Alpair12P gen2 standmount speakers

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At last I managed to find the time to build these speakers.

I've been promising Zman01 for some time now to get these built and posted so here goes:

They are a small vented standmount, ported from the rear to help with some bass boost from rear wall. The initial design is that of Scott Lindgren, (Scottmoose to you all on this forum) and drafted by myself with some small modifications. Scott did say the bass from these would perhaps not be as good as some the other MA drivers so with this in mind I decided to place the port on the rear.

The elegant curved stands were an inspiration from a design I saw at a local DIY meet some time ago of a small infinite baffle standmount pair of speakers using the Alpair10 drivers and designed by Ed Swift. The end result I'm quite pleased with. I think in this case it's more "imitation being the sincerest form of flattery". I do hope our Ed doesn't sue me for copyright ;)

I've only had about 2½ hours listen to these last night and the drivers are still not yet fully run in. However, initial listening impressions are very favourable. These drivers are very revealing with great soundstage. As Scott did mention bass is not the deepest or lowest I have heard from other MA drivers but the rest of the music reproduction more than makes up for this. But having said that the bass is very respectful indeed and can improve when the drivers are fully runin and the cabinets have settled down and are position up against a flat wall.

I'm reet chuffed with these.

A12P01.JPG
A12P02.JPG
 
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Hi congrats to them and Nice :)

Looking forward to that you can describe the sound, because I think even to buy a set.
For a start, I will make a set of pressure chamber boxes.

Remember:
Running in: Carefully run the drivers at low volume using light music (NO artificial signal generation of any-kind) for the first 100 hours. After this period, gradually increase to normal listening volumes with the introduction of music that contains some bass. The driver will reach optimal performance at around 800 hours of play time.

Therefore, next year maybe hi hi

Speakerbuilder Pro 2.0
2012-07-23_160904_Alpair_12_i_TK_.jpg



Old paper, but good knowledge
KEFTOPICS_vol3 no4 high efficiency with small enclosures
 
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Colin knows this. If you follow some of his previous posts, you'll see he's been running the drivers in in free air for the best part of a couple of months now following the recommended proceedure. So, only another couple to go then. ;)

To clarify a point, when Colin says I mentioned 'not as good', that is not meant in the qualitative sense. The contextual meaning is this: if your object is the maximum flat LF extension, the the Alpair 12p will typically have a higher F3 than, for e.g., the smaller Alpair 10.2. The tradeoff however is that the larger unit has the greater dynamic range and efficiency. Name your poison gentlemen. :) (I favour Connemara peated single malt Irish myself, although I do have inclinations toward Lagavulin. And Bushmills Black Bush. And Victoria Pendleton, come to think of it).

Oh, I'm sure Ed will sock you for millions Colin... his legal eagles are doubtless sharpening their collective beaks as we speak. I think the base needs to be bigger to prevent them looking top-heavy though. Possibly just the angle, or the dimensions of the 12p box.
 
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ScottMoose Okay :))))

I just wanted to wish him congratulations on the good speaker
As I also have a strong interest in, is actually just about to order them.
No attempt at wanting to know more or better, I listen / read even from the sidelines but have obviously not seen or read all the threads: o)

Free whiskey tastes best, and then comes the good sound
Both exhibit a breathtaking ability to drown in.
 
Scottmose wrote
I think the base needs to be bigger to prevent them looking top-heavy though. Possibly just the angle, or the dimensions of the 12p box.

Perhaps the bases a little but they will be spiked for extra stability and the speakers themselves will be bolted to the top support shelf. In reality there does not appear to be any 'top-heavy' or stability issues. The cabinets are constructed in 15mm BBP with the front baffle doubled to allow for the quite deep 11mm rebaate for the driver to sit flush.

I'm presently listening to Loreena McKenna 'An Ancient Muse' with them hooked up to my SE300b monobloc amps with the speakers placed about 150mm off a straight wall. In fact they are either side a 1200mm long fish tank sitting on to a 1500mm long furniture sideboard. Not the most ideal position but it allows them to fire down my 5m long listening room. They sound really good indeed and from such a small(ish) speaker one couldn't grumble at all of the bass these are producing. It is clean and concise though perhaps missing the bottom octave but this doesn't detract from the engaging listen. With a SE valve amp these are simply wonderful and invlving to listen to. The micro-dynamics and soundstaging is superb. Mark has produced a really good driver in the A12P gen2. My hats off to the designer.
 
