AMP Gains???????

[hussnainh8]

Are you running the amp directly from the PC? Are the RCA's from the amp hooked into the PC? If that's the case then that's likely the problem.

The RCA cables from the AMP go into a little 3.5mm adapter were my old subwoofers are connected to as well.. So I have 2 speakers running on 1 computer .. How can that be a problem?

 

[fatboytyler]

The RCA cables from the AMP go into a little 3.5mm adapter were my old subwoofers are connected to as well.. So I have 2 speakers running on 1 computer .. How can that be a problem?

I couldn't find it in a quick search, but I doubt the headphone jack may not be supplying enough voltage to properly drive that large of a signal.

 

[hussnainh8]

Are you running the amp directly from the PC? Are the RCA's from the amp hooked into the PC? If that's the case then that's likely the problem.

No you think the PC is giving power to the speaker which it isnt.. The AMP is getting its power from a Car battery and the speaker gets its power from the AMP, the sound is coming from the pc to the speaker there is nothing wrong with the sound it is all clear etc!!

 

[fatboytyler]

No you think the PC is giving power to the speaker which it isnt.. The AMP is getting its power from a Car battery and the speaker gets its power from the AMP, the sound is coming from the pc to the speaker there is nothing wrong with the sound it is all clear etc!!

But, your amp gain is based on your audio source voltage. So in a car, the stereo is typically 2-5V on its outputs and the amp is set accordingly. Your amp may not be sensitive enough to be set properly to the voltage of the PC (Again, I do not know what that voltage is). That would explain why you have to use bass boost, which basically boosts the input signal, hence why there is typically distortion present. However, nothing says that this is the problem. Just my .02

 

[Jeffdachef 5,000+ posts]

No you think the PC is giving power to the speaker which it isnt.. The AMP is getting its power from a Car battery and the speaker gets its power from the AMP, the sound is coming from the pc to the speaker there is nothing wrong with the sound it is all clear etc!!

Okay man you need to get straightened out before you start getting totally misinformed by yourself...

normally an amp connected to a head unit you set the gains to match the output voltage of the head unit its not the head unit thats powering it, its how strong of an audio signal the head unit is giving.

Using your laptop, the signal is not strong enough at all to provide any good amount of signal to the amp thats why you have to use bass boost. The thing is, bass boost normally leads to clipping, distortion and heat, which will kill your equipment in the long run.

You Cannot hear distortion with the human ear, you can only check to see if there's distortion in the signal with an oscilloscope. What might sound crystal clear to you might be a square sound wave on the oscilloscope.

 

[hussnainh8]

But, your amp gain is based on your audio source voltage. So in a car, the stereo is typically 2-5V on its outputs and the amp is set accordingly. Your amp may not be sensitive enough to be set properly to the voltage of the PC (Again, I do not know what that voltage is). That would explain why you have to use bass boost, which basically boosts the input signal, hence why there is typically distortion present. However, nothing says that this is the problem. Just my .02

I looked at a YouTube video on how to set the Gain and the guy said multiply the amps wattage and the ohms of the speaker and then find the square root of that number so in my case it is either 400 Watts x 1 OHM = 400 = 20 VOLTS or it is 400 Watts x 4 OHM = 1600 = 40 VOLTS. I don't know if my Speaker is a 1 OHM or a 4 OHM so I chose to set the gain at 20 VOLTS but this doesn't give out much Bass. I want to try 40 Volts now how ever I don't want to risk blowing the speaker etc?? What do you say about this? At the moment it is set at 20 Volts and I hear NO distortion at all.

 

[hussnainh8]

Okay man you need to get straightened out before you start getting totally misinformed by yourself...
normally an amp connected to a head unit you set the gains to match the output voltage of the head unit its not the head unit thats powering it, its how strong of an audio signal the head unit is giving.

Using your laptop, the signal is not strong enough at all to provide any good amount of signal to the amp thats why you have to use bass boost. The thing is, bass boost normally leads to clipping, distortion and heat, which will kill your equipment in the long run.

You Cannot hear distortion with the human ear, you can only check to see if there's distortion in the signal with an oscilloscope. What might sound crystal clear to you might be a square sound wave on the oscilloscope.

You could have given a more kind reply rather than "you need to get straightened out". Right so because it is connected to a computer rather than a Head Unit that is why I have to turn the Bass Boost up to hear any sound. That part understood. So far I have gotten no wires heating up not even a little bit, no unusual sounds etc.. I don't have an Oscilloscope to check if there's any distortion so that isn't an option for me. I am just thinking to set the Gain to how I feel is right somewhere were I can get good bass out of the sub but not push it to its limit, How does that sound to you guys?

 

[Jeffdachef 5,000+ posts]

How to Adjust Amplifier Gains Using a Digital Multi-Meter - Knowledge Base

If your amp does its rated power, then this method should work okay

 

[fatboytyler]

I looked at a YouTube video on how to set the Gain and the guy said multiply the amps wattage and the ohms of the speaker and then find the square root of that number so in my case it is either 400 Watts x 1 OHM = 400 = 20 VOLTS or it is 400 Watts x 4 OHM = 1600 = 40 VOLTS. I don't know if my Speaker is a 1 OHM or a 4 OHM so I chose to set the gain at 20 VOLTS but this doesn't give out much Bass. I want to try 40 Volts now how ever I don't want to risk blowing the speaker etc?? What do you say about this? At the moment it is set at 20 Volts and I hear NO distortion at all.

What do you mean its set to 20 volts? What are you measuring that says 20 volts? And I highly doubt a sub of that power is a single 1 Ohm coil.

 

[hussnainh8]

What do you mean its set to 20 volts? What are you measuring that says 20 volts? And I highly doubt a sub of that power is a single 1 Ohm coil.

When setting the Gain I use a 60Hz tone and play it on repeat then I get my multi meter and put the red and black wires onto the speaker terminals on the AMP and when turning the Gain knob on my AMP the Multi Meter numbers go up .. I carry on going until I get to 20V on the multi meter.. so my Gain is set to 20V maybe a little below that. If its not 1 OHM then its either 4 OHMS or even 8 OHM? Its most likely 4 OHMS then seeing as when the Multi Meter is set to OHMS - 2000 I get the reading 004?

 

[hussnainh8]

How to Adjust Amplifier Gains Using a Digital Multi-Meter - Knowledge Base
If your amp does its rated power, then this method should work okay

I am happy to follow the link you gave me however how do I find the OHMS of my speaker? The Multi Meter gives me the reading 004 when set to 2000 or the reading 066 when set to 200

 

[hussnainh8]

Another discovery!!! ... I now have the Sub woofer wires connected to the AMP like this https://www.dropbox.com/s/aj5aytg9pcizop6/DSC_1110.JPG

Before this they were connected like this .. https://www.dropbox.com/s/eitvrdlks48i2zd/DSC_1103.JPG

I checked with a Multi Meter how much voltage is given out when the Gain is set on max and the Bass Boost also on max and noticed when the wires are set like this https://www.dropbox.com/s/aj5aytg9pcizop6/DSC_1110.JPG I can reach more than 50V but when they are connected to the AMP like this https://www.dropbox.com/s/eitvrdlks48i2zd/DSC_1103.JPG I can reach a Maximum of 30V .. Now I have an idea of keeping the wires like the first picture and set the Gain and Bass Boost to 40V and see what happens.. Reason why I said 40V is because if the speaker is 4 OHMs then 400 Watt x 4 = 1600 and then Square Root of that is 40 .. Who thinks I should do this??