Alpair 12P cabinet options

frugal-phile™
Joined 2001
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Chris has commented on the 'Ken/Pencil comparison. The new 12 is to my mind a step up from the old, and less expensive. it is a very good driver. Its biggest competion is from other MA built drivers. It got heavy listening at the 1st of the diyFEST a couple WEs ago with lots of accolades, by the end of the fest the A7s & the EL70s were right up there too, from the comments an edge thru the critical mids (i didn't get much serious listening done, too much running around). Certainly does not go as low as the EL70 which in the trapezoid floorstander gave an impressive back deck performance with Dark Side of the Moon..

dave
 
I haven't seen much comment lately on the results of the new Alpair 12P in various cabinets. In particular, I am wondering if anyone has had a chance to compare the new driver in the old and new pencils or perhaps the new driver in the older dbr or *ken designs.

Jp

Since the new units are a bit of a fudge in the boxes for the old driver, I don't think that sort of comparison is going to tell you a great deal, other than the fact that a/ in the cabinet's operating BW, the box for an old unit is sub-optimal for the new, and that above that region, the drivers differ in the ways already debated.

IMO, the 12P is a significant step forward from the old model, which was already very good. The extra efficiency is nice to have, it appears to be better off axis (no measures, but that's what it sounds like, and the flatter cone profile should help promote that), response appears to be roughly as flat as before, but with more on the top end. It's even less forgiving of poor amplification though than the original. Essentially, this is the Alpair you'd go for if efficiency is what you need. If you want more LF extension from an Alpair unit, albeit with less efficiency & outright dynamic range, the A10.2 is one you'd want. You pays your money & you takes your choice. It boils down to system design; you pick what best matches your requirements.
 
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Horn construction?

Hi mostly directed towards Scott, is there a updated set of plans for your alp 12 horn (silbury?) But for the alp12p?

My thinking is to maximise the dynamic strenghts of the driver by going the horn route. Or would the updated super pensil box suffice?

Apologies for the english it's not my first language.
 
Your English is fine. Judging by your above post, it's better than some people for whom it's a first language.

I prefer not to discuss the horns on the forum, since they are commercial products, and my presence here is strictly as a DIYer. So please forgive me keeping my answer fairly short.

Avebury is the enclosure for the A12P. It required only minor revisions for this driver, and those were done some months ago. It's simply been a case that, due to time pressures, we haven't had chance to update the website with 'Alpair 12P' replacing 'Alpair 12' where appropriate.

Regarding the pensils, it depends on what you regard as being good enough for your requirements (there is a saying in design offices the world over: 'perfect is the enemy of the good enough'). They aren't bad in this regard; however, Avebury is the more efficient load, especially when boundary loaded as intended, and ultimately it has greater dynamic range.
 
Thank you Scott for the swift reply and the flattering comments on my poor english.

I truly understand and respect your reservation to comment about your commercial designs on this forum.

Expect a order for the plans on your woden site.

Best regards Robin Wallin.
 
Yesterday i heard the A12P at Twin Audio in Hong Kong, connected to their exellent tube gear. It was housed in the SuperPensil for the A12.
This combination was very, very good, truly fullrange, clean top end, excellent resolving of details, nice bass in that big speaker, excellent depth in the sound.
I bought the A12P pair, and I may be investigating smaller cabinet options, as the SuperPensil is really quite big.
 
Yesterday i heard the A12P at Twin Audio in Hong Kong, connected to their exellent tube gear. It was housed in the SuperPensil for the A12.
This combination was very, very good, truly fullrange, clean top end, excellent resolving of details, nice bass in that big speaker, excellent depth in the sound.

They work very well in the big SP's. I'm really enjoying mine.:yes:

jeff
 
Yesterday i heard the A12P at Twin Audio in Hong Kong, connected to their exellent tube gear. It was housed in the SuperPensil for the A12.
This combination was very, very good, truly fullrange, clean top end, excellent resolving of details, nice bass in that big speaker, excellent depth in the sound.
I bought the A12P pair, and I may be investigating smaller cabinet options, as the SuperPensil is really quite big.

So Talaerts, looks like you acted quickly upon the Hong Kong trip? :D

When you say Super Pensil for the A12 is it the old Super Pensil box you are referring to? Or the new one (for A12P)?

There is the Pensil 12P design also which is as tall but depth is less; it might end up sacrificing a bit of low end, but hope not much - mabe Scott can comment on that.

On small designs, Colin's compact bookshelf speakers designed by Scott is an option.

- Zia
 
It was in the "old" Super Pensil box, in fact they took the A12s out so I could listen to the A12Ps. Probably this box was not optimal for the A12P yet it was already very, very good.
Much, much better than most of the Fostex speakers in my opinion.
And I heard more details than with my quite ok Beyma coaxial-based speakers.

I wonder if the small bookshelf designs that I saw in other threads would need a baffle step filter. The sound in the wider Super Pensil was very good and balanced without extra filters.

As an aside, they had Lowther TP1s playing as well, and they were very nice too, without the "shout" that I feared. But inpractical speakers !
 
Not really -not, at least, the one I did, unless they're well out into the room, in which case you presumably wouldn't want a standmount in the first place. They're not going to shift air like an Altec 604, but within the constraints of a smallish standmount & a 6 1/2in wideband driver, they do a solid job in the kind of small - medium spaces they were intended for.
 
I have some bass reflex (rear ported) here that have damaged drivers and wondering how the Alpair 12P would fare in them.

I don't have details on internals but they are:

Dimensions: 23"H x 11.5"W x 11"D

Port you can easily fit adult fist through. 30 pounds each.

Ok, volume in the low 30's, a little big for the A12p in a BR, but not the end of the world bad.;)

So roughly a 4" dia. port? Somewhere around 8-8.5" long would do it. If it's a lot shorter, you may want to retrofit a smaller dia. longer port into the box. Would work as a "break-in" box while you build something better.

jeff
 
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