Sub output volume limitations and the 1124

[duxfan]

I'm finally meeting with success using the 1124 and REW with my four DIY 15" sealed subs!

The only issue with my system is that after setting my input levels to the 1124, running REW, adding the filters and playing with house curves, I only have one issue. Because the two amps I'm using (older Soundcraftsmens) don't have volume/level controls, I am unable to adjust the output (volume level) of the subs.

To rectify this, I have an old crown electronic crossover (that has output levels) I could put in line between the 1124 and my amps but would it be advisable to add another piece of gear in the chain.

Is there anything else I could do to adjust the sub output volume?

[Otto]

Hi there,

Yeah, you need some generic type of preamp. For me, it's best if it's remote controllable so that I can adjust the bass level on the fly, without modifying the input level to the BFD.

If you are going to do your bass managment in your receiver, and the crossover that you want to use for level adjustment can have its filters defeated, then it will most likely work. Just be sure that you aren't using two sets of crossover filters at the same time (one via BM in your receiver and another via the crossover itself). If that's the case, adjust your levels till your heart's content.

I'm using a little remote-controlled preamp called the Chase Technologies RLC-1. It's simple, it adjust volume (and a couple other things like balance and bass and treble, I think; I never touch those), it's remote controlled, and it's relatively cheap. I think I picked mine up for $65 shipped. It's perfect for the problem you have. The only problem with them is that they're a little hard to find. But if you search eBay frequently and Google around, you will be able to find one. It took me a few months, but I found one on Craigslist and the guy agreed to ship it to me. Well worth the wait and the price! And I always credit Wayne A. Pflughaupt for turning me on to that thing. It's just a great little device.

Good luck either way!

[Wayne A. Pflughaupt]

Thanks for the kind words, Otto! Unfortunately I don’t think the Chase is what duxfan is looking for. What he needs a signal booster because his level to the amps is too low. Remember that any pre-amp is basically an attenuator, so the Chase at its maximum level setting will be passing the signal at the same strength it was coming in. Make sense?

Duxfan, I’m not certain if a crossover will actually boost a signal or not, but I think it will. In any event, since you have it, it can’t hurt to try. Naturally, you want to use the low pass output, and set the frequency as high as it will go – which is hopefully quite a bit higher than your receiver’s crossover point.

Naturally, go back and check the basics, like making sure your receiver’s sub level is up high enough.

However, it seems to me that the consumer amps you have should have no problem being driven by a home theater receiver. (Typically when people have problems driving their amps it’s because they’re using professional models which want a hotter incoming signal than some home gear can deliver.) I’m going to hazard a guess that you only used cutting filters on the BFD, which has significantly dropped your output signal level.

I suggest starting over with a re-measure in REW, and this time, before you start equalizing, re-align the Target Level so that it’s at a good mid-way point between your response peaks and valleys or so that it tracks the bulk of your response (if that happens to apply in your situation). This will minimize the amount of cuts that need to be applied, which will give you a hotter signal output to the amps. Boosts of reasonable amounts shouldn’t be a problem if needed, so long as your downstream amps and drivers can handle it. From the looks of your drivers, and from what I recall about those Soundcraftsman amps, that shouldn’t be a problem.

If none of this gets you what you need, get back to us here – there are other remedies we can try.

Regards,
Wayne