Final-Audio New Series electrostatics

@madtrader Arcing is one of the common problems with electrostatic speakers and modern designs, including Final Audio, typically include various protective measures to prevent that.  In the case of my M35s one of those protections is a fast blow fuse that is designed to blow when the speaker is being overdriven.  Unfortunately, my M35 was shipped with the wrong fuse.  Instead of the 1 amp fuse that apparently went into subsequent speakers, my speaker had a 3.15 amp fuse that permitted me to overdrive the speaker.  I only experienced arcing on two tracks played well above my normal listening levels and that was when I had the incorrect fuse installed.  Final has told me it shouldn't be a problem now that I am using a 1 amp fuse.  I generally listen around 75-85 dBC and at those levels I have never had a problem with arcing.  And I occasionally listen with peaks going into the mid 90's without any issue.  But if you are trying to achieve truly deafening levels I suspect no electrostatic speaker would be the ideal choice.  At Axpona two years ago I was listening to the $250K Borresen speakers after hours and they cranked those up to 105 dBC on a sustained level.  That was impressive but also fairly painful and I would never recommend listening at those levels LOL.

Unfortunately people do not really understand that electrostatic speakers are very different than boxes with dynamic drivers in one critical area. That is the level of detail that an electrostatic can produce can be done at much lower listening levels (high efficiency horns being an exception). It’s not uncommon for people to try to drive ESLs as hard as they may drive  dynamic drivers given those dynamic drivers need the power to produce the same level of detail. That’s a recipe for disaster whether the ESL has a protection circuit or not.

The original Quad ESL was limited to a 35V maximum, but I have experienced many trying to drive them with amplifiers with much higher voltage ratings. The original Quad II designed for the ESLs was rated at 17 watts per channel. The Music Reference RM-10 was double that but met the 35V demand the bass panels would tolerate before arcing. It just so happened that Roger Modjeski owned Quad ESLs and so had the opportunity to  research the effects his amplifier had with these speakers. Building an amp that worked well with his Quads was not his intent, but he got lucky (the amp was built to work well with Vandersteen 2s, a dynamic driver speaker). Fused, clamp boards, what have you in terms of protection, what is important is understanding how the ESL speaker can best be driven to provide the best sound and what type of amplification and sound levels are required to do that. 

@clio09 I agree that the M35s don't need to be played as loud as my Magnepan 20.7s in order to open up, but that doesn't mean that they don't sound good at higher volumes or can't play loud.

I think you need to be careful extrapolating from the older technology in brands like Quad or Soundlab or Martin Logan when you are talking about Final or Popori speakers.  Both of those brands have been specifically designed to overcome the limitations in dynamics, frequency response, and dispersion that have historically been a problem with electrostatics.  All you need to do is look underneath the socks on new Quads or Soundlab to see that they are fundamentally the same technology that was used 30 or 40 years ago.  And Martin Logan continues to rely on curved panels to widen the sweet spot.and woofers to extend the bass response.

@pinwa I think you misunderstood my post but no problem. Personally, new technology or old, my interest is ultimately how it sounds. For Quad and Sound Lab, if something is working well why change it. For those developing new methods of designing ESLs that's great, but to the point @pindac made, these speakers cost quite a bit more, so the new technology should deliver the equivalent value to cost ratio and be reliable designs.

Both my ESLs can be played louder than my room can handle. I have heard lots of ESLs and I just prefer my Quads, their limitations and all. My other set is based on older technology with a few new twists. The biggest difference though is using direct drive amplifiers. Why none of the newer ESL manufacturers are designing their speakers to be used with direct drive amps is something I am curious about.

Many of the current FINAL owners in the US market are introverted and not particularly active on the forums unlike some of us!

I'm very introverted, but this thread drew me out.

Arcing is one of the common problems with electrostatic speakers and modern designs, including Final Audio, typically include various protective measures to prevent that.

I know what arcing is. I've heard of it happening to folks, but I've never experienced with Acoustats in the 40+ years I've been around them.

I generally listen around 75-85 dBC and at those levels I have never had a problem with arcing.

That's where I listen too, maybe even a touch higher than I do.

And I occasionally listen with peaks going into the mid 90's without any issue.

Another anecdote. Last year seemed to be Chicago themed for me. I'd never been and then I had 5 trips. On one of those I managed to catch a Chicago Symphony Orchestra (CSO) performance at their hall downtown. It was marvelous. It turns out there is a recording of one of the pieces they played by the CSO in that hall decades ago (so likely not the same players, and conductor). So I queued it up at home and listened. First of all, In the hall was louder than I prefer, but to try and see if my system could do it justice I cranked the volume up to where I thought it matched what I heard in the hall. This was with my Acoustat Monitors (4 panel speakers) driven by some heavily modified direct drive servo amps. It was very close. I think the imaging in my room was a little fuzzier than what I experienced in the hall. It still imaged, but I think I was able to pick out placement a bit better in the hall (of course maybe it helped that I could actually see the players). Everything else was there. I had the dynamics, the tonality, the volume, the detail. I was very happy. But, I've now moved and that room is gone. I'm starting over from scratch on the setup.

I have heard lots of ESLs and I just prefer my Quads

I was in the same camp with my Acoustats, even though the different models also sound different. My 4 panel Acoustats sound warmer than my 3 panel Acoustats. My Spectra series Acoustats have higher frequency extension (at least with strong enough amps) and better imaging than my non-Spectra series Acoustats. I think the key thing to take away there is for folks to keep in mind that specific implementation is just as important as fundamental theory of operation. We can't completely generalize away all electrostats as sounding the same or even having the same capabilities. Value is then at least one more step away from that. If you value midrange, and someone else values top end sparkle, you're going to come to different conclusions on which electrostat is any good. I think of Acoustats as a hell of a deal, but that's in-part because they're 30+ year old gear and the manufacturer is gone. If you get ahold of set now, it's likely you're not the second owner, but the fourth (or more). I'm happy we have a diversity of brands and offerings actually on the market. I will continue playing with my Acoustat gear, but I've bought into Final to see if they're "spiritual" successor to what Acoustat was in the marketplace. I anxiously await hearing Popori as well.

Why none of the newer ESL manufacturers are designing their speakers to be used with direct drive amps is something I am curious about.

I think Acoustat serves as a warning. They did that with their first models. The marketplace wasn't so accommodating. Audiophiles want to bring their own gear. They want mix and match to their preferences. At best you treat them like active speakers and traditionally those haven't sold as well to audiophiles. Acceptance of large speakers isn't high so we're a niche of a niche. If you need to sell well enough to be a viable company you need to work in terms of what the market expects to be able to do.

Twinstatic Audio in the Netherlands can build such an amplifier to be used with Final, which is an option I was looking into.

I'm actually quite keen to see if we could do some direct-drive on the Finals. It's my understanding that Twinstatic's amplifiers are highly modified Acoustat designs, but I've seen so very little discussion on them over the years. Their page mentioning Finals predates these new models in Final's re-introduction to the US market, so I don't know how different these new speakers configuration is from the old Finals. Is that still something the Twinstatic amps could be configured to drive? If so could some of the Acoustat direct drive amps be reconfigured to do the same and how hard would it be? I know there have been folks use them to drive other ESLs. I've even talked to a guy that used a modified SoundLab interface on his Acoustats.