color me disappointed

[husker77 10+ year member]

Well got my kid's stereo put in.

http://www.caraudio.com/forums/car-audio-build-logs-cars-trucks-suvs/548161-single-12-ext-cab-s-10-a.html

With the amp bridged it should be putting out 400 watts, but to get any output I had to turn the gain all the way up to get decent output. I tried to set it with a dmm on a 40hz tone I downloaded to my laptop. I had the laptop volume all the way up and set the deck volume at 20, it goes up to 30. It showed 40 ac volts with the gain all the way up so I thought that should be ok, but the amp seemed to be getting a little to hot.

So I put in my da7232 amp and wired the sub to one channel so should be pushing 500 watts to it. Still have to turn the gain all the way up to get decent output.

Voltage is staying over 14 volts.

This is the sub he is running... SW7124DVC-T2 Eclipse 12 Inch Subwoofer (SW7124DVC-T2) and it is wired to 4 ohm.

Here is his head unit...Alpine Electronics of America, Inc.

Poor choice in head units, my fault.

Here is the specs to the amp that is hooked up, like I said I am only running off one channel.

Output Power at 13.8V:

2 x 500W @ 4 ohms (0.005% THD)

2 x 1000W @ 2 ohms (0.007% THD)

S/N Ratio: >120dB

Freq. Response: 4Hz 3kHz

Crosstalk: >80dB

Damping Factor: >1000

Max Current Consumption: 200A

Here are the specs for the smaller eclipse 33250, I think this should power it decent.

Max. Power Output 310W × 2ch (2Ω) 310W × 2ch (2Ω)

2Ω 200W × 2ch 200W × 2ch

Power Output 4Ω 130W × 2ch 130W × 2ch

4Ω bridged 400W × 1ch 400W × 1ch

THD @ Rated Power @ 2Ω stereo 0.008% 0.008%

@ 4Ω stereo 0.004% 0.004%

@ 4Ω bridged 0.008% 0.008%

Signal to Noise 105dB 105dB

Freq. Response +0, –0.7 +0, –0.7

Crosstalk –75dB –75dB

Slew Rate 10Vμs 10Vμs

Damping Factor @ 60Hz >200 >200

Input Sensitivity 0.2 ~ 8V 0.2 ~ 8V

Max. Current Consumption (4Ω) 50 amps 50 amps

CHANNELFLEX CROSSOVER

Amp Crossover High Pass 12dB/octave 120Hz —

Low Pass 12dB/octave 50 ~ 200Hz 50 ~ 200Hz

Pre-Out Crossover High Pass 12dB/octave 50 ~ 200Hz —

Low Pass 12dB/octave — —

Subsonic Filter Freq. Range 0 ~ 50Hz 20Hz (Fix)

12dB/octave 12dB/octave

Slope 24dB/octave 24dB/octave

(Switchable) (Switchable)

Dimensions (W × H × D) 11.32˝ × 2.05˝ × 11.85˝

What am I doing wrong, why do I have to have the gains all the way up to get any output. I know the prefabbed sealed box is a limiting factor, and I intend to remedy it quickly, but I still should have decent bass shouldn't I?

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[05trailblazer 10+ year member]

check to see whats it wired too

 

[mazdakid 5,000+ posts]

Do you have the sub level on the head unit at +15?

 

[husker77 10+ year member]

check to see whats it wired too

The sub ohms?

Do you have the sub level on the head unit at +15?

At one time we did, now it is @ 5. Depends on the music.

I had my dmm on the speaker connections on the amp while playing music and never saw much in the way of voltage.

 

[goingdef 10+ year member]

It's your HU it has 2v outputs, the last deck I had with 2v out's would not allow most amps to reach there peak even with the gain at it's max setting. Try any other hu with 4v or better there will be a large difference.

 

[husker77 10+ year member]

So having the gain all the way up won't hurt anything then?

My wife is gonna crap, we just got him that hu for Christmas. I was pretty disappointed from the get go with it.

 

[VisceralSound 10+ year member]

The sub ohms?


At one time we did, now it is @ 5. Depends on the music.

 

I had my dmm on the speaker connections on the amp while playing music and never saw much in the way of voltage.

I may have read it wrong, but set the subwoofer control volume all the way up and then check it (if you did forgive me) but I know mine is quiet as hell with it off (0).

 

[mazdakid 5,000+ posts]

You should keep the sub level at +15 and you should be able to turn the gain down.

 

[09civic 5,000+ posts]

Your gain should always be set with the bass at 0 on the hu..

 

[chillin 10+ year member]

Does the amp have an input sensitivity switch? 2v head units have worked fine for years, i dont see that being the only issue unless eclipse does something weird with their amps because of their 8v head units.

 

[husker77 10+ year member]

Your gain should always be set with the bass at 0 on the hu..

Did that. The one thing I have always wondered about that. I if set my gain with the subwoofer set at 0 then if I ever turn it up don't I run the risk of clipping?

 

[trumpet 5,000+ posts]

You need to reset the gain with the head unit volume turned up higher. Also, set the subwoofer level about mid-way or even higher if needed to get adequate output. At +15 that's actually 0 dB, so when you turn it down it's attenuating the subwoofer level. You need to have the volume higher than 20 out of 30 because you're not even close to the rated 2V output. Make sure the test tone is attenuated and not 0 dB. -5 or so is good so you get more output.

When you set the gain all you're doing is matching up the head unit's output and the amplifier's input. They need to be on the same level so when you turn the volume up you're making the amplifier work like it should - not too little and not too much.

 

[husker77 10+ year member]

Does the amp have an input sensitivity switch?

nope

 

[groundpound4200 5,000+ posts]

IDK man... on my CDA-9887 I was able to run bass at +0 and have PLENTY of output but that also has a lot hotter preamp section.

 

[splwj47 10+ year member]

set volume to 25/30, set subwoofer level to +15, bass 0, treble 0, any eq's to flat, set gain.