Martin Logan Sequel II - Panel Sensitivity Issue?

TheOnlyGirl

New Member
Need some advice - - I'll probably have to check with MartinLogan too but I thought I'd start here!

Own a pair of Sequel II electrostatic speakers. One panel has become very directional, and it seems as though only the right half of the panel is producing sound. This is confusing the living daylights out of me, as it's a single panel design!

The part of the panel that is working fine is producing sound at a good volume. Other panel is fine.

Noticed this problem and noticed panel slippage at the same time. Rectified the panel slippage and cursorily vacuumed, but I'm getting the same thing.

My train of thought is thus:

Step 1 - Swap panels to rule out crossover / wiring / PSU issue.

Step 2 - Insanely pedantic vacuuming session if problem persists.

Step 3 - Ye olde panel shower if there's still an issue.

Step 4 - Wallow in misery and shed a tear if the panel shower fails.


Anything I'm forgetting here? Dammit, they're too nice to fail!
 
@TheOnlyGirl The panels do have a limited lifespan like @JoeESP9 says. 15 years, maybe up to 20 years, before performance degrades. Vacuuming will help, and I've read of giving the panels a shower. Neither will restore the full effects of aging, but at least you'll make the best of what life there is left on the panels. If they are still the original panels, you would be surprised to hear how much louder replacement panels would sound--it will restore how they originally sounded. They can also be rebuilt, but I don't think the coating is as durable as ML's.

My one Sequel II has some dead spots vertically in the panel, whereas the other one was completely non-functional when I got the pair. (The panels are known to slide down in the mounts; if they slide too far, the wire gets pulled off of the metal stator in the rear.)
 
The Sequel I and II used a panel coating that lost conductivity over time. Their next model, the SL3, used a different coating with a much longer lifespan. They fit the Sequels perfectly.

I had the Sequel I with the same problem you describe, and replaced the panels with SL3 panels. It was like getting new, even better speakers, as the diaphragms were a bit thinner, thus lighter and more responsive. I replaced them myself, it's easy, at a cost of $450 for the pair.

That was over 15 years ago — I don't know about prices now, or availability. But it's like getting a brand new pair of magnificent speakers, even better than the originals, at negligible cost. I know $450 is not negligible, but in this context it is. Martin Logan, by the way, was super helpful — I also don't know if that is still their attitude.

BTW, check the woofer surrounds. I discovered the surrounds on my Sequel I's were not glued to the basket! They just flapped around — this is why reviewers complained the Bass was too "loose" to match the panels' speed. I called ML and told them, they apologized that two "bad apples" slipped through QC, and immediately sent me two new woofers. For free. Again, great customer service.

But guess what — even the NEW WOOFERS WERE NOT GLUED TO THE FRAMES! The surrounds didn't "come loose" — there wasn't a trace of glue on the metal baskets, ever. I couldn't believe it. I glued them myself and they sounded better than ever. It wasn't two bad apples, it might have been the whole orchard on the Sequel I's. I don't know about the II's.

They were so good I preferred them to my Quad ESL 63's. Sadly I no longer have them. I moved house and an old friend offered to store them until I got the new place set up. He used them. He loved them so much he refused to give them back. I should have called him ex-friend...
 
The more recent ML models I was told have a "lifetime" coating on them.

I know the woofers in the Sequel II were not mated well with the panels--that is a common complaint. ML didn't really figure it out until the Aerius. If I decide to finish working on mine, a change in woofer is in the cards. It's no surprise, since there is this heavy, weighted dustcap on the Sequel II woofers that slows them down and leaves a gap in the response. (One of mine was dead when I got it, so I have to replace them regardless.) ML recommends a Scan-Speak woofer as a replacement, yet while it is a lighter weight aluminum cone that would fill in some of those missing frequencies, it loses some of the depth to the bass. I'm at the point where these need enough changes (in addition to refurbishing the panels) that I can't see throwing good money after bad, and am going to get one of the MLs made during the past decade or so. The Spire seems to be closest to what I'm looking for, so it's just a matter of waiting on that "deal of a lifetime" (and a tax refund :D ).
 
I find it ironic with the complaining about the Sequel

1) owning a beat up pair of Sequel IIs isn't the same thing if you have a nice pair of the Sequel IIs
2) owning a pair of Sequel Ones are not even close to the Sequel Two

I have both, and My IIs where, are fine and I had the factory panels in them up until I painted them last year. I swapped out the replacement panels that where new in the Ones moving them to the 2s and visa versa.

No noticeable SQ change was noted and both speakers sound like they did prior to the swapping around. The Sequel 2s are ported, the 1s are not, the Sequel 2s are bi-wired the 1s are not, the whole xover network is different.
 
I find it ironic with the complaining about the Sequel

1) owning a beat up pair of Sequel IIs isn't the same thing if you have a nice pair of the Sequel IIs
2) owning a pair of Sequel Ones are not even close to the Sequel Two

I have both, and My IIs where, are fine and I had the factory panels in them up until I painted them last year. I swapped out the replacement panels that where new in the Ones moving them to the 2s and visa versa.

No noticeable SQ change was noted and both speakers sound like they did prior to the swapping around. The Sequel 2s are ported, the 1s are not, the Sequel 2s are bi-wired the 1s are not, the whole xover network is different.

I too have a pair of Sequel Ones - still running on the original panels. My father originally purchased (1988?) and I'm of the belief that they have some sound degradation. I'm looking to diagnose them so I only replace or upgrade what makes sense. Any advice or help is appreciated. Thanks in advance!
 
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