I play in a band and have a very basic knowledge of audio electronics, and virtually zero knowledge of electrical engineering. I have done simple projects like create my own Yamaha Subkick, built a pretty sweet Contact Microphone, and of course I have customized my guitar with new pickups, volume/tone knobs, etc. I have even built my own guitar from scratch. My latest project is a little more ambitious only because I don't understand all of the elements involved and I am afraid I am missing something. So before I even begin I am hoping people who know more than me could shed some light on the subject.
Here is the deal:
There are times when my band needs to be able to rehearse in silence in order to avoid angry neighbors, etc. And for a long time I have been interested in buying one of these cool Jamhub devices.
http://www.JamHub.com
The JamHub allows every band member to plug in and basically create their own mix in their own headphones without effecting what the other band members hear. For example if I want to hear my own guitar a little louder than everything else I can turn down everyone else as much as I need to in order to make my own guitar stand out in the mix. The reason I haven't bought one yet is that there are a few things about the Jamhub that I don't like. First off it requires everyone in the band to sort of huddle around a small device in the center of the room. Second of all I don't want/need any of the built in effects that come along with it. Third at over $300 dollars I am certain I can build a comparable product for a lot less, that will better suit my needs.
So that's what I want to do. I want to build a simplified Jamhub, that is also modular so that every band member can have their own module at their respective amp allowing band practice to feel much more natural instead of everyone huddling together. Here is the setup, my drummer uses an acoustic drum set but has a digital drum set for silent practices. My lead guitar player, my bass player and myself all have amps with built in DI outputs allowing us to go directly from our amps into any recording device without risk of destroying said device.
So we already have all of the effect we could ever need built into our amps. Our amps also allow us to put as much volume into the device (within reason) as we need too while keeping the speakers silent. Thus the device can be passive and not require a preamp.... I think.
Here is what I drew in photoshop a few mins ago. (Click image for full size)
[IMGDEAD]http://img406.imageshack.us/img406/9570/inputmodules.png[/IMGDEAD]
This is by no means a proper schematic, for instance I don't have positive and negative wires in the diagram, it is really more of just a guideline so that I don't get lost while actually assembling this thing. Anyway I want to build 4 of these identical Input Modules, one for each band member. Into which we will each plug in our respective instruments off our amps. The amps will be amplifying the signal, but will not be heard in the room itself.
Each input module connects to the other input modules via the output jacks on the side, and input jacks on the top using standard ¼” speaker cables. This will allow all 4 players to hear all four instruments. Each player can then change the volume of the other players instruments, as well as their own via the volume knobs (might be replaced with sliders) on the device without altering what the other players hear. The Input modules job is to give every band member the ability to create their own personal mix via volume knobs/sliders.
Here is how the device should work: (Click image for full size)
[IMGDEAD]http://img840.imageshack.us/img840/9809/signalflow.png[/IMGDEAD]
As you can see there is a total of 4 signals going into each input module. #1 being the performers own signal coming in at the bottom of the device, and #2-4 being the other band members signals coming in at the top of the device from their respective input modules. Each signal has its own volume knob. Since obviously the signal cannot get any louder than it's source without a preamp built in, mixing will be done by turning down the things you don't need to hear as much, allowing the signals you do need, to stand out more in the mix. Your own signal is also split and sent to the other band members respective input modules via standard ¼” speaker cables so they can do the same, as well as forth output which can go to a mixer or recording device.
The result in a silent practice session to the outside world, while rocking out via headphones.
So I have a few questions.
Thank you in advance, I really need the help.
Here is the deal:
There are times when my band needs to be able to rehearse in silence in order to avoid angry neighbors, etc. And for a long time I have been interested in buying one of these cool Jamhub devices.
http://www.JamHub.com
The JamHub allows every band member to plug in and basically create their own mix in their own headphones without effecting what the other band members hear. For example if I want to hear my own guitar a little louder than everything else I can turn down everyone else as much as I need to in order to make my own guitar stand out in the mix. The reason I haven't bought one yet is that there are a few things about the Jamhub that I don't like. First off it requires everyone in the band to sort of huddle around a small device in the center of the room. Second of all I don't want/need any of the built in effects that come along with it. Third at over $300 dollars I am certain I can build a comparable product for a lot less, that will better suit my needs.
So that's what I want to do. I want to build a simplified Jamhub, that is also modular so that every band member can have their own module at their respective amp allowing band practice to feel much more natural instead of everyone huddling together. Here is the setup, my drummer uses an acoustic drum set but has a digital drum set for silent practices. My lead guitar player, my bass player and myself all have amps with built in DI outputs allowing us to go directly from our amps into any recording device without risk of destroying said device.
So we already have all of the effect we could ever need built into our amps. Our amps also allow us to put as much volume into the device (within reason) as we need too while keeping the speakers silent. Thus the device can be passive and not require a preamp.... I think.
Here is what I drew in photoshop a few mins ago. (Click image for full size)
[IMGDEAD]http://img406.imageshack.us/img406/9570/inputmodules.png[/IMGDEAD]
This is by no means a proper schematic, for instance I don't have positive and negative wires in the diagram, it is really more of just a guideline so that I don't get lost while actually assembling this thing. Anyway I want to build 4 of these identical Input Modules, one for each band member. Into which we will each plug in our respective instruments off our amps. The amps will be amplifying the signal, but will not be heard in the room itself.
Each input module connects to the other input modules via the output jacks on the side, and input jacks on the top using standard ¼” speaker cables. This will allow all 4 players to hear all four instruments. Each player can then change the volume of the other players instruments, as well as their own via the volume knobs (might be replaced with sliders) on the device without altering what the other players hear. The Input modules job is to give every band member the ability to create their own personal mix via volume knobs/sliders.
Here is how the device should work: (Click image for full size)
[IMGDEAD]http://img840.imageshack.us/img840/9809/signalflow.png[/IMGDEAD]
As you can see there is a total of 4 signals going into each input module. #1 being the performers own signal coming in at the bottom of the device, and #2-4 being the other band members signals coming in at the top of the device from their respective input modules. Each signal has its own volume knob. Since obviously the signal cannot get any louder than it's source without a preamp built in, mixing will be done by turning down the things you don't need to hear as much, allowing the signals you do need, to stand out more in the mix. Your own signal is also split and sent to the other band members respective input modules via standard ¼” speaker cables so they can do the same, as well as forth output which can go to a mixer or recording device.
The result in a silent practice session to the outside world, while rocking out via headphones.
So I have a few questions.
- Do I NEED to put resistors in the Input Modules to keep all the channels from bleeding into one another via their connection to the headphones? Or is that not likely to happen?
- If so is 10k too much? Too little? I settled on 10k after finding a tutorial on how to make a mixing board online.
- Is my placement of said resistors correct? I assume the resistors need to go immediately after the input and immediately before the outputs to stop any signals from traveling back the wrong direction.
- Will I need a ground? I am assuming I will, and have planned to install a common ground for all of the components to connect to. But is this necessary? I have noticed in the guitars I have owned, a few were grounded to the bridge while others had no ground at all. So I am a little unsure about when a ground is necessary in passive devices.
- Will a built-in preamp be required to successfully send the signal five or six feet through standard ¼” speaker cables to the other modules? Or will the signal be strong enough to travel that far by itself?
Thank you in advance, I really need the help.
there is simply no potential for the signal to exist anylonger
