Triple 12" OB H-frames

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Erpeder

Re: Triple 12" OB H-frames
« Reply #40 on: 18 May 2015, 02:56 pm »
Think he  meant actually sideways  , not laid down (thinner profile ? )
If that's the case, you can't turn them sideways,   you'll get   very little output as there are nulls at the sdies (front/rear waves cancelling)

jay

What about Dannys U-baffel with the 8" on the side. No body whrite about that project, is it a bad solution or to new project.

mlundy57

Re: Triple 12" OB H-frames
« Reply #41 on: 18 May 2015, 03:09 pm »
What about Dannys U-baffel with the 8" on the side. No body whrite about that project, is it a bad solution or to new project.

It is not a bad solution at all, just different. The speaker stands you are talking about ended up working like a ported box rather than an open baffle. 

If you are pairing them with a ported or sealed monitor and/or need to place them close to the front wall they would be a great choice.

However, if you are wanting the open baffle sound than those stands would not be what you want while the designs discussed in this thread would be.

It's just a matter of different designs for different applications.

Mike

Erpeder

Re: Triple 12" OB H-frames
« Reply #42 on: 18 May 2015, 04:02 pm »
It is not a bad solution at all, just different. The speaker stands you are talking about ended up working like a ported box rather than an open baffle. 

If you are pairing them with a ported or sealed monitor and/or need to place them close to the front wall they would be a great choice.

However, if you are wanting the open baffle sound than those stands would not be what you want while the designs discussed in this thread would be.

It's just a matter of different designs for different applications.

Mike
Thanks Mike. Will the U-baffel then load the room as a ported box or performe naturlig as an OB.

mlundy57

Re: Triple 12" OB H-frames
« Reply #43 on: 18 May 2015, 04:48 pm »
It is not a bad solution at all, just different. The speaker stands you are talking about ended up working like a ported box rather than an open baffle. 

If you are pairing them with a ported or sealed monitor and/or need to place them close to the front wall they would be a great choice.

However, if you are wanting the open baffle sound than those stands would not be what you want while the designs discussed in this thread would be.

It's just a matter of different designs for different applications.

Mike
Thanks Mike. Will the U-baffel then load the room as a ported box or performe naturlig as an OB.

As I understand what Danny said about it, it loads the room like a ported box rather than an OB

Mike

Erpeder

Re: Triple 12" OB H-frames
« Reply #44 on: 18 May 2015, 04:58 pm »
As I understand what Danny said about it, it loads the room like a ported box rather than an OB

Mike
Hm, if I am right there was a way to minimize the ported effect. If you make the U-baffel wider in the rear than the front. Is that right understood.

Captainhemo

Re: Triple 12" OB H-frames
« Reply #45 on: 18 May 2015, 06:00 pm »
Hm, if I am right there was a way to minimize the ported effect. If you make the U-baffel wider in the rear than the front. Is that right understood.

It was something that was discussed along with  adding  a shelving circuit to the amp but not sure if Danny has been able to get to it yet

jay

Tyson

Re: Triple 12" OB H-frames
« Reply #46 on: 18 May 2015, 09:03 pm »
Hm, if I am right there was a way to minimize the ported effect. If you make the U-baffel wider in the rear than the front. Is that right understood.

Basically a pair of angled "wings".  Yes, that should minimize the ported behavior, but on the other hand, it's now a lot more visually obtrusive since the wings go out to the side, even if it's at a pretty acute angle.  So I don't think it gains you anything over just a regular H-Frame, particularly with the 8 inch woofers.  But that's just my opinion :)

rak313

Re: Triple 12" OB H-frames
« Reply #47 on: 18 May 2015, 11:37 pm »
It was something that was discussed along with  adding  a shelving circuit to the amp but not sure if Danny has been able to get to it yet

jay
Danny will have to comment, but I believe the shelving circuit is added to the standard servo drive to add 6 dB/oct gain as freq decreases for OB. I believe Danny had to remove this circuit for his stand.

rak313

Re: Triple 12" OB H-frames
« Reply #48 on: 19 May 2015, 12:04 am »
The 12's are pretty wide,  if you use a doulbe (1.5") side panels,  you're  a 16" (15.5"  if you use Ruben's flat packs I think).
I've thrown the little X LS Encores up on top  and they sound  great togethe. The subs are so adjustable you  cna  combine them with pretty much   whatever

What if you stack a pair of 12" with the speakers firing sideways. Each speaker in an N-frame. I'm not saying this very well, but you would have a 8" W by 13"  D by 26" H cabinet.  The bottom half would have a 4" by 12" slot that a speaker would fire into sideways.  The other half of the bottom front would be blocked (so the sound would escape out the back).  The top half of the box would be a mirror image, so the speakers recoil forces cancel. The size would be pretty compact.

Edit: made a sketch of what I was thinking.  The resonant freq of the cavity is 1/2 of what that of the H-frame, but it would seem to me you could mitigate that by angling the speaker so that the cavities are triangular instead of rectangular.



