Helping Venhaus Audio Improve His Room Acoustics

by Nyal Mellor March 28, 2015

Customer Profile

The client, Chris Venhaus, is owner and operator of VH Audio. He has quite a bit of experience with acoustic measurements and had made an effort to acoustically treat his room. However he wanted to get an expert "second opinion" on his acoustic measurements and what further opportunities for improvement there might be.

Chris Venhaus listening room with measurement mic set up for room acoustic analysis

Project Overview

At the time of the project Chris used Legacy Audio Whisper XD speakers, which use a Xilica DSP unit for crossover, speaker and room correction. He had two Legacy LF Extreme 15" subs, Antique Sound Lab amplifiers, a Bent TAP transformer volume control, Empirical Audio OverDrive Signature USB DAC and a modified Mac Mini source. His room was well acoustically treated with RealTraps RFZ panels, 12 MegaTraps, 6 ASC ¼ rounds, ASC Soundplanks, Furutech RWL1 panels and some generic panels for ceiling 1st reflection points. His room a nice sized dedicated space of 17'x23'. 

Chris's listening room was well treated but still had some nagging acoustical issues

Chris was an advanced Room EQ Wizard user and had used the program extensively to position and integrate his subs and create EQ filters to reduce the negative effects of room modes.

 

Acoustic Frontiers Solutions

We agreed with Chris to work on an hourly basis to analyze his acoustic measurements, determine root causes and propose high level solutions. Essentially a Room Acoustic Analysis without the formal report.

Room acoustic analysis in progress!

The measurements we analyzed were left speaker by itself, right speaker by itself, subs by themselves and left/right/subs together. We also examined the lateral and vertical off axis response of the speakers in order to determine the spectral content of the major reflections in the room. Our main conclusions were:

• The way room EQ had been applied could be improved. There were filters in non-minimum phase areas of the response at 175Hz and 300Hz.
• The 2nd width mode at 51Hz and the 2nd length mode at 68Hz exhibited some residual ringing despite the bass trapping in the room. We suggested adding further bass trapping to deal with these issues.
• The interaction of the dual woofers and the ceiling was causing two phase cancellation nulls at 106Hz and 183Hz (i.e. speaker boundary interference). We recommended additional bass trapping be added to the ceiling.
  
  

The Results!

After the consulting work the acoustic measurements were improved and the sound was better.

Post consulting measurements, 1/3rd octave smoothing

 

In the Client's Words

"I was left with a few nagging issues with my room acoustics, after a year of shooting measurements with a calibrated microphone and special acoustic software, as well as tweaking positions and adding room treatments. It didn't take long to find out who the 'go to' pro for room acoustics analysis was…. Nyal Mellor. Nyal analyzed my acoustic measurement files, and then offered some suggestions on how to address the last remaining issue I had (related to Speaker Boundary Interference Response or SBIR), as well as assessed where I was with the rest of the measurements. I highly recommend Nyal's advisory services for any audiophile who truly wants to extract the last bit of performance from one of the most overlooked aspects of system performance: THE ROOM/SPEAKER/LISTENING-POSITION interface." Chris Venhaus / VH Audio.

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