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

My stands are on adjustable metal screws, securely anchored without piercing through the carpet.  Moon gels decouple so well that the vibration from the bass is not felt on the stands, and the vibration from the ground is not transmitted onto the speakers.

@lanx0003 

If you have a good floor the last thing you want to do is decouple the speaker from the floor. Ideally you would bolt it down to the floor. Spikes are the usual option. Why? Newton's 3rd law. You need a very massive, fixed mass (the floor) to control the reactive forces or the speaker shakes. Play a 20 Hz test tone and put your hand on the speaker. What you feel = distortion. Now spike the speaker to the floor and you will feel less shaking. You might also notice more aggressive bass. I'm afraid this whole speaker decoupling gig is an example of lay intuition. If a floor is so bad that it resonates in the audio band then fix the floor. Most floors dampened by carpet might only resonate in the 5 to 10 Hz range, great for causing footfall problems with turntables but not a problem for loudspeakers.

You might want to consider a MiniDSP SHD Studio. This assumes you have your own DACs. It uses Dirac Live which is similar to ARC. This unit is $1,300 and includes streaming. Benchmark Media Systems uses a Studio with their own DACs and is super pleased with the results. It also includes subwoofer crossovers and bass management. 

Ten Misconceptions About Loudspeaker Spikes
Clearing up misunderstandings regarding loudspeaker feet.
Article By Norman Varney see below:

Mike

https://www.enjoythemusic.com/magazine/equipment/0422/Ten_Misconceptions_About_Loudspeaker_Spikes_Review.htm

 

@mijostyn It seems I need to re-investigate the speaker decoupling subject.  I have used  the factory spikes under the stands on the tiles for my Wharfdale Linton and it works fine.  Bass is agile/nimble to my satisfaction.  But I have never try spikes under my Burchardts.  I guess these non-intrusive spikes below won't break my bank and worth trying.

For the room correction (RC), I do prefer the RC resided in the streamer rather than preamp section so it is processed digitally before the analog conversion.  I believe the digital EQ / dsp is more precise than the analog counterpart.  Moreoever, I have a pretty decent preamp that I do not wish to be swapped.  However, at the mean time, the digital EQ/DSP may sound more clinical / harsh due to its precision.  It is sort of double edged sword.  Your thoughts?

I guess, for the time being, since I have ordered Unison, I may just keep my finger crossed and hope the best.  Based on all the good reviews I have read so far, I have no doubt that Unison will do a decent job in RC but just worry about its preamp section may not be up to par.