My new Alpair 12's

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Thanks Dave. One thing that eludes me as far as these Alpairs cabs go - what are the advantages of, say the Pensil or GR or double reflex, etc. designs over a simple BR? I know the Super Pensil goes 10hz lower but other than that the F3 appears to be roughly the same for all of them...
 
frugal-phile™
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F3 is widely used, but Toole says it is not a useful spec -- F6 or better yet F10 should be considered.

I don't have an opinion on DBRs.

The high-aspect ratio slot-port designs effectively add a resistance to the port, pushing them away from pure BR towards sealed, improving their group delay, and making them more tolerant of the changes in tuning caused by the changes in T/S parametrs with varying volume/drive (either directly via the volume control, or the very dynamics of the music itself). A BR is a tightly tuned system, and unless you have a driver with completely flat T/S curves (good luck) will only be in tune at 1 volume.

The Pensils are in some senses related to a traditional TL, with the back wave being absorbed so that it has no chance of coming back thru the cone. Scott reached far back for the inspiration on these.... a concept largely abandoned because of the size and simplicity. I'd make sure the boxes are well braced, any big panels may reveal the box is there in other ways. I have a set of Pensil7 downstairs waiting for drivers,

dave
 
frugal-phile™
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I found sims of both...

dave
 

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Thanks.
That's not too bad for a smaller room vs. the larger footprint of the supper although i like the driver height of the supper better.
I plan to drive them with my Fi 2A3 set amp and am wondering if it would be advantageous to drive the smaller A12 pensil's 50Hz F3 rather then the supper's 40Hz?
 
frugal-phile™
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Efficiency above ~300 Hz should be unaffected by the box. My measures indicate 89 dB.

The MA drivers seem to be happy with less power than one would expect. I was quite shocked when Don (Doorman), with his 3.5W amp, swapped out his Fonken167 (92-93 dB) for CHR-Ken (10 dB less). I see A10.2 in his future.

Any of these can have an empty extension/base added to increase the height.

dave
 
Efficiency above ~300 Hz should be unaffected by the box. My measures indicate 89 dB.

The MA drivers seem to be happy with less power than pne would expect. I was quite shocked when Don (Doorman), with his 3.5W amp, swapped out his Fonken167 (92-93 dB) for CHR-Ken (10 dB less). I see A10.2 in his future.

Any of these can have an empty extension/base added to increase the height.

dave
I'm waiting as the "SS MarkAudio" makes it's way across the Pacific, with containers full of drivers, including MY pair!!
Best, Don
 
Way fatter than i like... i'm using cryoed 24g solid core OFC in mine. Look up motosapien's comments when i had him swap that into his Coniston^2 build.

dave

Interesting. 24awg sure is cheaper that's for sure...

I've got 50hrs on my 12s in a simple BR. Sounds pretty good but vocals and mids a little thin. I used an EQ and bumping up 100 - 400hz area seemed to help quite a bit. Does this mean I'll need a bsc circuit after all, or is this likely to fill in w/ break-in?
 
24g solid can be VERY cheaply mined from CAT5/6 cable

How big is your BR?

I wouldn't be putting any EQ on the A12 until they have gone thru the mandatory breakin
http://www.diyaudio.com/forums/markaudio/154223-running-alpair-7-12-a.html

And you can't start making any real evaluations until probably thr 200-300 hr mark.

dave

BR is 19L (I know, not ideal - but it's what I have at the moment). Running sealed (plugged ports), crossed to sub. Ok, I'll reserve thoughts til they break in then.
 
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