Rotary Subwoofer Install Blog

September 30, 2006

Lexicon MC12B RCA outs – not good for low bass

Filed under: Uncategorized — bassment @ 12:33 pm

A tip for all you bass hounds… the RCA out LFE cuts off around 10Hz, but the XLR LFE out goes practically down to DC.

We noticed this because the current TRW amp sports an RCA in and we saw much less output below 10Hz than the BAAS demo. I went to Guitar Center and got an XLR to RCA adapter cable, then took XLR LFE from the MC12B to the TRW amp, and all the 0-10Hz reappeared.

But it is quite cool that the MC12B does give the FULL spectrum in it’s surround processing… thank you dearly Mr Lexicon… you did the right thing damn it!

Also, I can confirm that the Crown K2 amp cuts off at 10Hz, just like it’s spec says… we were testing the Wilson XS below 20Hz, and the amp wouldn’t let us go below 10Hz. BTW, the XS does a more than impressive job below 20Hz, down to 10Hz… I would not have guessed it could reach the SPL’s it did… it is quite a respectable piece of subwoofer.  Respect out to Dave Wilson, once again.


  1. Ok, the crown shutting off would be so that it does not blow itself up. feedback goes in both directions repeating by the octave and drawing successively more energy as it goes down the spectrum… providing a frequency cutoff is a wise idea in amp design… although it sucks for your needs. you might want to look for a slightly older carver, those SOB’s were like armored tanks. QSC might do it as well.

    Comment by Chris — September 30, 2006 @ 10:27 pm

  2. Oh and tony… you are one sick SOB with your obsession for bass. But it is cool. i cannot wait to hear the final result. There is some music that must be really cool with the added infrasonics.

    Comment by Chris — September 30, 2006 @ 10:29 pm

  3. The Krell FPB MCx line of amps do not appear to cutoff at all, fwiw. Also off the shelf cheap $200 integrated stereo amps from Fry’s were also shown not to cutoff. So, some do, some don’t.

    Comment by bassment — October 1, 2006 @ 7:08 am

RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Create a free website or blog at

%d bloggers like this: