I am currently looking into the possibility for a small portable box for voice amplification.
It doesn't need to go lower then say 150Hz and cover the vocal range.
However I don't want it to be a harsh megaphone either.
For the driver I was thinking about using the B&C 6PEV13.
Can be used in a small closed box or a small reflex tuned at 137Hz. Don't know if the reflex would be a good idea tough.
other ideas are welcome but High efficiency is key here.
As an amplifier I am looking around some solutions. Dayton has some nice modules etc.
For batteries I'm gonna use a battery board from dayton or the like with 18650batteries.
The biggest issue I see is for getting a balanced microphone input.
The voltage would be +24v (from batteries) so making a small preamp that can work on an asymmetric supply is a challenge.
One solution could be using an input transformer and an opamp for this but I think it's a little bit overkill for this application.
Would be better If I could get an electronic balanced input. INA217 comes to mind but using an asymmetric supply this is tricky.
I also didn't found a small mic preamp board that I can use.
All ideas are welcome.
I would make a small cube in wood where everything would fit in.
Maybe an extra audio input or a bt connection.
It doesn't need to go lower then say 150Hz and cover the vocal range.
However I don't want it to be a harsh megaphone either.
For the driver I was thinking about using the B&C 6PEV13.
Can be used in a small closed box or a small reflex tuned at 137Hz. Don't know if the reflex would be a good idea tough.
other ideas are welcome but High efficiency is key here.
As an amplifier I am looking around some solutions. Dayton has some nice modules etc.
For batteries I'm gonna use a battery board from dayton or the like with 18650batteries.
The biggest issue I see is for getting a balanced microphone input.
The voltage would be +24v (from batteries) so making a small preamp that can work on an asymmetric supply is a challenge.
One solution could be using an input transformer and an opamp for this but I think it's a little bit overkill for this application.
Would be better If I could get an electronic balanced input. INA217 comes to mind but using an asymmetric supply this is tricky.
I also didn't found a small mic preamp board that I can use.
All ideas are welcome.
I would make a small cube in wood where everything would fit in.
Maybe an extra audio input or a bt connection.
Thanks,
Didn't know it was possible this way with a crude "virtual earth"
As long as there is no real current in the virtual earth this would probably work indeed. Thanks for the tip
Gonna see if I can get a simple amp module with some DSP and BT. That way I can make a steep HP filter and maybe a limiter is also possible.
I recently used a board from arylic and this works quite well
for the speaker. A closed box of around 2L max will do I think
I also tought about 8inch using the beyma 8MI100 or the B&C 8PE21 but the weight will go up and it will not be so portable anymore.