Martin Logan SL3 recapping questions

[ck102020]

I am here again to ask some questions about recapping my sl3s. I put in an order for new panels and they should be coming soon. I am upgrading the caps in my speakers but am unsure how many or which parts to order. I am doing this recap project with a friend who owns a stereo repair shop and knows much more than I do when it comes to repair. Does anyone have any information on how many caps I will need to purchase for redoing the caps for the woofer and panels? Which ones to order? Any advice or information would be very much appreciated! Thanks

 

[Russr]

Something you might want to consider and run by your friend as well, is turning the SL3s into Active (crossover) driven speakers.

Below is a link to a thead. The OP (@Brandon Hartwick) did this on a pair of Aerious speakers, and I am dead-keen on doing the same with my SL3s. I'm not entirely sure if any crossover is needed for the panels, and if so, what class/cost of components is required, but an amp with built-n digital High/Low or band-pass filters can be had for ~$400 USD. These Class D devices for all intents-and-purposes mimic the active bass concepts in the new ML range of speaker.

https://www.martinloganowners.com/threads/how-to-active-bass-section.19237/page-2#post-210445

 

[Tosh]

You will need to look inside yours and see which version of SL3 it is. Just replace whatever electrolytics are in there, and be done.

 

[ck102020]

You will need to look inside yours and see which version of SL3 it is. Just replace whatever electrolytics are in there, and be done.

Do you know if there any electrolytics that impact the panel’s performance? Or are there just ones that deal with the woofers?

 

[ck102020]

You will need to look inside yours and see which version of SL3 it is. Just replace whatever electrolytics are in there, and be done.

Tosh, I see a lot of responses from you about going to active bass. The process confuses me as I’m not sure exactly what amps I am in need of to achieve this. I run an emotiva pt100 and a sunfire cinema grand 200x5. I also have a emotive bass xa2 not in use anymore. With this amp setup, is there any way to go active? Or would I need to purchase something else? I have 3 other channels available on the sunfire and a subwoofer rca input left on the emotiva. I’d like your input if possible. I am still relatively new to audio and this is something I have never tried to do before. I tried reading through some conversations on here but was left confused. Thanks for any help.

 

[jmcmillanmisc]

Do you know if there any electrolytics that impact the panel’s performance? Or are there just ones that deal with the woofers?

I have a pair of Sequel IIs from about 1992. A few months ago, I replaced all the electrolytics AND film caps. I upped the voltages on essentially everything, particularly the film caps. There was a noticeable improvement which I think you would hear on the Sequel IIIs. Note that the electrolytics were replaced first so I did have a chance to hear them before the film cap replacements. This is a very easy and inexpensive upgrade that was well worth it on the Sequel IIs. I with I could comment on the more sophisticated upgrades others have suggested but that is above my paygrade. JM

 

[Tosh]

Tosh, I see a lot of responses from you about going to active bass.

It's all I ever talk about: It's all that's missing from these original ESL hybrids to bring them up to the bass performance of today's ML's. You just have to wrap your head around how to insert an active xo in front of the bass amp, so the amp can drive the woofer directly....

 

[ck102020]

It's all I ever talk about: It's all that's missing from these original ESL hybrids to bring them up to the bass performance of today's ML's. You just have to wrap your head around how to insert an active xo in front of the bass amp, so the amp can drive the woofer directly....

Do you know of any guides?

The “active xo” would be from the 2nd amp correct? What do you mean by “in front” of the bass amp?

Main amp powers ESLs while a second amp drives the woofers. How do you send the woofer signal to your preamp? How does volume control work with the two different amps. I apologize if these questions do not make sense I am just trying to learn. I just can’t comprehend this process. I am very much a visual learner. Thanks for your response.

 

[Tosh]

After the preamp, the signal is split: one to the main amp to passive high-pass xo-ESL as before, and the other goes through an electronic (active) low-pass crossover in front of the bass amp, which drives the woofer.

Here's Rod Elliot's old bi-amping guide:
https://sound-au.com/bi-amp.htm
more?
https://sound-au.com/biamp-vs-passive.htm

 

[Russr]

Do you know of any guides?

The “active xo” would be from the 2nd amp correct? What do you mean by “in front” of the bass amp?

Main amp powers ESLs while a second amp drives the woofers. How do you send the woofer signal to your preamp? How does volume control work with the two different amps. I apologize if these questions do not make sense I am just trying to learn. I just can’t comprehend this process. I am very much a visual learner. Thanks for your response.

In my reply (see first response ^^^), I included a link to a thread that goes into decent detail on this very topic.

Here it is again...
https://www.martinloganowners.com/threads/how-to-active-bass-section.19237/

I believe some mention is made of stand-alone digital crossovers, which you could use in conjunction with your veritable cornucopia of spare amplification channels...

Or get something like the Crown Brandon listed in his thread
(https://www.amazon.com/Crown-XLS1002-Two-channel-Power-Amplifier/dp/B011TI97VE?th=1).

