Pioneer DEH P880

brisgreat1 · Post by **brisgreat1** » Sat Jul 01, 2006 7:39 am

I finally saved up enough, purchased and installed it, and it was really worth every penny, but I don't understand some of it. I need help on how to use some of its features, here's what i dont get. . .
you get manual control on each speaker, its really cool, i can set the HPF for the fronts and the rears
Front L : 125 Hz
R : 125 Hz
Front HPF
Slope : 12 db / oct I have no idea what this means

Rear L : 125 Hz
R : 125 Hz
Rear HPF
Slope : 12db / oct

now i just have a general question, the head unit has the same shit for sub contol, but is the LPF on the sub going by my amp or head unit, i have the amp set to like 150ish and the head unit is at like 80hz, ill just mess around with that i guess but i dont understand the slope part, please help with that, reccomend what i should be setting my fronts , rears at. I got 4 way coaxials up front and 3 way coaxials 6x9s. also what should i set my subwoofer slope at, thanks in advance!

brent · Post by **brent** » Tue Jul 25, 2006 11:22 am

The LPF on the HU is the HU, has nothing to do with the amp. It will effect your sub when on hwoever. Turn that 80 hz LPF off and you will get more output. If you insist on having it on, you will have more output at 50hz. Why bother when you have a cross on you amp. The amp is the sub driver, not the HU.
The slope part I am not to knowledgable. Basically, and I could be wrong, the 12 db slope provides a boost at whatever octive it is set to. I think....

CaptainPioneer · Post by **CaptainPioneer** » Tue Jul 25, 2006 11:26 am

Oh jease i forgot how to set that thing... i have an older Pioneer HU without slope but my buddies has it... umm ill ask him and find out

JeremyC · Post by **JeremyC** » Tue Jul 25, 2006 2:51 pm

The slope is how many DBs per octave the x over cuts the output. So a 24db slope will cut the output by twice as much as a 12db slope.

You want the sub set to LPF and at around 80 herts or lower. For a 12 I say 80, with a 24 db slope unless your talking about a W7 XXX or something alike. Then you will want the x-over set lower.

As for the mids, try setting them at 120 (HPF) with a 12 db slope (with the sub at 80 with a 24 db slope) That should give you a good starting point.

Oh and don't use 2 x overs. Its ok to have the mids and tweets on the deck, and the sub on the amp, but try not to have the sub, on the amp and deck.

The way you have it set now, the sub is rolling at starting at 80 herts (the deck in control).

brisgreat1 · Post by **brisgreat1** » Tue Jul 25, 2006 3:04 pm

alright cool, gonna tune the LPF and mids to your settings, see how it sounds, thanks for all the help doods

kowboy · Post by **kowboy** » Sat Sep 02, 2006 7:43 pm

Thx guys. Helped me too.

MobileAudio219 · Post by **MobileAudio219** » Mon Sep 04, 2006 2:50 am

Now if you set the head unit at 80hz hz with a 12db slope and the amp at 80hz with a 12db slope what you are doing is doubling the slope to 24db, right?

Sorta like when you use a f-mod or something and stack them, right?

Please dont hate me if Im wrong...

kbakken · Post by **kbakken** » Tue Nov 27, 2007 4:29 pm

No. It is basically useless to have two things set to the same crossover point and settings. It does not double the effective rolloff, it's just redundancy. Although, one will be more accurate and effective than the other.

solacedagony · Post by **solacedagony** » Wed Nov 28, 2007 5:32 am

kbakken wrote:No. It is basically useless to have two things set to the same crossover point and settings. It does not double the effective rolloff, it's just redundancy. Although, one will be more accurate and effective than the other.

First off, this thread is over a year old :)

Second, why wouldn't it apply a 12db slope at 80hz twice? How does the HU know that the amp's crossover is on and how does the amp know the HU's crossover is on? Why would either care or know that either are in the signal path at all?

kbakken · Post by **kbakken** » Wed Nov 28, 2007 6:58 pm

solacedagony wrote:First off, this thread is over a year old :)
Second, why wouldn't it apply a 12db slope at 80hz twice? How does the HU know that the amp's crossover is on and how does the amp know the HU's crossover is on? Why would either care or know that either are in the signal path at all?

Ha, I realized the date afterwards.

Each device doesn't know what each of the crossovers are on. And yes, it would apply that 12db at 80Hz slope twice. Once at the HU, and again at the amp. This doesn't mean, however, that it will double the effective rolloff to 24db/oct. It is totally redundant to have those two things set up the same like so. The eq curve is what it is. You can layer an infinite number of devices all rolling off at 80Hz and 12db/oct, and that's what the sound characteristics will be: 80Hz rolling of at 12db/oct.

As the sound signal goes through any of those devices, they will apply the same rules. They do not compound on each other. If one device does not see anything over the cutoff limit, then it just doesn't have anything to cut off.

Hope this helps.