QuestionQUESTION: Would feeding 750 watts rms too much for a 600 rms sub. I found a couple of amps that do this for a good price. Here they are if you care to have a look.
Boss Audio GT1500D:
Technical Specification
RMS Power Range : 540-800 Watts
Number Of Channels: 1
Maximum Power: 1500 Watts
Low Frequency response: 20 Hz
High Frequency Response: 1500 Hz
Built In Crossovers: Yes
Channel Separation: Yes
Features
CLASS D MonoBlock Power Amplifier with Remote Subwoofer Level Control
Max power, 2ohm: 1500W x 1
RMS power, 4ohm: 540W x 1
RMS power, 2ohm: 800W x 1
Frequency response: 20-1500Hz
Signal-to-noise ratio: >100dB
Dimensions: 9-3/8"Wx2-5/8"Hx11-3/4"L
Remote subwoofer control
Line out (for system building)
Variable low pass crossover (24dB/oct)
Variable subsonic filter (24dB/oct)
Phase switch
Boss Audio SE2500D:
Technical Specification
RMS Power Range : 750 Watts
Number Of Channels: 1
Maximum Power: 2500 Watts
Built In Crossovers: Yes
Channel Separation: Yes
Features
Max Power @ 1-Ohm: 2500W x 1
Max Power @ 2-Ohm: 1800W x 1
RMS Power @ 4-Ohm: 750W x 1
Remote subwoofer level control
Low level inputs
Line outputs
Variable gain control
Input sensitivity selector
Variable lowpass crossover
Strapping capability:
Strap two amps together for twice the power
Variable subsonic filter
Phase shift selector
Power and protection LEDs
0-+18dB variable bass boost
Signal to Noise Ration: > 100 dB
THD: 0.01%
Dimensions: 11-5/16"W X 2-3/8"H X 12-11/16"L
I also heard that it is better to over power than under power. Is that true. Which one do you think is the better of the two. Or are those two even good.
ANSWER: Hi Michael,
I haven't personally used or installed Boss Audio amplifiers. However, I did manage to find the installation manuals of each of the amps you listed. Based on what I saw, I am extremely skeptical of the power output specifications they've published.
Each of the amplifiers uses two 20-amp fuses. That means that the maximum input current from the car's electrical system is 40 amps. If we assume the charging system voltage is 14.4 volts (the standard output of an alternator) then the maximum continuous power used by the amplifier is 576 watts. (Power is equal to the product of the voltage and current).
No amplifier can produce more power for the speakers than it takes from the vehicle's charging system. In other words, if the amplifier is using 576 watts from the battery, then it can't possibly produce 750 watts for the speakers (at least, not for very long). In fact, since no amplifier is 100% efficient, it can't even produce 576 watts for the speakers, because some of the input power is always wasted as heat.
The upshot is that Boss Audio's power ratings for these amps can't possibly be true. Since there's no way to determine the actual power output, I wouldn't recommend purchasing either of these amps.
You can't really compare amplifiers unless you can find reliable power ratings. Because of this, the Consumer Electronics Association created a standard for amplifier power ratings a few years ago. The standard is called CEA-2006. If you look for CEA-2006 compliant amplifiers, you can at least be sure the amp can actually produce its rated power; and you'll be comparing "apples to apples" when you're choosing an amp.
Not every manufacturer uses the CEA-2006 standard. Some manufacturers don't use it because they routinely inflate their power ratings for marketing purposes. Others, including some high-end competition amplifier manufacturers, don't use the CEA-2006 standard because their own rating standards are even more stringent. Unfortunately, I think the Boss Audio brand falls into the first group.
As for your other question: I don't agree that it's better to over-power than under-power a speaker. A speaker power rating isn't quite the same as an amplifier power rating; when a manufacturer lists a speaker as "600 watts RMS", they mean that 600 watts is the maximum continuous power that should be used with that speaker. Any higher power levels increase the risk of speaker damage. I generally recommend choosing an amp that's rated between 50% and 100% of the speaker's RMS power rating: for a 600-watt speaker, any amp that falls in the 300-600 watt RMS range will work perfectly well.
One final point: whether you're looking at speakers or amplifiers, always ignore the "peak" or "max" rating. These numbers are almost always purely for marketing.
Have fun!
Brian
---------- FOLLOW-UP ----------
QUESTION: What is the best amp besides the alpine. Which one would you buy because i like my music loud and i want people to hear me down the block. I listen to hip/hop and a little bit of techno.
AnswerI don't think there are any amps that will do better than the PDX1.1000, but it's pretty pricey.
Here are some other amps that would match up well with those subs:
Alpine MRP-M1000
Kenwood KAC-9103D
Kenwood KAC-9104D
Kicker ZX1000.1
JL Audio G-MAX
Precision Power PPI D3000/1
I haven't personally used all these amps, so I can't really make a recommendation out of the list. They're all either CEA-2006 compliant, or use comparable power rating standards, so you can trust the ratings. Any of them should give you the sound you're looking for.
