Need advice setting my amp

[Colossus]

I am getting pretty tired of running back and forth to the trunk to adjust my amp. I have a really SIMPLE set up (college funded) with a Kenwood 300 RMS amp and the good old Sony explode 330 RMS sub . Apparently there isn't an independant subwoofer control on my head unit (Boss BV8210) and I've just been using the "loud" button, when I want a good thump.

I've tried looking around the net for setting amp controls, with no straight forward answer.

This is what I have on the amp (Ive tried to adjust it the best I could) and I have very minimal audio knowledge.



I mostly listen to Alternative (QOTSA, Foo Fighters, Incubus...etc, with the occasional rap)

Thanks in advance.


ps..No Im not getting a new system anytime soon. kthnx

[I800C0LLECT]

First and foremost...recording quality and methods ARE NOT THE SAME between songs. Songs from the same album will sound similar but that's about it. So...

Throwing out recording quality your left with setting up the amp the right way. Listening to the music as it was recorded is very simple. Listening to it the way YOU want isn't.

1) Look in your manual, find out pre-out voltage on your head unit RCA jacks.
2) Turn your gain in that direction. i.e. 4V pre out?...use 4V on your kenwood's gain knob.
3) Turn that "bass boost" knob down to 0 or at max, 6 decibels. That knob will only prove to clip the signal being sent to the sub and fry it. You typically can't hear clipping that well in a sub until it surpasses 20% distortion. At that point...it won't last long with a good beat.
4) If it sucks, it's probably the song. Gain isn't a volume knob. The bass you prefer isn't present in every song either. If you try to "re-master" every song so it "hits" the way you want you'll end up like 90% of everybody else and blow the sub or fry the amp.

EDIT: Btw, if you're using that gain and bass boost as is currently ITS SCARY!! I can't believe that the Boss head unit has pre out voltage THAT low. If you have 2V pre-outs you better change that quickly.

[Colossus]

Thanks collect, I'll give that a try.

ps... any advice on the LPF and/or ISF????

[I800C0LLECT]

I'm guessing that ISF is supposed to be the infrasonic filter...if not, ignore what I'ma bout to say. I'd leave it at 25 since there typically isn't much information there and I wouldn't think your system could take advantage of any tracks that played that low.

The LPF looks fine where it's at but you can go as high as 100hz or 125hz in my opinion. It really depends on what your mids play. Play your sub too high and it'll muddle your sound. You'll definitely know.

[matt5112]

does your head unit have ANY controls for the sub at all?

[Colossus]

does your head unit have ANY controls for the sub at all?

I'm kinda embarrased to say no. It said it did online (probably regarding sub contol for the speakers in the doors/rear panel), but there is no specific control JUST for the sub.... on the back of the unit there was Audio (R and L) out puts for front and rear... I just used the rear ones.

[matt5112]

then robs advice is what you should follow

[chamilton89]

I think everyones advise is pretty good, having done quite a few stereos in my day with varying complexity it is hard to get a good sound just by looking at your system. Much of it is personal preference as well as the type and power going to each tweeter/midrange/woofer/subwoofer in your system. All that being said, I have a few suggestions.

First off, keep the low pass filter as low as you can get away with. larger cones were not made to handle anything, honestly higher above like 60-80 Hertz.

That being said, I don't know what the RCA voltage is on the head so Here is a rule of thumb I follow in initial tuning of my amplifiers.PUT YOUR EQUALIZER ON FLAT. On just a subwoofer setup,turn the gain all the way down and turn an average song up to as loud as it will comfortably go (no distortion in your mids/tweets at all) or as loud as you would care to ever listen to it. Then simply adjust the gain on your subwoofer amplifier till the clip light just lights or if there is no light, you hear audible distortion. At that point turn it down just a hair. This is a good way to set up an amp in a way where you have minimized your chances of ruining your subwoofer or amplifier.

Third, ONLY USE THE LOUD AT LOW VOLUMES. It is only met to provide an added high and low at low volumes and is never to be used at higher volumes.
Lastly, If you do what ive told you to do and your still not getting the bass that your looking for, you may manually tune your EQ on your HU to provide a bit more bass. Don't go overboard, use the LOUD at low volumes, and manually crank up the EQ a bit at mid volumes but if your nearing the upper range of your systems volume use a FLAT EQ setup.
No need to be embarrassed about your setup! Rock it hard! Tune it right! Make it beautiful and show it off. You still have a better system than 95% of us! Hope I helped.

[matt5112]

Can you clairify the bit about large cones not handling anything? Because that seems back-ass-wards.

You can calculate at what frequency a speaker will begin beaming, 18's dont beam till around 200 which is still not that low.

When you can hear audible distortion you're at 10% THD+N typically...

which is about 10 times as much as you want.

Loudness curves neutralize themselves as you turn it up... they take care of themselves.

[chamilton89]

Can you clairify the bit about large cones not handling anything? Because that seems back-ass-wards.

You can calculate at what frequency a speaker will begin beaming, 18's dont beam till around 200 which is still not that low.

When you can hear audible distortion you're at 10% THD+N typically...

which is about 10 times as much as you want.

Loudness curves neutralize themselves as you turn it up... they take care of themselves.

I would never push an 18 past 80 hertz. I am not worried about beaming in a speaker, just because I speaker can handle a frequency doesn't mean it should. anything above 100 hrtz gives terrible phase distortion as the loudspeaker is trying to produce a bass kick at 30 hrtz and a bass guitar at 80. a 5 and a quarter loudspeaker is capable of delivering down to like 30 hrtz but would you ever do that, hell no. There is a reason I have my 12inch subs crossover at 60 hrtz and my 8 inch woofers crossover at 120 hrtz, then my mids pick up above that. It gets muddy as the speaker cone gets larger and the frequency goes up, sure the speaker CAN but should it ever produce above 100 hertz, hell to the no.

[matt5112]

you also shouldnt have a crossover every octave lol

[boosted98]

O-Scope all the way.....but I have heard for people who cant afford it, they use DMMs.....still weary on that though....

[matt5112]

you can pick up o-scopes decently cheap used.

[I800C0LLECT]

I would never push an 18 past 80 hertz. I am not worried about beaming in a speaker, just because I speaker can handle a frequency doesn't mean it should. anything above 100 hrtz gives terrible phase distortion as the loudspeaker is trying to produce a bass kick at 30 hrtz and a bass guitar at 80. a 5 and a quarter loudspeaker is capable of delivering down to like 30 hrtz but would you ever do that, hell no. There is a reason I have my 12inch subs crossover at 60 hrtz and my 8 inch woofers crossover at 120 hrtz, then my mids pick up above that. It gets muddy as the speaker cone gets larger and the frequency goes up, sure the speaker CAN but should it ever produce above 100 hertz, hell to the no.

Are you trying to refer to 2nd and 3rd order harmonics? Typically, those issues are much more dependent on your ability to integrate the sub with mid-bass and mid-range. You should check out pro audio.

[matt5112]

pro audio is the best stuff ever.

dynamic range > sound quality

Mostly because dynamic range IS sound quality.

What is more real than replicating the massive range and dynamic peaks of live audio? Nothing...