How to use the phase knob on my amp?

[kingsxman 10+ year member]

Just got an old school mono block Lanzar Optidrive amp. (SL800D). Going to drive my 2 JL 10w6v2's on it. It has a phase knob on it that goes from 0 to 180 degrees. I havent hooked the amp up yet and thought I'd be "proactive" and ask....WTF is this for and how do I use it?

Thanks

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[regal8r 5,000+ posts]

its to change the phase of the subs...leave it at 0

 

[Bartak1 10+ year member]

Reverses polarity (like hooking the pos. to the neg, and neg. to pos.)

Try it either way, see what sounds/fits best.

 

[kingsxman 10+ year member]

Great. tHanks for the info.

 

[Dr. Dan 10+ year member]

When a signal is 180 degrees out of phase with an identical signal, such as between left and right side speakers or two subs with the same input, the two signals cancel themselves out resulting in silence. This extreme phase cancellation shouldn't occur unless something is wired incorrectly.

But phase cancellation of a lesser degree happens all the time due to reflections off hard surfaces and the distances between the speakers and your ears. It usually sounds like a hollow dip,buzziness or roll off. It's hard to describe in words. But turn the knob untill everything sounds as tight, focussed and even as possible, you should hear the difference.

 

[AllStar1500bd 5,000+ posts]

When a signal is 180 degrees out of phase with an identical signal, such as between left and right side speakers or two subs with the same input, the two signals cancel themselves out resulting in silence. This extreme phase cancellation shouldn't occur unless something is wired incorrectly. But phase cancellation of a lesser degree happens all the time due to reflections off hard surfaces and the distances between the speakers and your ears. It usually sounds like a hollow dip,buzziness or roll off. It's hard to describe in words. But turn the knob untill everything sounds as tight, focussed and even as possible, you should hear the difference.

thats a hell of a second post. nice job.

 

[PepsiFiend69 10+ year member]

thats a hell of a second post. nice job.

Amen. well put. welcome to the forum

 

[Dr. Dan 10+ year member]

thats a hell of a second post. nice job.

LOL!!

Hey Thanks Pepsi, Allstar. I'm not worthy

I'm just about to do my first car install, but I've been a recording engineer for 15+ years, and phase is one of my biggest enemies.

Dig this scenario:

A speaker and a microphone is almost the same thing, just operating in reverse. So in a typical session, I might use up to 13 or 14 microphones on a drum set, and all those mics have to be in phase. Some of the mics are inches apart, others could be 20 feet+ apart. Compare that to using 4 or 6 speakers in a car.

In other words, It's a Royal Nightmare of a B*!tch !!

Cheers!