Subwoofer gain issues..

[polyrhythmic81]

Hello. I just installed a HU, amp & sub, and I'm having some trouble setting the gain for the sub. Here's the problem: the stock speakers get too loud too quickly (as loud as I could want @ a volume setting of ~22 -- i think it goes to 40...not sure.) At this volume level, i have to crank the gain on the sub amp AND turn up the bass level AND turn up the sub output level on the HU to get a decent amount of bass. The best solution i can come up with is to get some new components for the front (which I want to do anyway) and hopefuly they would be a little quieter at such modest power levels (14W RMS). I was just wondering if anyone else has had similar issues and what they did about it....the HU is an alpine cde-9874, sub is a boston 12" G5 (4-ohm DVC) in a sealed 1 cu ft box being powered by an xtant A6001 (600W RMS).

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[Bass Addict 10+ year member]

i was in your scenerio a few days back as far as the woofer level on ur alpine.turn gain and bass boost down,turn up the woofer level to +15,now readjust ur amp to that.ur hu is not sending the proper voltage to ur amp unless the woofer level is at +15

 

[99grandprixGT 5,000+ posts]

i was in your scenerio a few days back as far as the woofer level on ur alpine.turn gain and bass boost down,turn up the woofer level to +15,now readjust ur amp to that.ur hu is not sending the proper voltage to ur amp unless the woofer level is at +15

ya i had the same problem with my alpine HU. make sure u set the gain proparly once u adjust the HU subwoofer control to 15.

 

[Bass Addict 10+ year member]

makes a BIG difference.

 

[scarolinablazin 10+ year member]

also make sure your DVC sub is hooked up properly.

 

[standbackimapro 10+ year member]

Yah how did you wire up the voice coils on the sub?

 

[polyrhythmic81]

I wired them in parallel--had to go back and check the manual to be sure. this sub uses ATC blade fuses as jumpers. there were definitely 2 fuses in there (as opposed to one for series) when i installed it in the box. I turned the HU's sub control up to +15 as suggested and turned it up 'til it distorted. Not that loud. And there was quite a bit of headlight/interior light dimming going on at idle. Maybe that's because it's a honda civic with a little battery and alternator? I think i'm just expecting too much slam from a single 12 in a sealed box. I used to have a single JL 10w6v2 in a slot ported box (about 1.5 cubes i think) running of a JL 500/1. I thought this might be similar, but that seemed to hit harder if i remember correctly. I'll probably end up throwing another sub in there at some point. Anyway, thanks for the help.

 

[JLranger 10+ year member]

dont do that just make a bandpass box with a slotted port..... keep what you got and make it work. go get a amp level control tune everything at the amp moderate (not to powerfull) just incase you want to roll out with not so much bass... then use the amp control knob to give it the boost. ive got the alpine 9887 and tuned my system at zero on the head unit. use your amp as much as you can then use the head unit.

 

[polyrhythmic81]

Okay, so the setting the gains with a multimeter was the way to go for me. Now i can be sure I'm getting the most out of my amp/sub and not trying to push it too hard. First I measured the impedence at the speaker terminals on the box. 2 ohms, so i hadn't blown a voice coil. sweet. Then I used a test tone (80Hz i think) recoreded at 0dB @ the volume level where the 1000 Hz tone started to distort on the full range speakers (about as loud as i like to listen anyway). I set the sub control to +15, because if you give me an inch i'll take a mile... I put a multimeter set to measure AC RMS volts on the speaker terminals and turned up the gain until i got ~ 31V. So my 450W rated speaker should get no more than about 480W. The numbers put my mind at ease. haha. I'm getting some good, solid, clean bass now. Setting the levels by ear was tough with the sub slamming in my face and my untrained ears trying to figure out where the distortion started. Also, by using the DMM I found out that the difference between 20V and 40V output was only like a 10 degree twist of the gain dial. Problem solved. Thanks again for the help.

 

[dredey 10+ year member]

what do yall use to measure?

 

[BoxdGM 10+ year member]

fluke true rms dmm ftw

 

[polyrhythmic81]

uhhh...radio shack multimeter. should yield true rms as long as the voltage you're measuring is sinusoidal. (sinusoidal test tone, NOT real music/instruments) I think true rms meters are several hundred dollars.

 

[MmatsDude 10+ year member]

fluke true rms dmm ftw

x2

 

[polyrhythmic81]

testing...1..2