Millions

So i just completed a budget install. Infinity 60.5cs Kappas components(75rms)-$15(craigslist), and a JL e2150 amp (45rmsx2)-$45(craigslist), and wiring $35, $95 total. I was coming from a bone stock system which i have dealt with since i bought the car new in '05. My goal was simply to make it louder so i could hear music with the top down. To keep it in budget, i kept the stock radio (which i like because it matches the interior and i don't have to mess with changing the dash controls), but needed an amp with high level inputs, which i found. Over all I am very pleased with the result, in fact it gets louder than i can stand for very long. So my question is, why on earth anyone would need 2, 3, or even 4x more power to their speakers?

cvjoint

Lots of reasons. Some speakers are inherently inefficient, this can be because of poor magnet qualities and cheap motors but sometimes the topology itself is low sensitivity. The Pioneer PRS set for example is underhung, and therefore hella inneficient. It's still a great speaker but it takes a bit more power to get to the same output.

Sometimes speakers are just badass and they can handle it. My mids can handle 200w continuous, or about 400w under most conditions. It has enough xmax and ventilation to perform at that output as well. It's also very efficient. So what you end up with is 3-4 times the output of a basic car speaker. Since they are 8 ohms I have to bridge a full size 4 channel amp 90watts x 4 4ohm to get 180watts at 8ohms x2.

I agree there are lots of people overdoing it with 5 killowatts and 99% of that goes to the subs only. I use between 1,500w and 3,000w. Nothing wrong with that. I use efficient speakers too.

lovegroova

In addition to the excellent post above, don't forget that 2, 3 or even 4x more power does not equate to 2, 3 or 4x more volume.

Roughly speaking, 20W is twice as loud as 2W i.e you need 10x the power to double the volume. dB is a logarithmic scale.

GrandMasterKhan

Ironically I think you just answered your own question.

The OEM radio is good for MAYBE 4-8 watts RMS per channel. The system you put together is 45watts RMS per channel. So, ask yourself again. WHY would anyone want more power?

cvjoint

Just want to add that I tested ambient noise WHILE PARKED to be over 100db with the A/C on. I dare you to do some math as to how much output you can get out of a standard speaker at 45W. Add in roadnoise and see if you can even beat the total background noise in this car.

My car is stock btw but with better sound treatment.

lovegroova

Wow, was that with the fan switched to maximum and the recirculate button on?

cvjoint

Yep. It's 92db with the A/C off and idling. The microphone is calibrated and I don't use any weighing method either so it's very accurate.

cvjoint

Yep. It's 92db with the A/C off and idling. The microphone is calibrated and I don't use any weighing method either so it's very accurate.

takeshi

It's not just a matter of loudness but of sound quality at higher volume levels. I can crank mine up without an amp and make it louder than I can stand but it also sounds like crap.

lovegroova

I'm a bit puzzled by your figures. I did a quick check last night, and my car was 55dB. Admittedly, I used my phone (set to "slow"), but it's pretty close to my sound meter.

Were you holding the sound meter, or was it resting on the centre tunnel or dashboard?

FWIW measured 35dB engine off, then 55dB engine on, and 100dB sound system on high, but not maximum, volume.