I have a problem with my current setup.

I am running
Alpine 9815
Rockford P5002 amp bridge
Rockford P2S108 sub in a sealed enclosure to specs

Now i dont know why and how bad this is for the subwoofer, but i have music coming out of the subwoofer. The filter is set to Lowpass i think. I have the SUBpreout going to the amp. Is this bad? How do i fix this problem?

I am thinking about taking my car to tweeter sooner or later and getting it all tuned so it sounds good. I also do not know how to use a lot of the functions of the stereo. Like time correction, frequencies, and don't know too much about the crossover function. Anyways thanks.

Nesar

 

what is the lowpass set at? you will likely have to turn it down, but to be totally technical, you should have music coming out of your sub :D

 

if its set on low-pass you really shouldn't have to many words coming out. make sure it is on low pass and set the frequency at 80-100hz. also the pre-out doesnt really matter the amps cross-over will take care of it.

 

The sub woofer output must be turned on, I assume you do not have the owners manual, so go to http://www.alpine.com click on support, then on owners manuals/wiring diagrams then on "continue without login" then type in CDA-9815 in the quick search box, then download the owners manual.

You have a very sophisticated HU, [I have an earlier version of it] you will be amazed at the SQ and control the HU gives you, but there are many things that have to work together to get that good SQ, it's not just bass/treble and maybe a few preset EQ curves, everything is adjustable and getting the adjustments right is not easy if you don't know how they work and what they do, read i-Personalize very handy 94

 

subwoofer output is on. Thanks.

 

What is the LP x-over set at? 94

 

lol umm i don know. I have to figure that out. I did as you said though and looked at the manual. It looks like its hard to setup the time correction and what not.

 

It's not. The only "hard" part about time correction is trying to hold a tape measure to your head and your speakers w/out help.

Set the sub to 100, the mids to 160, and work your way from there.

As for "wide", maybe someone can explain that to me cuz I don't know. Also explain slope maybe? Or I guess I could research it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Liquidgsr &raquo;</TD></TR><TR><TD CLASS="quote">lol umm i don know. I have to figure that out. I did as you said though and looked at the manual. It looks like its hard to setup the time correction and what not.</TD></TR></TABLE> Did you read the part about "i-Personalize" and read this... http://i-personalize.alpine.com/nam/index.html 94

 

yeah thanks its helping a lot. Only thing i don't understand is how i know what to set my DBs at also the Hz...my speaker specs are 30hz-35khz for the front.

 

The "Hz" or in this case, high-pass x-over point is picked by what the speakers will do, or what you want them to do, if you are running a 2way system, [HP/LP high-pass/low-pass] full range speakers and a sub(s) then you will divide up the frequencies into 2 groups H/P for the front speakers and rear speakers, [if you have them] and L/P for the sub woofer. Everything, [frequencies] above the H/P x-over point you pick, [also called lower cut] will go to the speakers, [front and rear] and everything below the L/P x-over point you pick, [also called upper cut] will go to the sub woofer.
The reverse is also true, nothing below the H/P x-over point will go to the speakers and nothing above the L/P x-over point will go to the sub woofer.
Although the above is a simplistic explanation of how the x-over works, it will do

You say your speakers frequency response is 30Hz to 35kHz, so by specs alone the H/P x-over point should be set at 30Hz, but it is doubtful that because of the way they are installed they would never be able to go below maybe 60Hz, so that means the H/P x-over point would be no lower then 60Hz.

If you are running a sub the L/P x-over point will be set to what the frequency response of the sub and cabinet it is in is, [probably someplace between 80Hz and 100Hz] it could be lower or higher.

Although the x-over points have limits, it really comes down to using the x-over points that work in the car with the speakers you have, the ones that sound the best, with the music you listen to, in other words, you pick them by ear, [within their limitations] a place to start would be to cross the sub, [L/P at 80Hz and the speakers, [H/P] at 80Hz, you can "under-lap" L/P at 80Hz and H/P at 100Hz or "overlap" L/P at 100Hz and H/P at 80Hz.

There are many ways to do it, but the one that sounds the best is as close to the right one as you can get.

As for "DBs", I assume you mean the slope, [-6 dB/oct, -12 dB/oct, -18 dB/oct, -24 dB/oct] thats harder to explain, but again, by ear works, it relates to how "steep" the x-over point is, I would try -12 dB/oct or -18 dB/oct, hard to say without hearing the system.

Don't forget about "i-Personalize" 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">
As for "DBs", I assume you mean the slope, [-6 dB/oct, -12 dB/oct, -18 dB/oct, -24 dB/oct] thats harder to explain, but again, by ear works, it relates to how "steep" the x-over point is, I would try -12 dB/oct or -18 dB/oct, hard to say without hearing the system.</TD></TR></TABLE>

Covered the jist of it.

A decibel is a way to track power.

The equation is 20log(vout/vin). So it is a measure of gain.

So if you set the corner frequency on a High pass filter to 120Hz and set it to -6dB then the first octave below 120hz will have the power reduced by 6dB. The next octave will have an additional -6dB loss. If you lower it to -12dB then the first octave below 120hz will be reduced by -12db and so on. For reference -3dB loss would cut the volume aprox in half.

In easy terms it lowers the volume on the frequencies you dont want to play though a specific speaker. On a high pass crossover this means the lower the frequency the lower the volume.