I recently upgraded the audio system in my XB and I'm left with a few things that don't make much sense to me.

I have the following components:

Jensen VM9021TS headunit
Total Mobile Audio T250.1 monoblock
Total Mobile Audio T320.4 4-channel amp
Total Mobile Audio T6.5SC2 6.5" 2-way components
Scoshe 10" XB rear cargo sub
Stock rear speakers

I did not install this system, I had it installed where I purchased all the TMA components. My problems are as follows:

1. All of the speakers are at different relative volumes. This is most noticable and irritating at lower volumes. Usually the components will be louder than the rears which is louder than the sub.

2. The tweeters are incredibly loud and bright while the 6.5" get bloated with moderate/high bass/volume levels.

Here's part of what confuses me. The components have a their own crossover. The amp they're plugged into has its own crossover. Also, the amp has a switch for hi-pass, flat or low pass and the corresponding hi-pass/low-pass selectable frequencies. When messing around with it, it sounds like channels 1 & 2 are powering the components and 3 & 4 are running the stock rears.

Basically, I'd just like to level out the signals for all the speakers and smooth out the top end with giving the midrange more punch and fullness. If I could accomplish this without having to really crank the system (like I do now) that would be the ultimate goal.

Any thoughts? Thanks!

 

I'd suggest:

turning gains all the way down on your 4channel amp... then put in some music and turn the HU to the highest volume you ever listen to it at. Slowly turn the gains up untill you hear distortion and then turn the gains back a little bit... repeat this for all gains on the 4 channel amp...

after that, do the same for the sub but just turn it untill it's balanced with the other speakers w/o distorting the sub.

I'd say that'll probably do what you're wanting..

 

I agree with SCI_TC_GUY here. This is the best way to go about balancing your amp's outputs to maximize your listening experience. Since your components have their own passive X-overs, set their X-over settings for their particular channels to FULL, or set the High-Pass frequency fairly low, like 80Hz or so. This will allow the comp's passive X-Over setup to do its job while offering the full capability of the comps during tuning. After you have your gains set appropriately, you can go back and fine tune the amp's X-Over frequencies to suit your needs. This may even allow for minor adjustments of the comp's amp channel gains up a minor amount. As for the stock rears, you will want to have their channels' X-Over set to High-Pass with the frequency set a bit higher (150Hz+) than the comps as they do NOT have the same luxury of a specificly designed passive X-Over. Set the gains appropriately to balance the output of the front comps to your liking. You can then go back and fine tune the X-Over frequency of the stockers to best suit your needs. Again, playing with the X-Over frequency may require a small adjustment of the gain to best balance the mix. Finally, set the X-Over for the sub to Low-Pass, with a frequency setting <120Hz. Now you can adjust your gains accordingly for the sub to balance the rest of the mix. You may be able to adjust the X-Over frequency a bit to accomodate your liking.
Remember, fine tuning your system may take some time to get everything set exactly the way you want it. Often, it is a trial and error process that may take several adjustments to get to your perfection.

 

Thanks for the suggestions and help! When I turn the gain for the 4 channel amp down all the way to off I can still hear both the front and the rear speakers playing at a low volume. Not low like I have to strain to hear it, just low like; well turned down.

Shouldn't there be absolutely NO sound coming from ANY of the speakers when the amps are at 0 gain?

 

The guys here are pretty much right on target but I'll add what I feel to be some more worthwhile info. One of the keys to having a good sounding system is to know what a good sounding system sounds like. That sounds silly but it's fundamental to the sucess of your audio system. There are many different ways to accomplish this but my favorite is listening to live music, preferably acoustic. A symphony is a great example but it can be anything. Once you have a good frame of reference you're ready to proceed.
1. My first step is to establish my maximum levels. I do this by taking a very dynamic recording and turn the volume to approximately 90% of the maximum on my source unit to allow close to maximum signal voltage and still have a little leeway if the recording is very low.
2. As tC said slowly adjust the gain from it's minimum position until you just reach the threshold of distortion and back off just a bit.
3. I mark the amp and the **** with a Sharpie to provide a visual reference. I normally start with the subwoofer first and once I have the levels set I disconnect the RCA's.
4. Then I would plug in the RCA's for the midranges and do the same. If you have seperately amplified tweeters now is the time do disconnect the midrange RCA's and hook up the ones for the tweeters.
5. Now that the maximum levels are set you're ready to tune. Take well recorded material that you're familiar with (try Sheffield Labs for CD's) and listen to it at a modest volume (90-95db). I normally don't mess with the level of the subwoofer. What I do is to implement some sort of subwoofer volume control, either using the subwoofer preout volume control on the deck, remote level adjustment on the amp, or remote level adjustment on the RCA cables (like the http://www.autosound2000.com N22V). That way if I want more bass I can have it and if I'm in a rough area of town I can easily turn it down.
6. If you are using seperate amps for mids and tweeters it's easier to make the levels match. If you are (and I believe you are) using the same channels for the mids and tweeters you may want to consider an external equalizer. Check out Audio Control and Phoenix Gold. Look for at least 13 bands. When adjusting an EQ start with the levels that are too high and cut instead of boosting bands that are too low as that can increase the likelihood of distortion.
7. Listen, Listen, Listen. Then realize the more you listen the more you will tune. Mark

 

One more thing...disconnect the rear stock speakers. They suck and you don't need them. Mark

EDIT- I forgot to mention that with your four channel amp you could purchase an external 3-Way crossover to adjust the crossover points and levels of all your amps/speakers very easily. If you can find an old MTX LSX2 that would be an awesome way to go. Mark

 

All your gain does, is tell the amplifier how much it needs to amplify the incoming signal in order to obtain the maximum RMS wattage to send to the speakers. If you have an 8v RCA (a relatively high voltage for RCA's) coming from your deck, for example, the amplifier will not have to amplify that signal as much in order to obtain the RMS wattage, therefore the gain will be set very low depending on its range. If the gain range on the amp is from 8V to 1V, the gain would be set at its lowest point or very close to it. If you had a very weak signal (say, 1V RCA's) then the gain would be turned all the way up. But in both these applications, the sound would be almost exactly the same.

 

Very well put. The situation where the gain is all the way down and you can still hear the speakers isn't a bad thing. Just adjust the deck to near it's maximum level and start tweaking. That probably means your deck has a healthy preout voltage and your gain will be quite low, reducing the chance of noise. That's a good thing! Mark