Martin Logan Purity sound issue

[mrmagoo]

Hello,

Hello, I have a pair of Martin Logan Purity speakers. I noticed recently that one of speakers seemed quieter than the other despite set at the same DB level in the receiver. I ran a test tone level test from the Denon receiver and heard the speaker going up and down in volume without any adjustments from me. Later on the speaker seemed to be functioning as normal, however this has happened a couple of times including one time with no sound coming from the speaker at all so I am wondering if the speaker is starting to malfunction or something is broken. I checked the wiring and power cable and it seems OK. Going to leave it powered off and try the vacuum method tonight to see if that helps. Any suggestions or recommendations on what I can do? Could it be Stat panel dying or maybe the Amp?

 

[Robert D]

Hello,

Hello, I have a pair of Martin Logan Purity speakers. I noticed recently that one of speakers seemed quieter than the other despite set at the same DB level in the receiver. I ran a test tone level test from the Denon receiver and heard the speaker going up and down in volume without any adjustments from me. Later on the speaker seemed to be functioning as normal, however this has happened a couple of times including one time with no sound coming from the speaker at all so I am wondering if the speaker is starting to malfunction or something is broken. I checked the wiring and power cable and it seems OK. Going to leave it powered off and try the vacuum method tonight to see if that helps. Any suggestions or recommendations on what I can do? Could it be Stat panel dying or maybe the Amp?

I have a Marantz receiver with the left and right channel amps going out. Sometimes it puts out sound fine to the speakers, but other times it's just silence. I don't get the up and down on volume effect.
You need to hook up a different set of speakers to the Denon and see if it still happens.

 

[Leporello]

Hello,

Hello, I have a pair of Martin Logan Purity speakers. I noticed recently that one of speakers seemed quieter than the other despite set at the same DB level in the receiver. I ran a test tone level test from the Denon receiver and heard the speaker going up and down in volume without any adjustments from me. Later on the speaker seemed to be functioning as normal, however this has happened a couple of times including one time with no sound coming from the speaker at all so I am wondering if the speaker is starting to malfunction or something is broken. I checked the wiring and power cable and it seems OK. Going to leave it powered off and try the vacuum method tonight to see if that helps. Any suggestions or recommendations on what I can do? Could it be Stat panel dying or maybe the Amp?

You might try hooking the speakers in series (easier to drive than parallel) and driving them with one channel of the Denon, just to rule it out. Otherwise, could be bias supply problem. Could be panel dying, but intermittency makes it less likely. Regarding the bias supply, could be either the high voltage supply itself or the circuitry that detects a signal and changes the bias from standby to on. Either of those is probably easier and cheaper to fix than a panel.

Yeah, try vacuuming first, after allowing them to discharge, preferably overnight. Could be a piece of crud between the stators. Do a careful inspection of the whole diaphragm. But my money is on the bias supply, if the speaker is at fault at all.

 

[Nuri58]

That sound exactly what happened to mine when less than 2y old. I got new panels fitted on both lS + new bias and all on the house since under warranty. Only issue was the 3 weeks it took.

 

[Leporello]

That sound exactly what happened to mine when less than 2y old. I got new panels fitted on both lS + new bias and all on the house since under warranty. Only issue was the 3 weeks it took.

Happy that ML came through with warranty repairs. But you never found out which it was? They probably wanted to rule out everything, and not see them back again for repairs.

 

[Nuri58]

I was left with the understanding it was the panel, but I had same issue with the cinima i resently, and same verdict both to be changed - almost same cost as a new EM C så I ended with a c18 demo greatly reduced that the importer had in his place and had i auditioned in his place, left with it and went to buy it from my dealer a few days later. Just a shame to ditch the cinema (waste of resources) but after 18y service I guess I can defend and the Focus is another class.

Anyway, I think your suspicion is correct.

 

[gvera]

Hello,

Hello, I have a pair of Martin Logan Purity speakers. I noticed recently that one of speakers seemed quieter than the other despite set at the same DB level in the receiver. I ran a test tone level test from the Denon receiver and heard the speaker going up and down in volume without any adjustments from me. Later on the speaker seemed to be functioning as normal, however this has happened a couple of times including one time with no sound coming from the speaker at all so I am wondering if the speaker is starting to malfunction or something is broken. I checked the wiring and power cable and it seems OK. Going to leave it powered off and try the vacuum method tonight to see if that helps. Any suggestions or recommendations on what I can do? Could it be Stat panel dying or maybe the Amp?

Hello,

What I would do if, after vaccum, the problem remains.
(I'm assuming your speakers are not under warranty)

- interchange the speakers (L<->R) to discard a problem with the amp and be sure the problem is in the speaker

- If so,
- open the faulty speaker and check for any loose connector that may cause an intermitent faulty connection. (WARNING: High Voltage)

If problem is not resolved,
- Start interchanging the speakers electronics between them.
If the problem now happens in the other speaker, the problem lies in the exchanged electronics
If the problem remains in the same speaker, the panel is the culprit