Expert: Wayne Tapia - 5/10/2011

Question
I have 4 speakers in my boat in which are the following specifications.
TI SERIES POWER RATING
150w Peak - 75w RMS
FREQ RESPONSE
70Hz - 20kHz
SENSITIVITY
91dB
I want to purchase an amp that is sufficient and was thinking of a sony marine amp with the following specs.
60 watts RMS x 2 + 150 watts RMS x 1 in 3-channel mode
built-in low-pass filter 80 Hz @ 18 dB per octave
high-pass filter 80 Hz @ 12 dB per octave
CEA-2006 RMS Rated
15-7/8" W x 2-1/4" H x 10-3/8" D
Water Resistant
60 watts x 4 RMS @ 4 ohms
Signal to noise ratio: 110 dB
Frequency Response (Hz): 5 - 50
Input Level Range (V) Line level input: 0.3 - 6
Input Level Range (V) Speaker level input: 2.8 - 12
Operating Voltage (V): 10.5 - 16
Current Drain at rated output (A): 32
Line/Speaker level inputs
Fuse rating: 25A x 2

This is all gibberish to me.....will that amp do the trick?
Thanks so much!

Answer
The only critical specs you want to concern yourself with are these:

On the speakers - the wattage rating (75 RMS) & the impedance (measured in ohms)

For the amp - the output watts per channel, as well as the output impedance (ohms).

For the wattage, it is preferable for the speakers to have a larger # than the amp output. In your case, you've got 60 watts x 4 RMS coming out of the amplifier. That means your speakers need to be at the very least 60 watts RMS or higher.

For the impedance (or ohms), you'll typically want to match this exactly. The amp says 60 watts x 4 @ 4 ohms. Check your speakers - if they are all 4 ohms, you're good to go. If the speakers are 8 ohms (or higher), you can still use them, but you may not be getting the full 60 watts. DO NOT UNDER ANY CIRCUMSTANCE use a speaker that has a lower impedance than the amp. This can severely damage both amp & speaker, and make you pull large chunks of hair from your head...