You could use the one Crown amp to drive the bass drivers of both SL3's, or put a digital crossover between a pre-amp out, and use it to route the signal to the respective amps for bass & panels. If you are using subwoofer(s), you can tweak the band-pass parameters for the SL3 bass drivers so they don't try stray into subwoofer terrain.

 

[ck102020]

After the preamp, the signal is split: one to the main amp to passive high-pass xo-ESL as before, and the other goes through an electronic (active) low-pass crossover in front of the bass amp, which drives the woofer.

Here's Rod Elliot's old bi-amping guide:
https://sound-au.com/bi-amp.htm
more?
https://sound-au.com/biamp-vs-passive.htm

I’ve seen people mention that having a power amp with built in dsp and eq abilities is necessary. These are usually class D amps. I have an emotiva bass xa2 that does not have eq abilities or built in dsp. It is A/B. However on my preamp I have the capabilities to change bass, treble, and balance. Is it possible to add an outside dsp? Or should I just go for a different class D amp. Thanks for all the guidance!

 

[Russr]

I’ve seen people mention that having a power amp with built in dsp and eq abilities is necessary. These are usually class D amps. I have an emotiva bass xa2 that does not have eq abilities or built in dsp. It is A/B. However on my preamp I have the capabilities to change bass, treble, and balance. Is it possible to add an outside dsp? Or should I just go for a different class D amp. Thanks for all the guidance!

So, if you currently use a Preamp, think of the DSP as a device that goes in-between your preamp and the amplifier you currently use. Now imagine the DSP as a "Y-splitter", where the DSP will send the configured higher-frequency signals to one amp (driving the panels), lower frequency signal to another amp (driving the bass units). Your preamp is totally oblivious to what happens "downstream"... it's just outputting a signal. If you use the tone controls to alter the output of the preamp, those alterations will go into your amp (current configuration), or DSP/amps (future configuration). Ideally, you want no coloration added by your preamp...

 

[ck102020]

Do you know if there any capacitors related to the performance of the panels?

 

[Mirolab]

To OP.... ck102020

You NEED to take the back off of your SL3 and see what's in there. I've seen pics of various SL3's and there appear to be 3 versions with same basic crossover values, but different parts and arrangement. Below is a pic of my SL3 crossover BEFORE I recapped it. The blue 330uF electro is the parallel woofer cap, and should be replaced with a new electrolytic, and bypassed with a film or poly cap. The ES panel series capacitance is 30 uF, and on mine it was made up of a 15uf electro + 15uF film cap (or whatever that yellow one is). I replaced those with a pair of 15uF Jantzen Z-superior caps. I'm not claiming those are better than anything else, as I've not tried anything else, but I am very happy with the clearly noticeable improvement!

I put new panels on my SL3's about 2 years ago... waited 6 months for them to settle in, and THEN I recapped it so i could really tell the difference the new caps made. I would not recommend doing both at the same time.

As for going active on the woofer... I see many people trying to steer you that way. If done right, they could sound amazing....
But forget those people! You are clearly a beginner at this. I can tell by your questions. And going active is NOT for a beginner! Just do a good job replacing your panels, and maybe the capacitors, and you'll be very happy with your SL3's (driven with the right amplifier).

Stock caps on my SL3's.....

 

[ck102020]

To OP.... ck102020

You NEED to take the back off of your SL3 and see what's in there. I've seen pics of various SL3's and there appear to be 3 versions with same basic crossover values, but different parts and arrangement. Below is a pic of my SL3 crossover BEFORE I recapped it. The blue 330uF electro is the parallel woofer cap, and should be replaced with a new electrolytic, and bypassed with a film or poly cap. The ES panel series capacitance is 30 uF, and on mine it was made up of a 15uf electro + 15uF film cap (or whatever that yellow one is). I replaced those with a pair of 15uF Jantzen Z-superior caps. I'm not claiming those are better than anything else, as I've not tried anything else, but I am very happy with the clearly noticeable improvement!

I put new panels on my SL3's about 2 years ago... waited 6 months for them to settle in, and THEN I recapped it so i could really tell the difference the new caps made. I would not recommend doing both at the same time.

As for going active on the woofer... I see many people trying to steer you that way. If done right, they could sound amazing....
But forget those people! You are clearly a beginner at this. I can tell by your questions. And going active is NOT for a beginner! Just do a good job replacing your panels, and maybe the capacitors, and you'll be very happy with your SL3's (driven with the right amplifier).

Stock caps on my SL3's.....
View attachment 24559

Thank you for the advice. I am currently learning about audio repair at a shop right now. I am in college and I love audio so I am rather new to the repair and modification side of it all. The person that is teaching me should be able to clarify my questions more. I haven’t talked to him much about this. I do want to go the active route to achieve optimal performance. Hopefully I can get things cleared up with the professional who is teaching me. My current amp is a sunfire cinema grand. With the crown amp for going active I should be able to achieve what the others are recommending. I just want to get inside the sl3s and figure out what I need to recap and what I do not have to recap. The new panels should be coming in soon and I will break them in as you recommend. Thanks again!