Bi amping my ML SL3 speakers


Few questions for the ones that know the answers :)

If I’d like to bi-amp my speakers how do I know how much power should I send to the woofer and how much to the rest of the speaker ? (for mids and highs)

Currently I am using a Rotel 1582MKII and if I really crank the volume woofers start to distort so I’m thinking this amp is too much power ?

Info on ML site is misleading one place says 80-200 but I also saw 20-400 WPC so which one is it. My rotel amp is rated for 200WPC at 8 Ohms and no 4 ohm rating.....my speakers are 4 Ohms rated

Also I am guessing that the amp dedicated for lows doesn’t have to be as high end as the one for the electrostatic panels ?

 

Last but not least I will need a pre amp that has two sets of pre outs so I can feed same signal into both amps correct ? I really don’t want to get RCA splitters because that defeats the purpose of having a nice set of RCA’s - this question has been resolved thanks to riley804. I will get some but amp cables :)

 

Lots of questions any answers or wisdom is much appreciated !

lehelke3

I am not comfortable of taking on such a big project unfortunately.

My experience is that when I take something apart it never goes back the way and always end up with extra pieces. I will do some more testing and come back with some results!

Quantity is much less important than quality here when talking watts. Don’t get hung up on amplifier power.

If you want to make what you have work, disassemble the SL3, check woofers, make sure all the screws are tightened, vacuum or wash the panels. Also check the rear of the woofer cabinet. Make sure everything is tight and nothing rattles. Reassemble and check how they sound. If still issues, sell the SL3 and move on. 

That’s one way to look at it. It’s another one if you need to buy an amp that’s 200WPC or 400 :) You wallet will suddenly feel the weight 3db carries:)

Any idea why these speakersxare rated either 80-200 or 80-400WPC on various ML documentation. That is a significant difference !

Not really. The difference between 200 watts and 400 watts in 3 dB.

'Any idea why these speakersxare rated either 80-200 or 80-400WPC on various ML documentation. That is a significant difference !'

Being concerned about the speaker power ratings is probably the least of your concerns, since your preferred listening levels never reach it's claimed output specs.

You have an older model ML as others have mentioned. Maybe time for a tune up, or upgrade to newer model/brand, or something completely different.

The amp suggestion was a reminder that what amp is driving your speakers also makes up for what the fuss is all about with panels.

 

 

I looked up that Rotel amp. It’s ok. Should be fine but what I suggested about moving to a newer model MLs (if you like the sound) has several benefits-

1. Newer design Montis (I had those), Summit, etc. have powered woofer. I drove the Montis with Rogue ST100 and later with Pass XA-30.8 So they’re easier to drive

2. Better, more seamless woofer/panel integration.

3. Newer/fresher panels - these things age. They also accumulate dust. Both the age and accumulation of dust impact the way they sound. You can vacuum the panels or even wash them in the shower (panels only).

 

After owning Aries I and Montis, I eventually moved on. But the MLs are great speakers without a doubt. 

 I bi amp my Kappa 8's with a Parasound A 23 (235 watts 4 ohm) for bottom end and a Para HCA 750A (110 watts 4 ohm) for the high end. The SQ isn't any better bi amped but they play much louder. I would bi wire with your set up.

I don't see your amp as the problem, those speakers are rated to 400 watts rms. Is it both woofers that distort or just one? Does it do it will all sources? I have refoamed my wooofers a few times but they are still the orignals from 1990. So unless you are pushing your amp too far I don't know why your woofers would distort.

I could. I am waiting for some alone time so I try different type of music see if distortion still there. Not in panic mode yet. I had the smaller version 1552MK2 and I was able to turn music on full blast no distortion thatsxwjen I realized I need more power.

Any idea why these speakersxare rated either 80-200 or 80-400WPC on various ML documentation. That is a significant difference !

 

Found on Rotel's site. At 800, the amp ought to control the woofers. Maybe having them looked at is an idea? Volume distorting at is not known.
 
More Specifications 
Intermodulation Distortion (60Hz:7kHz, 4:1)
<0.03%
 
Damping Factor
800
 
Speaker Impedance
4Ω minimum
 
I

I bought my SL3s in 1995 and they were my audio only/listening room speakers for 16 years (into home theater as mains after 2011). They are old. If you like the sound, a good suggestion is finding a newer model, used.

