This may be a stupid question, but I've seen quite a few very nice setups some of y'all have with 4+ base scanners. Most of these feed into what looks like ProScan, but I'm not 100% sure how you do it. Most scanners require a 3.5mm plugged into the PC, but most PC's only have 1-2 inputs. Anyone know any external sound cards that allow multiple 3.5mm inputs to your PC? I'm looking at grabbing 1-2 more base scanners to complete my setup, but right now I'm only running 1 scanner on ProScan.
For those with multi-scanner "comms center" style setups
- Thread starter RTmed519
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Can't presume to answer for whatever setups it is you have seen but here I have multiple PCs each with multiple soundcards.
Adding USB soundcards and channelising the audio to a mixer or to decoders is fairly easy. What I have never really got my head round was mixing the audio into a stereo landscape so it's easy to tell which audio relates to some of the specific receivers.
Adding USB soundcards and channelising the audio to a mixer or to decoders is fairly easy. What I have never really got my head round was mixing the audio into a stereo landscape so it's easy to tell which audio relates to some of the specific receivers.
I think the majority of folks that have multi scanner setups leave the audio on external speakers. Thats how mine are done. I only have data fed to the PC. However as said for scanner feeds its simple to add UCB sound cards to feed multiple scanners.
majoco
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I have a Behringer RX1602 8 channel stereo mixer which was reasonably cheap for what it does. I have paralleled each left/right stereo input from the mono line outputs of each receiver - I had to modify the BCT8's by taking a line out from the top of the volume control to a phono socket on the rear panel. The mixed output goes to a small stereo amplifier and then a pair of speakers left and right. At each input there are three controls - one for the gain, one for the monitor and one balance. The "monitor" feeds the headphone output but also another output which I connect to a computer running "Scanrec" so I can record the channels I am not actually listening to.
Now - the stereo landscape is easy to control by the balance control for each channel. As both L/R inputs are paralleled by turning the balance full left there is all the audio from the left speaker and similarly if I turn it full right from the right speaker. Putting the balance in the centre give exactly that, audio from the centre - so with some fiddling I can have the audio from five radio having five different 'position' across the sound stage. For the best results the listener needs to be at the apex of an equal-sided triangle with the speakers at the other points in a non-echoing room - AND it even works through the headphones!
RFI-EMI-GUY
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Almost all scanners and radios today have BTL Bridge Tied Load audio amplifier stages and must see only a speaker or other floating balanced load like an audio transformer. If one of the speaker leads is grounded or worse, tied to A+ there will be damage or at minimum distortion and noise. The manufacturers and even Broadcastify don't make this clear and the feeds on Broadcastify reflect these errant connections directly to an unbalanced sound card. You need an audio isolation transformer, a good one like Radio Shack used to sell. Not some Amazon cheapie which may or maynot have a transformer.
There is no sound card in my feed setup.
I have three feeds and four radios. The two ham feeds use their own barix instreamer per feed. The mono output has a monoplug - to stereo jack adapter. Each then leads into a short patch cable into a commodity stereo isolation transformer. This goes to a stereo plug to rca cable into the barix input. The right channel is discarded by the instreamer in mono mode.
My rail feeds is diffent. The loco/Road channel and dispatch channel scanning between on the left channel and the rail yard on its own radio on the right channel.
I have a special cable with dedicated left and right mono plugs leading to a stereo plug. From the shared isolation tranformer it's the same into the instreamer, configured in stereo.
The headphone out of each barix is patched into a cheap 4 port headphone switch.
The common out is connected to a cheap pair of pc speakers from the mid 2000s.
I have three feeds and four radios. The two ham feeds use their own barix instreamer per feed. The mono output has a monoplug - to stereo jack adapter. Each then leads into a short patch cable into a commodity stereo isolation transformer. This goes to a stereo plug to rca cable into the barix input. The right channel is discarded by the instreamer in mono mode.
My rail feeds is diffent. The loco/Road channel and dispatch channel scanning between on the left channel and the rail yard on its own radio on the right channel.
I have a special cable with dedicated left and right mono plugs leading to a stereo plug. From the shared isolation tranformer it's the same into the instreamer, configured in stereo.
The headphone out of each barix is patched into a cheap 4 port headphone switch.
The common out is connected to a cheap pair of pc speakers from the mid 2000s.
