Model 19 xover help (or not, you tell me)

[spwal]

Hello,

was going to ask you good people....

Iconic makes new xovers for the 19.... but they are a pretty penny to say the least. I briefly exchanged emails with them and at 700 a pair, that is simply out of the question. Of course they said their xover is MUCH better... well that doenst make me feel to good about my potential purchase now does it... ! Im not gonna lie, i was damn lucky to get a pair of 1980 Klipsch Cornwalls with the ALK crossovers brand new... boy did i luck out! But alas they have moved on, and here i am, ready to try Altec!

Is it ESSENTIAL to change the xover?

Do i HAVE to get new capacitors? That many new high quality caps is gonna cost a fortune... cost me 70 bucks for a pair of Angela coupling caps for my amp.. my stomach turns looking at all those big caps in the xovers!

I am concerned that I am going to get these and the caps are going to be all funked up. I dont even know what the symptoms of dried out caps are anyway... how am i gonna know???

I MAY get lucky with a pair of 19s locally. I will keep my fingers crossed. These may be too big for my own good, but I managed with cornwalls in my bedroom, whats another few inches in every direction lolz!!

Please help me out, put my mind at ease! Save me from buying an 8" Full Range Driver speaker (that i had planned on getting for months before i caught the bigger-is-better bug again)

I would really appreciate it.

Thanks,

Spwal

[spwal]

You know what...

after reading all the posts on the 19 in exhautium, i just think i better stay away. I dont know the last word in what drivers go in them, i dont know about the crossover, and everything else. I certainly wont have any $$ left over to spend on restoring them. I need a turnkey solution right out of the box that rocks. I dont even think the owner is interested in hooking these up for a listen before i buy them.

Anyway, please put me at ease, or dont.

Thanks

[scott fitlin]

OK, assuming everything is in working condition, they can be a good buy. After you have and listen to them for a bit, you can determine if you want to rebuild or buy new xover networks.

You could try calling Great Plains Audio in Ok City, and talking to Bill, he could suggest a cost effective solution for you. He could probably replace the old caps and L Pads on your existing crossovers, much less expensive than purchasing new crossovers.

GPA is also good for remagnetizing the old Alnico magnets, and he is reasonably priced.

Also, why wouldnt the owner want to allow you to listen to them before you buy? That would tell you right away if they work reasonably well, or not!

[hjames]

You know what...

after reading all the posts on the 19 in exhautium, i just think i better stay away. I dont know the last word in what drivers go in them, i dont know about the crossover, and everything else. I certainly wont have any $$ left over to spend on restoring them. I need a turnkey solution right out of the box that rocks. I dont even think the owner is interested in hooking these up for a listen before i buy them.

Anyway, please put me at ease, or dont.

Thanks

Well, I would always advise listening to a set of speakers before you buy them.
First, speakers can get old and not work as well as they should,
and second, because different speakers sound differently, and you may not like the sound of a given set of speakers.

Fixing them up and changing parts and such can be fun, but its only fun if you like that kind of thing -
its not recommended for everyone!

And if they won't hook them up for a listen, well - there may be a reason for that
- or not - only you can tell if you want to take that kind of a gamble.

But .. you wouldn't buy a car without driving it first ...

[scott fitlin]

And if they won't hook them up for a listen, well - there may be a reason for that - or not - only you can tell if you want to take that kind of a gamble. But .. you wouldn't buy a car without driving it first ...

Ditto.

You havent said how much the original owner is asking for the speakers. And, if they are in great condition, he should have no problem in allowing you a half hour listening, and playing with the L Pads, etc.

[John]

Stick with the original xovers, I am sure they are ok. Most likely if there is a problem it will be a dirty L-pad.

Stay away from hyped up super-xovers

[spwal]

Thanks guys... he sounds like a lazy old grumpus that doesnt want to take thetime to hook these up. he sells them "guaranteed" whatever that means lol...

Also:


"Stick with the original xovers, I am sure they are ok. Most likely if there is a problem it will be a dirty L-pad.

Stay away from hyped up super-xovers"

is my favorite kind of advice.

but seriously... how will i know if my xover network is failing me?? Is it obvious?

thanks!

[Todd W. White]

Model 19's - when operating as they were designed and are powered by excellent electronics and fed a QUALITY recording - are one of the most impressive sounding loudspeaker systems you will ever listen to.

Are they perfect?

No - what is?

But they're IMPRESSIVE!

By that, I mean this:

The Model 19 is capable of incredible dynamic range, excellent frequency response, and a naturalness of reproduction that is, quite simply, hard to beat at any price.

Can they be improved?

Yes, but what can't?

As an Altec dealer, I used to rebuild Model 19 crossovers for customers when the cap's failed or started to, the L-pads got dirty (or burned: one guy played his electric guitar through them! Tore 'em up pretty good!), etc. My experience was that, by following the original design for the crossover - which does a whole LOT more in the Model 19 than just separate the frequencies for the horn and the woofer - and simply upgrading the components with better ones that had the same electrical characteristics, there was IMPROVED performance from the unit, particularly in the middle and upper bandwidth.

More natural, more transparent. More alive, really.

Is it as expensive to do this as you think?

No.

Is it WORTH it?

Maybe - but only if the ones you have aren't working properly.

How can you tell?

LISTEN to them! But beware: if the recordings you use to listen are flawed, the Model 19 will reproduce the flaws - warts and all - so don't just take one recording with you. Otherwise, you'll blame the Model 19's!

The best thing to do once you get them is have Great Plains Audio rebuild the HF driver and woofer, and test the crossovers, repairing them, as necessary.

