4 scanners > audio mixer > L & R channels on wireless headphones

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N0BDW

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Howdy. Merry Christmas!

I'm looking to take the audio outputs of 4 scanners (3 BCD539HPs + 1 BCT15X), bring them into a mixer, and output one master output to my Arctis 7 wireless headphones. The transmitter unit for the Arctis 7 has a line input.

My question is, especially considering the audio output setup on the BCD536HPs, which mixer might be up to the task? What should I look out for? Something that can be rack mounted would probably be ideal, but not a strict requirement.

I want to run the audio from one of the 536 units into the L ear, another into the R ear, and the 3rd + BCT15X into both ears (but at a lower volume).
 

N0BDW

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Thanks. And that shouldn't have difficulty with the audio out from the 539s? Which port should be connected to the mixer - headphone or ext speaker?
 

toastycookies

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Thanks. And that shouldn't have difficulty with the audio out from the 539s? Which port should be connected to the mixer - headphone or ext speaker?
ext speaker or line out ports.

you are going to have to make some 1/8th phone jack cables depending on which mixer you go with.

The majority are either 1/4th phone jack or RCA with 1/8th being less common.
 

N0BDW

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ext speaker or line out ports.

you are going to have to make some 1/8th phone jack cables depending on which mixer you go with.

The majority are either 1/4th phone jack or RCA with 1/8th being less common.
That is one of the difficulties with the 536 units... they don't have a true line out. They have ext speaker but that does not provide line level audio.

I have a 536 connected to a mixer at my fire hall and if the volume on the mixer channel is turned up more than about 2 / 10 it produces a terrible hum. Turning the pre-amp on that channel off, and adding a ground loop isolator helped (can go to about 3.5 / 10 volume), but it is still not the greatest audio into the mixer.
 

GTR8000

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Be extremely careful with the 536 external speaker output. The audio amp has a floating ground, so make sure that any equipment plugged into that jack does not ground to earth!

Using an isolating transformer to keep the line from being grounded between the scanner and other equipment (PC, mixer, etc.) is the easiest way to protect the audio amp. Alternately, look for a mixer that features built in ground isolation.

I know you mentioned that you added a ground loop isolator to the current 536 in the station, but I just want to stress that it's not really optional with the design of the 536's audio amp, it's critical to keep the external speaker output isolated from earth ground!
 

cpetraglia

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I use a Berringer XENYX 802 mixer. Very nice as it has bass, mid and treble controls for each channel.
Also has pan, input levels and master out into 2 channels. (Under $100) I use the earphone jack outputs for each of 4 different scanners with no isolation transformers and no problems. I cant speak for the 536 since I don't have one, but the match between headphone out to mixer in is a whole lot closer than the speaker out on the scanners. If you use the speaker out, you should use a hi-lo adapter which are widely used in auto stereo applications. This also solves the floating ground problem.
 

N0BDW

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Is a hi-lo adapter the same as a ground loop isolator?

I was looking at the XENYX series... looks like what I'm looking for. Just need to find one that'll handle the inputs I want.
 

cpetraglia

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Is a hi-lo adapter the same as a ground loop isolator?

I was looking at the XENYX series... looks like what I'm looking for. Just need to find one that'll handle the inputs I want.
A hi-lo adapter takes the 8 ohm speaker signal and converts it to a higher impedance at a lower voltage so as to be used to feed an amp input or as in our case, a mixer. It also appears to the amp in the scanner as a speaker at 8 ohms which is what the output was designed for. The good quality ones use matching transformers which double as an isolator. You can order just about any cable combination you need. In my case, I make my own. Connectors can be had for real cheap. You just need some soldering skills. If you use the headphone jack on the scanner, it should already be a much closer match.
 

cpetraglia

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That is my exact mixer. The one answer I never got from any scanner question was whether or not the headphone jack was a stereo or mono jack. I always used a stereo patch cord and went directly from earphone to mixer and they work. I believe the jacks may be stereo, but are wired to provide the same audio to left and right as we know the scanner is not stereo. Having the ability to adjust tone controls will really make a nice difference. You can also feed a small amp with some bookshelf speakers and have a great sounding setup.
 

N0BDW

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I haven't been able to find a hi-lo adapter on Amazon. Do you have a link? I'm not looking to do a bunch of wiring and cable making myself. More than happy to pay for a solution that works out of the box.

Strictly from a neat cabling perspective it would be nice to use the rear ext speaker jack vs the headphone jack.
 
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toastycookies

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I haven't been able to find a hi-lo adapter on Amazon. Do you have a link? I'm not looking to do a bunch of wiring and cable making myself. More than happy to pay for a solution that works out of the box.

Strictly from a neat cabling perspective it would be nice to use the rear ext speaker jack vs the headphone jack.
You could add your own live level out jack in the rear of the device.

http://forums.radioreference.com/uniden-tech-support/303440-streaming-bcd536hp.html
 

jonwienke

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I know you mentioned that you added a ground loop isolator to the current 536 in the station, but I just want to stress that it's not really optional with the design of the 536's audio amp, it's critical to keep the external speaker output isolated from earth ground!
If the mixer has XLR inputs, it's a balanced input where neither one is connected to ground. If you connect the 536 to an XLR input, you probably don't need a ground loop isolator. The trick is connecting between a 1/8" stereo plug and the XLR without using the ground pin on the XLR plug. Most adapter cables connect the ground to ground and the tip to one of the XLR balanced inputs. You'll need to connect tip and ring to the XLR balanced inputs.

A good mixer will allow you to pan each input left or right independently.
 

cpetraglia

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I haven't been able to find a hi-lo adapter on Amazon. Do you have a link? I'm not looking to do a bunch of wiring and cable making myself. More than happy to pay for a solution that works out of the box.

Strictly from a neat cabling perspective it would be nice to use the rear ext speaker jack vs the headphone jack.
Search in google "Hi-Lo audio adapter". Amazon has plenty as well as many other sellers.
 

cpetraglia

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That's all your going to find. The bare wires are intended to connect to an existing speaker wire pair. About the only way to do it easily is to use the front headphone jack and order a cable with the appropriate connectors. No one said it was real easy. You don't need the adapters if you use the headphone jack.
 

N0BDW

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That's all your going to find. The bare wires are intended to connect to an existing speaker wire pair. About the only way to do it easily is to use the front headphone jack and order a cable with the appropriate connectors. No one said it was real easy. You don't need the adapters if you use the headphone jack.
Okay, thanks. I think I'll try using the headphone port instead.
 

AnikF1R

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I wanted a way to listen to two scanners plus my satellite receiver through headphones. The Mackie 402-VLZ3 mixer did the trick, and at only $40 shipped on eBay.

One thing that surprised me was that I couldn't hear some of the sources' audio through the mixer, even with their volumes maxed out and the Gain on the mixer as high as it would go. Fortunately, I was able to activate the mixer's "instrument" mode on two of the inputs. My guess is that this feature acts like a Direct Injection (DI) box, which in this case is transforming impedances. Audio experts, correct me if I'm wrong.

I can also pan two of my sources to L and R, or I can keep them mono (both signals go to both ears).

You mentioned that you have four sources that you'd like to monitor. Technically, the 402 mixer can do four, but I don't haven't tried it myself, so I cannot vouch for its fitness.
 

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