Modell 19 Crossovers!

[dgwojo]

Thanks Gary, I posted the request for Ron Kramer, he was having troubles logging on. I unsoldered the coils in a parts unit and found these coil values with my inductance meter; L2=.25mh, L1 and L3 = 1.8mh. Where did you get your values??

[aeyb701]

The N1201/N-1201-8a IS identical, according to several threads on this board. It was listed as factory Xover for later versions of the A7 (ca 1976 or so) if you check this website or the Altec Library over at Lansing Heritage.
I've seen pairs of M19 xovers come up on eBay every couple months or so, ditto for the N-1201's.
I bought two pairs of the latter for under 300 a set at different times in the last year.
-Jon Archibald

[whitebroncoii]

Originally posted by dgwojo:
Thanks Gary, I posted the request for Ron Kramer, he was having troubles logging on. I unsoldered the coils in a parts unit and found these coil values with my inductance meter; L2=.25mh, L1 and L3 = 1.8mh. Where did you get your values??

<font size="2" face="Verdana, Helvetica, sans-serif">The schematic posted is copied from Altec Lansing historical documents that I have in my files.

[speakerdave]

I think it would be beneficial in many (perhaps all) cases to have DCR values for the stock coils. The iron core coils that I see in Altec crossovers may well have a lower DCR than the air core coils that seem to be favored by folks making reproductions unless those air cores are made with very large gauge wire (and I think they usually are not). I don't see how a crossover made with a different resistance in the coils can have the same performance.

So, anyone who has copies of the stock crossovers, if you could post the schematics WITH the DCR of the coils, I think that would be very useful information. Photos of the stock crossover's innards would also be helpful.

<font color="#FFFFFF" size="1">[ October 25, 2008 03:20 PM: Message edited by: speakerdave ]</font>

[speakerdave]

Oops. Looking for the delete button.

<font color="#FFFFFF" size="1">[ October 25, 2008 03:24 PM: Message edited by: speakerdave ]</font>

[gamalot]

This discussion comes around here and at the LH site like a merry-go-round.

I don't know squat about electronics or those MFers in the caps.

When I first built a set of 19 clones, DGWOJO came to my rescue because I had a set of N1209-8A XOs. The number above is exactly correct 1209-8A.
They sure did not sound like the 19s I remember.

I bought a set of 1201-8As as and there was a world of difference in my 19 clones. Now they sounded like 19s!

I have since had numerous sets of Model Nineteen crossovers and can't hear any difference between them and the 1201-8As

I honestly believe the 1209-8A XOs were designed with the 808-8A HF horn driver in mind and that particular driver usually has a loading cap and phenolic diaphragm and it always has a circumferential phase plug.

The model 19 speaker has an 802-8G HF driver and this driver has a Tangential (Tangerine) phase plug, a very delicate 23744 (Light) diaphragm and no loading cap.

It makes perfect sense that the 19 XO would have some built in difference to accomodate the very different HF driver.

I can't get into a discussion about the attributes between Altec Home, Altec Pro and Altec MI (Music instrument) speakers. What I can say for certain is the 1209 is not the same as a 1201 or a model 19 XO. If you use the 1209 in a real model 19 speaker you will certainly hear a marked difference that probably won't be good. Going the other way and useing a 19/1201 XO in an A7 with a 416-8B woofer and 808-8A HF driver with phenolic diaphragm and loading cap might just tame the beast of the higher end a bit.

Gary