Then you KNOW you've got them right!

If, after a while, you feel like you'd like to upgrade the crossovers, you can do so at a time that matches your cashflow situation and actual needs.

By the way - if the old fellow won't let you listen to them, I'd offer him 2/3 what he's asking for them, unheard, unless the price is waaaay too high, then I'd go for 1/2 of that and tell him why.

[Paul C.]

With the Model 19 (and other Altecs) the crossover comes out easily.

Fortunately the coils and resistors are seldom damaged. You usually don't have to worry about replacing them.

The L-pads can get noisy and intermittant. You might be able to clean them, but the best thing to do is simply replace them.

L-pad, Mono, 100 w, 3/8" shaft Parts Express (www.partsexpress.com) 260-262 (you will need two for each crossover, total 4)

Capacitors age, dry out, change value. (I am talking old speakers in general, not just Altecs) These usually have to be replaced. Finding the exact value can be difficult, but getting the nearest standard value is good enough. These are Parts Express numbers, too:

21 uf - This is not a standard value. Use 027-348 (NP Electrolytic 22 uf) *

8 uf - This is not a standard value. Use 027-426 (Dayton metalized poly 8.2 uf)

16 uf - This one IS a standard value. Use 027-578 (Solen metalized poly 16 uf)

6 uf - This is not a standard value. Use 027-427 (Dayton metalized poly 6.2 uf)

(You will need one of each value for each crossover, order 2 of each value)

These values are close enough.

* A NP electrolytic will work fine for the shunt capacitor in the woofer low pass section, but if you simply must use a poly for the 21 uf cap you may use 027-436 (20 uf) and parallel it with 027-410 (1 uf).

Simply snip out the old caps and solder in these. Only rework one crossover at a time so that you have the other one for reference. These caps will be a little larger than the original caps. Do not use hot glue to glue them in place. Use E6000 or Aleene's 7800 craft glues (craft section of Walmart or hobby/craft stores).

[Storm]

Would you recommend updating the crossovers in my 846 Valencias?

What parts do I get?

Is it easy to do, or should I get someone to replace the stuff for me?

Thanks.

-Storm

[Todd W. White]

Paul - your post is right on the money.

This is exactly what I did when rebuilding them for others back years ago. The only difference was that, at that time, I could still get the original parts from Altec, so I didn't have to mess around with components of different size or values. Usually, I recommend replacing the L-pads with fixed resistors. I have a re-worked version of the Model 19 crossover schematic that Jerry Hubbard did, and, using one of my personal, unused, original Model 19 crossovers, he placed the knobs at the optimum point, then measured them to arrive at the values for replacing the L-pads with fixed resistors. Works really well...

One caution - if you use iron core inductors, be SURE they have LOTS of iron, else they will saturate (read: sound BAD!).

Also, if memory serves, to get an air-core inductor to perform the same as the iron-core's, I believe they end up being pretty large.

Seems like I also remember there being a problem with certain capacitors we tried - some of them tended to physically resonate, as I recall. I'm sure newer components wouldn't have that problem...

[spwal]

With the Model 19 (and other Altecs) the crossover comes out easily.

Fortunately the coils and resistors are seldom damaged. You usually don't have to worry about replacing them.

The L-pads can get noisy and intermittant. You might be able to clean them, but the best thing to do is simply replace them.

L-pad, Mono, 100 w, 3/8" shaft Parts Express (www.partsexpress.com) 260-262 (you will need two for each crossover, total 4)

Capacitors age, dry out, change value. These usually have to be replaced. Finding the exact value can be difficult, but getting the nearest standard value is good enough. These are Parts Express numbers, too:

21 uf - This is not a standard value. Use 027-348 (NP Electrolytic 22 uf) *

8 uf - This is not a standard value. Use 027-426 (Dayton metalized poly 8.2 uf)

16 uf - This one IS a standard value. Use 027-578 (Solen metalized poly 16 uf)

6 uf - This is not a standard value. Use 027-427 (Dayton metalized poly 6.2 uf)

(You will need one of each value for each crossover, order 2 of each value)

These values are close enough.

* A NP electrolytic will work fine for the shunt capacitor in the woofer low pass section, but if you simply must use a poly for the 21 uf cap you may use 027-436 (20 uf) and parallel it with 027-410 (1 uf).

Simply snip out the old caps and solder in these. Only rework one crossover at a time so that you have the other one for reference. These caps will be a little larger than the original caps. Do not use hot glue to glue them in place. Use E6000 or Aleene's 7800 craft glues (craft section of Walmart or hobby/craft stores).

It is stuff like this that really makes the world a better place. This should go down in the record books as a step by step xover overhaul for the 19. THANK YOU. Couldnt find anything on the net that was this helpful.

Now i either need to learn how to solder, or take my Electrical Engineer friend out for beers...

[johnaec]

Now i either need to learn how to solder, or take my Electrical Engineer friend out for beers...

Just don't let him drink the beer *while* he's working on your crossovers...

John

[spwal]

No text....

please see Paul C.s posts for a breakdown on crossover parts from parts express.

Thanks

[Gary L]

Here is two pics of Model 19 XOs.
The first is all original and completely stock and 29 years old.

The second is completely new parts on the same frame and built by PaulC above who gratiously provided the wish list of parts.
The two copper windings are air coils while the green coil is an iron core.
Note the larger size of the black capacitors and the work involved in fitting the new but larger electronics.

If you can't do it yourself then contact PaulC to see if he will help. He is very reasonable and does nothing but meticulous work.
If your knobs are nasty, contact me, I have a supply of original NOS knobs that are the exact same ones you have.





Gary