Beyond frequency response measurements

[alaios]

Hi all,
I am new to measuring for quantifying problems with audio. I wanted to ask what type of measurements do I need to find out if are problems with the speakers.
I am giving one example:
Assume that the floor is not very sturdy, with old wood planks and they resonate as the subwoofer plays. How can we measure if this happens?

I would like to thank you in advance for your reply.
Regards,
Alex

 

[ppataki]

Besides the frequency curve, these are the ones that you can take a look at:
- phase curve: in an MPL measurement (main listening position) probably it will look pretty bad but it will give you an idea about reflections above the Schroeder frequency and potentially any crossover issues
- distortion graph: this will tell you about any distortions, probably this can be a good indicator for your floor resonance as it might appear as distortion too
- group delay: again, in case of an MLP measurement it will probably look messy but it is supposed to tell you how much the lower frequencies are lagging behind the rest of the range
- RT60: this shows you your room reverberation, typical value for a room bigger than 50m3 shall be 400-600ms above the Schroeder frequency
- Impulse response: will give you an idea about where reflections occur in your room
- Step response: the integral of the impulse response, used to give you info about the ringing in the lower frequencies
- Waterfall: will show you how energy decays over time, for frequencies above the Schroeder frequency it will give you an idea about echo/reverberation while for lower frequencies it will show you where excessive ringing will occur (in case of an MLP measurement)
- Spectrogram: can we configured to show you the waterfall 'from above' (Gaussian) and it can also be configured to show you on a micro-level the energy decay and delay for each frequency (Wavelet)