Doh! Wanted to do a before and after comparison with the two new speakers and amp, prior to adding the sub. I installed the amp in fairly tight quarters, as can be seen here based on the OEM install.



Guess I had the gain set too low, as I got no sound from the new speakers, and didn't want to go too far with the volume because of time of day and the fact that the head unit is still driving the old speakers. Unfortunately, the gain controls are on the far side of the amp, and inaccessible with the tools I had at hand. Guess I'll have to pull it and rig longer RCA jacks on a temporary basis, or use a mirror, flash light, and stubby screw driver to adjust gain where it sits. Then I'm gonna have pull this stunt again when I get the sub enclosure built and installed. Better stick to my day job.

Nice job...

Here is a tip.

I made a MP3 file that is basically a frequency sweep. Copy it to iPod or whatever you need to play it through your stereo.

Start with a low volume and run the MP3.

All loudspeakers have a resonant point where they vibrate uncontrollably. When put into an enclosure, mounted to a board, or whatever, this resonance is dampened, frequency shifted, or eliminated alltogether.

And even if eliminated, it can still vibrate the surface it is attached to, which can cause something else to vibrate. Say that cup holder - maybe at a certain frequency, it could vibrate due to the speaker. Its not a problem if it does, unless it is audible. Then you want to keep it from vibrating.

So the MP3 file is an aid in detecting unwanted audible vibrations in nearby components, kick panels, or other things.

I am sure we have all seen the kid that put a subwoofer into their car and the quarter panels are vibrating wildly and making an awful noise.

So what this MP3 file does is to sweep through all of the audio frequencies. The purpose is to detect any unwanted vibration in the speaker, surface it is attached to, or other nearby objects.

As the frequency sweeps, you might find that cup holder vibrating at one spot along the sweep. If not, crank up the volume a bit, and try it again. Continue cranking up the volume in steps until you are satisfied that nothing nearby is vibrating and making noise.

While not perfect due to the MP3 format, the waveform should sound fairly clean. If you hear any distortion, something is probably either vibrating. You may not be able to completely get rid of the anomalies, but you should be able to improve the sound.

If that cupholder is vibrating, a bit of VHB or silicone will secure it. You might also find you have to tighten down a screw or two near the speaker. You might also find that you may have to wedge in, glue in, or 5200 in a small stiffener piece of wood somewhere to completely get rid of the vibration.

I need to stress that vibration itself isn't usually what is annoying, but rather when the vibration causes a panel to audibly rattle is what you are trying to fix.

Anyway, its a nice way to perfect your sound system that you paid a lot of money to build.

Here is the MP3 file. I created the file so there are no copyright issues.

http://members.toast.net/boatguy/sweep.mp3

It doesn't cost anything to do this, and takes maybe 20 minutes out of your time, but in most cases will improve your sound system.