Hello. I just picked up the Alpine CDA-9827 HU for $198 CDN. For the
features I wanted, and that price, I don't think it can be beat.
I am running a Rockford Fosgate P2002 Amp which is driving my Infinity 1030W
10" Subwoofer. Now my questions a (please excuse if stupid.)

What should I set the frequency of my amp to AND my bass frequency on the
HU? Do they have to match? I am noticing that unless the gain and the
frequency on the amp are cranked, my sub isn't hitting at all. I've also
heard some bad things regarding the SUBOUT on this particular HU. Any ideas?
I'd like to control the sub using the SUBOUT functionality (one of the
selling points!) but I find that it has to be cranked to the max of 15, and
like I said, the amp gain and frequency have to be pretty much all the way
up.

Thanks for reading this long post and any answers/ideas/suggestions are
highly appreciated.

I should also say that I do not want to have that much bass coming from my
speakers. Only 2 are aftermarket and I'd rather just let the sub take care
of the bass. But again, with the bass settings down on the HU, the sub
doesn't hit at all. And as I move the bass settings up on the HU, the
speakers sound like crap. I just can't win!


"James Killner" wrote in message
news:0IxYd.648777$Xk.345352@pd7tw3no...
Hello. I just picked up the Alpine CDA-9827 HU for $198 CDN. For the
features I wanted, and that price, I don't think it can be beat.
I am running a Rockford Fosgate P2002 Amp which is driving my Infinity
1030W 10" Subwoofer. Now my questions a (please excuse if stupid.)

What should I set the frequency of my amp to AND my bass frequency on the
HU? Do they have to match? I am noticing that unless the gain and the
frequency on the amp are cranked, my sub isn't hitting at all. I've also
heard some bad things regarding the SUBOUT on this particular HU. Any
ideas? I'd like to control the sub using the SUBOUT functionality (one of
the selling points!) but I find that it has to be cranked to the max of
15, and like I said, the amp gain and frequency have to be pretty much all
the way up.

Thanks for reading this long post and any answers/ideas/suggestions are
highly appreciated.

Start by setting all "bass", "loudness" "EQ", "megabass" and other
onboard processing on the HU to flat. You don't want to amplify the
bass going to your full-range speakers in any way. If more bass output
is needed, only the sub channel should be adjusted. This will relieve
your full range speakers. Then, uses as much of the amp gain and/or HU
"sub level" setting on the HU that is needed. That's why the are there.

I had a CDA-9815 that indeed needed the full 15 on the sub level seting.

Second, try using bass blockers on your full range speakers.

Also note that any "bass boost" included on an amp should be used as a
mean to tweak the sound, not as a way to amplify the bass (despite the
name!)

If insufficient bass output cannot be attained with all this, maybe
something is defective or improperly installed/connected.

Good luck!

--
Eric (Dero) Desrochers
http://homepage.mac.com/dero72

Hiroshima 45, Tchernobyl 86, Windows 95

"James Killner" wrote in message
news:0IxYd.648777$Xk.345352@pd7tw3no...
Hello. I just picked up the Alpine CDA-9827 HU for $198 CDN. For the
features I wanted, and that price, I don't think it can be beat.
I am running a Rockford Fosgate P2002 Amp which is driving my Infinity
1030W
10" Subwoofer. Now my questions a (please excuse if stupid.)

What should I set the frequency of my amp to AND my bass frequency on the
HU? Do they have to match?

I'm a little confused by this statement. Do you mean you are using the
crossover on the HU as well as the amp? I have an Alpine HU (7863) and when
I used the low-pass x-over on the HU, this SEVERELY reduced the amount of
bass. I ended up turning it off and using the x-over on the amp instead.
This gave me way more bass. If you have not tried this, this may completely
solve your problem. I found that the built in x-overs in my Alpine (both
low-pass and high-pass) created more problems than they solved and I have
heard others complain about this as well.

If this is not the problem, as someone else has mentioned, crank the gains
on your sub amplifier. If you find you are still not getting enough bass,
then perhaps something is wrong with your gear as this should produce tons
of bass. Another possible fix would be to purchase a line-driver
(line-level pre-amp) and install it between your HU and your sub amp. This
would boost you line-level sub output, and would probably increase the
dynamics of your bass.

MOSFET

I have the same head unit. I also had the same problem...had to turn
the SUB-W all the way to 15. First, the 9827 doesn't have built-in
x-overs. You can boost the bass at certain frequencies and choose the
bandwidth for that boost. I use the x-over on the amp itself. I solved
mine by taking the output of my other amp and hooked it to the input of
the bass amp. If you don't have another amp you can take the RCA's from
your SUB OUT and move them to the FRONT or REAR out. You lose the SUB-W
control, but like mine, it doesn't seem to work the way you want anyway.
If you still want SUB-W volume control your amp may offer an optional
BASS BOOST control knob or there have been posts on here of how to build
one with a 10k ohm varistor.

Hope this helps.

DA

I also have a 9815 but haven't had the same problems you talk about. I have
the Headunit sub crossover set 120 Hz at 12 db rolloff. I send that to my
Alpine MRV-T707, gains set to about 1/3 of max with the crossover on the
amplifier off. This goes to a single Alpine dual 2 ohm Type R 10" subwoofer
in a ported enclosure.. about 1.0 cubic feet. Normally the sub output on
the Headunit is between 9 ~ 11 depending on the music. There is no lack of
bass at all.


"Eric Desrochers" wrote in message
...
Start by setting all "bass", "loudness" "EQ", "megabass" and other
onboard processing on the HU to flat. You don't want to amplify the
bass going to your full-range speakers in any way. If more bass output
is needed, only the sub channel should be adjusted. This will relieve
your full range speakers. Then, uses as much of the amp gain and/or HU
"sub level" setting on the HU that is needed. That's why the are there.

I had a CDA-9815 that indeed needed the full 15 on the sub level seting.

Second, try using bass blockers on your full range speakers.

Also note that any "bass boost" included on an amp should be used as a
mean to tweak the sound, not as a way to amplify the bass (despite the
name!)

If insufficient bass output cannot be attained with all this, maybe
something is defective or improperly installed/connected.

Good luck!

--
Eric (Dero) Desrochers
http://homepage.mac.com/dero72

Hiroshima 45, Tchernobyl 86, Windows 95