Denon AVR vs. Martin Logan Electrostats


My main speakers are Martin Logan "Source" (ESL electrostatic panels) added to a system powered by Denon AVR-X3000. Previous main speakers were Martin Logan SLM-XL (part of the Motion series), and volume was fine. Now with the ESL's, the AVR can't deliver enough volume, and because of the low impedance of these speakers, fear the AVR is struggling with the load. Martin Logan website recommends using 'quality' amplification, which they define as, "...nearly doubles power from 8ohm to 4ohm load, and doubles again to 2ohm load...". Denon says their "X" receivers nearly double power between 8ohm and 4ohm, but no mention of 2ohm (so I suspect 4ohm is their limit).

My question is, will an upgraded Denon AVR with more power (AVR-X4500H, or 6500H) supply the needed power to get the most of these Martin Logan's, or is a pre/pro required.

I am a fan of the Denon feature set (for HT), and have thoroughly enjoyed the X3000 for many years, so wouldn't mind upgrading if that will fix the problem. But anything above that (cost-wise) or loss of features is not the direction I want to go.

If Denon doesn't offer an AVR that will push these ESL's, then I'd rather replace the ESL's with something else. DefTech is out (can't tolerate the shrill sound of those aluminum tweeters), and I know from the Martin Logan SLM-XL's that I really like AMT tweeters, and am perfectly ok with any good soft dome. Most likely speaker substitute would be either Golden Ear (which I have auditioned - they are awesome and awesomely expensive) or Emotiva (which I have not heard) - both have good reviews. I have also heard Martin Logan Motion 60XT, but was underwhelmed (too bright and with cabinet resonance when pushed). 

Any thoughts would be appreciated. Hoping others with ML ESL experience could tell me straight if Denon AVR-X**** just won't deliver, and I need to go speaker shopping. Will be tough giving those up, if that's the case - these electrostatic speakers are truly amazing (even when underpowered).
mwatsme
Keep your Denon AVR-X3000 and use the pre-out jacks on it to drive a high-current power amp. There are several Perreaux 2150B's available now on EBay. 200wpc/8ohms, 400wpc/4ohms. Clipping at 300+wpc and 500+wpc, respectively. Can easily drive any electrostat! I bought one for use with my restored DQ-10's. Typical price around $700. 
Just curious, did you re-run the HT Receiver Setup after inserting the new speakers into the mix? If not, do so to eliminate a potential setup issue causing insufficient power to go to the front L&R main speakers.

If the setup is correct, you can add a high quality power amp, using the HT Receiver pre-outs, as Robert mentioned. Remember, you will need to run the setup program again after inserting the power amp into the mix.
I use a Denon as well, though with much easier to drive speakers. My thought would be an upgrade, perhaps to one of the Anthem or NAD AVRs. They are generally of a higher quality....and cost, of course.
@mwatsme

Your ML Source ESL electrostatic planar are prety awesome and I wouldn’t sell them and get Definitive Technology if I were you. Your ML Source ESL are better but the ML Source impedance is low their nominal impedance is below 6 ohms and its minimal impedance is below 2 ohms. That makes it hard on amplifier and there isn’t a single AVR that will be able to handle such low impedance and thus unable to drive the speakers properly. Upgrading to the top of the line AVR will not do any good.
You will need a good quality amplification (good quality external power amp or integrated amp) in order to do those speakers justice.

I recommend you sell your Denon AVR. Since you like features on the Denon you should highly consider getting a used discontinued Marantz AV8802 preamp surround processor (pre pro) that can be had for less than $2k in used markets. Denon & Marantz are sister company and they share same HDMI boards they have exact same feature sets same GUI, OSD, same setup feature. This Marantz AV8802 pre pro will perform and sound way better than any Denon AVR’s preamp processor section.

And for a five-channel power amp I highly recommend the Rotel RMB-1585 five-channel amp currently retails for $3k but you can find a used one for around $2k in used markets if you can find one. The Rotel RMB-1585 is a spectacular amp and will drive those ML Source ESL with ease and will sound very good very refined very musical and will be a major step up from any AVR’s power amplifier section, including the high end AVRs.

These Marantz AV8802 processor/Rotel RMB-1585 amp combo will elevate the performance of your system to a whole new level.
I ran the Source speakers with a 3311ci (125W) for quite a while and it worked fairly well, no issues at all with volume or quality. It even drove the combined Source + Stage center with no real problems.

Last year, I upgraded to the X6400H and it made a HUGE difference. The monolith discrete amp design does a fairly decent job even with the smaller panel MLs. More importantly the DACs, power supply, overall build quality/design put it in a different league.

