Audio/Video Q&A Thread

[Asim]

its a 4 V output from the HU (Alpine 9886)

Subwoofer level control at HU has steps from -15 dB to 0 dB. Right now set to about "11" which I guess would mean something like -4 dB

Amp input gain is set to almost minimum for the front and rears. It overpowers the sub and I am trying to get more response out of it.

Amp input gain on the subwoofer along with HU choice is what I am trying to get at. Amp input gain for subwoofer I believe is set to "normal" which is halfway

[timot_one]

Is everything set to 0 or normal on the head unit?  Whenever you're tuning an amp, you want to make sure the output of the head unit is right in the middle or set to 0.

[Asim]

Is everything set to 0 or normal on the head unit?  Whenever you're tuning an amp, you want to make sure the output of the head unit is right in the middle or set to 0.

I didn't know the sub level was actually a negative ramp so to zero the sub I'd need to run it at 0db or "15 sub level"

Treble and Bass on HU are both in the middle

Speaker gain at Amp is on a low setting
Sub gain at Amp is on middle setting

[ikethegreat]

Just installed a new pair of 6x9s in the rear deck.  Does it matter that the trunk spring is pressed against the magnet on the bottom of the speaker rather tightly?  It was like that on my old pair too but I figured I would ask...

[Asim]

Well I set the gain properly now. Wishing the bass response was better.

What can I do to improve this (without changing the amp)?  I could change to a ported box

[timot_one]

Just installed a new pair of 6x9s in the rear deck.  Does it matter that the trunk spring is pressed against the magnet on the bottom of the speaker rather tightly?  It was like that on my old pair too but I figured I would ask...

You may want to space them up a little so they don't rub the spring.  That's what I would do.

Well I set the gain properly now. Wishing the bass response was better.

What can I do to improve this (without changing the amp)?  I could change to a ported box

What frequency do you have the front speakers crossed over at?

[Asim]

There is no deck cross over as far as I know. I set a HPF on amp to ~90Hz
I set LPF for sub to ~100Hz

[ikethegreat]

This is probably a dumb question but I'll ask it anyway.

Since I'm hooking up my speakers and sub via RCA cables from my amp to my HU, I don't need to bother with the wires circled in the pic below right?  I just need to tape them off? 

[cna]

Yes you can just tape them off

[ikethegreat]

Yet another question for you guys.  

I have component speakers up front and 6x9s in the rear.  All four speakers have crossovers attached.  Does this mean I should turn the "xovers" on my amp off?  

[timot_one]

They are 2 different types of crossovers Ike.  The passive crossovers you have that came with your speakers take the full range signal and essentially split it so the high frequencies go to the tweeter and the low frequencies go to the midrange/midbass driver.  The crossover on your amp are a high pass crossover and allow you to not send frequencies below what your interior speakers are able to produce.  You should have an adjustment knob on the amp so you can select the frequency crossover point.  You want to leave the crossovers on your amp on, and adjust the crossover point for them if you can.  If it were my set up, I would set the front crossover point to 80 Hz and the rear crossover point at 100 Hz for your interior speakers.

[ikethegreat]

Ahhh ok, that make sense.  Thanks!

One more amp question while I'm thinking about it.  In the picture above, you can see the input level button.  Should this be set on low or high? 

[timot_one]

Depends on what that means.  You should be able to find what low and high are actually (i.e. - input voltage), then find out what the output voltage of the RCA's on your head unit are, then adjust appropriately.  Most amps have an input gain knob on them though, which is weird that you have a switch for just high and low.

[ikethegreat]

My amp does have gain knobs on them also which was why I was confused as to the point of the button.

This is what the manual says about it:

2. Input Level - The RCA inputs on Kicker ZX amplifiers are capable of receiving either Hi or Low-level
signals from your source unit. If the only output available from your source unit is a Hi-Level signal, simply
press in the Input Level switch on the amplifier.

[ikethegreat]

Saw this in the amp manual too

Input Sensitivity:
Low Level: 125mV-5V
High Level: 250mV-10V



My Kenwood Excelon DNX6990HD manual, it says "Triple 5.0V Pre-outs with Crossover System". 

I guess that means it should be set on low?