material for sure.

Looking at the design again, though.  Maybe doing a rounded top (like the fancy V's) AND a rounded bottom could get you most of the way "there" on the look and avoid the acoustic issues?

[iamediam]

Danny,

Could the open baffle subs be pointed 90 degrees away from each other like with the V2s, but pushed out to the sides? Something like this?

[Danny Richie]

Danny,

Could the open baffle subs be pointed 90 degrees away from each other like with the V2s, but pushed out to the sides? Something like this?

First of all welcome to AC.

It would change the cancellation pattern but would work pretty well. It would be a little bit like a U shaped baffle where the woofers are mounted on the sides and it is open in the middle only to the back. This moves the cancellation pattern only to the back side. I have been wanting to build some stands like that for our 8" servo subs. It would basically cancel at the front wall and minimize room gain from the wall. It would make an ideal stand for a set of mini-monitors that are limited to close wall placement.

[iamediam]

First of all welcome to AC.

It would change the cancellation pattern but would work pretty well. It would be a little bit like a U shaped baffle where the woofers are mounted on the sides and it is open in the middle only to the back. This moves the cancellation pattern only to the back side. I have been wanting to build some stands like that for our 8" servo subs. It would basically cancel at the front wall and minimize room gain from the wall. It would make an ideal stand for a set of mini-monitors that are limited to close wall placement.

Thanks Danny.

Regarding this U shaped baffle. I'm having a little trouble visualizing this. Does that mean that the woofers would be oriented 180 degrees from each other and pointing out the sides of the speaker? And that each woofer would be in a cube that's open on the back side of the speaker?

[Danny Richie]

Thanks Danny.

Regarding this U shaped baffle. I'm having a little trouble visualizing this. Does that mean that the woofers would be oriented 180 degrees from each other and pointing out the sides of the speaker? And that each woofer would be in a cube that's open on the back side of the speaker?

Yep, that's it.

Imagine a U shape that is about 25" tall, about 7" wide, and about 10" deep. The open part faces the back wall. On the inside panel at the bottom is mounted a HX300 amp: http://www.rythmikaudio.com/compact_amplifiers.html  Just above it on the opposite side is an 8" servo woofer: http://gr-research.com/sw-12-08-1.aspx  Then on the inside panel near the top is the second woofer.

It will need some bracing between each woofer and amp to help hold it together.

Force cancels movement as the woofers are both using positive polarity connections. And the cancellation pattern is in the back only.

[ebag4]

HX300 amp

Yep, that's it.

Imagine a U shape that is about 25" tall, about 7" wide, and about 10" deep. The open part faces the back wall. On the inside panel at the bottom is mounted a HX300 amp: http://www.rythmikaudio.com/compact_amplifiers.html  Just above it on the opposite side is an 8" servo woofer: http://gr-research.com/sw-12-08-1.aspx  Then on the inside panel near the top is the second woofer.

It will need some bracing between each woofer and amp to help hold it together.

Force cancels movement as the woofers are both using positive polarity connections. And the cancellation pattern is in the back only.

So with a "U" frame the woofers can be mounted on the side without a null effect in the front that the "H" frame  has to the sides?

Something like this?



I can't find the dimension info for the servo 8" or the HX300 amp, can you let us know what those are?



Thanks,
Ed

[Danny Richie]

You are pretty close.

The width of the whole thing only needs to be the same as the mounting depth of one woofer. So stagger the woofers.

The amp is 7.625" wide and 10.25" tall. Mounting depth is 3.5".

The woofer is 8.75" across. The through hole is 7.5". And the mounting depth is 5". And that is leaving a small air space for the vented poll piece to breath.

So it the side walls are 1" thick then the whole thing can be just 7" wide.

[ebag4]

You are pretty close.

The width of the whole thing only needs to be the same as the mounting depth of one woofer.

The amp is 7.625" wide and 10.25" tall. Mounting depth is 3.5".

The woofer is 8.75" across. The through hole is 7.5". And the mounting depth is 5". And that is leaving a small air space for the vented poll piece to breath.

So it the side walls are 1" thick then the whole thing can be just 7" wide.

OK, stagger the woofers, thanks.

What impact will this have on the output as compared to the "H" frame? 

Are there size ratios (driver/volume) that come into play? 

If I wanted to do this with 12" servos what  would the dimensions need to be, whatever will fit or should it be larger?

From what you have mentioned in the past I assume the more bracing the better.

Thanks,
Ed

[Danny Richie]

OK, stagger the woofers, thanks.

What impact will this have on the output as compared to the "H" frame? 

Are there size ratios (driver/volume) that come into play? 

If I wanted to do this with 12" servos what  would the dimensions need to be, whatever will fit or should it be larger?

From what you have mentioned in the past I assume the more bracing the better.

Thanks,
Ed

Total output may increase slightly.

The smaller air space to one side of the drivers will load them a little more. The room will be loaded differently too. You will get a little more forward output, but a null in the rear. It should be ideal for applications where space behind the speakers are limited.

You can do it with the 12" servo subs too, but to keep the height down for purposes of using it as a stand then the amp will need to be mounted externally.

[ebag4]

Thanks Danny, this opens up more options! 

Just to verify, the opening is in the back of the speaker facing the front wall, or is the opening at the front of the speaker facing the listening position and the back wall?

[Danny Richie]

Thanks Danny, this opens up more options! 

Just to verify, the opening is in the back of the speaker facing the front wall, or is the opening at the front of the speaker facing the listening position and the back wall?

The opening has to face the front wall not you.

[skalos]

Danny,

This U frame idea looks very interesting. 

This 7" x 10" x 25", 2x8" servo, semi-open baffle (open to the front wall) looks like it would make a great sub-woofer and stand for my N3S speakers that I have almost completed (which I purchased because I don't have room behind the speakers for an open baffle to work). 

Am I missing something?

[Danny Richie]

Danny,

This U frame idea looks very interesting. 

This 7" x 10" x 25", 2x8" servo, semi-open baffle (open to the front wall) looks like it would make a great sub-woofer and stand for my N3S speakers that I have almost completed (which I purchased because I don't have room behind the speakers for an open baffle to work). 

Am I missing something?

It would work great with those.

[HAL]

Here is a picture of three 8" servos with the 8" wideband driver in the OB.  Gives an idea of the height below the full range driver.

[corndog71]

Yep, that's it.

Imagine a U shape that is about 25" tall, about 7" wide, and about 10" deep. The open part faces the back wall. On the inside panel at the bottom is mounted a HX300 amp: http://www.rythmikaudio.com/compact_amplifiers.html  Just above it on the opposite side is an 8" servo woofer: http://gr-research.com/sw-12-08-1.aspx  Then on the inside panel near the top is the second woofer.

It will need some bracing between each woofer and amp to help hold it together.

Force cancels movement as the woofers are both using positive polarity connections. And the cancellation pattern is in the back only.

Like this?

[mlundy57]

Any idea what the footprint for the base of the MMTMM section would be?

[jn316]

Since the cabinet is only 10" deep, the two woofers would be aligned vertically. They are 8.75" wide. Otherwise, that looks right.

Like this?

[Danny Richie]

You don't even have to stagger them from the top view. It could be less than 10" deep.

[corndog71]

[Danny Richie]

Yep. Nice little stand huh?