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

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.

https://www.diyaudio.com/forums/atta...1&d=1502337540

dave

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?

Can you post Scott's "ML-TL"

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 don’t know that this has been released for free public use. As is, it is only a twin driver design but could esily be repurposed for a single driver.

Here are the Mar-Ken of which Chris speaks:

https://www.planet10-hifi.com/boxpix...en-1st-pic.jpg

And the ML-TL:

https://www.planet10-hifi.com/boxpix/A12pw-MTM-comp.jpg

dave

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.

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

So is this a 2.5 or 3-way design? Why the two crossover points?