Xanth's Audio Build (Page 3/8)
Blacktree JAN 28, 12:48 PM
Yes, turning down the gain does reduce power output.

Custom2M4 has a point. The main enemy of speakers is clipping. However, running the speaker way above its rated power will make the voice coil get hot. If it gets hot enough, the heat will damage the voice coil.
Mr.PBody JAN 28, 04:31 PM
Mine will be getting 500+RMS, but then again I have a 12...
Xanth JAN 28, 04:56 PM
In theory, the max output of mine is 203 watts bridged the way I have it. It is more than enough for the small sub I have now, and should have no trouble with an 8inch should I choose to upgrade.

I'm waiting on the part now that I'm going to try and modify so I can control the amp volume using the performance sound overhead, I'll get some pictures of it and what I'm doing once it arrives.

[This message has been edited by Xanth (edited 01-28-2008).]

Xanth JAN 30, 05:52 PM
Here's the toy that arrived today, PAC LC2 RCA Line converter and level control. This unit converts high-level inputs into low-level RCA outputs:



Knob that controls the volume of the RCA outputs:



High-level Inputs and the low-level RCA outputs:



Next step will be to pull it apart. The unit itself will mount by the amp, where the speaker connections are at the moment. The speaker harnesses will now connect to this unit, and I will make short RCA cables to go to the amp.

The knob will be removed, I will be determining how I can modify my performance sound overhead to control this unit. Easiest thing would be to mount the knob, but I am determined to retain the factory style slider.

One idea I had was replacing the knob with a small gear driven by the slider, would work but not very pretty.

[This message has been edited by Xanth (edited 01-30-2008).]

avengador1 JAN 30, 08:22 PM
You might be able to wire in the slidder in place of the knob, they are both probably variable potentiometers. You just need to see if they are in the same range.
Xanth JAN 30, 09:17 PM
Possibly, I don't want to get my hopes up yet though. My multimeter and overhead unit aren't with me, so I can't check into it yet. Would be great if they were close. I could probably find another slider potentiometer that would meet my needs though. All RadioShack has is rotary pots, guess I'd have to snoop around online to find what I need.
Xanth JAN 31, 11:05 AM
Well, here's the LC2 pulled apart:


And here's what I was worried about:


Hard to see in the picture, but the POT has two sets of three terminals. I was concerned it may be like this. One layer for left channel, one layer for right. I don't know the technical term for this type.

So what I'm thinking ill do, since I'm fairly certain the performance sound is only a single unit as it controls the amp gain, I'll replace the performance sound POT with two slider pots mounted together.

So sliding the performance sound knob will move the two slider pots, controlling this unit. Where the knob is currently mounted on the unit I'll have a connector for the wiring harness.

Edit: I'm seeing something called "Stereo" pots here, maybe that will do what I need?
http://www.labelec.be/products.aspx?sid=181

[This message has been edited by Xanth (edited 01-31-2008).]

Blacktree JAN 31, 12:47 PM
The non-linear stereo slide pot is what you're looking for. If you can find one with the right resistance range, you're set.

[This message has been edited by Blacktree (edited 01-31-2008).]

Xanth JAN 31, 12:48 PM

quote
Originally posted by Blacktree:

The stereo slide pot is what you're looking for. If you can find one with the right resistance range, you're set.



Excellent, that is what I was hoping

With luck I'll find one that will fit well in the overhead.
Arns85GT JAN 31, 01:29 PM

quote
Originally posted by Eau_Rouge:

Hey guy's, sorry but I've got what might be a stupid question to ask so I appologize ahead of time.
My question is - does adjusting the gain on an amplifier reduce the watts RMS that is sent to the subwoofer. I've also got a similar set up to Xanth's in my car with the exception of the amplifier as I'm afraid to use my current amp which is rated at 170 watts RMS x 1 channel. If reducing the gain to minimum will reduce the RMS watts then that will save me from getting another amplifier. Can someone confirm whether adjusting the gain does anything to the RMS watts sent to the sub. I've got a sub that's rated at 50 watts RMS and I don't want to over power it and blow it up.

Thanks!



Bringing down the gain just drops the strength of the signal contained in the current. It does not change the current. You can ramp down an amplifier pretty easily. What you do is change the ohms of the speakers upward. In other words, if the amp operates at 500w @ 4 ohms, put it into a 16 ohm speaker system and the wattage effectively drops down to possibly as low as 100 watts. (more heat though) Also, the maximum wattage is at maximum volume. Run your volume at 1 or 2 and you are also effectively reducing your wattage. Hope this helps.

Also, check the wattage rating. Is it maximum wattage or RMS wattage? Huge difference.

Arn