Will inverting a LFE coax cable change the phase?

[ParanoidAI]

In my dual sub headaches, somebody mentionned that creating a custom LFE coax cable(inverting the connection), will change the phase from it.

Does that make sences? I've turned google upside down on this question, and found nothing.

I know I can do it from the Speaker Front Right and Left feed, but I need doing it from the LFE signal..

Thanks!

 

[trnqk7]

I'm confused on how you would plan to do this-a LFE connection is a single cable that contains both the ground and signal in one cable. You can't invert it I wouldn't think

If you mean switching the left sub to the right sub's connection (or front to back, wherever they are located)...then the only way you might see a problem is if there was true "stereo" bass recorded and being sent to the subwoofers. But, even at that, bass shouldn't be able to be localized, so you shouldn't notice it.

I wouldn't worry about it-just try it and see if you like it or not.

 

[PeterWhite]

In my dual sub headaches, somebody mentionned that creating a custom LFE coax cable(inverting the connection), will change the phase from it.

Does that make sences? I've turned google upside down on this question, and found nothing.

I know I can do it from the Speaker Front Right and Left feed, but I need doing it from the LFE signal..

Thanks!

If you reverse the polarity at one end of the cable, yes, you'll reverse the phase by 180 degrees.

 

[GlocksRock]

If you want to alter the phase, your sub should have a switch for that, if your sub doesn't, then your receiver should.

 

[j_garcia]

Can you collocate the subs? That should eliminate phase issues.

 

[TLS Guy]

In my dual sub headaches, somebody mentionned that creating a custom LFE coax cable(inverting the connection), will change the phase from it.

Does that make sences? I've turned google upside down on this question, and found nothing.

I know I can do it from the Speaker Front Right and Left feed, but I need doing it from the LFE signal..

Thanks!

You could not invert an LFE cable. If you did invert one end, you would have no signal, as the signal would short to ground. I assume you are soldering on your on plugs. The center hot wire goes to the tip, and the screen to the body of the plug. I fail to see how you could get that wrong and still take care of yourself.

 

[Djizasse]

You can't invert the signal on the coax, but maybe you could do that inside the sub. Inverting the high level signal will invert the polarity.
If I'm wrong I know someone will say so

 

[Haoleb]

You can't invert the signal on the coax, but maybe you could do that inside the sub. Inverting the high level signal will invert the polarity.
If I'm wrong I know someone will say so

Nope you got it , If you switched the leads on the driver you would be inverting it.. Of course, Then you would have to take the driver out and change it back if you ever wanted it back to the same phase.

 

[ParanoidAI]

Well.. thanks thanks for all who replied..

So there's was no definite answer, I tried it.. Inverted a Coax cable..

Guess what, it does reverse polarity!

So that works perfectly!

Thanks again to all who replied!

 

[TLS Guy]

Well.. thanks thanks for all who replied..

So there's was no definite answer, I tried it.. Inverted a Coax cable..

Guess what, it does reverse polarity!

So that works perfectly!

Thanks again to all who replied!

If it did work, then something is not grounded properly. Both the outer part of the RCA sockets on both your receiver and sub, should be at ground. So if you reversed the connection on the RCA plug of your sub, the hot should then be connected to ground, and you should have no signal, as you should have grounded out your LFE output.

If you are getting a signal through with the hot wire connected where the shield should be and the screen connected to the live tip, then you have serious and hazardous problems with your set up.

 

[Haoleb]

If it did work, then something is not grounded properly. Both the outer part of the RCA sockets on both your receiver and sub, should be at ground. So if you reversed the connection on the RCA plug of your sub, the hot should then be connected to ground, and you should have no signal, as you should have grounded out your LFE output.

If you are getting a signal through with the hot wire connected where the shield should be and the screen connected to the live tip, then you have serious and hazardous problems with your set up.

Not all signal ground are tied to chassis ground. Don't just assume the guy has a serious problem when most likely he doesnt.

 

[TLS Guy]

Not all signal ground are tied to chassis ground. Don't just assume the guy has a serious problem when most likely he doesnt.

