N-501-8b Inductors

[dread64]

GM,

Looks like I found a good match for my speakers.
I'm running 902Ts (Yes, they have loading caps.),
416-8b in an A7 cabinet. Currently using the 1285 crossover, bought the N500s because I like the 500hz setting, but wanted to an x-over that didn't have all of the unnecessary stuff on it.
Figured--With fresh caps and coils,(And slightly higher quality parts.)it would be a sweet set-up.

Marty,
I had already purchased 2.7MH coils before the 2.7 vs. 3.6 MH question arose. So, I figure I'll try them. If they don't work out, i'll put the old coils back in.
At any rate, I'm thinking that your meter is working properly, and it will all work out just fine. Bada-Bing!

You Guys are Awesome, and I appreciate all of your effort! It was above and beyond.

Salut!
Dave

[dread64]

GM

Yep, that's right, four caps per channel. and two inductors. These are currently out of the cabinet. The guy I bought them from said they came from a set of A7s. And that's what I'll be installing them in when the work is done.

There is also a 15,5, and two 3.9 ohm resistors
in the circuit.

Dave

[dread64]

GM,

The guy also had a pair of 416-8b woofers, and 902 HF drivers for sale. But I don't know if they came from the same cabinets. I'm assuming so.

Dave

[dread64]

GM

And that part number on the inductors Marty stated is correct also.

Dave

[GM]

Greets!

$%^&*()_ Altec in their later years! -A, -B, etc., are minor revisions to existing designs, not for designating completely new ones!

Ok, thanks, without a schematic I can only guess as to what they did, and sorry for the mis-information/false on-set of 'buyer's remorse'.

GM

[martyh45]

GM,
Sorry, I don?t recall if the drivers were T versions or not. The 8500 was user selectable 800 or 500 Hz. I?m not sure if they had selectable CD EQ like the 1285 though.

Dave,
If you want to experiment, you could series in some 1mH coils. Just make sure they don?t magnetically couple or it will throw off the value. Use the same orientation you would with any other pair of coils. The first thing I would try though is bumping the 28uF caps a bit. I think the 416 should be near its minimum impedance at 500 Hz, if it dips to 6 ohms another 10uF would get you a textbook 2nd order with the 2.7 mH coils. More or less what they were aiming for when the ignored the fact that speakers don?t have a constant impedance.

[GM]

Greets!

Thanks! Apparently not: http://tinyurl.com/2g79ug

GM

[dread64]

Marty,

Thanks for the info/advice, it will go to good use.

Dave

[Tenorman]

You did not screw up ordering the 2.7 mH inductors. The 2.7 mH ind (for both inductors) + 28 uf cap will give a Butterworth crossover at 580 hz.

That's good, gets the crossover up above the 511b's cutoff.

[dread64]

All,

I've finished this little project using Jantzen coils and caps. The 2.7mH coils seem to have worked out just fine. The only problem I've encountered is what I believe to be a weak solder joint in the left channel bass section. I will be slaying this dragon tomorrow. At any rate, when the bass isn't cutting in and out in the left speaker, the sound is way better than it was with the stock 1285 x-overs. So in my opinion the effort was well worth it. Once I've trouble shot the intermittance issue, it should be heaven.

Dave