Phono Stage upgrade to complement Dohmann Helix One Mk 2

As I mentioned, I've never used subwoofers before.  Based on limited reading, it seems that there are multiple approaches to connecting the subwoofers to a system.  (e.g.   All subwoofers have at least an RCA input for line level connection from your preamp or variable output on your amplifier. Do not use the record or tape output! These are fixed and you will have maximum bass at all times no matter what your main volume is set at! Some subwoofers have left and right inputs. If your preamp has left and right outputs, use two RCA cables for these. The subwoofer combines the channels inside. If your preamp has left and right outputs but there’s only one on the sub, use a Y combiner adapter. These can be had for $5 or so. Lastly, if you don’t have a subwoofer or preamp output on your amp or preamp, subwoofers such as the RELs we sell have a specific high level input which runs off your amplifier’s speaker binding posts. This cable simply piggybacks on your main speakers and does not draw any power from your amp. In this way, no matter what your system is, there’s a sub for you. )

Is there a "best" approach for monoblock amplifiers with two sets of binding posts?

Lew, the high pass is made it at the input of my amps ( cap/resistor ) the low pass is made it by the Velodyne electronics. Maybe you can do the  same or look for a second hand Bryston croosver.

In the link I just posted you can read about 12"/15" drivers characteristics inside the same catalog models.

After last week’s talk about a system I find ^this^ humerous.

 Lastly, if you don’t have a subwoofer or preamp output on your amp or preamp, subwoofers such as the RELs we sell have a specific high level input which runs off your amplifier’s speaker binding posts.

There is a certain simplicity and elegance in running the sub input off of the speaker’s binding posts. Not sure if it is just REL and Vandersteen, or if there are others as well.

Is there a "best" approach for monoblock amplifiers with two sets of binding posts?

I’m not sure I understandI?

I am guessing that the speakers have bi-wire posts?
So it sort of depends on whether you 4 sets of wire pairs, or a bundled bi-wire and whether it is a single end at the amp, or if there are two set of ends… and whether they can splay wide enough to hit both sets of outputs.

Thanks for the info, Raul.  You remind me that long ago I did consider just adding a capacitor in series with the input of my main amplifier, to create a Butterworth type hi-pass filter.  That still seems the least harmful way to do it. I calculated a .02uF capacitor (or two per channel for my balanced amplifiers) would do the trick for my amps, with an 80Hz flex point.

Holmz, I am no fan of the REL approach, for the reason that if you drive the subwoofer off the main amplifier output, then neither the main amplifier nor the main speaker derives any benefit in terms of reducing the workload inherent to reproducing the lowest bass frequencies. Moreover, any distortion in the output of the main amplifier is presented to the REL subwoofer amplifier at its input. Unfortunately, I long ago concluded that you cannot obtain all the major benefits of subwoofing unless you're willing to add a high pass filter on the main amplifier.

Holmz, was that "humerus" or "humorous"?  And why did you find it humorous?

@lewm

I suppose this means that your preferred approach would be to use both the XLR and RCA outputs from the pre-amplifier: one set for the monoblock amplifiers, and one set for the subwoofer.

If that’s the case, then it seems like my pre-amplifier would need a low pass and high pass cut off for the speakers to receive their proper signal and the subwoofers to receive their proper signal. Of course, another option would be to run the pre-amplifier signal through the subwoofer, which would be designed with low pass and high pass filters, and that signal would then pass to the amplifier to the ESL speakers. But I would think that this latter approach could degrade the signal going into the amplifier and ESL’s. It might be a no-win situation. . .

Holmz, I am no fan of the REL approach, for the reason that if you drive the subwoofer off the main amplifier output, then neither the main amplifier nor the main speaker derives any benefit in terms of reducing the workload inherent to reproducing the lowest bass frequencies.

Well I am not sure what the REL approach is other than reading @Rauls words that it derives the input from line level rather than RCAs or XLRs. So it sounded like the it was similar to a Vandersteen, however the manual is a bit light light on specifics… other than that there are the speaker inputs.
But whether the main amp to speakers are high pass filtered did not pop out.
It was 30 pages and i skimmed it, so maybe I missed it… but it does seem like it is not the same as how the Vandy unit works. That unit HPF the main speakers, and then the sub rebuilds the bass back up to where it should have been without a HPF going to the main speakers.

Moreover, any distortion in the output of the main amplifier is presented to the REL subwoofer amplifier at its input. Unfortunately, I long ago concluded that you cannot obtain all the major benefits of subwoofing unless you’re willing to add a high pass filter on the main amplifier.

Well that is what I posted a while ago, and it was a high pass filter to derive that benefit that you point out.
Then the sub rebuilds the signal back to where it should be at.

One can roll their own capacitor, or use a host of HPF to do that at various price points from a capacitor to a Harrison labs one at $50 to ones at kilo$...

Holmz, was that "humerus" or "humorous"? And why did you find it humorous?

I read too much Homer in my youth, as I had a great 7th and 8th grade literature teacher. And hence the spell checker is Greek to me.