Phono Stage upgrade to complement Dohmann Helix One Mk 2

@lewm , quite correct. You have to factor in the weight of the cartridge. The single best way to do that is by measurement. If the resonance frequency is off, too high, mass can always be added. This is the advantage of having an arm on the light side. It is much harder to remove mass from a heavy arm. The Schroder arms have cartridge mounting plates of three masses and counterweights of three sizes. They can be adjusted for just about any cartridge. 

@drbond, the CH is a fine phono stage. It is not the Channel D Seta L20. I have a naturally aspirated 911, a Speed Yellow C4S.  You only drive around at 40 mph. I prefer 100 mph. Above that in New Hampshire is classified as reckless driving which takes speeding to a whole other level legally. You would still benefit from a proper subwoofer array, just not as much as someone who listens to Metallica at 100 dB. It is not just the added bass but the lower distortion everywhere else. Any bass note in a full range speaker is going to Doppler distort everything else the driver is trying to reproduce. If you can see the diaphragm moving it is Doppler distorting all other frequencies. I have observed naked ESRs on numerous occasions. You can see diaphragm excursions up to about 100 Hz. Which is where I cross over to subs. Even at 100 dB you can not see my diaphragms move. The difference in sound quality is exceptional. 

Where do you live? 

Or you can come to my house and hear great bass response from a pair of 845PXs with no subwoofers. ESLs don’t “hate” bass. They are hampered by diaphragm to stator spacing, bias voltage, panel size, and phase cancellation. And by amplifiers.

@mijostyn @lewm 

So, it sounds like all three of us have SoundLab ESL's!  That's quite unusual.  Insofar as bass in SoundLabs is concerned, I would have to agree with @lewm .  I've had the Atma-Sphere MA-2's hooked up to my speakers, and while the sound is quite pure, and the mid-range is perfect, they do have difficulty producing bass in the speakers.  It seems that the SoundLabs perform very well without subwoofers with my amplifier.  But, it appears we are veering off topic. . . 

Unfortunately, we live in opposite poles of the country, as I'm in Florida, so I don't know that we'll be able to compare components easily.  

@mijostyn 

Does that track for resonance frequency on the Test LP inform you which frequency is being played; if not, how is it determined which frequency the stylus is vibrating to? 
Thanks. 

@drbond , Yes of course. It announces every frequency as it goes down and has two tracks, one for vertical resonance and the other horizontal.

I do not have to worry about MA2’s making bass. I cross to subs digitally at 100 hz, 48 dB/oct. It is not about bass. It is about distortion and realistic volume levels. If you play a Bill Evans record, say Waltz for Debby at the volume the music had that night at the Village Vanguard, without subwoofers the SoundLabs will crap  a brick regardless of what amp you are using to drive them.

I am down in Florida all the time. My sister lives just north of Miami and my step mother just south of Miami. You never come to New England? You need to come up the second week in October and see the colors. In Florida all you have is endless flatness, a few palm trees and hurricanes not to mention DisneyLand.

"If you play a Bill Evans record, say Waltz for Debby at the volume the music had that night at the Village Vanguard, without subwoofers the SoundLabs will crap  a brick regardless of what amp you are using to drive them."

With all respect, this is just wrong. Even though I am sick of "Waltz for Debby", though never sick of Bill Evans. And while I am sure there may be a rendition of WfD on one of the live VV performance albums (I’d have to check), he also recorded it in at least one studio session. Here’s where I debate whether to bring up the modification I made to the SL crossover that improved both efficiency and the impedance curve to suit our OTL amplifiers. The 845PX can reproduce the lowest frequencies of the bass player (Paul Motian?) on WfD at very satisfying SPLs. What it cannot do is blast you out of your seat on a hard rock recording, which I am sure Mijo’s subwoofers CAN do. And my Atma OTLs are more like MA1s than MA2s in terms of power output. (They are neither, use type 7241 triodes as output tubes on MA2 chassis’ using MA2 power transformers.)