How to choose a amp?

[Tailgatepro]

How to choose a amp by spec??

 

Copy & paste from one of the amp spec:

 

High-Pass Crossover Frequency: 30 - 400Hz ( how to choose this? is it 10 - 600hz better then 30-400 hz?)

High-Pass Slope (Per Octave) 12dB ( higer dB better or lower?)

Low-Pass Crossover Frequency 30 - 400Hz ( border ranger better?)

Low-Pass Slope (Per Octave) 12dB (higer score of dB better or lower?)

Total Harmonic Distortion 1% ( i think i know this, lower % the better)

Signal-to-Noise Ratio 78dB ( i think lower the better, correct?)

 

[Fastfive1]

from what i know Signal-to-Noise Ratio the higher the better.

[Mona-vie]

These specs you mentioned is not that important. More important is power output.

 

How many watts at 8ohms, 4ohms? Also at what THD? If they rate 10% THD @ 200W, this amp is probably capable of only 100W or less (no one can listen with 10% THD).

 

Also, can the amp produce enough current to drive the speakers. If its rated at 200W 8ohms but just 300W 4ohms, this means it cannot produce enough current to double power for 4 ohms speakers.

 

Then have to read reviews like sound quality, imaging, brightness etc.......

 

Cause specs alone does not tell the whole story about the amp.

[Mona-vie]

Btw, there is one thing about power matching. You need to know the sensitivity of your speakers as well. Less sensitive speakers need more power to drive. Hence need to match the amp to the speaker.

 

[Kinrad]

Here's what I do with out the Specs before I buy or use any amp or sound system in my car

 

First, I ask the salesperson or installer what power rating you should consider

based on your existing stereo, speakers and musical taste.

 

Then probably select two or three amplifiers to compare.

 

First, Compare amplifiers power ratings using the same parameters - ohms rating, voltage or frequency.

(Most people in the industry use ohms rating as the standard of comparison, and set the standard at 4 ohms.)

 

Ask the salesperson to plug the possible amplifiers into a radio and speakers that are similar to the ones in your car.

 

Listen to the performance of each amplifier and select the one that sounds best to you.

 

Check the physical size of the amplifier to make sure it will fit where you plan to put it.