BHK Preamp and Subs via RCA outs - do I understand it correctly?


#1

Hi,

I’m currently auditioning a BHK Preamp and using the RCA outputs of it to connect to my SVS SB 2000 powered subwoofer. The current setup is: DS Jr. — xlr — BHK Preamp — xlr — M700 amps.

My questions are:

  1. Since I’m using the RCA outs on the Preamp, they are affected by the volume knob setting of it right?
  2. If so, then should I set the volume control of my powered subwoofer in turn to 100%?

Thanks in advance!

-JJ


#2

I am a little unclear about your question. Are you asking if the RCA outputs on the BHK preamp go up and down with the BHK preamp’s volume control? If so, the answer is yes.

The subwoofer’s level should be adjusted so the sub sounds properly balanced with the main speakers. Rarely that would be set to 100. Once set for best sound the BHK preamp volume will go up and down in accordance with your control of it via the
front panel.


#3

Hey Paul, Yep. You’ve understood and answered my question. :smile:

Thanks!


#4

It’s a morning miracle! Than ks for letting me know.


#5

Hi Paul. I have my subwoofers on the same configuration as well with the OP. My question is, would it be better to run a ‘Y’ XLR adaptor to the subwoofers if they accept XLR input from the BHK preamp so it’s on the same balanced circuit, or would there be a sonic difference at all? I figure that the XLR has more voltage going out than the RCA out from the preamp, but realize that the level of the subwoofer gain would compensate for that.


#6

Yes, the only advantage I see from the splitter would be to balance the load on the BHK preamp - which frankly doesn’t matter a lot. I do something similar on Arnie Nudell’s reference system using a Y-splitter for the XLR outs on the BHK because I just like
everything balanced. I am not sure it actually matters.


#7

I also used to have my subs (MartinLogan Depth-i) connected via the single-ended outputs from my BHK Pre, and a few months ago, just as an experiment, I decided to try connecting them using their speaker level inputs. If your sub has speaker level inputs, I would HIGHLY recommend trying them out as an alternative to using a line level signal from the preamp. I’ll never switch back…


#8

What are you main speakers moburns92? Do you then use the variable crossover setting and dial it into your room?
Thanks


#9

My main speakers are MartinLogan Prodigy’s, and I still run them full range. I don’t use the speaker level crossovers in my subs…they are essentially just connected in parallel to the Prodigy’s.

One of the things I struggled with for years was getting the subs to “track” properly when changing volume. In other words, I never felt that the bass was optimal at all volume settings, meaning I had to set up the subs the way I liked them for the volume at which I normally listen, but then they were a little “light” at lower volumes, and slightly boomy at higher volumes. Using the speaker level inputs, I don’t hear that issue, and I get what I consider appropriate bass response at any listening level.

Also, even though Paul said that the additional “loading” of the preamp from the interconnect driving the subs “shouldn’t” matter, in theory it still does present a different load impedance to the preamp. My general thought would be that the output of the preamp would be more sensitive to changes in load impedance than the output of my power amp (Krell FPB-200), so relieving the preamp of having to drive a long single-ended interconnect cable to a subwoofer should be a good thing…

I know Paul has written about using speaker level inputs for subwoofers as the preferred method, I just don’t know where I read it.:thinking::thinking: