New (to me) Altec 19s

[tinears]

My Altec 19s arrived last week, they are DIY cabinets with the correct drivers and crossovers. They are not pretty as they have been painted white and look bigger than huge. The "aesthetic controller" had a bit of a wobbly, "Where are you going to put then, they're not staying there" and so on. I stood my ground for awhile then offered a compromise, "What if I built a a pair of oak or wallnut cabinets, would that be okay?" The compromise was accepted which is fine as I Intended to build new boxes anyway, so I'll start construction when I get my current projects finished.

I have a pdf of the 19 cabinets to work from, should i build exactly to that or are there any modifications I should incorporate? Someone suggested using MDF rather than particle board but I'm not convinced there will be any benefit and MDF is not my favorite material.

Regarding the crossovers, I've read the posts on replacing the caps with polystyrene, I've never seen polystyrene in values much above a few thousand pF, do they exist and is that the way togo? What about air core inductors instead of the iron core jobs in there?

After some brief listening tests I'm not sure if the HF drivers are working as well as they should. Is replacement of the diaphragm assembly something the reasonably able person (builder/fixer of all things electronic/mechanical) can do?

Any advice on any aspect of the 19s will be appreciated.

Ken

[yggdrasil]

What seems to be the problem with the HF drivers?

[Ian Mackenzie]

Welcome to the Lansing Forums.

Don might be able to assist,

He has had recent experience with the 19's.

I recall Great Plains Audio handle servicing of some Altec components...best confirm what the issue is first.

Edit...Sorry I see you are mainland Aust.....cool. What can you tell us about the history of the 19's?

Ian:)

[tinears]

What seems to be the problem with the HF drivers?

Given that the tests were only brief, the boxes were in the middle of the room, I'm probably not doing the speakers any favours. Familiar music sounds different, it didn't appear consistent, some pieces more top, some more middles etc. than I'm used to. Always clean and distortion free which I suppose indicates the drivers are OK. I'll retract my HF observations if I may and report back when I move them into a better position in the room and check the obvious things like phasing of the drivers.

Ken

[tinears]

Welcome to the Lansing Forums.

Edit...Sorry I see you are mainland Aust.....cool. What can you tell us about the history of the 19's?

Ian:)

Very little on the history of the 19s, the prvious owner had them for a few years but in storage, nothing on their life before that. I'll work on him for more info.

The bass drivers appear to have new cones, they don't have the faded, dusty aged look. In fact all the components look like they came out of the factory this morning.

Ken

[Michael Smith]

They sure look like 19 cabinets to me!
How do you know infact that they aren't,there are some pretty strange dudes around and plenty of them failed at Interior Decor 1.
The majority of 19s brought into Oz were in kit form and the boxes made here.
Your H/F problems could infact be knackered pots.
Go check. twiddle the crap out of them and see if you can get any contact,If you still have hassles PM me
Good Luck
Michael

[tinears]

[QUOTE=Michael Smith]They sure look like 19 cabinets to me!
How do you know infact that they aren't,there are some pretty strange dudes around and plenty of them failed at Interior Decor 1.
The majority of 19s brought into Oz were in kit form and the boxes made here.
Your H/F problems could infact be knackered pots.
Go check. twiddle the crap out of them and see if you can get any contact,If you still have hassles PM me

G'day, How do I know they are not genuine boxes? Because the connectors are on the back, not the base, there is no manufacture's code stamped inside and there's an exhaust bracket supporting the horn...

The pots are OK, I gve them a good twiddle when one horn wasn't working, it has now come to life.

I intend to rebuild the crossovers, 20+ year old C's can't be too good.

Where are you in the Big Brown Land?

Ken

[Regis]

Regarding the crossovers, you're going to have a mix of passive components, resistors, capacitors and coils. Unless the caps are leaking or the resistors are burnt, there shouldn't be a whole lot to do here. If you feel you must replace the main caps, you should do the research here using the search engine. I'm not sure what Altec used in the 70's, but JBL used mylars of pretty good quality. The reason I'd like to advise you here is that there are caps that can dramatically change the sound of your speakers good or bad, so you should be prepared to experiment. If everything looks ok on the crossovers, then I'd consider applying 'bypass' capacitor technology to it. It works really well on older crossover networks. Use the search function and you'll see a lot of info here on that subject. I recently did the same to my 20+ year old JBL L-300 Summit speakers and I was pleased with the result.

[Dylanl]

Here is a set of crossovers a friend of mine is using in his 19s. They sound very good.

[tinears]

The caps are plasric/bakerlite cylinders with epoxy ends, suspect have the foil and paper innards which I would think would have shifted in value by now, they are not leaking though. The resistors look fine.

Bit suprised to see iron core inductors in there, they are physically small, is there a risk of saturation at high power levels?

I could take off one end off of the Cs and measure them.

I've been reading the bypassing threads, if the Cs are OK I will add small bypass Cs otherwise I'll search out replacemets with appropriate characteristics that shouldn't need the bypass C across them.

Ken.