Of that batch I should think Ms. Pendleton easily the most dangerous to one's health, though I have no personal experience w/ the Connemara. Shall have to look that up next time I restock. Lagavulin and Black Bush already have a home in the cabinet. :D



Name your poison gentlemen. :) (I favour Connemara peated single malt Irish myself, although I do have inclinations toward Lagavulin. And Bushmills Black Bush. And Victoria Pendleton, come to think of it).
 
Thought I'd post up another photo but from side view. This I think shows more the elegance of the shape of the pedestal stands.

A12P03.JPG


I must say these have surpassed my expectations. Anyone who does not fancy the likes of the excellent Pencil designs for the A12P could do no worse than build a similar sized BR box. The likes of WinISD are free and easy to use and should produce a similar sized box to these here. The stands are purely an indulgance on my part and any style stand would suffice. I would expect the larger of the two Pencil designs to give a little deeper bass. But believe me these little babies are not lacking quality bass if corner loaded or placed near a wall. Hence the rear firing port.
 
Planet10 wrote
I look forward to seeing them dressed up -- you come up with some fantastic veneers.

Well dave, I'm torn between rounding over the edges of the speakers and having them professionally spray painted in a colour to match the cones, or veneer them in something like a nice light Birch Burr as per the below photo.

BIRCHBURR.JPG


vinylkid58 wrote
Soundstage isn't their strongest attribute IMHO.

Well last night I had a play with different amps. My SE300b monoblocs, a SE6EM7 integrated and a SS PassLabs F5. The interesting thing with this experiement was the difference portrayal of the soundstage. The tube amps by far outperformed the SS amp even though all 3 amps share the same basic unity gain pre with Silk TVA's. So the only conclusion I can come to is these drivers excel with a tube amp.
 
Colin - I'd vote for the veneer every time - the Birch burl shown is particularly nice

by the time you factor in all the material and labour cost/time to get a pro paint job worthy of these drivers, the veneer and simple clear coat finish could easier be cheaper

while fine for stands & bases, I'm simply not a fan of painted (or plastic laminated) speaker boxes

and as to the synergy between the 12P and the amps you named, maybe there's more to it than just the numbers ;) - these guys also work quite well with P/P like triode connected EL34, or pentode EL84
 
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+1, I'll second veneer over paint!

Re: extension, iirc, it was said the A12P MarKen really required a sub, do you find your project satisfying without the need for a subwoofer? Mind if i ask the tuning frequency of the port?


FWIW, the tuning and enclosure bracing protocol that Dave has employed in the "-ken" series has always emphasized smoother rolloff - even if starting at higher frequencies than any of the conventional BR methods. For me this results in leaner / cleaner bass - I notice it in more articulated harmonics of acoustic bass instruments and hand-stricken drums (tabla, etc), and in cases where the bass impact / extension is lacking, add woofers to taste.

I've also found that regardless of driver make / model they ('kens") excel in imaging and soundstage dimension compared to MLTLs, such as the Pensils, Brines' excellent M10A10, the P10 Castle Microtower, to name but a few. IINM, that's what Jeff was referring to in his comment:

Soundstage isn't their strongest attribute IMHO.

jeff
as of yet Dave has lived with the Markens for a few weeks, but hasn't heard the SP A12P, while Jeff & I have.
 
Most seem to be pushing for a veneer finish over paint. I agree :up:

I emailed my veneer supplier yesterday to enquire if he still had any the Birch Burr in the photo and though he is presently on holiday he promised to check on Monday and post some to me for delivery Tuesday. If I remember when I originally enquired of this veneer a couple months back, 3½ leaves (237cm x 70cm) was £140.00, Shipping - £12.00 and VAT = £30.40. Total to pay = £182.40. :eek:

For these smaller speakers and stands I only need perhaps 1-leaf but to be safe I've ordered 1½ -leaves. Still gonna cost around £84.00 UKP. But still likely cheaper than a pro paint job if I don't factor in my time to cover them. :(
 
Agreed Jeff.

Another really stunning light veneer is Tamo Ash. This per sq ft is about twice the price of the Birch Burr. I'd love to cover these speakers in that. However, my supplier mainly sells the exotic veneers to the motor trade and Rolls Royce are their main buyers for this veneer. They will only buy full bundles of around 16-leaves and this will all go into a single RR car! They will not buy a part split bundle so my veneering company will only sell to me a full bundle. That's over £1000.00 UKP :eek:

If you can buy smaller quantities Stateside then this is one to check out.
 
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