Multiple Radios - Speaker Question

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ILuvXMRadio
Posts: 228
Joined: Tue Jun 21, 2005 1:50 am
What radios do you own?: Plenty

Multiple Radios - Speaker Question

Post by ILuvXMRadio »

Having some time in the cockpit of a small aircraft, I'm used to being able to route different com radios into my headset or speaker. I'm thinking why can't this be done in our mobile installs? So I'm looking to see what options I have for putting some type of 'mixer' or audio panel in place to manage all audio into one speaker in my vehicle.

I still in the planning stages of my tahoe (nothing installed yet)... but.. I'm planning 'big picture' to have an AM aircraft transceiver, an astro spectra vhf, xtl5k Uhf, and hopefully another 5k for 7/800.

I know the output of the radios are amplified.. so its not something we can just 'wire' together... but there has to be some 'way' of combining the audio from 3-4 radios into 1 speaker, saving space and clutter.

Any thoughts/ideas? Anyone doing this now? What type of equipment are you using to accomplish it? Anything you wish you'd had done differently?

Just trying to get the plan down before I start this whole process.

Thanks.
tvsjr
Posts: 4118
Joined: Fri Nov 28, 2003 9:46 am

Re: Multiple Radios - Speaker Question

Post by tvsjr »

I'm running three 4-port speaker combiners from Fleet Radio Products. This company, sadly, was bought out by Command Communications (www.cmdcomm.com), and I'm not sure if the combiners are still produced. They weren't cheap but do work well.

Beware, you lose the "spacial diversity", which can make it more challenging to determine which radio is talking. If all four radios are going to be talking all the time, I'd recommend separate speakers.
ILuvXMRadio
Posts: 228
Joined: Tue Jun 21, 2005 1:50 am
What radios do you own?: Plenty

Re: Multiple Radios - Speaker Question

Post by ILuvXMRadio »

I guess that's true.... never thought about that spacial component. Maybe two speakers (two into two).
Hmm.. Good point. Where did you locate your speakers tvsjr?
tvsjr
Posts: 4118
Joined: Fri Nov 28, 2003 9:46 am

Re: Multiple Radios - Speaker Question

Post by tvsjr »

Two are mounted on the false floor ahead of the main console... third is mounted on the right side of the rear console.

I'm running Kenwood KES-5 speakers, as they are capable of handling significant power and sound fantastic (yes, better than Moto).
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W1HVN
Posts: 417
Joined: Tue Dec 09, 2008 11:46 am
What radios do you own?: MX300 w/DVP

Re: Multiple Radios - Speaker Question

Post by W1HVN »

http://www.ncsradio.com/commercial/

Check out the C250

Pricey, and a bit more overkill, but wanted to share it anyhow.

You can by the way use a Sigtronics or other aircraft intercom in a console if you felt so inclined. You can use Com 1 amd 2 and Nav 1 and 2 line level audio into selector and tx select for Com 1 and 2. If you find a commercial aircraft com panel on ebay, you can use that, it has lots of com inputs and tx selections.

Just depends how deep in the weeds you want to get with this.

Good Luck. Fly safe.
Skooter92
Posts: 65
Joined: Tue Jan 10, 2006 7:31 pm

Re: Multiple Radios - Speaker Question

Post by Skooter92 »

This might be something to take a look at for combining audio feeds into one speaker. http://www.bhphotovideo.com/c/product/3 ... Mixer.html
*************************
Fairly well grounded......
k2hz
Posts: 531
Joined: Tue Mar 01, 2005 7:27 am

Re: Multiple Radios - Speaker Question

Post by k2hz »

Skooter92 wrote:This might be something to take a look at for combining audio feeds into one speaker. http://www.bhphotovideo.com/c/product/3 ... Mixer.html
That unit is for unbalanced line level input and output, not for speaker audio.
Jim202
Posts: 3609
Joined: Sun Sep 09, 2001 4:00 pm

Re: Multiple Radios - Speaker Question

Post by Jim202 »

Unless I have missed the comment here, it is important to at least mention it again. You DO NOT WANT TO GROUND EITHER SIDE OF THE SPEAKER WIRES on any Motorola radio. You will blow the audio output section of the radio. Many other radio brands also can be damaged in the same manner.

You might even be advised to put a series capacitor in line with your speaker connections your trying to make on these radios. That way if there is any DC voltage on either wire, you will not short it to ground with what ever connection you jury rig up. In the radio interoperability field that I work in, we normally use a 1 uf capacitor as a general rule for any receive audio connection our cables make to any radio. That way there is no finger pointing done when the radio stops working.

Jim
tvsjr
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Joined: Fri Nov 28, 2003 9:46 am

Re: Multiple Radios - Speaker Question

Post by tvsjr »

The proper way is through a 1:1 isolation transformer. Fleet Radio Products used to build a nice (but not cheap) 4-channel combiner that had isolation built in, however they don't appear to be around anymore. I have three of their combiners in the truck.
motorola_otaku
Posts: 1854
Joined: Tue Jan 13, 2004 7:03 am

Re: Multiple Radios - Speaker Question

Post by motorola_otaku »

I saw this suggested on RadioReference: http://www.rdlnet.com/product.php?page=85. So far that is the best alternative I've seen to the Fleet Radio Products combiner, but they need at least 24VDC and can't drive a speaker by themselves. I'm strongly considering trying one with an amplified Motorola speaker.
Anything you wish you'd had done differently?
You can only put one speaker at the very top of the B pillar in a Tahoe. Anything lower will interfere with seat travel.
cmdcomm
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Re: Multiple Radios - Speaker Question

Post by cmdcomm »

I own Command Communications and we do have the Fleet Radio Products 4-Channel audio combiners in stock. www.cmdcomm.com 1-877-263-2666
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