next gen Alpair 12.3 diy community development

[mp9]

Submitted for your approval, ideas encouraged for next gen A12.2 production run work in progress:

1) sensitivity to break the 90db barrier for the "Deep triode" low watt club members, without giving up to much of it's current attributes

2) less of a peak in the 7khz- 10khz range of the current model

3) 8Ω ohm impedance

4) Fs ≤50 Hz for full range use without the need for a sub

5) similar TS parameters as current A12 to allow for drop in or slight modifications to current cabinet designs

6) Alnico magnet

[_henry_]

how about Neo magnets?

its light.

cheers
henry

[planet10]

1) sensitivity to break the 90db barrier for the "Deep triode" low watt club members, without giving up to much of it's current attributes

Already within margin of error of that. I measured 89.5 dB/watt on a pair of Alpair12eN earlier today, More efficient than FE127eN.

3) 8Ω ohm impedance

The same as current.

4) Fs ≤50 Hz for full range use without the need for a sub

Pretty close already (meaured at 53 Hz). Decreasing Fs fights more efficiency.

5) similar TS parameters as current A12 to allow for drop in or slight modifications to current cabinet designs

Fs, Qes (ie efficency) cannot be changed much without changing T/S from current.

6) Alnico magnet

$$$$$

I'd be happy to see the same driver with more finesse (ie 3d sounstage closer to A7). This could come with as little as the spider improvements already underway, and the voice coil tech from the A10.2,

dave

[zman01]

Originally Posted by planet10

I'd be happy to see the same driver with more finesse (ie 3d sounstage closer to A7). This could come with as little as the spider improvements already underway, and the voice coil tech from the A10.2,

dave

Dave,

Good points you make.

Can you please elborate the end-customer/listener benefits you are expecting by improving the voice coil tech and spider?

What about paper cones? I hear the CHP-70 and EL-70 are awesome.

-Zia

[planet10]

Originally Posted by zman01

Can you please elborate the end-customer/listener benefits you are expecting by improving the voice coil tech and spider?

During the voice coil testing on the A10.2, the rectangular would VC was found to elicit more detail than the one similar to that on the current A12.

dave

[mp9]

Dave, i like your suggestions. I didn't know the A10.2 had a different spider then the A12. Was thinking about the spider Seas uses in their fullrange driver but thought i was already pushing it requesting Alnico. I had vaguely remembered Mark describing the possibility of the coil upgrade in a previous post so did a search and found it:

Originally Posted by markaudio

The 10.2's rectangle wire winding eliminates any small gaps inside its winding. This coil is almost 0.5g lighter than the Gen 1 Alp10. The rectangle coil is more electro-mechancically efficient. When added to the rest of the up-grades (Multi-form cone, low mass rear suspension etc.) the 10.2 is a step forward. its impedance response is slightly flatter than the Alp12, thus suiting many tube amp, especially those warm soft clipping types.

The more critical question is: "what do I up-grade on the next batch of Alpair 12?". most likely the coil for the Alp12 will follow the design of the Alp10.2. But I'm some time away from this project as the Alp12 remains an advanced driver with the most complex suspension I've made to date.
Cheers
Mark.

Pensil 10.2 or 12 wrt bass extention?

[Scottmoose]

V. little time, but a couple of brief thoughts on magnets:

-AlNiCo per what Dave said. Excellent properties (so long as you look after it) but it costs a heck of a lot, so it would likely end up as a high priced model with different design objectives / physical properties etc.

-Don't like neodymium much from an engineering POV. Unless there is a very good reason to use it (e.g. a requirement for huge motor strength & cost no object) I'd rather have a good ferrite.

A lot of what is said re. magnets is marketing waffle anyway. It's less about the material & more about how it's used.

[zman01]

Scott, Dave,

Any commments on paper vs aluminium or that is a moot discussion with a Speaker like Alpair 12 or 10?

Btw, good to see Scott posting again.

-Zia

[chrisb]

Originally Posted by zman01

Scott, Dave,

Any commments on paper vs aluminium or that is a moot discussion with a Speaker like Alpair 12 or 10?

Btw, good to see Scott posting again.

-Zia

Until the official invitees contribute, my POV - having lived with "budget" range of CHR & EL70 as well as Alpair 7 and 10.2s, the question is not so much moot as "subjective".

Mark has obviously invested much of his engineering and production expertise over the past several years in advancing metal cone wide-band drivers, but one can only imagine what he could achieve with some of the more exotic paper formulations that are currently fashionable.

[planet10]

Originally Posted by Scottmoose

-Don't like neodymium much from an engineering POV. Unless there is a very good reason to use it (e.g. a requirement for huge motor strength & cost no object) I'd rather have a good ferrite.

Note that the price of neo is skyrocketing. China cornered the manufacturing resources and are now taking advantage of being close to sole supply, Expect neo motor drivers to significanyly increase in price,

Many of the neo motors and not taking advantage of its character... one has to rethink motor design to max it out.

Expect new magnets to come out of current tech work being done for wind generators, electric motors, etc.

dave