Hi!
My car-audio setup: The empeg's front outputs feed a four channel amplifier for the front and rear speakers, the empeg's rear outputs feed an mono amplifier for the subwoofer. I control the bass volume with the empeg fader. Normally I have the fader set nearly to "front-only", and if I sometimes want more bass, I change the fader towards it's centered position.
The only problem is that there are only a few steps to adjust the volume of the sub; the "fader-resolution" is a bit low. Since I never change the fader beyond the centered postion towards rear (this would decrease my front & rear volume), I would need a "sub-fader" which only changes the rear output with a higher resolution than the normal fader. Would it be easy to implement this in software or with hijack?

cheers,
thorsten

So I look at the thread title and think how's he going to control a fish? I need more coffee.
-Zeke
Bass.

Better now?

Have you considered something more direct, such as a subwoofer amp that includes a remote gain control, or putting an inline stereo attenuator on the RCA's to the subwoofer amp? If you do that, you can (potentially) wire it so that you get your front/rear fader back. (As illustrated).

In the meantime, have you tried:

- Adjust your subwoofer's gain down a bit, and put your fader in the center as the "normal" position. That way, when you adjust the balance between fronts and sub, it's smoother because you're not suddenly "turning the sub on", but rather just decreasing the fronts a bit.

- Use the Hijack bass control and the player's loudness control to alter the amount of low frequency without altering the fade (only works if you've put the fader in the center).

I've found that using Loudness is the best way to add kick to those songs that need it. It uses a special algorithm to increase the lower frequencies without distorting the upper ones. It is better than just Bass control or the fader because it "does the right thing" if you are trying to get more kick out of your subs. Adjusting the EQ and Bass is intended to be a 'set and forget' thing... The EQ tries to make your car sound good at all frequencies and the Bass for adjusting the song to match what you think it should sound like (i.e. it was mastered wrong for your car).

I used to use the fader to do exactly what you were doing untill I got used to playing with the Loudness (and found the gain sweet-spot on Sub-amp). Besides, Loudness just a single long-knob-press away with Hijack.

Adjusting the gain on a sub-amp is strange because you think you want it 'as high as possible' so you can get as much bang for your buck... but in reality, you want to adjust it so it matches the rest of your system. So when you adjust the volume, the sub adjusts at the same rate (i.e. acceptable bump at high volumes, and loud enough so it is still around at low volumes). By having the fader all the way forward, you are attenuating the signal as much as possible (i.e. as close to negative (-)infinity). Everything to do with sound is logarithmic; the fader attenuation is doing it's best to make useful adustable steps, but the steps will always be more extreme (and inaccurate) at the maximum setting.

You could also use the EQ (in 4 channel mode) to adjust the subwoofer 'gain'. ( FAQ ) You are probably already doing something like that anyway. If not, you should seriously consider remapping the Q values (basically, the steps that the EQ sees) so you can tune the low frequencies to the characteristics of your Sub+enclosure. Otherwise, you can adjust the fronts (= all normal speakers) down (-) by a few db so the dynamic range for the sub is 'more' than the rest of the system.

The philosophy behind sound calibration is to attenuate as little as possible because it is never perfect (or linear - the same across all frequencies and amplifications). Never amplify (+ EQ) if you can avoid it, always Attenuate (- EQ)

But, if you can, Tony's suggestions about adjusting the gain on the sub-amp is "the right way" to do it.

It uses a special algorithm to increase the lower frequencies without distorting the upper ones. It is better than just Bass control or the fader because it "does the right thing" if you are trying to get more kick out of your subs.

It's probably a lot simpler than you're making it out to be.

It's merely a bass boost that lessens as you turn up the volume. Its purpose is to compensate for the fact that low frequencies seem to get lost most easily when the stereo is played quietly.

One of my dreams is to one day be able to adjust its parameters on the empeg. Right now, it's not "doing the right thing" in my setup. Its boost frequency is too low for my system (makes the sub work too hard in the super-low frequencies without really properly compensating for the loss of perceived bass in the 100-300hz range), and its ramp cutoff positions aren't where I'd want them to be (too much bass boost when volume is cranked very loud). So I end up not really using it on my system. But I understand that it works great for others, so there you go.