What You Don’t Need to Know
Frequency response (±X.X dB)
This most important speaker spec reveals how natural the speaker sounds. For flush-mount marine speakers, something in the ±6 decibels (dB) range is pretty good. If the manufacturer specifies only a frequency range without a plus/minus dB figure, the rating isn’t very useful.
Sensitivity (SPL @ 1 watt/1 meter)
This tells how much sound pressure you’ll get from a speaker with 1 watt of power. Every additional +3 dB of sound requires double the power, i.e., a speaker rated at 88 dB/1 watt requires 2 watts for 91 dB, 4 watts for 94 dB, 16 watts for 100 dB, and so on. Most people consider 100 dB quite loud.
This tells how much load the speaker puts on the amp, and also how much power you’ll be able to pull from it. The lower the number, the more power you’ll get from your amp — but if you go too low, you’ll tax the amp too much. Marine speakers should be in the 4-ohm range.
Resonant Frequency/Bass Extension
There are technical differences between these two ratings, but they’ll give you a general idea of the lowest frequency you’ll get from the speaker. The lower the number, the deeper the bass you’ll get. With flush-mount speakers, the size of the space behind the speaker will have a big effect on bass extension. Generally, the bigger the space behind the speaker, the deeper the bass you’ll get.
Recommended RMS Power
Ignore this number. It’s rarely the result of technical evaluation. Usually it’s just a mix of the engineer’s gut feel and the marketing guy’s need to show a certain spec. Paradoxically, sometimes a less-powerful amp is more dangerous to your speaker because the less-powerful amp will probably distort more, and distortion tends to damage speakers.
Another number you can largely ignore. While there are legit ways to test this, it usually has more to do with marketing than anything else. (Notice it’s almost always a nice, round number?) It would be great to know if a speaker can tolerate blasting at 105 dB for hours, but a vague maximum power spec will never tell you that.
There is more to a good speaker system than the way it sounds, and we also took note of ease of installation, included hardware and templates.
Clarion CMD8 Play Head
This stereo head’s cutting template was the best we experienced. It was a clear sticker that adhered to the panel, giving crisp cutting lines and drill points. As good as that was, “driving” a jigsaw from drilled corner hole to corner hole isn’t as easy as it looks, and we had to do a little filing and grinding to get the fit perfect.
Clarion XC6610 Amplifier
The compact footprint of this amp was welcome in the GT 150, but it was designed for a flat mount. Not so lucky in this boat, but the factory reps said it would still cool adequately in a vertical orientation. Trim panels attached with Allen screws give access to the mounting-screw holes and¬ then can be replaced for a handsome, sleek look.
“Why pre-drill only four holes on the mounting flange?” we asked ourselves. The screws go through the grille and speaker to fasten it to the mounting surface. We think Clarion should have drilled four more holes through the subwoofer’s aluminum flange to mount the speaker and then used the four screws through the grille and flange.
In both the speakers and subwoofers, the grilles used a twist-lock mechanism after the speaker was screwed in place. Very handy.
They included both white and silver grilles.
Screw caps were included with the speaker grilles to cover the screw heads and beautify the installation.
Sony’s speaker templates were perforated into the box, giving the best stencil guide. Cutting paper templates, then tracing, and then cutting leaves too much room for error.
Only Fusion used spade connectors on the subwoofers. Jensen, Clarion and Sony use screw-clamp fixtures for a more positive connection.