Hi everyone, I've just found the interesting world of DIY hifi and have been enjoying reading the forum here.
I'm relatively new to audio and electronics in general, so I may be biting off more than I can chew here, however...
I have an idea for a powered speaker with chromecast audio built in. The idea is that each speaker can be used as a single, mono, chromecast connected speaker or paired with another for stereo (so each speaker is set to either left or right channel) I'd also like the option of using the speaker to power a passive partner, so that a stereo pair can be made.
To provide all of this flexibility my plan for the audio path is as follows:
Chromecast (CC) stereo output -> 3pin 4way rotary switch (switch setup as SW1 below, aiming to allow switching between CC Left only, CC Right only, CC Stereo and an Aux stereo in)
Rotary switch centre pins -> input on a class T amplifier (model to be decided)
Stereo Outputs of amplifier -> 4pin 3way rotary switch (switch setup as SW2 below, aiming to allow switching between left from internal speaker / right from speaker out, right from internal speaker / left from speaker out and a mono mix from the internal speaker)
(internal speaker here is shorthand for the crossover etc for whatever speaker array I decide to use within the unit)
I understand that simply bridging left and right inputs like this is a bad idea as it can ruin the amp due to differential voltages in the stereo mix. However, I THINK, I understand correctly that a combination of resistors across this bridge can solve this problem. As per the second diagram here: Why Not Wye?
SW1 - 3pin 4way:
A - Left Out -> connected to left in on amplifier
B - Right Out -> connected to right in on amplifier
C - Ground Out -> connected to ground in on amplifier
1 - Left from CC
2 - Left from CC
3 - Ground from CC
4 - Right from CC
5 - Right from CC
6 - Ground from CC
7 - Left from CC
8 - Right from CC
9 - Ground from CC
10 - Left from Aux
11 - Right from Aux
12 - Ground from Aux
SW2 - 4pin 3way:
A - Left +ve from Amp
B - Left -ve from Amp
C - Right +ve from Amp
D - Right -ve from Amp
1 - +ve on inbuilt speaker
2 - -ve on inbuilt speaker
3 - +ve on speaker out
4 - -ve on speaker out
5 - +ve on speaker out
6 - -ve on speaker out
7 - +ve on inbuilt speaker
8 - -ve on inbuilt speaker
9 - +ve on inbuilt speaker
10 - -ve on inbuilt speaker
11 - +ve on inbuilt speaker
12 - -ve on inbuilt speaker
(outputs 9 through 12 would be via the mono downmix)
I hope that makes sense? I would appreciate people's thoughts on whether this would work or if i'm going to break something!
I'm relatively new to audio and electronics in general, so I may be biting off more than I can chew here, however...
I have an idea for a powered speaker with chromecast audio built in. The idea is that each speaker can be used as a single, mono, chromecast connected speaker or paired with another for stereo (so each speaker is set to either left or right channel) I'd also like the option of using the speaker to power a passive partner, so that a stereo pair can be made.
To provide all of this flexibility my plan for the audio path is as follows:
Chromecast (CC) stereo output -> 3pin 4way rotary switch (switch setup as SW1 below, aiming to allow switching between CC Left only, CC Right only, CC Stereo and an Aux stereo in)
Rotary switch centre pins -> input on a class T amplifier (model to be decided)
Stereo Outputs of amplifier -> 4pin 3way rotary switch (switch setup as SW2 below, aiming to allow switching between left from internal speaker / right from speaker out, right from internal speaker / left from speaker out and a mono mix from the internal speaker)
(internal speaker here is shorthand for the crossover etc for whatever speaker array I decide to use within the unit)
I understand that simply bridging left and right inputs like this is a bad idea as it can ruin the amp due to differential voltages in the stereo mix. However, I THINK, I understand correctly that a combination of resistors across this bridge can solve this problem. As per the second diagram here: Why Not Wye?
SW1 - 3pin 4way:
A - Left Out -> connected to left in on amplifier
B - Right Out -> connected to right in on amplifier
C - Ground Out -> connected to ground in on amplifier
1 - Left from CC
2 - Left from CC
3 - Ground from CC
4 - Right from CC
5 - Right from CC
6 - Ground from CC
7 - Left from CC
8 - Right from CC
9 - Ground from CC
10 - Left from Aux
11 - Right from Aux
12 - Ground from Aux
SW2 - 4pin 3way:
A - Left +ve from Amp
B - Left -ve from Amp
C - Right +ve from Amp
D - Right -ve from Amp
1 - +ve on inbuilt speaker
2 - -ve on inbuilt speaker
3 - +ve on speaker out
4 - -ve on speaker out
5 - +ve on speaker out
6 - -ve on speaker out
7 - +ve on inbuilt speaker
8 - -ve on inbuilt speaker
9 - +ve on inbuilt speaker
10 - -ve on inbuilt speaker
11 - +ve on inbuilt speaker
12 - -ve on inbuilt speaker
(outputs 9 through 12 would be via the mono downmix)
I hope that makes sense? I would appreciate people's thoughts on whether this would work or if i'm going to break something!