Amps produce less distortion when driving a purly resistive load as oposed to driving a reactive load (such as a speaker). Speakers store energy and pump it back into the amp via reverse emf. The ability of the amp to absorb this energy will effect the THD. Also the amp may have difficulty driving the low impeadances that appear at certain frequencies and produce distortion. I've designed amps and have measured the distorion into different loads. I'm sure there are some other EE's out there that can back me up.

 

I kept the head unit and replaced the speakers with JL components (tweeters in front of door handles), 70Wx4 JL amp, level converters, and ran RCA's to the amp. My audio system sounds significantlly better than stock! I can actually listen to loud distortion free music while driving at 80MPH with the windows and top down.

Note: I wanted to keep my head unit because I love the stock remote controls and at the time it didn't look like the remote fixes for aftermarket heads were fully baked yet.

I am not an audiophile and my new audio system probably isn't optimal but it sure sounds MUCH better than before and I can always replace the head later.

Hey Pinky, all those monkeys flying out of your butt must be painful. Just Kidding but you can hate me if it makes you feel better.

-Mike

 

[QUOTE]Originally posted by NSXS
[B]Amps produce less distortion when driving a purly resistive load as oposed to driving a reactive load (such as a speaker).

 

Thanks MacGyver. I'm not saying it's a big difference, but lets say you add a line converter and new amp that has a wider power bandwidth and lower output impedance than your head amp, you will probably end up with less overall distortion than before.


It does matter what line converter you use. That depends on your need. There are three basic types, resistor divider, resistor and transformer, and active (recognized by having power leads). They come in different power ratings and with or without level adjustments. The purely resistor based line converter is the cheapest, but also produces the least distortion since it only has resistors. They can be used with low power heads that have common ground outputs. The next version, one with small signal transformers, is used with head amps that have floating outputs (pretty much all high power heads). The transformers will add some distortion, but not too much. Radio Shack makes a resistor divider line converter that I believe works with floating outputs. Make sure before you buy it.

The most expensive line converters use an active buffer between the voltage step down input stage and the RCA preamp outputs. This may dispense with the transformers, and provides a low impedance output to drive the long length RCA cables found in car stereo installations. In this case you want to mount the line converter near the head. Even though you are adding an additional active stage, this may produce the lowest added distortion, especially if you have long low level cable runs. This is by no means the full dirt on line converters, but I hope it helps the newbies.