PSW350 Calibration Question

jgido759

Picked up the S&V Tune-Up Calibration Disk and calibrated my system. Sounds so much better. Now I have a question concerning the calibration of my Polk PSW350. The sub is connected to my Yamaha RX-V595 via a subwoofer cable connected to the "Sub Out" on the receiver and the "LFE IN" on the sub.

Is it "better" to run the subwoofer amp volume control higher (12:00 position) and the A/V receiver sub output signal lower (i.e. -5 instead of 0, receiver range is from -20 to 0) or to run the receiver wide open and adjust with the sub amp? Which will produce the "cleanest" sound?

Dr. Spec

jgido759:

When you crank up the volume on anything with an amplifier, you are also proportionally cranking up any background hum and noise along with it.

As a test, simply stick your ear next to the sub with no signal input and max out the volume control. You will hear a noticeable increase in noise and hum.

This concept is known as the Signal to Noise ratio, or S/N for short.

The hotter your input signal is to the sub (say 0db or higher), the easier it will be for the sub amplifier to convert that signal to useable sound with a minimum increase in its own inherent noise and hum. This situation would have a high S/N ratio, and that's a good thing.

Conversely, if you feed your sub a very weak signal (say -20db), it will be harder for the sub amplifier to convert that signal to useable sound, and you will need to crank the volume control on the sub much higher, and the associated increase in noise and hum will be proportionally greater. This situation would have a low S/N ratio, and that's a bad thing.

As such, I run my receiver sub volume at +1 db, and adjust sub volume at the sub.

Hope this helps............

Spec

jgido759

Dr. Spec,

Thanks for the explanation. That is how I currently have it set up. I just wanted other people's opinions as to how they would calibrate their sub.