Urei 811A Trouble

[4345]

I just bought a pair a few days ago. I am having trouble with one speaker. The high frequency does not sound very good. Sounds kind of hollow and not nearly as bright as other speaker.

1. I did adjust and turn many times the pots on the front with a screwdriver.
1. I switched the speaker wires and nothing happened. The same speaker still sounded bad. So, it is not my electronics.
2. I swapped the crossovers on the back. Still the same speaker sounded bad.
3. Now, what should I try next? How about the level pots on the front of the cabinet? Could this be the next thing to check. If so, what do you look to do?

FYI. The speakers are dusty and a little dirty, but to my eyes it looks as if the 604's have never been removed from the cabinets. So, I do not think someone has put in a wrong high frequency diaphragm. Also, to my ear the horn on the bad one is working, just not well.

Thanks for any advice.

[4343]

I'd guess that one of the diaphragms has cracked, or burnt to make the difference in the sound. It is possible that there is a faulty connection at or inside the HF driver. Time to take it apart and see what's what...

[4345]

I think I found the problem. I think the diaphram was an aftermarket. It worked but sounded bad. Can anyone confirm that Altec never made a diamond pattern surround like this? The back plastic cap looks wrong also.

Thanks.

[edgewound]

I think I found the problem. I think the diaphram was an aftermarket. It worked but sounded bad. Can anyone confirm that Altec never made a diamond pattern surround like this? The back plastic cap looks wrong also.

Thanks.

Wow...How creative. It's a "Lansing" diaphragm....just the completely wrong Lansing.

What you have there is a JBL D8R2416-1 diaphragm crammed into your Altec driver. No wonder it sounds wrong....because it is.

You need an Altec diaphragm, now manufactured by Great Plains Audio, or an aftermarket by Radian. GPA no longer makes the Symbiotik (Kapton suspension) diaphragm, so the Radian with the Mylar suspension would be a great alternative.

[4345]

Edge,

Thanks for the reply. I did call GPA and have ordered the right one. However, I would assume it is the all alumunimum version that I need, not the symbiotik. This is for extended top end not high power.

Thanks.

Wow...How creative. It's a "Lansing" diaphragm....just the completely wrong Lansing.

What you have there is a JBL D8R2416-1 diaphragm crammed into your Altec driver. No wonder it sounds wrong....because it is.

You need an Altec diaphragm, now manufactured by Great Plains Audio, or an aftermarket by Radian. GPA no longer makes the Symbiotik (Kapton suspension) diaphragm, so the Radian with the Mylar suspension would be a great alternative.

[4343]

Edge,

Thanks for the reply. I did call GPA and have ordered the right one. However, I would assume it is the all alumunimum version that I need, not the symbiotik. This is for extended top end not high power.

Thanks.

Without opening the other one you won't know what you need to match...