The first thing to do is determine whether it's a room issue or a speaker issue. A large peak at 141 sure sounds like a room resonance or standing wave to me, and the best way to deal with that is acoustic treatment.
Some DAWs (ProTools, Reaper, Vegas Pro) can play video and record new audio tracks alongside it. That would solve the real-time sheet music issue. So you would download the video, load it into the DAW, record your practice performance as a new track while listening to and watching the video...
The size of the waveform doesn't matter, but one way to do that is have some percussive sound with high peaks but a low average level. The peaks will visually merge and make the level appear high when you zoom out.
If you're using the mic that's provided, the gain is probably already set close enough to what you need. So that's mostly just a matter of bringing it up in your ears. Start your receiver turned down a bit from maximum then have him raise the mic level while you sing until it's about right. Then...
Only the left inputs of the stereo channels are mono. They're connected internally to the right channel inputs by default, but that connection is defeated if you plug something into the right input, making them stereo. You could use either left or right output.
An aux send is typically mono...
Bizarrely, the text of the manual doesn't explain much about the stereo line inputs. All the other connectors and controls seem to be covered, but all they say about the stereo inputs is that there's a +4/-10 operating level switch. I had to go to the schematic diagram to find out that they...
It really depends on what you're doing with the mixer. If it's for live use, a pre-fader aux might be preferable. If it's just for home rehearsal, you only need one mix (main out).
If you're in control of the main mix, it's not a major detraction that the aux is post fader because the main mix won't be subject to adjustment by a sound person. For that matter, just listening to the main mix is fine for home rehearsal. Having a separate independent mix is needed when there...
Just for fun, I did some quick and dirty frequency response measurements of a few bookshelf speakers I had lying around, NAD 8225 (blue), Electro-Voice S-40 (red) and Mission M71i (yellow). These were done in my living room, so not an acoustically perfect environment, but I tried to place them...
Well, you could tailor the sub's low pass filter to work with the natural rolloff of the monitors, but that's usually a more gradual slope. One of the disadvantages of crossovers is that, even if you align levels/polarity/phase at the crossover frequency, there's going to be a little response...
There may be a good rationale behind the advice not to high pass the monitors, but there's also good reason to do it. One Dave explains above, but there are also the challenges home recordists often have mixing in small spaces where LF interactions in the room cause problems. Since monitor...