[e92justin]

I recently put 2 10" alpine type r's in my car powered by an alpine m1000. This thing hits harder than my previous 2 12" kicker cvrs. Only question is, is it bad to turn my gain and bass boost all the way up? Its tempting to do so, yet i know it could have bad effects. People say some amps can handle it and others cant. Im running this set up with the stock head unit also. Was going to get the alpine in dash but i heard, replacing head units on these cars could have bad effects.

[skinrock]

It's not so much as the amp handling it (although you could cause it to overheat). The gain is used to match the voltage, it should NOT be cranked up just to make it "louder". Doing so, as well as cranking up the bass boost, can lead to clipping, which you don't want. The gain needs to be set properly, and the bass boost should be kept at 0. It's always tempting to turn them up, but if it's not producing the output you desire, you need a different setup.

[808MGuy]

Originally Posted by skinrock

It's not so much as the amp handling it (although you could cause it to overheat). The gain is used to match the voltage, it should NOT be cranked up just to make it "louder". Doing so, as well as cranking up the bass boost, can lead to clipping, which you don't want. The gain needs to be set properly, and the bass boost should be kept at 0. It's always tempting to turn them up, but if it's not producing the output you desire, you need a different setup.

Correct. The gain is not a volume control. It is used to match the output voltage of the head unit to the input section of the amp such that they end up clipping at the same time. Biasing it one way or the other will only result in less than optimal performance.

As far as the bass boost, I wouldn't say 0 is the rule but you want to keep it as low as possible.

[skinrock]

Originally Posted by 808MGuy

As far as the bass boost, I wouldn't say 0 is the rule but you want to keep it as low as possible.

I should clarify. The problem is most people abuse bass boost and crank it because it sounds good (I won't deny that sometimes you just get in the mood for some heavy bass). It should be pretty obvious when you start to distort, though, and that's when you need to cut back.

Gain = set it right, don't change it
Bass boost = like alcohol, use in moderation

[fdriller9]

It's best not to use bass boost at all...

Especially on the alpine amps since...I don't think you can set the frequency at which it boosts.

[slim142]

0 for bass boost.
gain = match with voltage from rca

trust me. You dont want to boost bass, it makes your music sound horrible and clip your amp signal almost immediately.

[ChrisJadesFireF82]

i like ur set up and im new to bmws....just got my 08 e92...questions since i just started looking into uping my system a lil...where is the stock amp located? i was thinking of a similar system to yours i just want a lil more sound n bass nothing crazy like replacing headunit and interior speakers

[ctuna]

http://www.e90post.com/forums/showthread.php?t=365866

look inside the links in the above thread


http://www.e90post.com/forums/showth...Stock+Amp+2010

http://www.e90post.com/forums/attach...2&d=1266451970

[ChrisJadesFireF82]

Originally Posted by ctuna

http://www.e90post.com/forums/showthread.php?t=365866

look inside the links in the above thread


http://www.e90post.com/forums/showth...Stock+Amp+2010

http://www.e90post.com/forums/attach...2&d=1266451970

Thanks for the info

[Atorsesh]

So what is the decided "correct" voltage setting for the systems? Does the voltage increase as volume increases?

[talisman311]

Originally Posted by liliceman13300

So what is the decided "correct" voltage setting for the systems? Does the voltage increase as volume increases?

Correct gain setting is to set the receiver volume to a setting right before it starts clipping and then setting it about the same on your amp. Rule of thumb is that the highs can have about 5% distortion vs subs with about 10% distortion at high volume before most people can perceive it - IIRC (used to be an installer for 5+ years at circuit city and we tuned every amp install with a test cd).

Voltage and volume go hand and hand, more voltage, more volume. Setting the gain can be kinda tricky especially with regular music. The best way to set it is using test tones, but you have to be careful. Test tones can blow speakers pretty easily if you don't know what you're doing. You can put in a resistor inline with a speaker to be safer (and protect your ears).

See if you can find a 1kHz test tone.. with the amp gain all the way down, turn the receiver volume knob up until you hear the sound starting to clip, then back it off until it stops. Now perform the same on the amp. For the subs, do the same but use a 100Hz test tone.

Hope this makes sense..pretty sleep deprived right now.

[wren57]

Originally Posted by talisman311

(used to be an installer for 5+ years at circuit city and we tuned every amp install with a test cd).

The best way to set it is using test tones

I find it hard to believe that as an installer for CC you didn't have access to a multimeter.

OP, get a multimeter. A cheap one will do. Then research your amp and see what voltage you should set the gain to. Turn the head unit up loud (but before distorting other speakers. Generally 75-80%) and measure the voltage at the amp. Adjust gain until it is the same as the amp specs. This is a much better procedure than "listen for a pop then go one click down".

[808MGuy]

Originally Posted by wren57

I find it hard to believe that as an installer for CC you didn't have access to a multimeter.

OP, get a multimeter. A cheap one will do. Then research your amp and see what voltage you should set the gain to. Turn the head unit up loud (but before distorting other speakers. Generally 75-80%) and measure the voltage at the amp. Adjust gain until it is the same as the amp specs. This is a much better procedure than "listen for a pop then go one click down".

When you say measure the voltage at the amp, are you talking input voltage or output on the speaker outputs? The gain setting references input voltage which will be determined by the source. Even then, the output of the source is not constant and not always linear through the volume range so the measurement of the source voltage does not always match the optimal gain setting of the amp. I don't know of too many amps other than JL that actually publish what the output voltage should be at rated power. You can calculate it but there's nothing wrong with the method previously described unless you have an O-scope to do it better. I still use the listen and back off method and with the help of todays amps that have clip lights, its good tried and true method.

[talisman311]

Originally Posted by wren57

I find it hard to believe that as an installer for CC you didn't have access to a multimeter.

OP, get a multimeter. A cheap one will do. Then research your amp and see what voltage you should set the gain to. Turn the head unit up loud (but before distorting other speakers. Generally 75-80%) and measure the voltage at the amp. Adjust gain until it is the same as the amp specs. This is a much better procedure than "listen for a pop then go one click down".

I have a fluke I used to set LOCs amongst other things.

Dont listen to this guy.. If you have questionable feel free to PM me. I check the forum sparingly.

[wren57]

Originally Posted by talisman311

I have a fluke I used to set LOCs amongst other things.

Dont listen to this guy.. If you have questionable feel free to PM me. I check the forum sparingly.

Yeah, listen to a CC installer. They always do top-notch work.

http://forum.sounddomain.com/ubbthre...r/65167/page/1

or

http://www.soundsolutionsaudio.com/f...mplifier-gain/

If you do it by ear you're risking clipping and distortion. You can't hear all distortion and clipping but you are still damaging your equipment. Do it by the numbers, not "by ear", and you'll have much better, cleaner and safer results. Enjoy.

[talisman311]

Originally Posted by wren57

Yeah, listen to a CC installer. They always do top-notch work.

http://forum.sounddomain.com/ubbthre...r/65167/page/1

or

http://www.soundsolutionsaudio.com/f...mplifier-gain/

If you do it by ear you're risking clipping and distortion. You can't hear all distortion and clipping but you are still damaging your equipment. Do it by the numbers, not "by ear", and you'll have much better, cleaner and safer results. Enjoy.

Damn right I did top notch work. Repeating customers for the 5 years I worked there. What about you?

Good thing you posted links that actually made a lick of sense this time.

[wren57]

I've only done 7-8 installs, but it's not like any are that difficult (unless you get into heavy fab), just takes time to do it right.

As for the links, they say the same thing I did. I'm just shocked a self-proclaimed awesome installer wouldn't use the correct scientific method to setup systems.