Problem:-Sub playing the frequecies higher then LPF!!

[Gill]

I have a problem!I am running fronts+sub-woofer setup. Rear speakers are powered from HU but the internal amp of HU is turned off.With fader set to rear, one can hear the vocals and music played by sub-woofer.LPF is set at 80 hz.What could be the root of problem and what is the way out!

[low_bass_makker]

Music is heard from the sub some part but a very little. Do you feel the sub is playing full range try changing the RCA`s.

[Bass&Trouble]

Which head unit? If you have LPF on the head unit set to 80Hz and are using the correct channel (subwoofer out) to hook to the subwoofer amp, there's no way the sub can play mid band.

Try switching in the LPF on the amplifier and see if the mids go away. If it does, then you are using some incorrect pre-out for the sub.

If you have switched off the head unit's internal amp, how are rears running?

[Gill]

Originally Posted by low_bass_makker

Music is heard from the sub some part but a very little. Do you feel the sub is playing full range try changing the RCA`s.

One can hear the Vocals and higher fequencies to an extent and one can hear it sitting in driver's seat.

Originally Posted by Bass&Trouble

Which head unit? If you have LPF on the head unit set to 80Hz and are using the correct channel (subwoofer out) to hook to the subwoofer amp, there's no way the sub can play mid band.

Try switching in the LPF on the amplifier and see if the mids go away. If it does, then you are using some incorrect pre-out for the sub.

If you have switched off the head unit's internal amp, how are rears running?

Head unit is Alpine 9887.RCA is conected thru sub pre-out to JBL bridged rear two channel.
Ajay bhai rears are not working, i am using fronts+sub only.Crossovers of HU are functional and AMP is running on flat settings.

[navin]

Originally Posted by Gill

I have a problem!I am running fronts+sub-woofer setup. Rear speakers are powered from HU but the internal amp of HU is turned off.

Originally Posted by Bass&Trouble

If you have switched off the head unit's internal amp, how are rears running?

I almost always prefer to use the LPF and HPF on the amp as it is less liable to be changed by my driver or when my car goes for service.

I think Gill has an ingenious idea. Using this set up, when the car engine is running one can fade the subwoofer and front levels up there by using the amp. when the car is stationary fade the front and rears down hence the amp is now just idling. With Class D and Class AB amps this really saves the battery and one can still listen to some music while waiting in the car.

Gill, just check if the XO freq. and the slope have both been set. if te XO freq has been set to 80hz but the slope is 0db/octave then you will still have fullrange coming from the subwoofer. Set your slope to atleast 12db/octave (2nd order).

[Autophile]

Originally Posted by Gill

Head unit is Alpine 9887.RCA is conected thru sub pre-out to JBL bridged rear two channel.
Ajay bhai rears are not working, i am using fronts+sub only.Crossovers of HU are functional and AMP is running on flat settings.

Do the following steps:

1. Check the RCA Cable Connection, should be connected to Low RCA outputs on the HU.

2. Turn off the crossovers from the amplifiers.

3. Set the crossovers from the 9887 - Crossover Menu.

4. Check the slope setting of the subwoofer crossover. If it is 0 then the crossover is bypass. Set it to where ever it sounds better.

Start with 12dB (Second Order) and choose between 12, 18 & 24 which ever sounds better. After the selection of the slope flip the phase of the sub woofer and use the one where it sounds blended with your front speakers.

[ScarySkulls]

Originally Posted by low_bass_makker

Do you feel the sub is playing full range try changing the RCA`s.

You mean the RCA cable or how it's connected to the Pre-Outs?

[low_bass_makker]

Originally Posted by ScarySkulls

You mean the RCA cable or how it's connected to the Pre-Outs?

What do you suggest

[Gill]

Just Re-checked the RCA,all is fine at this end.
In 9887 there the four options in cross over menu which are like this:-
And these are the current settings too.
BAND Output level cut-off freq slope
High 0 80 12
Mid 0 80 12
Low 0 80 12

Even when i brought down the lows to 63hz n 50hz the voacals were audible with fader set to rear but when set at 50hz the level of vocals and music went down considerable yet they are audible.

[ScarySkulls]

Originally Posted by low_bass_makker

What do you suggest

I believe the Cables used are good quality and connections were made perfectly well.
Now what would I suggest except asking you to please clarify the reply as it can mean either of the two things, the way it's written.
Isn't it?

[low_bass_makker]

Originally Posted by ScarySkulls

I believe the Cables used are good quality and connections were made perfectly well.
Now what would I suggest except asking you to please clarify the reply as it can mean either of the two things, the way it's written.
Isn't it?

I think Gill knows what I said. So I think there is no point discussing it further.

[low_bass_makker]

Originally Posted by Gill

BAND Output level cut-off freq slope
High 0 80 12
Mid 0 80 12
Low 0 80 12

In this the 0 is the level 80 is the cut off freq and 12 is the slope.

So according to this everything should be fine.

[Gill]

any other pointers!RCAs are working fine checked them both from HU end and Amp end!
I would love to learn what difference does high n mid crossovers make in my set up,when both are set at 80Hz.

[Autophile]

Your subwoofer amplifier is running of the Rear preouts. Hence the subwoofer is playing 80Hz and above.

Switch the RCA to the Low output of the HU and it will be fine.

[ScarySkulls]

Originally Posted by low_bass_makker

I think Gill knows what I said. So I think there is no point discussing it further.

There is a difference between "Discussion" and a mere "Request for clarification", Raghhvinder.

Anyways, I guess you were pointing towards checking the connections. Didnt automatically assume that, because checking for the most likely errors would have been the first thing that would have come to your mind, when you met Gill and Auditioned his setup. Looks like you guys hardly met for 5 minutes or so. Out station travelling means a pretty hectic schedule, I'm sure.

Anyways, glad to know Gill did the needful now.

So, Gill sahab, the RCA cable, that connects to the rear channels of the amplifier at one end, is correctly connected to Sub Pre-out at the other end then?