For sure using the X3000 as a pre is an option. But be mindful the pre-out quality will be average at best since it’s a mid-range receiver.

All depends on how critical of a listener you are and your budget. You may be happier just getting a higher end receiver first. You will get better and more modern HDMI and processing capabilities, better amps, and far better pre-outs for future use. If that is limiting then get a lower cost external amp.

The Source speakers have small panels so they are MUCH easier to drive than the larger ML panels. The bigger the panel the more importance goes to the amplification and source. When you move up to the bigger panels (like Impression 11A up) you really need an external amp, they are very revealing and will definitely dip below 2ohm on the higher frequencies.

PM if you want to discuss further, I spent a lot of time with the Source speakers, especially with Denon receivers, external amps, and various speaker cables, etc.

UPDATE: @caphill has a good point above - if you have the budget, a AV8802 + external amp will be a far nicer and longer term solution.  The only thing to think about is you will be spending WAY more than the value of your speakers.  FWIW, I upgraded to the ML 11As and in doing so I added a McIntosh mc452 amp.  For the 11A's they were night and day addition.  When I tried them with the Source speakers the difference was marginal at best.  Sure they sounded nicer, just not sure the Source speakers are as demanding as the bigger panels.
Thank you for the replies, and some great ideas. The point of running setup again should have been obvious, and probably would have if I'd had a monitor connected to see the Denon on-screen menu. As it was, we moved into a new house nearly a year ago, and before the HT was unpacked, basement flooded, inspiring many months of work on my part. During that time, purchased the Source speakers and they sat in storage (after a quick connection to be sure they worked). Now the Denon is out of moth balls, but still no monitor connected. Rerunning Audyssey should be the next step, if previous settings are still in effect, the mains are probably set to "small speaker". Also, I was reading in the manual of AVR-X6500H, that impedance is selectable in the menu too, and this is probably true for my X3000 as well.

Also appreciated the idea of using pre-outs to another more capable amp for the Source speakers. This would be a great option, especially if Source's might be upgraded later to larger electrostats. I am fond of their qualities.

Taking it to the next level with Denon's sister Marantz is another good idea. Although, not sure I'm that much of a hobbyist. It opens up another level of upgrade potentials that seem endless. I was looking at Emotiva amps (really like the modular construction), and thinking that might work, then noticed the price of the matching preamp, and thought oops - this game is for enthusiasts with a different budget for such endeavors.
I wouldn’t get the Emotiva amp. Get the Rotel RMB-1585 amp it’s way better than the Emotiva the Rotel RMB-1585 costs more than the Emotiva but it’s way more refined sounding and more capable and competent amplifier than the Emotiva. No comparison.

So a combination of the Marantz AV8802 preamp surround processor and the Rotel RMB-1585 five-channel power amp will make those ML Source sing and do those speakers justice. 
That Rotel RMB-1585 will drive them effortlessly as the ML Source can dip into below 2 ohms. 
Is there a 2-channel version of the Rotel RMB-1585, or another equal performing recommendation for 2 channel? None of the other speakers in the system are as demanding and could run on AVR power.

Unless the Source's are replaced with another set of larger ML panels, and repurposed for surround use... and so begins the never-ending spiral of upgrades.

Seriously though, is there a 2-channel amp recommendation? To be used with Denon X6***-series AVR pre-outs.
Yes there’s a stereo version of the Rotel RMB-1585 called the RB-1582 MK ll currently retails for $1600 new. Basically the same amplifier as the RMB-1585 except it’s two-channel. This amp will pair really well with your ML Source.

Both the RMB-1585 & RB-1582 MK ll have unlimited power reserve and able to drive just about any demanding power hungry speakers out there and they sound excellent for the money. You can never go wrong with Rotel when it comes to amplifiers. They make great gears for the money. When Kal Rubinson of Stereophile reviewed the Rotel RMB-1585 he used the amp to drive his big B&W 800 D2. These B&W 800 D2 are power hungry and require high current clean quality amplification and the Rotel RMB-1585 had no problem driving his B&W 800 D2 and drove them effortlessly.

Rotel also makes its flagship stereo power amp called the RB-1590 retails for $3k new. This is a dual monoural design. This is a monster amp weighing for around 91 pounds. The RMB-1585 five-channel amp is also a monster huge weighs in around 80 pounds. Has 2 oversized main toroidal transformer power supplies, one for the front LR channels and the other is for the center and surround channels. They are great amps for the money and will outperform or sound better than those amps in similar price ranges or even higher.