 
« Last Edit: 19 May 2015, 03:04 am by rak313 »

Captainhemo

Re: Triple 12" OB H-frames
« Reply #49 on: 19 May 2015, 03:36 am »
Danny will have to comment, but I believe the shelving circuit is added to the standard servo drive to add 6 dB/oct gain as freq decreases for OB. I believe Danny had to remove this circuit for his stand.

you maybe right about him removing it although  I thought it was the opposite,  thought he started with a standard HX300/500 (don't remeber whcich) and Brian was going to send himj the  OB shelving circuit addon to try   :scratch:

Captainhemo

Re: Triple 12" OB H-frames
« Reply #50 on: 19 May 2015, 03:52 am »
What if you stack a pair of 12" with the speakers firing sideways. Each speaker in an N-frame. I'm not saying this very well, but you would have a 8" W by 13"  D by 26" H cabinet.  The bottom half would have a 4" by 12" slot that a speaker would fire into sideways.  The other half of the bottom front would be blocked (so the sound would escape out the back).  The top half of the box would be a mirror image, so the speakers recoil forces cancel. The size would be pretty compact.

Edit: made a sketch of what I was thinking.  The resonant freq of the cavity is 1/2 of what that of the H-frame, but it would seem to me you could mitigate that by angling the speaker so that the cavities are triangular instead of rectangular.



Ouot of my  comfort level but.   if I were to take a  stab at this,      the back side of the drivers is open to the front/rear ?   Would  you  just  not  end up canceling  all the output  from the opeings on the front side of the drivers  (one front / one rear ) ?    IF they didn't cancel,  you may  run into the  slot acting as a port  similar to what happened  with Danny's U-Frame .

Again,  just  thoughts , Danny will  have to actually answer  this for you

jay

Danny Richie

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Re: Triple 12" OB H-frames
« Reply #51 on: 19 May 2015, 03:55 am »
What if you stack a pair of 12" with the speakers firing sideways. Each speaker in an N-frame. I'm not saying this very well, but you would have a 8" W by 13"  D by 26" H cabinet.  The bottom half would have a 4" by 12" slot that a speaker would fire into sideways.  The other half of the bottom front would be blocked (so the sound would escape out the back).  The top half of the box would be a mirror image, so the speakers recoil forces cancel. The size would be pretty compact.

Edit: made a sketch of what I was thinking.  The resonant freq of the cavity is 1/2 of what that of the H-frame, but it would seem to me you could mitigate that by angling the speaker so that the cavities are triangular instead of rectangular.



That's what we call a buzz box. Those large un-braced panels are as bigger than the woofers. They will be under a LOT of force and flex and buzz like crazy.

That will also really load the driver and cause a peak in the response all in one place. 

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Re: Triple 12" OB H-frames
« Reply #52 on: 19 May 2015, 03:58 am »
Do these kind of subs sound any different if they are turned sideways? I'm looking for a thinner profile.

If you take an H frame baffle design and turn it sideways then you are sitting in the null area (no output).

Danny Richie

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Re: Triple 12" OB H-frames
« Reply #53 on: 19 May 2015, 04:00 am »
Tyson and Mike, thanks for the great feedback.
Maybe Danny can weigh in on this question.
Are the 8's going to be faster / more accurate than the 12's?

Thanks again everyone.
Neil

Dragsters are slightly faster than Funny Cars, but they are both a lot faster than everything else.

Danny Richie

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Re: Triple 12" OB H-frames
« Reply #54 on: 19 May 2015, 04:09 am »
The concept of the stands with the two woofers was to make a really small and narrow stand for use with mini-monitors.



They worked great and sound great. They are ideal for small rooms and small speakers only. They are not for playing high SPL levels in this configuration.

I did have to by-pass the shelving circuit on the HX300 amp to keep from over driving the woofers with really low notes. The servo system just wanted to keep the response linear all the way down to the low 20's and the two 8's just ran out of X-max if pushed to high volume levels.



Erpeder

Re: Triple 12" OB H-frames
« Reply #55 on: 19 May 2015, 09:57 am »
Danny, what is  a small  room for you? And is a sealed box with one 6,5" and a tweeter a minimonitor?

lokie

Re: Triple 12" OB H-frames
« Reply #56 on: 19 May 2015, 11:51 am »
Quote
Danny, what is  a small  room for you?

Good question. And...

What "rule of thumb" is a good room size bench mark where one would go from 2 to 3- 12"ers H-Frame per side? Moderate "normal" listening levels w moderate "normal" music, etc., etc..

rak313

Re: Triple 12" OB H-frames
« Reply #57 on: 19 May 2015, 01:34 pm »
That's what we call a buzz box. Those large un-braced panels are as bigger than the woofers. They will be under a LOT of force and flex and buzz like crazy.

That will also really load the driver and cause a peak in the response all in one place.

I see, what if those panels are eliminated and the speakers are angled to like 35-45 deg?

Danny Richie

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Re: Triple 12" OB H-frames
« Reply #58 on: 19 May 2015, 01:39 pm »
Any room as small or smaller than the typical hotel exhibit room is a small room. They are about 13' by 19'.

Danny Richie

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Re: Triple 12" OB H-frames
« Reply #59 on: 19 May 2015, 01:41 pm »
I see, what if those panels are eliminated and the speakers are angled to like 35-45 deg?

Keep in mind that at 90 degrees off axis there is a null where there is no output. Open baffle designs need to face the listener.