* @buddrousa lurks in the shadows *
majoco
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* @buddrousa lurks in the shadows *
Hope you understand what the guys are on about. We don't have "feeds" here but what we do have is plain language emergency services - no encryption or any 'scrambling' but what we do have is laws about privacy and secrecy of communications. I'm happy with that and long may it remain. If there is any really confidential stuff, the police tend to use their cellphones but the disadvantage of that is not everyone gets the info which may be pertinent to a chase or similar.
I'll join you in the 'lurking room' - I'll bring the beer.
Hope you understand what the guys are on about. We don't have "feeds" here but what we do have is plain language emergency services - no encryption or any 'scrambling' but what we do have is laws about privacy and secrecy of communications. I'm happy with that and long may it remain. If there is any really confidential stuff, the police tend to use their cellphones but the disadvantage of that is not everyone gets the info which may be pertinent to a chase or similar.
I'll join you in the 'lurking room' - I'll bring the beer.
RFI-EMI-GUY
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Pretty clever!
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Most of my ideas come from Rich but are just a little different hardware still sticking to the old school ways taught in electronic school in the late 70's.
If I understand you all correctly, you are feeding scanner audio into a computer, which is privately monitored. And you're looking for multi-input sound cards. In the recent past I also setup private feeds, from several radios. I was able to use $1 sound cards I purchased online. They plug in to a USB port and each give you an input. I ended up using a powered USB hub to hold them though, as when you get to like 8, it was the best way to connect and power them.
This thread got me to thinking about my own mixing design. I am also considering feeding my multiple receiver outputs to a mixer feeding a powered stereo speaker system with an attached sub-woofer. I was wondering about using some 600 ohm T-Pad volume controls on each of the receiver-speaker to audio-mixer input. I have about a dozen of them from a public address system install from many years ago. Saving me from buying a bunch of isolation tranformers. Anything I should watch out for? Thanks gang....
majoco
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I don't have any external pads or isolation transformers - all my mixer inputs come from "Record" sockets or line level outputs that I have installed into receivers that didn't have them - every input wire is screened audio coax. I don't have any hum or noise unless I wind all the gains up full and audio is very clean. In fact the only hum I can hear is mechanical from the transformer one of the HF receivers that I can't run from 12volts. The two three-way speakers I feed the mixed output into are not exactly hi-fi but then I am only looking for 'communications quality' not disco music! I would be wary of feeding a sub-woofer for fear of bringing out any hum that could be there - don't forget that the audio passband of most transmitters is limited to 300Hz to 2700Hz having already come down a phone line so whats the point of trying to hear something that's not there?
I'd like to hook up 3-4 total radios/scanners to feed into my private logging system, out of curiosity do you know which USB sound cards you used?
Ubbe
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Some scanners, like most of Unidens, have high pass audio filters that doesn't pass frequencies below 250Hz and sometimes audio filters are only enabled when you select to use a subtone decoder. Trunked voice channels usually has a low speed data signal in the audio and conventional analog channel often have a subtone included. Whistlers TRX scanners doesn't use any highpass audio filter and even when using an external 2-way radio speaker they produce a very annoying low frequency tone from channels that use CTCSS/DCS tones.
I wouldn't recommend any type of sub woofer being used and also recommend to turn the bass control, if there is one, towards it's minimum setting until the subtones are not heard. As the audio in radio systems are restricted in high frequencies to some 3000Hz-3500Hz there will only be noise in the higher audio frequency range and Unidens scanner have low pass filters set to the proper range but other scanners might not and there could also be high frequency audio noise from the internal electronic circuits in a scanner that will be heard if you listen through a HiFi audio system. High frequency audio noise are extremely tiresome to listen to and often gives headache and fatigue as the brain goes into overload trying to filter that out.
/Ubbe
The speakers/subwoofer I referred to is what I have connected to my primary PC (an old Altec Lansing setup from 20 years ago). Another set of speakers for my radio PC and then, of course, a half dozen RCA (Radio Shack 40-5002) speakers for my various radios. I was considering of clearing out the speakers down to the primary set and using a multi-channel mixer to consoldate all the audio(s). Considering the suggestions (I have to dust off my audio engineering brain from the military of 45 years ago) and rethink this project. Thanks gang....
I made more than one purchase. They were all from eBay. I simply searched for "USB Sound Cards". What I found today is $2.95
Been following this thread - how is the audio quality with those cheap interfaces?
I use a creative labs, for contrast.
So currently for my alternate setup, I'm using this one, but it looks like I'll be buying a few more if my PC will allow multiple of them. The one I have has pretty good quality, I don't notice any issues. I do have a ground loop isolator on hand (this one), since one of my scanners has quite a few issues.
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