I've fiddled with lots of amps and bi-wiring and bi-amping the SL3s over those years. I've run them plenty loud with only 60 watts of solid state. Seems strange the woofers are distorting from the Rotel. Any idea what decibel level distortion starts at and the general frequency area? Low bass, mid bass?   

And, I am sure the Rotel is NOT overpowering your speakers. it may have a low damping factor and woofer control; I don't know.  

I'm now running single-wired mono-block Wyred 4 Sound SX500s on the SL3s with 500w or so into 4ohms and my woofers really 'woke up' when I moved from a mid-level AVR to separates for the five channels. W4S claims damping factor of 2000; I don't know if that mattered but the performance is remarkably better.

A Y splitter is fine for preamplier-out left and right channels. If using different amps be sure the dB gain level's are similar.

 

Try not to jump on the what better train...there is always something better

I would like to make what I have work. If it fails for my ears or I see problems will make the necessary moves. I am open to amp change for now :)

Great this is really going to right way, one person says my amp is no good another says replace your speakers :)

I just really needed some help to understand some concepts which I kind of got so I do thank all of you for chiming in !

"I already have a rotel amp that is overpowering the wiofers so I really think I would benefit from bi amping."

The 1st post about overthinking it is what I would agree with.

Your amp isn’t "overpowering the woofers". There isn't anything near 200 watts ever feeding your speaker.

Consider trying a different amp. I use a pair of Theos, and they sound fine through a 70 watt tube amp or a $250 20+ year old SS 80 watt Harman Kardon reciever.

 

 

Bi-wiring or using another amp will not solve that issue. The SL3 are old. Even new they never felt comfortable playing at concert levels. It’s possible something is wrong with woofers so you can look into it. Give ML customer service a call. 

What I’m suggesting though as a better path forward instead of spending on speaker cables and amplifiers, upgrade the speakers. Anything Montis or newer should be a big improvement over the old SL3 if you want to stay with ML. 
 

Thanks for your feedback. Agreed panels can go as low as 1.5 Ohms

. I was hopping with that big toroidal transformers rotel can handle it but maybe not. Interestingly enough when I crank it its not the panel that is having an issue it's the subs, they bottom out....to answer your question.

They sounded like when you provided to much power to a subwoofer

+1 on suggestions to use one good amp and bi-wire the speakers. However…
Few things to consider here -

1. The ML panels present more challenges to the amplifier than the woofers do. This is because the impedance on the panels can dip below 2ohms. I do not think your rotel is a good match for these speakers and bi-wiring is unlikely to improve things much. 

2. When you say your woofers distort, what kind of distortion are you talking about? What does it sound like? Could have nothing to do with amplifier and bi-wiring is unlikely to resolve it. 

Thanks guys seems like aftercreading the article provided by Mike I should try bi wiring with my 1582MKII Rotel amp see if sound improves....

You don't need a preamp with dual outputs.  You simply use a Y splitter off the pre, into two signal lines.  Not saying two amps is the right way to proced,  just addressing the dual output question. 

I usually go 4 times more power for the low end. Active crossover to get the most benefit. I also bypass the internal passive crossover. Yes tube or class A for high end.

Interesting read I know I shouldn't have gone down that road this is not car audio where I use to ran active crossovers as opposed to the passive ones that came with my 6.5" component set all the time for precise control and SQ results. 

So to get back to what really matters....do you guys recommend I get one amp for the woofers and another maybe class A or tube amp for the mids and highs.

 

Speaker posts in back encourage that since there is a dedicated pair of inputs for woofers and another one for the panel ?

Your speakers are designed for passive bi-amping not active bi-amping. See articles below:

Mike

https://sound-au.com/biamp-vs-passive.htm

 

 

I already have a rotel amp that is overpowering the wiofers so I really think I would benefit from bi amping. Just need to figure out how to devide power between bass and mids/tweets ....

 

Would be nice to be able to use a crossover and drive the lows with specific power as opposed to full range. For the electrostatic panels I would like to get something nice might even go with tube so I can get the best sound out of my speakers 

Personally I think you are overthinking it and mixing kind of OK amplifiers. Get 1 solid amp and you'll be happier.

The issue with ESL's is that they are low impedance at the worst place (high frequencies) where even solid state amps tend to be going the wrong way.

Consider instead getting a single Sanders amp which are specifically designed for this situation, and that way you can get whatever pre you like which sounds good to you.