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Audio Mixers For PCs?
ps writes: "Like many people, I work in a cubicle. I am also surrounded by several computers each with their own speakers and sound cards. And people complain that they are too loud (the volume won't go any lower!) I would love to have a simple "mixer" that I could wire in all my sound cards to one set of headphones. Nothing fancy, I just want to hear the alerts on all my boxes. Any ideas? I don't want to spend a fortune on this..." As michael puts it, like an KVM switch, but for audio.
A Tip Ring Sleeve plug can be used for unbalanced applications, where the tip is one channel (usually the left), the ring is the other channel, and the sleeve is common, or ground.
In a balanced application, like low-impedence microphones (which usually use an XLR or "Cannon" plug, rather than a quarter-inch phone plug) or some audio patch panels, the tip and the ring are both "hot", but, just like the 2 hot lines of a 240 volt power circuit, each is 180 degrees out of phase with the other at any given instant. Any induced noise winds up on both conductors in the same phase so that when both signals are input to the 2 ends of a tranformer winding or the inverting and non-inverting inputs of an amplifier the noise signals cancel each other out.
If I understand what you mean by an insert cable, then the jack it plugs into has switches that are operated whenever the plug is inserted or removed. These switches either pass the signal coming into them on to the next stage uninterrupted when there is no plug in the jack or pass the signal from the insert cable along instead when the plug is inserted, sort of like the reverse of a headphone jack that cuts off the speakers when headphones are plugged in. Alternatively it could be wired to pass along the regular incoming audio and mix in the audio from the plug when the plug is inserted.
It's easier to explain this stuff with diagrams. I f you need a better explanation, e-mail me.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
Are we talking about small, low power speakers here? Is the amplifier on the sound card or in the speakers? Either way, using resistors to throw away some of either the signal to powered speakers or some of the amplifier output power to unpowered speakers is probably the cheapest and simplest way to go. E-mail me if you need to know how.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
If you want to go cheap, and don't care about the actual "mixing" of sound, which it sounds like you don't, stop into The Shack and get a handful of 1/8" stereo patch cables, some Y-splitters, and a long extension cable. Run patch cables from each sound card to a "splitter-farm", then the long extension from the "farm" to your speakers/headphones. You will probably experience some sound degradation, though.
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audio is AC? I didn't think so.
Are you sure about this? I don't mean to undermine, but do you have a link? I'd like to read about it.
All bunch of questions popped into my head when reading this, like how does a Tip Ring Sleeve insert cable work, if the audio signal as AC? hmmm.
S
Use 'Y' adaptors to split one signal into many, not to combine many into one.
I agree. You're effectively feeding the output of one card into the OUTPUT of another card if you use these things this way. Which could be bad.
Unless you put diodes in line from the sound card to the Y, but I think you're better off buying a cheap (<$200) 4 or 8 channel audio mixer.
Remeber, transformers don't work on DC current, yet they work nicely on audio signals.
I'm not sure how I can make it any more clear to you.
If a tree falls in the forest, and it falls on a mime, does anyone care?
Not knowing what types of systems you are running this may not work for you but the enlightenment sound daemon might do the trick for you. You can set it up to play the audio on a different machine over the network so all you would have to do is setup a main audio machine to listen to all the incoming audio connections from your other computers. This means that you only have to hook your headphones up to the main audio computer and software will do the rest.
Of course this will not work on all systems, but there may be alternatives for other systems that I am not aware of.
If people complain aboue the noise, start pressuring your boss to give you a closed office :)
-Billco, Fnarg.com
Change the warning sounds from beeps to phone ringing sounds, office gossip sounds, boss walking arround sounds, incoming text message sounds, loud farting etc. etc.
People wont bother you then as it seems everyone expects those sounds.
Combining signals using 'Y' adaptors or cables isn't a very good idea because you'll have many sound cards trying to drive the line to different levels simultaneously. This can cause volume and frequency response problems, and may place undue stress on the output stages of the soundcards. Use 'Y' adaptors to split one signal into many, not to combine many into one.
The simplest way to combine signals is with a 'passive' mixer, which is nothing more than a resistor in each signal line. Have a look at this page for instructions on how to build one yourself. I keep a few combiner cables around, where I have built 4K7 resistors inside the plugs.
I've never tried to use a mixer like this to drive headphones directly. It's designed to drive an input with a high impedance, while headphones have a relatively low impedance, so I don't think it would work very well. However, for a system with N soundcards, you could use the passive mixer to combine N-1 outputs at line level, and send that into the line input of the last soundcard. Mix the line input with the other signals from that card, and output to your headphones in the normal way. You'd also get a master volume control this way.
Some people have suggested an 'active' mixer, such as those from Radio Shack, Soundcraft, etc. I can't see that they offer any significant advantage for this application, unless you want the extra flexibility in signal routing, metering, reduction in crosstalk, or if you just like the idea of having lots of knobs to play with.
Steve.
If it's the later any Radio Shack, or Dick Smith will have 50c 2input->1output so just buy half a dozen and they'll concatenate to 1 signal (with surprisingly little loss of quality), then just drop some plain cable about. If you want quite high quality, though, spend $5 and get a proper audio mixing kit with seperate volumes and other guff - less connections ensure quality.
If you it's the prior, haven't a clue sorry. Does anyone know of something that would send audio via the network though?
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It might be enough to change the sounds played on all of these events. Some sounds just are really "abrasive", and get annoying fast. That quickly makes them sound louder than they actually are. Experiment with what works best.
If that still doesn't help, just take your favourite sound editor and modify the sounds so they're at half-volume on disk. Either way, you've got a solution that can be set up in a short period of time for no money at all.
It's only software!