Was the salesperson right? Amplifier question.
 

So I went to a local big name retailer to purchase a 2 x 10" subwoofer setup with amplifier. I decided on the Polk MM1040's since I liked their sound and price point. In terms of amplifiers I was aiming towards the Hifonics amp but the salesperson recommended Crunch amp. I was under the impression that class D amps were usually the best for subwoofers because of their efficiency producing power. However he told that this the Crunch amp would be better choice since it puts out more power and is also an A/B amp so it will have less distortion. I just wanted to get a second opinion, I've had bad experiences with this big retailers in the past so I took his suggestion with a grain of salt.


Polk Audio AA3104-A MM1040 10-Inch Subwoofer
4 OHMS, 350W RMS, 700W PEAK.
MM1040 Car Subwoofer from Polk Audio


Crunch Ground Pounder GPV2000.1 Maxx Watt Power A/B Class Mono Amplifier
1 x 500 W at 4 Ohms, 1 x 1000 W at 2 Ohms, 1 x 2000 W at 1 Ohm Maxx Power
Amazon.com: Crunch Ground Pounder GPV2000.1 Maxx Watt Power A/B Class Mono Amplifier (Silver): Electronics
Hifonics HFi1000 Hfi Series D-Class Mono Amplifier
1 x 475W @ 4 OHMS, 1 x 750W @ 2 OHMS, 1 x 1000W @ 1 OHM
Amazon.com: Hifonics HFi1000 Hfi Series D-Class Mono Amplifier 1 x 475 @ 4 OHMS, 1 x 750 @ 2 OHMS, 1 x 1000 @ 1 OHM: Electronics

Re: Was the salesperson right? Amplifier question.
 

My lil cousin is using crunch amp in his civic... its not that great. Maybe he has a cheaper model? who knows. I would recommend MTX...

Re: Was the salesperson right? Amplifier question.
 

well based on the specs

subs are 350W rms (single 4 ohm voice coil) each. So 350x2 (paralleled coils= 750w @ 2 OHM)

the amp is 750W rms @ 2 OHM

So basically its actually a pretty good match for each other.

Re: Was the salesperson right? Amplifier question.
 

I am not sure what he is talking about "less distortion" with a class AB. Class D would have the least I would think given that it's either always on or always off. AB runs linear which would be very inefficient for a sub system I would think

Re: Was the salesperson right? Amplifier question.
 

Crunch amps don't even do their rated power and they're noisy as hell.

There's a reason they cost pennies. did u get single 4 ohm subs or dual 4 ohm?

Re: Was the salesperson right? Amplifier question.
 

I believe that Crunch test their products on a 14v test bed. Many companies do this and that's why cheap amps can give big power numbers. I would go with a mono channel amp. Kenwood make great amps for the price.

Re: Was the salesperson right? Amplifier question.
 

first, Hifonics and Crunch are made by the same company and the guy was right, D class is a more dirty amp then an A/B class, that's how they gain the effeciancy, just look at the THD numbers.

Re: Was the salesperson right? Amplifier question.
 

what other amps do they have?

Re: Was the salesperson right? Amplifier question.
 

Distortion you can't hear. I'd like to meet some of those who can pick out amplifier topologies in an automobile while it is in motion. What is the average noise floor on the most quiet of luxury vehicles? 60 decibels, give or take a few. Now let's start talking about "normal" vehicles with higher noise floors. Sure, I believe someone can hear the circuit switching while driving.Crunch is the lower end of the maxxsonics line. I installed their 3kw amp and boy that thing sounded like shit. You do have to have a keen ear for distortion, though. Your average joe wouldn't be able to hear it. I wouldn't get the crunch for the sole reason it doesn't do what it says it does. The newer hifonics stuff is alrite and so is the mb quart stuff.

Re: Was the salesperson right? Amplifier question.
 

I have yet to notice any sort of distortion in a class D amp that is set up properly. At the frequencies that sub pick up and the power they need a class D amp is the way to go. Just listen to a well set up system that uses a class D amp and tell me if you can tell any sort of difference if you were to use a class A/B

Re: Was the salesperson right? Amplifier question.
 

i've had all kinds of systems, i'm not saying a normal person would hear it, but it is there. I've heard "muddy" bass from d class amps, where all the drums kind of go together. but you are correct, d class is the way to go for bass.

Re: Was the salesperson right? Amplifier question.
 

Class D amps are more noisy. The important thing is to understand where they are more noisy. Class D amps apply a switching supply directly to the output. That is why they are so efficient. They then run that output through a filter to remove the high frequency switching noise. What you are left with is a relatively clean low frequency output. This is primarily why Class D amplifiers are subwoofer only amps. Although high end class D amps are also used for higher frequencies. Your subwoofer will use the most power so it makes more sense to use class D on subs and class A or AB on mids and tweets. As far as muddy bass hogwash.

I tried to make that as simple of an explanation as possible and glossed over a lot. In summary I wouldn't hesitate to buy a class D amplifier for my subwoofer. Your electrical system will thank you for it.