Hi, I've recently started learning how to record at home. The genre I record is bluegrass. My signal chain is Audio Technica AT2020->Tascam Us200->Laptop/Reaper. My room isn't the best acoustically, but I've started adding bass traps as per the advice on the forums. Anyway, on to my problem!
In my recordings, the guitar and mandolin sound fine. I really like the tone I'm getting. My fiddle, however, is giving me fits. It sounds boxy, flat, and nothing like how it sounds in real life. Also, once I get above A440, it suddenly becomes screechy sounding. I think the problem may be flutter echoes, as my room has parallel walls with wood paneling. Here is a plot spectrum of the open a string on my fiddle (440hz). Does that look like flutter echo/comb filtering or is simply the natural harmonics of the instrument? Also included is a mp3 of my very first mix. where you can hear the boxiness of the fiddle.
I assume if it is flutter echo, I need to treat my parallel walls. The room is only 12x14x8' so I assume I will need absorption rather than diffusion?
With respect I would suggest that it is impossible to determine if flutter echo is present from that plot, it is just a sample (or average) at one point in time of a fairly complex waveform (fiddle). The easiest way would be to walk around your room making one single hand clap at various locations. You will hear flutter by multiple returns probably with a distinct "ringing" at various frequencies. You would be better recording the hand clap and analysing that rather than your fiddle which is, as you mentioned, rich in it's own harmonic structure. Additionally if I were you I would also look to display the impulse response (ie in the time domain) at locations you suspect you have a problem to confirm which reflective surfaces are causing the problems.