Theater ESL Panel crackle at high volume

[terlcartman]

Greetings!

I am looking for some advice from this very experienced group of fellow ML enthusiasts. I have a Theater center channel stat panel that is consistently crackling (sounds like a hundred black cat fireworks going off very rapidly or the sound professional fireworks make when they have the extra sparkle/sizzle and crackle after the big bang) This only happens at high volume levels at specific frequencies and I wanted to see if anyone has any advice. The scene I am using to repeat the issue is from the opening scene in TOP GUN when Goose says "and I will clean them and fry them" and then the two F14's separate with a lot of jet noise. I reached out to ML (they have been great), vacuumed several times after discharging, fully disassembled the speaker, taken pictures of all electronics and sent to ML (they did not see any issues), even bought a new power supply and installed it, but still have this crackle/static sound coming from the panel at high volumes. Unfortunately panel replacement is not an option for this speaker per ML. Also before focusing on the speaker I tried different Pre Pro and different Amps and even put in a old center speaker I had lying around and the issue is clearly the stat panel. Would love to hear any thoughts or advice around if this sounds like arcing, a dying panel, things to check or if I should go down the shower path as a last resort.

Thanks very much!

 

[Robert D]

Is it possible that its the tweeter? I had a theater i and remember that it had one or two tweeters in the center. Did you listen to it and narrow it down to the panel?

 

[terlcartman]

Yep, I removed the tweeter panel completely and disconnected the woofers. Definitely the panel.

 

[Robert D]

I had a theater i and felt like it was underperforming my Prodigy speakers with their new panels, so I sold it and bought a new Focus center channel. Im glad I did. Only thing that sucks is that they just raised the price on it for the 2nd time in a little over 1 year. Im surprised that ML did not have any ideas of what was causing the sound. DId you try sending them an audio recording of it? Maybe Ron could identify the problem from the sound itself?

https://www.martinlogan.com/en/product/focus-esl-c18

 

[terlcartman]

Ron is who I have been working with and he has been awesome. Yes I did send a recording and he was hopeful it was the power supply. I only just replaced that yesterday and as I said it did not fix the issue. Based on our discussions this was our last hope as he said if not the power supply it was the panel, but I was not sure what that meant so I hit google, which is how I found this forum.

 

[Len44]

I presume we are certain -- absolutely certain -- that everything that needs to be plugged in is fully and tightly connected. I promise, no offense intended. Sometimes it is the simple stuff that gets us.

 

[terlcartman]

None taken! I am asking for the advice so happy to check anything. Any thoughts on what to check? I did a close look at the wires going to the stat in the dark so no arcing there and insulation seems to be well done. I replaced the power supply and had the same issue so all those connections are good. Visually inspected the cross overs and sent pics to ML so think it is ok there. I did not swap the power cord so that is an idea. The speaker cable, amp, interconnects etc work fine with the other center so those should all be good. Thoughts?

 

[Robert D]

Some on here have reported having debris in the panel and that can causing arcing. Washing them like you said could help. A number of guys on here have had good luck with that. I think I remember at least one other member on here describing a sound like that, but i dont remember him saying that it only happened on high volumes.

 

[roberto]

Basically two things can make the panel to arc. One is over power...sometimes the panel does not have the efficiency needed due to ageing. The Theater model was launched in 1999. Second, there is a possibility that the material that is avoiding the panel to arc has lost the property of isolation. On both, you need new stat panel. The life span of the stat panel is uncertain, but usually 10 years is the life of them. There are some that had last a lot, and others in less than of two years have needed to be replaced.

Sorry for not bringing good news. If you did find the way of how to cure it, please let us know. Remember that the panel is like a big capacitor...and if there is no way of how to dissipate the energy supplied, what it must does is an arc.

Happy listening!

 

[Robert D]

Basically two things can make the panel to arc. One is over power...sometimes the panel does not have the efficiency needed due to ageing. The Theater model was launched in 1999. Second, there is a possibility that the material that is avoiding the panel to arc has lost the property of isolation. On both, you need new stat panel. The life span of the stat panel is uncertain, but usually 10 years is the life of them. There are some that had last a lot, and others in less than of two years have needed to be replaced.

