next gen Alpair 12.3 diy community development

[markaudio]

Originally Posted by zman01

Mark,
Thanks for sharing some of the technical details and the tweaks you are incorporating. From the point of view from the end-user/listener, what would these tweaks result in?
-Zia

Hi Zia, Guys,

The main objectives are:

1 - Increased SPL (hopefully going above 90dB)
2 - Increased dispersion generated via the shallow cone profile.
3 - Increased emittance in the high range.

These objectives follow the wish list of this thread and those wanted by Diyers for the new CHR's, Alp7's etc. I'm also hoping to increase the air shunt capacity of the driver (increased Vas). This should suit those guys who'd like to use the drivers in large BR, vented and other mass loaded designs.

Please let me know if you'd like to see others for this new Full-range Alp12 version.

Now for the more challenging part, its tough to accurately predict these outcomes. From my calculations, we should make these improvements but as an "applied engineer", I'll only trust hard data generated from within an anechoic chamber. Naturally I'll keep all you guys informed with the results.

Cheers

Mark.

[winslow]

And this is why I want to run your products in my car.

[Bill poster]

Ouch, just read through the thread. what happened to those 3000 spiders?

[Spike415]

I haven;t personally heard the alpair 12's myself, but from hearing the alpair 7's in a set of TL's i made myself, they are awesome!

The increase is SPL will definitely help build around Valve amps which i would be interested in. For such a sized cone 50Hz seems resonable.

Personally what made me in the end pick your driver was your quality of control, but also the results i have got from designing them around Transmission line enclosures. They seem to sustain themselves in the lower range over drives just don't.

So guess my 2 cents if it's of any value from someone who is designing and building speakers alot now.

1) 89+ dB SPL
2) Flatish response over higher end range (3,000hz<)
3) Good output for TL's

Paul

[wupsie]

any news on the new 12 mark??

[markaudio]

Originally Posted by wupsie

any news on the new 12 mark??

Hi Wupsie, Guys,
Yes, we are progressing. I've scrapped the neck-less Type 2 cone as its design profile isn't giving enough close control on the 1-kHz to 6-kHz region. Currently the Type 2 con has a +/- 8dB peak/dip variance on a mean output of 90.5dB. In essence, it gets a bit too shouty on vocals once the volume levels are moderately raised.

On low-profile 900 to 1500 micron alloy based emitting surfaces, controlling micro-resonance and the peak/dip variance in the usable bandwidth becomes a major challenge on diameters of +88-mm. The relationships between the cone's profile, material thickness and type and the front suspension is very complex. I've tested 7 of my formulas on the type 2 cone variants, but I'm not convinced that the outcome will be satisfactory on this particular design.

I identified this challenge in my early days that led to the design of the first Alpair 10. Many commented how docile this driver was, too restrained for some tastes. Since then, as many of you know, I tweaked cone design to emit increased micro-resonance and greater bandwidth. I still feel the need for some emittance restraint in the design and making of full-range metal cones.

I'm now working on a new Type 3 cone design (see drawing). Its more closely based on the original Type 1 cone found on the current Alpair 12. Note the red numbers 1, 2 and 3. Compared to the Type 1 cone, this emitter has the following changes:

1 - The radius on this section of the outer profile has been modified to further open the cone.

2 - The radius on this section of the mid profile has been modified to increase the + micro-emittance in the 1-kHz to 4.5-kHz bands.

3 - The result of the change in radii reduces the cone height from 26-mm (type 1) to 22-mm on this type 3. The result is a 0.95g reduction in mass.

A note on the cone designations. The current cone design has a "CHR" designation while its under test. It doesn't mean there's a CHR-124 driver in the making. All being well, this prototype cone is destined for the Alpair 12.

The objectives remain the same as mentioned in post No.41. Will keep you informed as we progress.

Cheers
Mark.

[mp9]

Following along with the design process is cool. Thanks!

[mp9]

Quote from Fullrange Forum 70gen 1:

Originally Posted by markaudio

...The new Alpair 12 is gradually taking shape, so let me know by posting your desires: More SPL, dispersion and bandwidth V more power?:
next gen Alpair 12.3 diy community development
Cheers
Mark.

Since you asked again in the X-games discussion, i'd like to take the opportunity once again to ask for a higher SPL.
In past A10.2 vs. A12 wars i was looking for 2A3 compatibility. Now i'm compelled to ask you to push the SPL higher as i've become enamoured with the 45 tube and i'm confident you can make it happen

[ultrakaz]

Not to beat a dead horse but....

I'd really like to see a paper version alternative.

[chrisb]

Originally Posted by mp9

Quote from Fullrange Forum 70gen 1:
Since you asked again in the X-games discussion, i'd like to take the opportunity once again to ask for a higher SPL.
In past A10.2 vs. A12 wars i was looking for 2A3 compatibility. Now i'm compelled to ask you to push the SPL higher as i've become enamoured with the 45 tube and i'm confident you can make it happen

Originally Posted by ultrakaz

Not to beat a dead horse but....

I'd really like to see a paper version alternative.

OK, I was about to say give the guy a break, but realize that the latter would certainly be on my wish list also.