What happened to my room acoustics


I measured the spectrogram for my room at my MLP, and the FFT results are as follows:

- There is a roll-off before 20kHz.

- A dip is present around 12kHz.

- There is a noticeable boost between 50Hz and 1.5kHz.

- The bass rolls off around 33Hz at -3dB, consistent with the factory rating.

Comparing these measurements to the Burchardt measurements, there are some differences:

- It doesn’t exhibit a roll-off before 20kHz.

- The dip is around 15kHz.

- The boost between 50Hz and 1.5kHz is not as pronounced as in my room.

I’m curious about what might be happening with my room acoustics. If a fix is possible, what would it entail?

Spectrogram from my zoom

 

My room / speakers setup

 

Measurements from Burchardt

lanx0003

@lanx0003 

It is always best to use three spikes. They should be driven clean through any carpet and padding into the plywood. Three spikes on tile is OK as long as you lower the speaker gently. 

The best digital signal processing units sound like whatever you make them sound like. You can create any target curve you like within certain limits. After 25 years of doing this I can look at a curve and tell in a general way what the system will sound like. You can not determine imaging this way. I have to see measurements on each channel separately to get an idea, again in a general way. The best units are now using 64 bit floating point systems with powerful processors. They run at a minimum of 24/192. There is no characteristic sound. It all depends how you program it. Most system like Dirac Live run on their own algorithms leaving you little room to play. You have to accept whatever they do with minor adjustments. With my old Tact and the new DEQX units you can let them do their thing and walk away or you can grab the bull by the horns and program the unit yourself which IMHO produces the best results once you learn what you are doing.  

Sorry for having strong feelings on this...but it was what saved my system/and my speakers from the chopping block.I read an article in galen carol website..."everything matters".This was after searching for some answers on setup.Turned out just some loose spikes under sound anchor stands...Tightened them down/re setup speakers....Totally transforming.Sound stage snapped in,had tight bass,ect.I had to redo setup a skosh... but the work was worth the effort.Sorry for add butt...

https://www.usaudiomart.com/details/650038696-isoacoustics-gaia-ii-carpet-spikes-2-sets-of-4/

@digsmithd @mijostyn I found myself repeating an experiment I had conducted before concerning the decoupler/coupler between bookshelves and stands. This might turn into he says she says situation. Among springs, Moon gel, and rubber (by 3M), once again, Moon gel outperforms rubber and springs in terms of bass note weight and articulation. Springs are the least effective yielding soft bass. Rubber does have some degree of coupling effect. I agree with what you and others have mentioned about spikes being couplers. While spikes may tighten up the bass, they can also make it sound lean. I recall Paul McGowan attesting to this before.

Sorry, I just need to trust my ears in this case.

@lanx0003 

What you are listening to is distortion, bass resonance. Little loudspeakers do this all the time intentionally to give the impression of bass. I can understand wanting more bass power and weight. The best ways to do this are Digital Signal Processing and subwoofers. 

 

@mijostyn  I cannot speak for Mr. McGowan, but I respectfully disagree with you regarding the distortion you have proclaimed. I believe, as a bass guitar player in a college band, I can discern between distortion and natural bass. Overly tight bass can become unnatural. Two-channel system listening experiences are subjective, and it's essential to learn to agree to disagree.

I am on board with DSP and I hope it works to resolve the issues I was having.

Subwoofer is another contentious topic for tomorrow.