couple kinda dumb questions

[jdawg90 10+ year member]

I'm setting the gain and filters with a dmm. I always just used a 40hz sine wave at 0db, set the gain, did the ssf/lpf by eye and called it a day. However now I'm sending my subs over double their rms so I want to make sure everything is setup properly.

First I turned the filters off and gain all the way down. I played a 0db 40hz sin wave, and turned up the gain until my voltage was 50v (which was my target). I played various tones from 20hz to 70hz and the voltage is different on all of them. HU equalizer is flat loudness off. Is this normal?

Also when setting the ssf should I stop as soon as my voltage begins to change? I put on a 30hz tone which is where I want my SSF and adjusted it till the voltage dropped like 2v, then played a 25hz tone and I was only like 4v below where I am at 30hz. 5hz is 1.3rd an octabe and on a 24db slope I should be at -8db at 25hz vs 30hz which is def more than 4 volts. though I guess outputting a diffrent voltage at various frequencies is a factor, still something doesn't seem right.

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[jdawg90 10+ year member]

just went back and wrote everything down. set volume 45/62 played 40hz test tone, set voltage to 50v. Had to turn the gain almost all the way up, at 42/62 where I wanted to set it it wouldn't put out 50v with the gain all the way up.

20hz- 57.5v

30hz- 57.4v

35hz- 56v

40hz- 50.0v

45hz- 46.7v

50hz- 32.5v

70hz- 25.4v

BTW all these are on an ipod hooked up via usb interface which what I play all of my music from

 

[garychoffmann 10+ year member]

Where is your low pass crossover set? Or is it set yet?

 

[jdawg90 10+ year member]

low pass is turned all the way up (300hz) and ssf is all the way down (10hz). On headunit EQ is flat, loudness off.

This is not normal?

 

[garychoffmann 10+ year member]

I don't use the dmm method so I can't say at the different tones. But it looks pretty consistent like the power is being cut as the tone increases. I'm assuming this is unloaded on the amplifier?

 

[Massive spl]

Lpf 80hz-100hz is were most ppl set there's

 

[jdawg90 10+ year member]

I don't use the dmm method so I can't say at the different tones. But it looks pretty consistent like the power is being cut as the tone increases. I'm assuming this is unloaded on the amplifier?

meaning no subs? yes.

Idk wth is going on. I think it might be my 4 year old ****** headunit causing it but I can't say for sure. I fucked around with it but left the settings the same and it seems to be okay now (within 3v for the most part until I get past 60hz) . My only concern is the crossover on my amp. It doesn't seem to be sloping of fast enough.I have it starting to crossover around 40hz but only slight. With the ssf set I'm roughly:

45hz:~50v

40hz:~50v

35hz:~48v

30hz: ~44v

25hz:~40v

20hz: 35ish I think

So at 25hz, 10hz below tuning I'm still giving my pair sa-12's 1600 watts //content.invisioncic.com/y282845/emoticons/thumbsdown.gif.d22f25895e9b40f2300c953691dacfa2.gif Move teh ssf up anymore and I start cutting more power at and above tuning.

 

[dragon.breath 10+ year member]

Check the eq settings on the iPod.

 

[jdawg90 10+ year member]

Check the eq settings on the iPod.

it was off, changed it to flat to see if it did anything and it didn't

 

[jdawg90 10+ year member]

Also twice I have set my gain only to find it different than what it was. I've been subless up until a few weeks ago. Hooked up my 1500 set gain, check it later and I'm reading over 10v higher than where I set it. Got a new amp the other day and the same thing happened with that. I'm starting to think something is going on with my deck. Either that or multimeter though it's a nice one.