Ultimate Open Baffle Gallery

frugal-phile™
Joined 2001
Paid Member
A buddy had Planet 10 make him a pair of Onken like cabinets for him with 12PW Alpairs.
He claims the 12PW are a better driver, with the -3db point of 15000 hertz a moot point

Bernie actually made them. Solid Mahogany IIRC. A hifi stand in the same too. Drivers EnABLed, wired with solid core cry-treated 24g, with WBT next gen banana plugs.

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I really like the A12pw. And i much prefer the A10p to the A12p. We have a floor-stander & the sand-mount version pictured for these. The A12pw is killer in a Woden ML-TL. We use a pair with A7.3eN in a WAW. I have no reason to dipubt the sims that suggest response to the mid 20s.

Top end really starts to disappear above about 10k. It makes XO very flexble if you decide to use them in a 2-way. We XO the WAW at 250 Hz, Scott to the A7p at about 1kHz (example below build by Mario shown at the latest BAF — i saw a better pic, ut this is what i could find quickly), or to a dome or ribbon between 2-5kHz.

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dave
 

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How would you keep it looking great in an open baffle?


Easy, function over form and a wife who lets me do what I want with regard to my system.

The plan is to cover the front with black speaker fabric. The baffle was a test made from 6mm MDF and 7mm ply sandwiched with Sikaflex polyurethane adhesive, they sounded so good I have left them as is.


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I used Edge to model the baffle size and driver placement for the smoothest response with NO BSC.

Any artifacts that are not part of the original signal will effect imaging and detail. I concentrated on reducing resonance of the woofer box as well as diffraction and baffle vibration in the fullrange. The FR is sat on top of the woofer box it is not fixed but de-coupled with felt.

These image amazingly, deep and wide sound stage that extends way beyond the speaker placement. Detail good enough to hear someone pick up guitar from a stand and pluck the E string at the beginning of Fleetwood Mac's The Chain.


FR rolls off at about 14K or so but I'm over 50 (very late 30's as the wife says) so I can hear over 16K any more.
 
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Bernie actually made them. Solid Mahogany IIRC. A hifi stand in the same too. Drivers EnABLed, wired with solid core cry-treated 24g, with WBT next gen banana plugs.

MK12pwxwT-SM.jpg


I really like the A12pw. And i much prefer the A10p to the A12p. We have a floor-stander & the sand-mount version pictured for these. The A12pw is killer in a Woden ML-TL. We use a pair with A7.3eN in a WAW. I have no reason to dipubt the sims that suggest response to the mid 20s.

Top end really starts to disappear above about 10k. It makes XO very flexble if you decide to use them in a 2-way. We XO the WAW at 250 Hz, Scott to the A7p at about 1kHz (example below build by Mario shown at the latest BAF — i saw a better pic, ut this is what i could find quickly), or to a dome or ribbon between 2-5kHz.

attachment.php


dave

The standpoint ones look similar to my friend's.
Martin's are solid walnut, I think, and also beautiful in fit and finish.
 
The W frame gets you to how low a frequency? 30 hz or lower?

What freq/slope do you cross to FR?

I'm not sure how low they go I have not measured that. I only measured at the XO point from 100 to 5kHz. XO is set at 235Hz 24dB LW. I used Rod Elliot's kit P09 for the XO.

They sounded so good I moved on to get my analog rig working as it should, when I'm done with this I will go back and measure and tweak the speakers.


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It's the diffractions of the rectangular baffle that are smoothing the response Frequently Asked Questions I wonder how much smearing of the image this causes Diffraction from baffle edges


In my experience quite a bit as does baffle vibration.

The additional detail adding baffle damping is very audible. as is de-coupling the FR from the woofer vibration. Each step that added detail was kept. You can see the table over the woofer this made no audible difference so was discarded.

Here are a few iterations of my development. Pic 2 and 3 should be reversed. Pic 3 was the woofer box from Pic 1 cut down same W300 woofers.


Pic 4 sounded very shouty and it was the raised edges of the trim around the baffle causing the midrange peak. Pic 5 is the same baffle cut and chamfered 45deg, sounded much smoother.

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In my experience quite a bit as does baffle vibration.

The additional detail adding baffle damping is very audible. as is de-coupling the FR from the woofer vibration. Each step that added detail was kept. You can see the table over the woofer this made no audible difference so was discarded.

Here are a few iterations of my development. Pic 2 and 3 should be reversed. Pic 3 was the woofer box from Pic 1 cut down same W300 woofers.


Pic 4 sounded very shouty and it was the raised edges of the trim around the baffle causing the midrange peak. Pic 5 is the same baffle cut and chamfered 45deg, sounded much smoother.

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Do you prefer chamfering over a roundover?
 
I prefer the felt over chamfering, never tried the roundover, problem is the chamfer needs to be a large radius to work effectively, my baffle is only 12mm thick, this is why I used felt. I also had a copy of the BBC design document for the LS3/5A (which I can not find ATM) and their use of felt was preferred over other methods of controlling these artifacts.


I tried felt on the rear and could not hear/measure any difference so I removed it. I do have sound absorbing panels behind and inside the speakers, these make an audible difference to the depth of the image. I suspect reflections from the TV are the issue there.
 
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I've spent 10 years refining this design, reducing the vibration of the baffle has IME far more effect than isolating the FR from the woofer. Although the W frame reduced vibration and a forward mount woofer may introduce IMD.

I made the magnet mount from 12x3mm aluminium bar. To form it I used 18mm plywood circle cut the same diameter as the magnet.

First I bent the mounting flanges at 90deg, this needs to be accurate or the FR will sit at an angle.
 
I was thinking an answer might be to make the baffle very heavy, but the independent mount of driver and baffle makes more sense to me.

The W frame (to reduce vibration) makes sense too.

Your most important ‘component’ might be the partner who allows ‘anything goes’! I also am fortunate that way :).

I will start with the felt. Will take some thinking on how to remount drivers before Inget to that.

Thanks again!