Help! Subwoofer Newbie Problems!


Folks,

I’m new to subwoofers (having usually hated subwoofer set-ups almost anywhere I heard them).

However, I’m trying to downsize a bit from my Thiel 3.7s to the smaller 2.7s, and I’m trying out a couple JL Audio E-Sub e110 subwoofers with the 2.7s.

I have very little time to evaluate them before deciding to send back for a refund, so it’s a quick and dirty set up, just to see if I hear anything promising.

I’m using Conrad Johnson Premier 12 140W/side tube monoblocks, and the CJ Premier 16LS2 tube preamp.

I want to at least first try running the speakers full range and crossing the subs over at a lower crossover. So I’ve started by running speaker wire from the Thiel’s speaker terminals back to the subs high inputs. This is the way REL subs are usually set up IIRC.

First results (after dialing them in a bit), is that, yup, there’s subwoofers in the system. Lower lows. But it’s also really changed the sound. The good part is that the sound seems more spacious, rich and 3 dimensional. In that respect, they start competing with the larger 3.7s. However, there’s also obvious tonal change - the system now sounds a bit rolled off, darker, more full and lush in the mids, but also distinctly softer with transients being softened. It looses the energy factor.

I’m wondering what accounts for this tonal change. The subs are active, and so as I understand it, having them share the speaker terminals with my Thiels shouldn’t be drawing anything more from my CJ amps and making them work harder or anything. So...what gives?

To try and check this out, I’ve just received long RCA interconnects to try connecting the subs via my pre-amp outputs instead. This gets me into confused newbie territory.

My CJ Premier 16LS2 pre-amp has two sets of outputs. I have presumed that I just keep one outputs sending to my CJ amps as I normally do, and simply run the L/R signal of the second pair of outputs to the subwoofer RCA inputs (making one sub L and one sub R).

Problem is: I don’t seem to be getting any sound out of the subwoofer this way! If I use the speaker line high level inputs from my Thiel speaker terminals, I clearly get the subwoofers working. When I unplug those and send the line from my CJ pre-amps second outputs....nothing.

Any advice?
prof
Yeah, I better check that my CJ is actually putting out sound from both sets of main outputs.

The preamp SHOULD be putting out signal from both outputs simultaneously, shouldn't it, so both outputs can be used at the same time?  (I don't see why there would be two sets of outputs otherwise).
Yes it should. You can swap the outputs to verify it. Are you sure there is no switch to activate the second output?

I have swapped the outputs and verifed both sets of main outputs on the CJ preamp are working.  I also tried L signal from one set of outputs and R signal from the other, to verify the amp sends a signal to both outputs at the same time.

I'm therefore baffled as to why I'm not getting subwoofer levels when I send to the JL subs!
Are you sure that the IC’s going into the subs are good? Are you sure that they are going to the input and not the output of the sub? If all checks okay then the sub is the culprit! BTW, try using one sub and see if that works!
Make sure the sub is not set in Slave Mode, (not sure about the e110, I have F112's) what do you have the crossover set at on the subs? Does it have a reference and variable switch?
? Are you using the phase switch?

How far away are the subs from the mains?