New Alpair 5?

[mondogenerator]

Mark,

Ive recently, and eventually, bought some Alpair5's. Ive been running them side by side with TB's W3-1285SG, which are almost exactly the same cone area, and diameter (apparently, and if you discount the fact the phase plug doesnt 'radiate' sound as a dustcap would).

Firstly, I agree with some of the posters here, that maybe the overall bezel diameter is a little big. However, I dont think its a deal breaker in any way.

Secondly, I prefer the reversed half round suspension, compared to the TB's which 'sticks out' like MOST drivers, and i agree with the philosophy for its use in the Alpairs case.

BUT...given the lack of spider on the Alpair5, I would possibly prefer to see a sine or double sine surround, to provide a little more lateral stability to the cone. IM by far no speaker expert, but it just seems to me that the possibility of 'bell mode' flapping movements is greatly increased. this is especially true, if, as i imagine, the magnetic gap is oversize, in order to accomodate any movement laterally, without rubbing. would also explain the difference in sensivity between the 2.

Also, im not entirely sure why the outer circumference of the surround is butted up against the driver bezel. in my mind at least, i see a hard boundary which would reflect cone resonances, rather than dissipate them.

Whether this is the case or not, in actuality, i do not know.

And thirdly, performance wise, I have yet to find a serious gripe with the Alpair5. Sound is spot on, maybe eff. is slightly lower than i would like and slightly lower than 'rival' products. The TBs cost me a similar amount here in the UK as a pair of 5's, maybe 10% less. given the small production volumes (relatively) that you produce, the price point is very competitive.

And, with respect, the TBs are also very good little drivers. keeping a 1" VC maybe the TBS downfall, since the radiating surface is really just a ring ~2" diameter and 1/2" wide.....the TBs are deep in comparison, which isnt a problem for me, but may be for others.

[planet10]

Originally Posted by mondogenerator

BUT...given the lack of spider on the Alpair5, I would possibly prefer to see a sine or double sine surround, to provide a little more lateral stability to the cone.

Lateral stability is maintained by the ferro fluid in the gap.

dave

[mondogenerator]

Originally Posted by planet10

Lateral stability is maintained by the ferro fluid in the gap.

dave

seriously?!? ferro fluid.... i didnt know that. im not sure thats a good thing, especially in the long term...not an expert, but i dont know how that could be good in a driver with a 'relatively' large xmax, when compared to a tweeter.

If nothing else the mechanical losses within the fluid, and flux losses caused due to a wider mag gap, have to be very close to the losses of employing a 'special MA' spider..... just wondering why use the ferro at all.

im singing the drivers praises, but Dave, I hate to say it, you have just given me a reason to prefer the TB's.......very very sad moment.

still i love the A5s ill just have to put them in something sealed, and treat them with care.

[planet10]

The ferro fluid used in woofrs is VERY different than that used in tweeters. Its use in small mid-tweetera i believe also extends to the Jordan Jxr6 (developed along side the J6T which evolved into the A5).

New Euro rules on recycling ferrofluid have put sealed to the spiderless A5. But with Matsubara-san (sp?) now doing spiders, i expect the A5.2 will overcome the loss.

In the end, it is all about whether it works.

dave

[mondogenerator]

thats great then. the tree huggers and the seals,
(and yourself) have restored my confidence that the ferro fluid wont evapourate, like so many tweeters..!!

.....i still dont understand.....large impedance peak WITH ferro fluid?.......

Either way, spiderless or with nifty spiders, sound is king. but practicality is queen.

the only thing i can criticise about the A5 is that ill probably destroy them, with loud rock music!!! a spider would increase their longeveity, in my household for one.

[planet10]

Originally Posted by mondogenerator

the only thing i can criticise about the A5 is that ill probably destroy them, with loud rock music!!! a spider would increase their longeveity, in my household for one.

Or use them as mid-tweeters as was intended when they were originally designed.

My A5/twin EL70 FAST just needs final assembly and XO development.

dave

[mondogenerator]

Thanks. I was just a little unsure how much a shallow HP filter would reduce excursion. Im planning something FAST-esque with them, yet to choose a woofer. maybe bass-wide A10? anyway off topic i guess lol.

[planet10]

Alpair10 bass were made in only small quantity and are pretty much NLA.

We are encouraging Mark to do a bass driver based on the A12 tooling.

But with an XO 300 Hz or less there are a lot of good mid-basses that are suitable candidates. A pair of MA #6 woofers in Scott's ML-TL (with a bit of rearrangment) i can personally attest to how well they perform in that range.

dave

[_henry_]

something like JX-150 will make me happier

[mondogenerator]

OOOOOOOOOOOOOOOO

A12 were ~8"? A12 size basswide A12.....sounds very interesting. And environmentally friendly! low mms and Fs and good xmax......