another gain setting question

[teen 10+ year member]

im trying to set the gain on a sundown 3000D amp. i bought the DMM yesterday from HD. pulled the speaker wire from the amp and connected the DMM. set my HU EQ to flat, turned loudness to the "off" position and raised the SW level on the HU as high as it would go.

this amp has bass boost along with a remote bass knob. i turned the bass knob all the way down and turned the bass boost level on the amp all the way down. put in a test tone, 32hz at 0db. (I choose 32hz because thats what my box is tuned too. thought i read thats what you were supposed to do somewhere, but i think i should have choosen somehting a bit higher?).

my HU volume goes to 62. the highest ill ever turn it up is right around 45, so i turned it up to 42 and played the tone.

now, when the gain was all the way down, i was getting a 0 voltage reading. i turned the gain all the way up and the highest reading i got off the DMM was like 4v. so now i started playing with the SSF, LPF, phase, and bass boost on the amp as well as the remote bass knob (all of which i set as low as they would go at first). after messing around with these and the gain, i got the DMM to read 49v (using the formula, i came up with a setting of 50v. sqrt(2500w*1ohm)).

does it seem like i did everything correct? i thought when setting the gain, the SSF, LPF, phase and bass boost(as well as the remote bass knob) should all be set as low as they can go. thing is, when they are all set as low as they go, the DMM only reads as high as 4v?

do you think i should try setting it again using a different tone? which tone would you guys suggest?

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[thaster 10+ year member]

try 80 hz @ 0 db

 

[Qbenjamin 10+ year member]

Is your test tone a sine wave @ 0db's?

 

[teen 10+ year member]

i downloaded a single 32hz tone and a sine wave, 30hz to 50hz. but i only used the single 32hz tone to set it.

 

[mokedaddy 5,000+ posts]

Your tuning frequency will usually have a large rise in resistance. Try another frequency.

 

[teen 10+ year member]

im going to try another frequency then.

any others i should try other than the 80hz @ 0db? and was i correct in turning the SSF, LPF, bass boost and remote bass all as low as they go? or is it normal to have to adjust those when setting the gain?

 

[mokedaddy 5,000+ posts]

im going to try another frequency then.
any others i should try other than the 80hz @ 0db? and was i correct in turning the SSF, LPF, bass boost and remote bass all as low as they go? or is it normal to have to adjust those when setting the gain?

0db or -3db

Turn ssf as low as it will go. Turn lpf off or as high as it will go. Unplug remote gain.

 

[teen 10+ year member]

a member from team sundown told me to turn the SSF to 30hz, since my box is tuned to 32hz. he said set the LPF dial at about 10:30/ 11:00.

im not doubting either one of you, just curious as to which one will help me set this amp with a lesser chance of clipping.

 

[mokedaddy 5,000+ posts]

a member from team sundown told me to turn the SSF to 30hz, since my box is tuned to 32hz. he said set the LPF dial at about 10:30/ 11:00.
im not doubting either one of you, just curious as to which one will help me set this amp with a lesser chance of clipping.

Thats probably about how I would set it too. I set those after I set gains though since its a sine wave anyways.

 

[darsum 10+ year member]

Turn ssf as low as it will go. Turn lpf off or as high as it will go. Unplug remote gain.

X2

 

[darsum 10+ year member]

when you first got the AC output from your amp. you only had 4V, right?

that was because you were setting the LPF at the lowest point~35 hz.

with your test tone at 32 hz, the output was affected by the LPF in some way.

 

[teen 10+ year member]

im gunna try setting it both ways right now. see which gets better results.

 

[jrwalte 10+ year member]

I've always read 50hz is the best to use. And most people use a -3 because real world music won't hit your amp like a sine wave does.

 

[teen 10+ year member]

the 80hz tone made a difference.

when i set the gain with the ssf as low as it will go and the lpf as high as it will go, i set it to 49v. when i moved the ssf to 30hz and the lpf to about 10:30 on the dial, the volts dropped to about 36.

so now should i bring the gain back up to 49v with the ssf at 30hz and the lpf at 10:30? or just leave it at 36v?

 

[darsum 10+ year member]

with the LPF at 10:30, it is set around 120 Hz, methinks.

but to answer your question, the 49V-50V is just a theoritical limit supposedly to avoid clipping the output of your amp.

you may not need to increase the output of your amp. that high.

just look and listen.

Look at the excursion of the sub., if it's not over-excursing and listen for distortion.

A distorted sound from a sub. sounds loose and it doesn't hit hard anymore.