Mod thoughts, regarding stock ALTEC Model 19 crossovers.

Hi ALL,

On Friday, I bought a pair of Model 19s advantageously, off of Craigslist, and have been looking it over today. I have a few ideas, that I wanted to share or voice for other's input.

On the stock crossover, if one is KEEPING the stock three inductors: (a) why not turn the middle one 90 degrees, for less field interaction.? ALSO, why not space the two "outer" inductors, each about 3/8ths of an inch closer to the edges on the stock ALTEC Model 19's metal plate, for less interaction??

On the " grounding the rivets mod ", It appears to me, only the Input rivet, and the two Output rivets, are electrically in the ground path. Instead of wiring all four rivets together as previously shown on this forum, ( a large " C " ) why not take the input ground, and STAR wire two ground runs, to individually run the output grounds...?? That way, the tweeter will not be sharing the woofer's ground run currents.

Oh well, have a good day

Regards,

Jeff.......... Low Ohms

nice find Jeff. :)

I myself would leave it as stock as possible, but that's my preference.

Jeff,

You bought just the crossovers correct?

I have 2 sets. One just used the rivets as grounds. The other had all the grounds wired together.
So Altec either thought it was important at some time, or cheaped out and saved a foot of wire by leaving them out.......
Who knows.

The set that I used to have that came in the A7X speakers I bought actually had a box around them, and spade connectors on the back. They were N1201 but were the same circuit as the M19.

The two I have now that actually say Model 19 are just flat plates with the input and output wires just soldered to the terminal strips.

Only the LF inductor handles and real current, so maybe turn that one. I forget though which one it is.

Separating grounds is never a bad idea. Will you hear it? Hard to say.

BTW, those pots get noisy. The covers come off for cleaning though.

Enjoy

Jeff, Classic domestic Altecs. If they weren't as rare as hens teeth Down-Under they would have been my choice.

Orientation of air-cored inductors is much less important than for iron-core ones. Air-cored inductors can be much closer together than iron cored inductors. X,Y,Z axis arrangement can be beneficial if desired component placement is constrained by space considerations. This arrangement looks better than the one in the link, below: Altec Lansing Model 19 Crossover NEW ?€? $178.00 - PicClick , but may give a different result to the original.

Grounding: If joints are in good fettle there is no audible difference between a short bus-ground and a star-ground in an LV passive crossover.
One version of the M19 crossover appears to use riveted connections to ground-plane These would be OK if welded but if solely riveted may suffer oxidation over time.
See here: help with m19 crossover wires - Mod. shown.
(Inductor layout would disturb purists but it worked well).

The high-pass filter prevents LF 'sharing'.


The Model 19 is possibly the most discussed Altec system on this forum and there are several crossover alternatives and mods. posted by forum members. I frequently find Google more useful than Hostboard Search.

Enjoy, as they used to say.

Quote:

---

Originally Posted by RonSSS

Jeff,

You bought just the crossovers correct?

I have 2 sets. One just used the rivets as grounds. The other had all the grounds wired together.
So Altec either thought it was important at some time, or cheaped out and saved a foot of wire by leaving them out.......
Who knows.

The set that I used to have that came in the A7X speakers I bought actually had a box around them, and spade connectors on the back. They were N1201 but were the same circuit as the M19.

The two I have now that actually say Model 19 are just flat plates with the input and output wires just soldered to the terminal strips.

Only the LF inductor handles and real current, so maybe turn that one. I forget though which one it is.

Separating grounds is never a bad idea. Will you hear it? Hard to say.

BTW, those pots get noisy. The covers come off for cleaning though.

Enjoy

---

Thanks, I appreciated your comments. No, I bought a whole pair of Model 19s on Friday. Missing one 802.

Since I like my A7-800 VOTTs, ( mass loaded and rewired ) and don't have the room, I will have to re-sell these in my area ( Kansas City ). Onto Craigslist !!

Jeff .... Low Ohms

Ah. In that case, I'd just leave them be and let the new owner muck with them if he chooses.

Your not going to at least give them a chance? For many the Model 19 is the end game. Not sure of the drivers on your VOTT but if it uses 802's I'd do some swapping and give them an honest try.
Do some research on what you have before being so hasty to unload them.

BillWojo

The 19's would have 802-8G if they had 802's.
Otherwise they will be 902-8A. Marked with a paper label.

Quote:

---

Originally Posted by BillWojo

Your not going to at least give them a chance? For many the Model 19 is the end game. Not sure of the drivers on your VOTT but if it uses 802's I'd do some swapping and give them an honest try.
Do some research on what you have before being so hasty to unload them.

BillWojo

---

Bill,

I have, in my A7-800s, 515Bs and re-done ( GPA ) 802Ds, on Emilar EH-500 type horns. I use a VERY custom crossover, DIY, 390 pounds of mass loading per box, and special mil spec wiring internally.

I like the 825-828 enclosure's horn loading of the 15 inch 515B, and so, I doubt a M19, ( with a woofer in a reflex box ), will "cut it" as well, particularly from 135 HZ up, where the A7 is horn loaded on the 15 inch driver.

Had I not had the A7-800s, I would mod and restore the Model 19s.

Each crossover film cap in a Model 19, ( Valencia, or A7 ) for the tweeter circuit, are in DIRE need of thoughtfully-added high-frequency bypassing, whew !! No one except one individual seems to do this , or knows how to do it well.

Thanks.

Jeff ........... Low Ohms.

Have you spent some time listening to the M19's Jeff? I'm sure they could use some new caps. Maybe you could tweak them to your liking. I don't think a recap and some bypass caps would hurt their value.

Since you are missing an 802G, you could throw your pair of 802D in there instead. For testing purposes of course

Some speakers have no right sounding as good as they do. Like was mentioned above, these are "last speakers" for some people.

Also did you figure out which woofers you have?