**Amplifier Gain setting tutorial**

[jntar]

Originally Posted by rj.gordon

I recently put an entire Kenwood system in my 95 Sub. I put in 2 x 1200w sub woofers, and ever since, when I turn the bass up to a decent level, the amps cut out. Is this a grounding issue? power issue? or are my speakers too big for my amps ( 2 x 400w )?

Did you set your gain using this tutorial

[cajundragger]

why does my amp put out more power at 40hz than any other hz? I figure its because I put my DMM in AC, but thats the right setting right?

[jntar]

Originally Posted by cajundragger

why does my amp put out more power at 40hz than any other hz? I figure its because I put my DMM in AC, but thats the right setting right?

Yes set it using AC voltage.

I am not sure what you mean by "why does my amp put out more power at 40hz than any other hz?". Are you telling me that your amp does put out more power at 40hz or are you asking me why you set the gain at that frequency?

If you are telling me that 40hz has more AC voltage it could be a combination of a few things. Impedance rise is the main factor. EQ settings, your actual signal voltage from your headunit, bass boost...It could be many things.

If you are asking...between 40-70hz is where most music is based. IIRC a 4 sting bass guitar's lowest E string is ~37hz. So with normal music you are looking at 40-70hz. So you would want to set it with the frequencys that are present the most.

[cajundragger]

yea it puts its most power out at 40 hz, this is with the HU set all zero for everything, and bass boost on 0....

[jntar]

Originally Posted by cajundragger

yea it puts its most power out at 40 hz, this is with the HU set all zero for everything, and bass boost on 0....

Sounds like impedence rise.

Here is a little on the subject http://www.soundsolutionsaudio.com/f...showtopic=2690

[95Silverado]

So if I have a dual 4ohm subwoofer that will be wired parallel to give the amp a 2 ohm load, I would use 4ohm in the equation, correct?

So would it be: Voltage= sqrt(250wrms(rating of sub) x 4)

And do you get 31.3V for the answer as well?

Thanks in advance

[neptune1230]

I need some help....Here is what I have done and the results:

amp- 1200/5ch.(4x75w@4ohms,sub ch. bridged for dvc, 1x400w@2ohms)

using the calcs, I figured 17.3 for speakers and 28.3 for sub.

I used a test cd, 50hz and 500hz, I set the amp channels for those frequencies. I used the ohm meter to adjust each channel to match calcs.
Now this is what I do't understand, I set the amp using the ear method about 6 months ago when all equipment was new. When I set the amp using the amp meter the gains are less than 1/3rd the old settings. I don't listen to music loud and have never pushed the volume past 50%.
My max setting is 64, using my old settings, I was listening @ about 15,maybe 25 with the windows down.
Now, with the new settings, I have to turn the volume to 25 sitting still and upwards of 40-45 when driving. what's the big difference? The reason I am concerned is that I am about to install some CDT's and want the system correct? Any help or comments are greatly appreciated, thanks

[cantburn]

great post

[nebraskaz71]

ok kinda confused ........ i have a jbl 600 amp that does 300 - 325 rms per sub on 2 subs wired to a 2ohm load...... what should gain be for that?

also have 125x2 amp on 4ohm components?

[jntar]

Originally Posted by nebraskaz71

ok kinda confused ........ i have a jbl 600 amp that does 300 - 325 rms per sub on 2 subs wired to a 2ohm load...... what should gain be for that?

also have 125x2 amp on 4ohm components?

OK...

JBL amp
sqrt(600x2)=34.64v

2 channel amp
sqrt(125x4)=22.36v(individual channel)




If any of you still have problems from earlier posts that I missed feel free to email or PM me.
jntar@yahoo.com

-Justin

[camaroguy69]

ok let me make sure i got this.I have an Us amps AX2000 should be 2000 watts rms i have it at a 4ohm mono.My volts should be at 63.24???correct

[dleccord]

it does 2000rms @4ohms? should be around 89V

[Danielson]

Im running 2 10 inch kicker compvrs off of an auro rpm2300 with 150 wrmsx2 at 4 ohms. the speakers can handle 300 rms a peice. I have my amp at 3/4 gain and bass boost half way. Will it make my amp last longer by keeping 3/4 gain and half bass boost. I want to turn it up but also would like to keep the amp in good shape. Thanks. One more question not about amps. Where can I get cheap kicker grilles for my 10 inch cvrs? thanks

[dleccord]

hard to say but i definitely think you are sending clipped channels to your subs, i could be wrong though. best thing to do is set your gains by using this tutorial

[jntar]

Originally Posted by v6chevyoffroad

Im running 2 10 inch kicker compvrs off of an auro rpm2300 with 150 wrmsx2 at 4 ohms. the speakers can handle 300 rms a peice. I have my amp at 3/4 gain and bass boost half way. Will it make my amp last longer by keeping 3/4 gain and half bass boost. I want to turn it up but also would like to keep the amp in good shape. Thanks. One more question not about amps. Where can I get cheap kicker grilles for my 10 inch cvrs? thanks

You have 300rms total out of your amp...Trust me you will be better off setting it to 300 total and then saving for a more powerful amp if you are unhappy.

Most shops that sell kicker sell the grills too...I paid $20 for the 12" versions a few years ago.

[OoMesKoO]

When finding square root... is it the impedance of the total ohm load? Like..... 2 4ohm drivers = 1ohm load??

[x6369x]

Originally Posted by OoMesKoO

When finding square root... is it the impedance of the total ohm load? Like..... 2 4ohm drivers = 1ohm load??

SVC or DVC subs?

Try this ...
http://www.the12volt.com/caraudio/boxcalcs.asp#par

[jlansaw]

I'm not sure I understand....would you use the sum of the two amplifier channels or one channel to determine the amp output? Do you use the total speaker load if using more than one speaker or do you use the impedance of an individual speaker? The overall process makes sense, I just want to be sure I'm using correct data....garbage in, garbage out...

[jdstephens]

I am totally lost...
I get the idea, but figuring out what my voltage needs to be is a dinger for me...
I have 4 8ohm subs
using one channel@ 2 ohms/240 watts
I get confused easily...Can someone help me please?

[tylers88]

i just picked a volume for my fronts to distort at and put my rears on for one more than that un hooked my rca to my 4 channel and cranked my head unit put in the bass nob on my punch 75 25-life and started turning them up till they distorted then turned it down about a 1/16 of a turn re hooked every thing and she hits in the 130-137 db range all day long