Final Amplifier for Martin Logan CLX

[MylesBAstor]

Couple of points. Did you follow the ML setup instructions regarding toe-in and upper octaves? Also did you play with the angle of the panels?

Side reflections aren't as much of an issue with the panels.

But in contrast to the room frenzy folks-or those that would have selling all your gear-it seems to me the issue might be the front-end not the amps. MLs are notoriously revealing of everything that's in front of them and the problem might be your digital source. Have you tried any other sources or digital players?

Lastly, are you using any silver wire?

 

[audioarcher]

More power! You either need to go big with tube power north of 400 wpc or big with SS power and use a tube preamp. I agree with others that the room looks very reflective.

 

[awsmone]

Thanks Myles for your reply

Yes I have followed set up ( in fact in previous room, despite the size limitations, and people claiming I am incompetent, I followed their set up instructions to the mm ( glass windows excepted)

Played a lot with panel angles and they do ameliorate issues, but then raise other ones such as bass and midrange

removed silver wire cabling, which I think was a big problem

Despite everyones comments about the room

It is actually a great sounding room in general:bass and midrange and treble incredibly detailed and scaled, but at certain pitches it is very unnatural
, when other pitches it sounds wonderful
This issue seems to be only at certain pitches

It is much more a problem with Solid state amps including the blue circle which I bought as Gilbert loves ML electrostatics

There is not an issue of driving the panels in the room

It to me seems to be about the effect of SS on the panels

My showing the other room was that in a very different set up ( yes much inferior ) to current, the same timbral issues occur

Yes and your right, CLX are very revealing of any change

Just changing the power cord on the 900 makes an enormous difference

 

[awsmone]

Room set up from listening position today

Sorry its dark autumn mornings in Canberra lol

 

[awsmone]

My understanding from previous owner is the coating on tiles is sound deadening despite shiny finish

Certainly the room is nowhere near as alive as photo might suffest

 

[GaryProtein]

You have a great system from the cd/sacd transport and dac all the way through to the speakers.

The room is the only fault I see and least expensive to correct.

It is every bit as live as it looks! DON'T RESIST!!! We want you to have a successful resolution to this.

The previous owner has no idea what he is talking about regarding sound deadening on the tiles.

To start, get more rugs.

 

[awsmone]

Thanks

your right its a cheap option and the room is pretty great otherwise

Will try coving the floor

what do you think for ceiling

 

[JonFo]

Let me join Gary in reinforcing the importance of treating your room, and I say this from experience setting up and tuning a large ESL system over the past decade +.

Based on your descriptions, and judging from what I see in pics of your current room, you likely have serious HF ringing that will mask *any* change in upstream gear.

HF Ringing is the bane of many an ESL setup, but once tamed, you will love these speakers even more once you get to hear the music, and not just room resonances.

So please put down some rugs right away, dampen the rear wave even further with absorption behind the speakers, and if your seat is indeed more than 2m from the rear wall, add diffusion back there.

Please read and look at the amount of room treatment it has taken to tame a set of Monoliths and Sequels and a custom center in a room designed and built just for them. Click to see my page on the HT space.

And this to see a diagram of all the acoustic treatments in that room

Again, dealing with large dipoles is a very specialized thing, and much of the 'common wisdom' rarely applies. Measuring, testing and re-measuring (and listening) are required to really tune the system.

 

[JonFo]

Now, since the original question was about amps, I have one answer: Sanders Sound System Magtech Monoblocks.

Guaranteed to let you get the max out of those CLX's.

These amps are designed for the complex loads of an ESL and have huge current reserves.

I use mine to direct-drive the panels (no passive X-over, I use active X-over before the amps) and they just cruise with that difficult load.

 

[awsmone]

Thx for that advice
Ringing at a set frequency makes some sense from what I am experiencing
Back and front wall have absorbent panels as more than 2 meters
Think floor and ceiling are next to attack
Any way I can measure the band effected and selectively just it down
There are no big peaks on high frequency sweep

Thx for your experience I appreciate it

 

[JonFo]

...
Any way I can measure the band effected and selectively just it down
There are no big peaks on high frequency sweep

Thx for your experience I appreciate it

HF ringing will not easily show on a frequency response chart, but is clearly visible in the waterfall plots or in long-window impulse response of select HF bands.

