Buzzing sound from L1®

[packman]

I do KJ. I have gotten a bad buzz from time to time. Finally found that if the video wire was hooked to a bar TV and the bar tv was still hooked by the coax to the local cable system I would get a terribly loud buzzing. I disconnected the coax and the buzz immediately was gone.

[djrhouse]

Brian; I never heard of those before "Ferrite chokes". What do they do?

The Bose Tech is sending me a power supply. He thinks that is my problem because I am using one digital and one analog channel and they may not mix well and maybe causing the left right phase cancellation. I should get it tomorrow or Friday at the latest. I will post my findings afterwards.

[brianharris]

Ron,

ferrite chokes cut out radio frequencies that interfere and cause that buzzing sound and/or radio stations coming through.

This is what they look like:




Go HERE

[djrhouse]

Ok Guys, the power supply did the trick but I still hear hissing but I think if I adjust the gains properly it will deminish quite a bit. Hopefully something will be added to a future wiki that L-1 Model II users must have a power supply when using the T-1 if you are going to use two L-1 Model II systems for DJ use. Here is how my setup is and it's balanced sound with bass and high frequencies:

Mixer Output to 4/5 input on the T-1
Analog Input on the L-1 Model II to Aux Output on the T-1
Analog Input on the second L-1 Model II to Master Output on the T-1

Plug in the power cable, adjust the gains properly and that is it.

Special thanks to ST, Dan, Brian and the Bose Rep who took care of me with the power supply.

Ron

[ST - Pro]

Hi Ron,

Just to clarify so I can put something in the wiki...

You got rid of the phase cancellation by running both T1®s using the analog outputs to the Power Stands?

In order to do that you would need an AC adapter for each T1®.

Have I got that right?

[Mark-at-Bose]

quote:

Originally posted by DJ Ron:
...Here is how my setup is and it's balanced sound with bass and high frequencies:

Mixer Output to 4/5 input on the T-1
Analog Input on the L-1 Model II to Aux Output on the T-1
Analog Input on the second L-1 Model II to Master Output on the T-1

Just to be clear, by using "Mixer Output to 4/5 input on the T-1" it is summing to mono at the T1. Is this what you wanted? Or did you want to retain a discrete stereo image?

...Mark

[Dan_Cornett]

It "reads" to me as if, when using a mono signal, if one Model II is digital and the other Model II is analog, then there was -- with this particular T1 -- enough of a difference to cause the bass (probably mid-low) to sound weaker with both Systems than with just one System. And that 'weakness' is not present when both Systems are driven analog.

It seems to be separate from any "dual mono cancellation".

I don't have two Model II's to try to reproduce that setup ... it would be nice if someone else could try that same setup and report on what they hear.

I'm not sure if properly-performing T1's and Model II's should have that effect ... based on what I've read on this forum.

[djrhouse]

I wanted Stereo sound but I am happy that it is not out of phase like it was with one digital output and one analog.

ST; I am using one T-1 for both Model II systems. The AC adapter eliminates the phase cancelling I was having using one analog and one digital signal

[DJStyles]

I was just running a line level to the base unit Analog input and this is the second time I tried it. Today alot of hum and buzz.  I first isolated the laptop and lifted the ground off the power strip and then put in the line a ART Clean box II    http://artproaudio.com/isolators/product/cleanbox_ii/

This box reduced it to almost nothing