Alpair 10 Gen. MAOP Prototype TW-1

[ultrakaz]

Originally Posted by markaudio

Hi Guys,
Here's the MAOP - TW data:

Technically, I like the look of the frequency. It looks well controlled across the range. There are a couple of moderate peaks at the 8 to 10-kHz region but nothing wild. The new Mastubara san spider is looking good. The parameters are close enough to the standard model to make retrofitting into most existing box plans easy.

Mark.

The response is pretty darn flat considering the bandwidth it covers and is a metal cone. Given the size of the driver, I'm guessing that the breakup should have started around 5kHz or so. Nicely, mitigated. (Perhaps, it is the new coating?) And I'm not a fan of metal cones in general. No need to extend the top end at the expense of listening to peaky cone breakup. Actually, the extension goes to about 17kHz so more than adequate for most, although most will be lost if listening off axis. Of course, I've never heard it yet, but it looks promising.

Mark, how does the "Matsubara san spider" affect the sound of the driver?

[doorman]

Interesting! My 10.2's have rec'd Dave's "full-monty" eNABled treatment, it would be interesting to hear 'em side by each---
don

[markaudio]

Hi Ult, Doorman, guys,

Yup, MAOP is an applied process so there will be a "damping" effect. So far its very subtle. To my ears its mostly evident in the lower to upper mids (1 to 8 kHz) regions. But rather that trusting my ears, I'll get other guys to try them and feedback.

THe Matsubara san spider looks like a winner. I've ran a 1000 hour test, its the most linear so far remaining well inside its 1.9/50 spec @ +0.7. Normal commercial rated spiders will vary by +1.3 to +1.8 after being worked for 1000 hours. Its really good to work with Matsubara san and the other X Foster group guys and Evan Yu who's excellent sample maker. Between us all, there's some 200 working years of technical knowhow being put to good use.

The first test will be this afternoon and Tony and Kenneth's place in Fotan on some super-duper 300B monblocks in Pensils. Graham (Alpair 12, Ella KT88 guy: Graham's hifi page) will also be there. All these guys are very picky so I'm feeling a bit nervous.

Cheers

Mark.

[markaudio]

Originally Posted by chrisb

is it possible to apply this process in a masked or CNC controlled pattern?

Hi Chris,
Sadly, at this stage we don't have a masking method available. I talked to Dave last week about how this process could also be added into the Enabling mix.

I was thinking of making a new set of Multiform moulds with CNC's pattens pressing into the cone. This might be a very nice job but the cost won't be low.

Cheers

Mark.

[borispm]

Hi Mark,
Is the new motor slightly weaker than the old one? It seems the Q is slightly higher than before and so is the BL factor...

[markaudio]

Originally Posted by borispm

Hi Mark,
Is the new motor slightly weaker than the old one? It seems the Q is slightly higher than before and so is the BL factor...

Hi boris,
No, its the same sub assembly as Gen. 2
M

[Scottmoose]

I'm liking the look of it thus far. That sort of balance comes into its own over extended periods.

[borispm]

Originally Posted by markaudio

Hi boris,
No, its the same sub assembly as Gen. 2
M

Mark, does that mean the difference is caused by measuring variations? Or is it due to a new coil winding or interaction between spider and coil?

Built in patterns will be quite interesting, and I wonder if that can be done by drawing via oil based ink prior to the MAOP, and then remove the ink with organic solvents... I am not sure if that's the right way to get the patterns though...

[markaudio]

Originally Posted by borispm

Mark, does that mean the difference is caused by measuring variations? Or is it due to a new coil winding or interaction between spider and coil?

Built in patterns will be quite interesting, and I wonder if that can be done by drawing via oil based ink prior to the MAOP, and then remove the ink with organic solvents... I am not sure if that's the right way to get the patterns though...

Hi Boris,
Designing the dynamics of the power-train for non-linear loads takes allot of work. For example, the spider: The resistivity, mechanical compliance and positional excursive stability are just 3 factors of 9 that apply to the operational capacity of just this component. Changing the operational specification on just 1 component within the power-train has the potential to radically change its total performance envelope.

Re MAOP and your ink idea. Such a method would risk too much surface contamination.

Thx
Mark.

[borispm]

Originally Posted by markaudio

Hi Boris,
Designing the dynamics of the power-train for non-linear loads takes allot of work. For example, the spider: The resistivity, mechanical compliance and positional excursive stability are just 3 factors of 9 that apply to the operational capacity of just this component. Changing the operational specification on just 1 component within the power-train has the potential to radically change its total performance envelope.

Re MAOP and your ink idea. Such a method would risk too much surface contamination.

Thx
Mark.

Hi Mark,

Thanks for explaining that. It seems the new design trades off a bit high end and efficiency for smoother response curve. I suspect that's due to the new spider, right? I was somehow worried about the flexibility of the new spider when I saw those reinforcements but now I am not.

And yes I forgot about the contamination issue. The ink may make its way down to the MAOP so it's impossible to remove all of the ink. Maybe I should come up with another way...