29 replies to this topic

[Mick83]

Greetings
I am by no means an audiophile. I have a pair of large Advent speakers that I bought in 1977 or 1978 on the advice of a friend who was an audiophile. I have the utility boxes, not the real wood. I have been listening to them ever since. About ten years ago, I replaced the woofers, if I recall correctly. The foam was shot and I didn't know any better so I replaced the whole woofers. Anyway, of late it seems the speakers don't sound so good. I don't know how to describe it except to say that they sound like AM. No real life. I understand it's hard to dianose the problem based on the information I've provided, without hearing or examining the speakers, but any ideas? Thank you.

[ironlake]

check the tweeter output. put the rear switch on extend and listen to the tweeter with a toilet paper tube on the tweeter with ear on other side. you should have strong output if not these may be burned out and would give the lifeless am sound from the woofers only. If they are burned out the red of the tweeters should be very dark from heat buildup. otherwise you crossover caps may be bad.

[Mick83]

Thanks. I tried the toilet paper deal and did not hear much from the woofers.
They looked ok, though, not real dark, but I don't examine them often.
Crossover caps?

[ironlake]

You mean tweeters, not woofers. I would guess either burned out tweeters or xover caps.

[Mick83]

Yes tweeters, sorry.

[JKent]

You mean tweeters, not woofers.

The little speakers, not the big speakers
If you are getting SOME sound from the tweets that may be a good sign. In any case, the caps should be replaced. I just did a pair of OLA Utilities last week--foam and caps. They sound good.
Maybe try pulling the suspect tweet and run your amp straight into it at LOW volume with music that does not have thundering low notes. Many advise against this but I have never destroyed a driver running it straight at low volume.
Is it BOTH tweeters that seem weak? How is the woofer output? I would probably test all 4 drivers out of the box and see if there seems to be a dud.
Kent

[Mick83]

I did the tp roll deal again. This time I adjusted the bass on my receiver to -10 and increased the treble to +10.
I don't think I heard anything out of either tweeter. And Jon Anderson was singing .
When I find time I'll test each speaker individually.
What's a crossover cap, how do I replace them, and where do I get them???

[JKent]

What's a crossover cap, how do I replace them, and where do I get them???

Take a look at this thread: http://www.classicsp...?showtopic=6623 It rambles a bit but you will get the idea. There is a link there to Pete's excellent Advent crossover page. Once the speakers are open (remove the woofer then remove the blocks of foam stuffing) you will see the crossover. There will be a few things in there: A switch, a resistor, a couple of inductors and a couple of capacitors. The capacitors are the gray (or black) cylinders that have a wire emerging from each end. If you have the NEW large Advent you'll have 2 resistors and one capacitor.

Most people here get "film" caps from Parts Express, Madisound or Erse. We can discuss that once you know what you need.

So... First things first. Check all those drivers. If the tweeters are both dead, you will need to replace them and you don't "have" to replace the caps, although most of us here probably think it's a good idea. The original caps are "non-polar electrolytic" and have a life expectancy of 15, 20, maybe even 30 years, sometimes more. But yours have reached the end of their expected lifespan. Film caps will last longer than the drivers themselves.

Good luck.
Kent

[Mick83]

^{I took both tweeters out of the boxes and listened to each one up at my ears.
Nothing from either one.
I disconnected one of them and hooked the speaker wires directly. Nothing.
The woofers seem to be working ok.}

[JKent]

Do your tweeters look like this? I have 2 spares (I think). If you would like to buy them send me a PM and we can discuss. There are several for sale on eBay, too.
Kent

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[dynaco_dan]

Do your tweeters look like this? I have 2 spares (I think). If you would like to buy them send me a PM and we can discuss. There are several for sale on eBay, too.
Kent

Hi Kent

I don't know what's happened to this site but there certainly is some very sharp and clear photos being posted here.

Perhaps HD?

[Mick83]

Kent the stuff in that thread you recommended was way over my head.
My tweeters kinda look like that but they are mounted in the speaker box straight up and down/straight across, not pointed up and down and left and right like those in the pic.

[JKent]

Kent the stuff in that thread you recommended was way over my head.
My tweeters kinda look like that but they are mounted in the speaker box straight up and down/straight across, not pointed up and down and left and right like those in the pic.

Sorry. It's not that hard. Probably gave you TMI.
Can you post a snapshot of your tweeter? Also, either a photo of the back plate or just write down exactly what it says. OR: Here is a thread that is NOT technical. Do you have the "New Advent" as pictured in post #2?
http://www.audiokarma.org/forums/showthread.php?t=126376

[Mick83]

I could not view the photos in that link, apparently because I am not registered there. I tried to register but failed so far. I would like to view that thread so I will again attempt to register. Meanwhile, the back of my speakers says The Advent Loudspeaker, one says U362601 and the other says U362565, Advent Corp, Cambridge, MA.
Also I expanded your photo and gave it a second look, and my tweeters are not the same.
Thanks for all your help by the way.
Mick

[JKent]

Is this your speaker?

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[Doug G.]

Wth those serial numbers, he's got New Advents and they have the new tweeters with the flush-mounted cones. Same basic troubleshooting, though.

Doug

[Mick83]

Is this your speaker?

Yup that's them.

[JKent]

There is a pair of what I "think" are the right tweeters for sale on ebay for $50/pr here: http://www.ebay.com/...=item43ad57a630
Probably a fair price. You may do better by putting a free ad in our For Sale/Wanted section here: http://www.classicsp...hp?showforum=10
Maybe try sending a PM to member Carl (Carlspeak). When I needed an Advent tweeter I bought a nice one from him. It's very possible others here may have some.
Kent

[Mick83]

OK I ordered those tweeters.

"Most people here get "fim" caps from Parts Express, Madisound or Erse. We can discuss that once you know what you need."

I guess that's next.

[JKent]

Sorry--that's FILM
Here is the Erse site
http://www.erseaudio...ucts/Capacitors
The PulseX are their highest quality. The PeX are very good and they are economical. You can't go wrong with either.
I've never been inside the NLA but according to Pete's website: http://baselaudiolab...VENT_LA_XO.html you need one 13uF cap per speaker. That's a bit of an odd value. Erse makes PeX in 13uf but you have to buy 500. Just get a 12 and a 1 and wire in parallel. May as well get the PulseX: http://www.erseaudio.../MPX25-03-13-00
Kent