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Alpair 12PW Recommended Enclosures

Interested in building some enclosures to run some tests.

Sealed Enclosure (Sphere) 1.25 cu.ft
Egg Shaped Rectangle 1.6 cu.ft staggard with a 3" port 7" long below it.

Testing some builds to try and accomplish flat response across entire bandwidth 20-20khz possible thinking of using a passive radiator to assist the driver.

Please Advise ......

TX
 
frugal-phile™
Joined 2001
Paid Member
and accomplish flat response across entire bandwidth 20-20khz

You are unlikely to achieve that. The A12pw. Scott’s ML-TL reaches into the low 20s F10. The A12pw is a wide range and starts to fade above 10k. Still very listenable as a full-range. And a very nice one. I like it better than the A12p.

We already have an MTM in Scott’s ML-TL with an A7x. We are also working on one with the A10p in our large Mar-Ken enclosure.

1.25 ft^3 ~35 litre, you’ll get in the low 30s F10.

The reflex enclosure has a pretty ungly bump at resonance, it needs to be tuned lower.

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dave
 

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Recommendations

:) TX again.

I will probably use a egg shaped to tear drop type enclosure to reduce backwave, diffraction, drag but my question to you would be the optimal airspace to accomplish flat broad range response even if its starts to fade on upper and lower end?
 
I'm running the MTM's Dave mentioned above, and would agree with this assessment of the 12PW over the P - the latter of which I've heard in both a compact standmount and Scott's SuperPensil small fridge sized enclosure.


To achieve the bass performance of which this driver is capable will need something much larger than a small box of any shape and PR.

If you're up for a more elaborate build than a simple rectilinear box, take a look at the Trapezoid floorstander design of Dave's - Bernie Foucher built a stunningly gorgeous pair in solid maple that deliver in spades.

Yes, while they are completely benign to my ears operating full range, they definitely need a tweeter for at least the last 2 octaves.
 
I'm privy to a lot of development / prototype drawings that don't get built locally - or in the case of Mark Audio drivers, some that are published by them - and I'm sure I recall a few sketches MLTLS for the A12PW - a tall single, a folded single, as well as a narrow baffle version of the MTM shown above.
 
frugal-phile™
Joined 2001
Paid Member
Was any sort of crossover used in the ML-TL version? I'm guessing that's an A7 with the 12PW's?

Yes, A7.3eN. We tried a number of XOs. PLLXO 1st order at 240 Hz. 4th order digital that was built into Chris’ Onkyo HT receiver. A 4th order (acoustic, about 800 Hz) passive XO that Aaron worked up for us.

Currently living in Chris’ HT with the passive XO and A7 MOAP. He is using the extra 2 channels for height speakers.

dave
 
Ok so you have a pretty wide range of crossover frequencies you can use. With two of the 12PW's I would think you could get fairly good bass impact from the pair?? I had a Alpair12 in SuperPensil12 cabinets (single driver in each) and the bass response went pretty low, although didn't have much impact. I've since sold the speakers and am now starting to think about doing something a bit different this time around hence my interest in this arrangement :)
 
frugal-phile™
Joined 2001
Paid Member
The plans are part of our ongoing miniOnken paid plansets (contact me).

Chris has heard these, as have i, but they have been mostly living at Bernie’s were he has used them as is and tried them with a number of midTweeters.

We built a standmount version out of solid walnur which was a hit with the customer who uses them as full ranges.

dave