I have serviced a lot of gear, and have never seen an RCA input outer not connected to the ground. If he has a two pin sub and it malfunctions then the a high voltage could pass to the live pin of the LFE output of his receiver and do serious damage. I would never consider operating equipment in that fashion.

At the least he should see with a meter if the RCA shield of that sub is connected to the chassis. I bet the Shield of his RCA output is connected to the chassis. Without very thorough investigation of this situation. It sounds highly risky on lots of levels. That is certainly not a good or sensible way to reverse phase, and I highly doubt it is safe.

 

[ParanoidAI]

I have serviced a lot of gear, and have never seen an RCA input outer not connected to the ground. If he has a two pin sub and it malfunctions then the a high voltage could pass to the live pin of the LFE output of his receiver and do serious damage. I would never consider operating equipment in that fashion.

At the least he should see with a meter if the RCA shield of that sub is connected to the chassis. I bet the Shield of his RCA output is connected to the chassis. Without very thorough investigation of this situation. It sounds highly risky on lots of levels. That is certainly not a good or sensible way to reverse phase, and I highly doubt it is safe.

You're probably right on this... It did work, but at high volume, I noticed a small humm since that setup.

Let's stop that non-sence thread.. I'll forget my redneck setup and but a phase control box or something like it..

Thanks a lot to all...

 

[Haoleb]

I have serviced a lot of gear, and have never seen an RCA input outer not connected to the ground.

I'm sure I havent worked on as much gear as you have but I have seen designs with the signal ground not connected to the chassis ground. And of course if thats the case with his subwoofer theres no more chance that it would damage other equipment than it would if his RCA's were properly hooked up.

Really, if you wanted to invert phase like has been said already you can just switch the polarity on the subwoofer driver. Would be a 10 minute fix unless they are using different size quick connect's or the wires are soldered.

 

[TLS Guy]

You're probably right on this... It did work, but at high volume, I noticed a small humm since that setup.

Let's stop that non-sence thread.. I'll forget my redneck setup and but a phase control box or something like it..

Thanks a lot to all...

This sub I suspect has a two pin connector or you are using a ground break. The hum is coming because the chassis of your sub is connected to the hot pin out of your receiver.

If you want to revers the phase why not either reverse the driver connection, or even easier reverse the connection to your other speakers?

Anyway I'm relieved you are not pursuing that highly irregular connection.

 

[TLS Guy]

I'm sure I havent worked on as much gear as you have but I have seen designs with the signal ground not connected to the chassis ground. And of course if thats the case with his subwoofer theres no more chance that it would damage other equipment than it would if his RCA's were properly hooked up.

Really, if you wanted to invert phase like has been said already you can just switch the polarity on the subwoofer driver. Would be a 10 minute fix unless they are using different size quick connect's or the wires are soldered.

I have only seen that with balanced connections. I have not seen it with RCA unbalanced connections, and actually I'm at a loss to see how it could not be connected to the common rail of the circuit, even if the common circuit rail were isolated from the chassis. So it still would be poor practice.

Any way his easiest solution is to reverse the connections to his other speakers.

 

[Sheep]

If your subwoofer doesn't have some sort of phase adjustment, you need to upgrade.

SheepStar

 

[Audioholics]

If your subwoofer doesn't have some sort of phase adjustment, you need to upgrade.

Well, or just move it. Moving the sub will effectively adjust the phase of the signal in how it relates to the room.

I think Sheep is saying that almost anything current that is over $150 is going to have at least a phase switch, so the presumption is that you have an old HTiB sub or something that is a holdover from a cheaper system. Of course, we don't know what you have and could be mistaken.

 

[ParanoidAI]

Well, or just move it. Moving the sub will effectively adjust the phase of the signal in how it relates to the room.

I think Sheep is saying that almost anything current that is over $150 is going to have at least a phase switch, so the presumption is that you have an old HTiB sub or something that is a holdover from a cheaper system. Of course, we don't know what you have and could be mistaken.

I got two nice subs, two PRD10 from paradigm. They retail for 400$ each, but the newer version has a phase switch now. I have Monitor 7 as front and mini monitor as surrounds..

Those two subs is a good match I think. I wont upgrade now, definitly.