As for can they be damped down, yes they can, first with room treatments, then with judicial EQ or DRC. Dirac seems to do wonders cleaning up the impulse responses. But an untreated room over-energized with multiple square meters of radiating surfaces is a challenge few DRC's can realistically overcome.

 

[awsmone]

Thx Jonathan

I have a copy of Dirac

Will Dampen first

then measure

But might be able to work it out from pitch of violins and eq down at that pitch

Will try all three and see what happens

Thx

A

 

[awsmone]

Thanks Jonathon you have beena great help


Layed down old carpet squares all over the floor today

Big change!!!!

Still a little "sizzle" at some pitches but maybe 10% of before

Huge improvement in articulation and inner detail

Getting that amazing effect where instruments start projecting in front of the speaker plane

So must be on the right track

Bluecircle BC208 down for repairs ( nothing blue circles fault, a workman set his ladder up amongst the speaker wires and they touched .... indoor lightening!!!!)

So cannot test it yet

Soundstage and layering maybe 200% better


I would like to thank everyone for their patience and acute observations

Warm regards

Andrew

 

[radicalsteve]

Andrew, firstly congrats on great speakers and welcome to the club! Having lived with CLX's for over three years now, in different rooms, I find they are easier to place than conventional box speakers. 3' back from the rear wall is fine and 1' in from the side works well, then its all a matter of the room dimensions versus the LF response for imaging. I have tried SS amps and tube amps and your original concern is the opposite of others where the HF falls off because of the impedance curve versus the amplifier specs. The use of carpet in front of the speakers does calm down the edgy HF response for sure. I do find a small tilt back on the vertical angle also reduces the stridency and help on the imaging since there is very little ceiling reflection issues from the ML design versus other speaker designs. FWITW, I have had great success driving CLX's with Classe CT Ma600's; Musical Fidelity KW750: Plinius SA-250 and never felt I was missing any emotions versus tubes!!

 

[awsmone]

H Steve

Thx for your input

Yes you are right most tubes drop off at 16khz
The BC208 r flat thru they have flatter treble response
I compensate for tube drop off with Bee engineering ribbon super tweeters these are crosses in at 16khz
This compensates for this with only smaller drop at 20khz at the sitting positions

I think you are partly right the problem with SS in fact is they have flatter treble response so any HF ringing problem is made worse

Room treatment have helped a lot, and yes panels are angled back

Thx

Will post new room pic and frequency response

warm regards

Andrew

 

[awsmone]

Room with increased softening

 

[morricab]

Having had numerous electrostatic speakers, I can only tell you that Solid State is not really the right choice. The impedance swings are too wide and often the speakers have too high impedance in the mids, which leads most SS to sound thin through that region on the speakers.

To avoid back EMF issues you need a good tube amp without negative feedback. If you look at something like VAC, I would go back in time a bit and try to find a pair of the PHI 70 monoblocks. These will deliver plenty of power to your CLXs and sound extremely good. Nevermind the 70 watt rating there is plenty of head room and they will deliver the voltage your speakers need through the higher impedance midrange. Other big push/pull triode or triode wired amps should be considered like the CAT JL2 signature (it should be stable). The Coincident 211 based push pull monos should also be on the audition list. You shouldn't discount big SET amps either from the likes of NAT (SE2 or Transmitter) or KR Audio (Kronzilla DX monos will work beautifully with the CLX), which would be my own personal preference over the push/pull designs.

 

[microstrip]

Thanks

your right its a cheap option and the room is pretty great otherwise

Will try coving the floor

what do you think for ceiling

Covering the floor can be a negative thing if done inadequately - see this WBF thread http://www.whatsbestforum.com/showthread.php?13805-What-is-the-best-acoustic-material-to-place-on-the-floor

IMH experience large full range panels need less room treatment than dynamic speakers as the ratio between the areas of direct radiated sound and the reflected sound is much larger. However they need careful placement in the room - distance to front wall and some (just some!) absorption at the front wall are critical.

BTW, a pair of Electrocompaniet Nemo's should sound great on your CLX.

 

[oldears]

View attachment 15101

Like the beer fridge!!

 

[oldears]

Seriously, have you considered turning the room around, speakers on the long wall more widely spaced? I liked Monoliths that way, even had a Watt centre channel. I will second previous posts, valve amps, avoid silver interconnects I liked vdHull the seconds with ML Monoliths. Have 2 x 5 meter lengths of the second and a single 6 meter length, if you want to give them a try.