Suggestions on using -3DB or -6db test tones. My problem.

[paintballer 10+ year member]

hey guys. I have two amplifiers, one 4 channel powering my components and coaxiles, and one mono amp powering my 12' subs. Im not going to go into the models and such for that its not important here. I already set the gains on the 4 channel amp by ear and withouth test tones. I feel that setting the gains on a dedicated speaker amp(mid's and highs) by ear, and using the music you generally listen too is better than test tones, beause unlike lows(subs) there is such as wide range of frequencies being played in the music which therefore, you can get a overall better gain setting, because the tweeters and mids are all getting action. I tried to play one of the cd's too i knew was recordeed a little louder than usual. I have the HPF filter set about 120 for the 4 channel amp, and that i did use a 120 hz test tone. and the speakers sound good.

BUt heres what the subs come into play. I set the gains on them too using a radio shack 20 dollar DMM, and i first used a 0 db 60 hz test tone, with the LPF all the way up so as to not interfere at all. I plugged the numbers into the formula,

(400rmswatts *2 ohms)=sqrt800=28.3. So i set the gains so that the ac voltage read 27.7 on the DMM.

I listen to metal mostly, bands like lamb of god and shadows fall, and lots of soft rock too. but occassionally ill listen to rap to get the fun out of having loud BASs, and also some rap is tolerated to my tastes. But with my metal music, i wasnt satisfied with the amount of bass being put out. and when i set the gains, i had the sub volume at max on my alpine deck (+15) and the master volume at 25). I also unplugged the subwoofer speaker wires before connecting the DMM thingys, and i unplugged the 4 RCA speaker plugs on the 4 channel amp. With that said, the bass was not loud enough.

SO i went to a 60 hz -3db, test tone, and re set te gain. it puts out more bass now, alomst to my liking, but i would stil prefer more. and my LPF is at 100 hz.

Ive heard that most metal peaks at -6db and -10 DB for the lows, but is that true. I would like to try to use a -6DB 60 hz test tone, but is that going to low? or should i be fine considering my music taste. from time to time, i will pop in a rap mix cd , and i know rap peaks at higher bass volume. so if i used a 60 hz -6db test tone to set my gains, would that most likely put my amp into clipping if i listen to some rap and some metal cds that are bass heavy. I want to be safe, but i still want more bass. -6db would be perfect, i just dont know if its safe for my situation.

THanks guys

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[BassAddictJ 5,000+ posts]

since metal and bass drums arent as "loud" as bass tones or rap tones it makes more sense to set with quiter tone....or just set it by ear and be sure to turn it down on the remote gain knob or HU sub preout when you you play rap. if you sub's RMS is close to what the map's RMS is at full tilt then you shold be fine, if your sub can handle alot more then you would be more prone to clipping it if you tune by ear. turn it up until it sounds good on music.....

 

[paintballer 10+ year member]

the only reason why i didnt set the gains by ear for the subwoofers as well is because for me, it seems like its verry hard to detect clipping in subwoofers. Maybe it isnt, i just dont knoiw what clipping in a sub will sound like. If i went through with the dmm again, would -6 db be fine you think then.

I thought it would be fine because of the fact that only peaks reach realy high limits, not the continuous notes. and if only peaks reach high db levels, then it would be for a such a short period of time, and isnt a little bit of clipping ok and not bad at all, considering my subwoofer RMS is 450 and my amp is only 400. Arent the amps and subs designed to go a little higher than RMS, isnt that why they have a peak wattage value labeled all over the box and what not?

THanks man.

 

[BassAddictJ 5,000+ posts]

ya since the bass isnt continuous it wont be as bad....and yes it is harder to hear clippiing in subwoofers...typically the onyl way i can hear it is when you get to a point with the gain near full tilt wherethere's a large audible power spike after you turn it up to a certain point, this is caused by all that exra clipped power (easily heard useing tones)....though this isnt a garuntee everytime, its a good rule of thumb to go with. with the type of music your playing youll be fine tunign it by ear. just remember to keep that level down when you play rap and tones

 

[DBfan187 5,000+ posts]

-10dB tones for level setting.