new amp need install help

well i have the amp now just installed it and they sound terrible the mirrors dont even shake and the 500 max sony i had shook every mirror easily. i dont know why they sound so bad but i looked at how the subs were wired since my brother-in-law wired them for me the first time, anyways the subs have a wire running to the positive pole on the basket and then one to the negative and then 1 wire is on the positive and just ran to the other negative so its not going anywhere and they sound like crap on that amp and ive already messed with the gain and bass eq could it be they have no air room(truck box in my back seat)?

so there is only 2 sets of wires from each sub so how should they be wired for this amp besides new subs thats out im only 16

Originally posted by ShakinPlates



Originally posted by rickster6924



Originally posted by ShakinPlates



Originally posted by rickster6924



u need a 2 ohm class d amp because that amp is 2ohms per channel or 4ohms bridge ur subs r dual 2ohm so u can only hook them up at either 1ohm or 4ohm per channel! Or 0.5ohms and 2ohms bridge

He doesnt need a class D. What are you talking about??? Just read crutchfields deal.

why don't u tell me why he don't need a class d ampClasses of amps are related to the circuitry and how the power is switched and distributed throughout the amp. In no way is it manditory to run a certain class amp....

U don't go by class u go by ohms and wattage! Class d amps r usually rated at 1ohm stable and 2ohm stable and class AB r usaully rated at 2ohms per channel or 4ohms bridge! To get full power out of the amp u have to wire it at the lowest ohm level it's stable at. Going lower than what the amp is stable at is what causes the amp to shut off when turned up loud be cause the amp tries to produce more power than what it was designed for so the protection circuitry kick's on and the amp shut's off

Edited: 10/30/2006 5:00:11 PM by rickster6924

Originally posted by rickster6924



http://www.audiobahn.com/Audiobahn06/pages/tech.html

http://www.rockfordfosgate.com/rftech/wiringwizard.asp

You don't need new subs. Yours are fine. You don't have to get a class D amp either.
Your amp is fine. My suggestion would be to wire the voice coils on each sub in series to make them each a 4 ohm load. Then I would hook one sub to each channel. That is the safest way to get the most power out of that amp. I will take a stab in the dark and say you will need a bit more airspace than you have. With your old amp were you using these same speakers in this same enclosure? If all you changed was the amp then that would be your problem.

if u hook them up at 4ohms per channel then u will only be getting about half the power

you need dual 4 ohm subs or an amp stable at 2 ohm mono,last i checked crunch doesn't make an amp that is 2 ohm mono stable and i am pretty sure the alpine subs use a small enclosure so i doubt thats your problem(also check the rms power of the amp thats what you will be getting at 4 ohm per channel, they probably sound bad because they are starved for power

your subs are wired right your problem is the amp. Ive been an installer for 15 years and you do need either a 2 ohm stable mono amp or a 1 ohm stable 2 channel amp. your problem is that your amp is only going to put out 1200 watts if it is at 4 ohm mono (and lightning hits it) and you are in 4 ohm stereo so YOU ARE ONLY GETTING HALF THE POWER if your lucky. Go get yourself a new amp and youll be fine check out the rockford power series or punch series and youll find something that will work. Probly cost a bit more but well worth it!

rule of thumb in car stereo- one dollar=1 watt meaning if you paid $199 for a 1200 amp,you got ypurself a 200 watt amp,---lol

Edited: 10/30/2006 6:43:55 PM by waylowwhitey

Edited: 10/30/2006 6:41:07 PM by waylowwhitey

Originally posted by rickster6924



if u hook them up at 4ohms per channel then u will only be getting about half the power

As I said, that is the SAFEST way to get it working. I did not say it would give him all the power in the world. I merely implied that it would give him sound without risk of melting the MOSFETS inside, as is generally what happens to a AB class amplifier when pushed past its' limits. I have noticed over the last 15 years of working with electronics that inexpensive brands of amplifiers generally have a loosely regulated (read that as "cheap)power supply. I imagine that a Crunch amp falls into this catagory. These power supplies don't like very low impedance loads, especially if you consider that the impedance changes as the frequency varies. A 4 ohm nominal load can drop as low or lower than 1 ohm, but only for short bursts.I think we can all agree that 1 ohm loads on this particualr amp will produce less than satisfactory results. If it was 1 ohm stable, that would be different. Making it a class D would not immediately make it 1 ohm stable. That would be comparing apples and oarnges.If you want top notch results, buy top notch stuff, i.e. Kicker, PPI, Orion, etc.If you choose to stay with the amp you have, then wire it as a 8 ohm bridged load, or as 4 ohms per channel. Only other option would be to purchase external resistors that would put your impedance in the acceptable range, + - 5 %Edit:I will agee that you will not see 1200 watts from that amp unless lightning strikes it. I give it more along the 200-300 watt range, if everything is in ideal working condition.