Sorry for not bringing good news. If you did find the way of how to cure it, please let us know. Remember that the panel is like a big capacitor...and if there is no way of how to dissipate the energy supplied, what it must does is an arc.

Happy listening!

The panel I had in mine was about 20 years old and sounded ok. It did not arc. I'm assuming it was the original panel. I owned it for about 5 or 6 years.

 

[terlcartman]

Thanks for the explanation on the arcing, much appreciated. I took the final step of rinsing it in the shower today just to see if that has any effect. Looking like a replacement may be the only option, but if the rinsing has any effect I will report back.

Again thanks very much to everyone who reached out to try and help!

 

[Russr]

I could've sworn I saw a posting on here where a panel for a Theater (or Theater i?) was replaced... I seem to remember the price was like $600, too... at the time I had just been quoted ~$250 to replace the 3 tweeters, and with some scanspeak mids I was thinking I could have a "new" Theater for less than $1,000!

Darn...

 

[terlcartman]

I asked about it and Ron at ML said they can no longer get the metal for the Theater or Theater i Stat.

 

[Duke]

Would ML be able to use the existing stator on your failed panel? I would consider using their OEM shipping box and have them do it when they can using your speaker parts. Even with a several month backlog, it would be worth it if it is basically worthless as is. If ML demurs, someone like JonFo or your personal research on this site may be able to direct you to other vendors who might make a one off replacement for you.
If you do find a way through this, please post it here. Let me know as I am interested in having my panels done.



Not trying to hijack the thread but, I replaced all four woofers with SEAS W18E001 on a stacked theater i and a theater when the OEM (of one) woofer failed out. I had it re-coned but that did not hold up. There is more detail with that swap to the SEAS speaker within the crossover band of the speaker. I noticed this difference at times on familiar music. The speakers performed noticeably better at hot temps than the original speakers, or said another way, when the speakers got warmed up. Since I was working with a stacked pair, I was able them both up at once to warm them up and then to just fire up and listen to one warmed up speaker at a time. One speaker with and one without the new drivers. I had forgotten was that crossover band was as I did not do the work. I do remember that the SEAS speaker that was chosen as a replacement looks great within the ML Theater crossover. I think the SEAS were probably much more expensive. It was available at Madisound and I live reasonably close to that speaker distributor in Madison, Wisconsin. There probably are many more speakers to choose from and I imagine you can find a better one than that.
I would love to see a schematic of the Theater and Theater i speaker to update the capacitor.
I am always looking for better built tweeter, or new OEM, but I think the panel and the woofers get the most of the output. I am not relying on anything but my personal experience. I read somewhere on the site that this relatively inexpensive tweeter Theater center ribbon tweeter mod was a big improvement.

 

[JonFo]

Would ML be able to use the existing stator on your failed panel? I would consider using their OEM shipping box and have them do it when they can using your speaker parts.

That's actually a great idea.
If the original powder coating is still good, they can deconstruct the panel and rebuild using those.
But based on my experience separating old panels (used in my sidewall treatments), one might damage the powder-coating, so they might need to sandblast, re-coat, and rebuild.
So a rebuilt theater panel would be whatever the prior cost was plus any extra labor to separate, and possibly sandblast. One assumes their panel cost already factors in a coating.

 

[terlcartman]

Great suggestions. I am about to hook up the panel after washing it yesterday in the shower and having AC blow on it for 36 hours, but if that fails I will definitely ask ML about that option as I have the original box up in the attic.

 

[terlcartman]

Washing unfortunately did not fix the issue. I also swapped out the power cord just to check that as well and no change. I will see what ML says about me sending it in and using my parts to make a new stat.

 

[ES347]

..I have a 20+ year old Cinema and it's breaking up at high volumes. Pulled the PC so was listening to the woofers and tweeter only..no break up so panel is the culprit. Was quoted $485 for a new panel but ultimately decided to go with a new Focus C18...even though ML has jacked the price by $1K...grrr..

 

[Russr]

Washing unfortunately did not fix the issue. I also swapped out the power cord just to check that as well and no change. I will see what ML says about me sending it in and using my parts to make a new stat.

Did you get hold of ML about sending a panel in for them to refurbish?

 

[smanuta]

Please adjust the crossover on your a/v receiver. Maybe 120hz cut off or higher. The traditional center channel bring in slot of bass and etc.