Im all out of ideas. I concluded it is not my Audiobahn that is screwed. I swapped amps, and guess what? Same thing.

Now, let me tell you the symptoms....

Bass used to hit hard everywhere....

Now, if I play a CD, the bass is almost non-existant...cant hear it at all on rock CDs. (ie Greenday)

Radio is a slight hit.....but not much either.

If I turn up the bass to the max on the headunit to max, then it hits a drop harder, but nothing like it used to.

So what the hell is it....

Cant be the sub, I had it checked out, and it is perfectly fine.

Cant be the RCAs because the signal is obviously going through.

Could it be something on the headunit????

Any help is much appreciated.

 

Dave I don't remember... what HU are you running?

 

Alpine 9807 John.....

I checked to make sure the sub was on (on the headunit)

I wish I had a spare HU to test....It cant be something fried because my sub wouldnt work. It DOES play, just not loud....like muffled. Ive never seen something like this before.

Maybee this will help....

I listened to Greendays basket case on an original CD, nothing but highs.....no bass at all. Later than night, I heard the song on the radio, and there was ok bass (still not full potential, but better than off a cd)....

It seems like something with a crossover or something...

*Note my infinities has nothing to do with this, as they are powered by another amp.

 

actually -- radio stations very often bump up the equalizer on their output for both highs and lows... so, that's probably why it was louder for the radio stations.



Dave -- can you hammer down what your current settings are on the HU? bass, crossover (is there one on the HU?), etc?

also, can you explain to me how you've wired up the amp to sub combo?
when you tested this last time -- did you run the Rubi like i said in the other post?

remind me again -- before this happened, had you changed anything?

i assume you have a meter - what's the resistance load across your sub coils? do you know what it should be?

finally -- do you have a spare set of RCA's try running them over the top and into the amp... you could have 1 bad RCA of 2 and thus be only getting a partial input signal.

and it always could be crossovers -- how are yours set?

 

finally -- do you have a subwoofer output gain control on yours?

and be sure the defeat isn't set to on....

(not sure if you have all these features, i'll need to pull your manual.)

 

Ok....on my alpine....everything is set to 0....except now I cranked it to 7...so that I can head *some* bass.

Nothing really changed....after I installed my TV, it worked fine...the next morning, no bass. (car wasnt driven or anything, after the install, i tested it, and that was it for the night)

The sub, I had checked at circuit city and they told me the sub is 100%. (both coils are fine)

I guess I will try to check with another set of RCAs, but I know that both the RCAs are carrying the signal.

The gains on on 3/4 and the frequency is at about 65hz.

 

and you're going to trust CC to check your coils? i'd still take a meter to your sub real fast...


and you should be able to also take your meter to the RCA's going into the sub and measure a voltage from the center pin to the sleeve.... it should be the same for both.

make sure that the subwoofer level is set at +15 on the HU and wasn't accidentally dialed down when you were fiddling. main knob push, cycle through balance, fader, defeat (should be off), subwoofer. (i'd be willing to be this may be your problem.)

also, try inverting the sub's signal at the HU.

when you put the TV in -- did you touch the sub and/or sub amp at ALL?

is that a DVC sub?

try this -- hold down the 'center' button on the HU to get to the BASS TYPE menu. make sure that's it's set for off.



still reading the manual.

 

Ummmm.... did you happen to move the gain controls at all? You must have disconnected the battery to install the new equipment. So with that said maybe you should try resetting the amp. Pull all the fuses out of the amp itself so that it will reset. Unless you've tried that already.

 

Ok...

CC used a meter...I watched him do it, and both coils were fine. They are fine....cause I can make the sub play pretty loud with the +18db switch on the amp.

The headunit.....
sub at 15, bass type off, bass +7, defeat off.....Pulled 1 rca at a time, and both have signal.

John, when I installed the TV, I didnt even go near the trunk, nor did I disconnect the battery....didnt have to.

Im gonna order another set of RCAs today, and go to my friend's RSX and use his headunit to check it out. If it still doesnt work, well work from there.

I just played with it a little....
and it hits.....but not like it used to....clear/loud.

I put on the +18db, sub at 15, bass at +3 gains at 1/2 , 60hz

It plays ok.......but still, I just dont get it. Damn these car audio gremlins.

Thanks for the help boys.....after I try everything else...Ill ressurect this thread and tell you whats up!

If not....Im just going to buy everything new, and start over.

 

SWAG - did you check the Alpine setting for "loudness"? They call it something else, I can't remember what, but I remember Sony calls it "Xplod" instead of what it really is - a loudness contour.

Loudness is what boosts bass (a lot) and treble (a little) at low volume settings to compensate for our ears' natural insensitivity to lows and highs at low-medium volumes. The thing is, for most HU's any volume setting below about 1/2 way is in the "loudness boost" zone. Since that's where most people listen to music they end up setting their systems to sound "right" with the loudness turned ON.

I wish I could remember what silly term Alpine uses for loudness but I think it's mixed in with the other tone control settings.

.