Distorted sound Apogee Full Range

[dazzdax]

Hi all,

I would like to ask you if there is anyone who experiences distorted sound from a fully restored Apogee Full Range.
When listening to strings (upper register) and a female soprano (like Lisa Gerard of Dead Can Dance) I hear distorted sound from one channel. It's as if the sound becomes discontinuous (gritty). Could this be a diffraction effect from the edges of the front cover of the speaker or is it related to an electrical issue?

Chris

[Zardoz]

Hi,

What source are you are you using? Does it do it from all sources, CD. TT, Streamer, etc? If you swap speaker cables from the amp, left output to right speaker, and right to left, does it stay in the same speaker or switch channels? You need to at least do the last one to make sure it's the speaker.

Best,
Z

[dazzdax]

Hi, I have tried the following actions:

- Interchanging the right and left interconnect cables from the preamplifier to the crossover.
- Interchanging the right and left interconnect cables from the crossover to the power amplifiers.
- Interchanging the right and left power amplifiers.

All these actions did not result in a difference: The distortion remained and is still coming from the left channel.
So I have the suspicion that it could be related to the speaker itself.
My question is: Could such distortion be caused by the speaker and what would be the culprit of this?

Chris

[Scinemaniac]

Imperfect contact somewhere?
however unlikely...

[Zardoz]

Sounds like something to do with the ribbons. Are there and obvious tears or sags in the mid ribbon?

[dazzdax]

Hi,

I can't find any damage of the midrange ribbon. Visually it looks fine.
Should I ask Henk (van der Hoeven) to get a closer look at the ribbons?

Chris

[Graz]

That makes sense. I have contacted Henk regarding this in the past, and put forward suggestions. He should be able to locate the problem...


Take care - Graz

[dazzdax]

General problem description: After many years the dampening stripes which "tame" the resonances of the bass panel are rotting away. Once this happens, you can hear a noise which is often described as a "buzz".
The only competent way to fix this problem is to replace those stripes.

I didn't know there are dampening stripes with the bass ribbons in the Full Range.
Could the distortion I hear from the bass panels be the result of this dampening stripes issue?
Btw, I don't hear a buzzing sound but a very nasty distortion.

Chris

[Scinemaniac]

For some reason, "the buzz" is rare or doesn't occur with the FR !!

It is may be a loose connection - if you can make access, break & re-make all electrical connections - especially where the "tags" makes contact with the foil. If some oxide got created in a loose connection, perhaps some weird diode or battery effect.

Another possibility is a rattle, perhaps a loose magnet or a "foreign object" got trapped in a place not so visible.

If you listen very closely, from where does the distortion emanate: from the top, the bottom of the assembly - is it localised?

Or is it coming through the ribbon all over, which might be an electrical connection thing.

Another possibility is the inductors in the coupling box (if this is your set up) may be rattling, are they fixed down?

However it could be something in your amplifier chain, faulty electronics (but you say that you eliminated that possibility). Mistracking cartridge?

Or sympathetic oscillation from a wine glass or other trinket placed near that speaker?

best wishes