Audio Mixers For PCs? 25
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.
mixer (Score:1)
16 stereo inputs, rack mountable, built-in headphone amp.
Mackie 1202 [mackie.com] is nice too, but you'd be wasting the wonderful mic preamps, and it has fewer stereo channels.
Can't beat that.
hehe. Not cheap, but not overpriced either.
KVM for audio? (Score:1)
I don't know exactly what they're called, but I think Target (a department store) carries one made by Recton, going for about $15 USD (IIRC). It's not a mixer, just a push-button switch box -- 4 inputs, one output... just push the button for the source you want to listen to. Made for home entertainment systems, obviously, but it might work for your uses.
mix 2 channels the right way (link) + question (Score:1)
Does anyone make a mixer with a tv-style remote? It would be nice to amplify cd player, computer, and tv through my only set of surround speakers, and selectively quiet/silence one channel like when commercials come on.
Re:mixer (Score:1)
I'm personally using Behringer's MX802A [behringer.de] for two sound cards as well as some various other sources.
Re:Too easy. (Score:1)
But my confusion about insert cables is that they only have 3 connectors, and I didn't think it was possible to share ground between two separate (send, return) AC signals.
Most of my electrical/electronic theory stuffs is DC based..
Great idea... (Score:1)
And the comparison to KVM switches is flat wrong. A KVM switch takes multiple inputs and only displays one output at a time. A *mixer* takes multiple inputs, and combines them into one output (in this case, headphones). Mixers can be expensive (I've looked) but you can maybe find a used one for ~$50-100. Much too expensive for a "throwaway" project, and with a cheap mixer you'll be lucky to get 2 (maybe four) inputs.
Perhaps a little better would be to wire up each ear of a set of old stereo headphones to 2 different boxes. Ask some engineering types how to do it, and they'll probably be glad to help. Maximum price is $10 at Radio Shack, but you'll only be able to combine 2 boxes into one set of headphones.
--Robert
Just a standard audio mixer. (Score:1)
I would recommend finding one with a real slider for each audio channel. The radio shack one has four line level inputs, each with a slider. Some mixers might have like 6 inputs but they share them between 2 sliders. This won't work all that well for what you want.
Most of these have a headphone level output jack, so you can use headphones instead of speakers, or both. I've been thinking about getting one of the plantronics dual-use headsets [plantronics.com] which let me use the same headset for phone and computer use.
One word of warning - most computer speakers will require a headphone-level output to work. They won't work on the standard line-level output on the back of these mixers. Actually that's not 100% accurate - they will work but might not be able to get all that loud - which might be exactly what you want.
Re:Folio Notepad (Score:1)
Ok, problem.. most sound boards are not wired for stereo input. They are wired for balanced and unbalanced inputs. Your best bet would be to pick up one of those radio shack dj booth boards. They have stereo connects.
If all you have is a standard sound board with balanced and unbalanced inputs (3rd ring is ground not a second channel) You need to split the left and right stereo channels onto separate sound board channels and then pan them left and right appropriately. Take it from me, it sounds better than just jacking a stereo connect into an unbalanced connection (very bad signal quality that way).
Im head sound tech at a local underground (the best places to work) px rock avenue and regularly use multiple cd players, mp3 players and computers on the same boards without trouble using this method. Only a few low end boards will have stereo phono inputs on one slider. I belive it is because most professionals use large 40+ channel boards that have more room to double up with and they also use phono cable or 1/4 leads that dont have to be split with stuff from the "extra parts" drawer.
You might want to check fullcompass.com [fullcompass.com]. They will send out a heafty catalog if you request it.
It's an analog world.... (Score:1)
Daisy-chain them together - easy, cheap (Score:1)
output of machine #2 to input of machine #3,
output of
It's super cheap, super easy, and the last machine on the chain will be your master volume control. For more flexibility, you could attempt to use the line-in AND mic-in to make a "mixer", but be careful that the signal going into the mic-in is super low.
Re:Too easy. (Score:1)
Unless you put diodes in line from the sound card to the Y
Diodes won't work here, because the audio is an AC signal. An appropriately sized resistor has the desired effect without causing the massive distortion that a diode would.
but I think you're better off buying a cheap (<$200) 4 or 8 channel audio mixer.
An active mixer would do the job, but you have to wonder if it's good value when compared with the cost of a few resistors (<$0.20).
As someone else has mentioned, it may be possible to daisy-chain a number of sound cards by connecting the line-out of each into the line-in of the next. No resistors required. Balancing the relative levels of the signals will be a little more difficult, and the degradation of the signal through many cards might be noticable, but it's definitely a possibility.
Steve.
Re:Too easy. (Score:1)
A "Tip Ring Sleeve" insert cable gives you a mono unbalanced insert with a normal unbalanced stereo jack (headphone) plug.
Before or after the EQ (sometimes selectable) in a mixer the signal is sent to the insert plug.Here you can plug in a compressor or gate etc. The send and return uses sleeve as the ground while ring is send and tip is return. If you disconnect the cable, the insert circuit is bypassed.
An other way to do this is by having separate send and return plugs. This way you can keep the signal balanced. Another advantage is that you can split the signal by connecting something to the send plug because the signal is only broken if you connect something to the return plug. This solution is used in pro $$$ mixers, but they use bantam plugs instead of jack plugs. (Bantam plugs are smaller than jack plugs but bigger than minijack (walkman) plugs)
To have an electric signal, whether it is AC or DC, you need two wires. With audio you also need sheilding. If you connect the ground to one of the wires the signal is unbalanced, if you use a separate wire for ground the signal is balanced.
AC means ascending current and audio is ascending current. If you connect a speaker to the wallplug, you will get a loud 50/60 (Europe/USA) Hertz sound. It will wake your nabours and probably blow the speaker. Don't do this at home kids.
Re:Too easy. (Score:2)
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.
How will you know which computer is beeping? (Score:2)
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.
"Y" (Score:2)
--
Re:Too easy. (Score:2)
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
Re:Too easy. (Score:2)
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.
Re:Too easy. (Score:2)
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.
Folio Notepad (Score:2)
Audio via Network (Score:2)
Of course this will not work on all systems, but there may be alternatives for other systems that I am not aware of.
Keep the noise. (Score:2)
Stop them moaning (Score:2)
People wont bother you then as it seems everyone expects those sounds.
Re:Too easy. (Score:2)
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 [wintektx.com] 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.
Too easy. (Score:2)
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?
-- Eat your greens or I'll hit you!
Change your sounds (Score:3)
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.