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What’s Wrong With Audio?

By March 20, 2012No Comments

The Sonic Issues

Robert Green, in the April issue of Absolute Sound examines how speakers interact with the room and especially the floor. His discussion focuses on the frequency range from 100Hz.-300Hz. This is the frequency range where are vocals are present. He sums up his position by stating:

“Somewhere between 100Hz.and 300Hz. there is typically a deep and quite wide trough in the in-room frequency response. The problem is not primarily the speaker’s anechoic response, but the speakers not being designed to interact with the floor correctly. Some of the designers who presumably cannot figure out how to deal with this contend that it is not a problem and that floor bounce is a natural thing. This is nonsense. The natural floor interaction of the original event is already recorded, and whatever floor interaction a system adds, if it does, is spurious and musically devastating.”

Sound Effect

This frequency range that Robert refers to holds the key and emotional connection to our vocals. This is the range where most female and male vocals lie. Male vocals inhabit the range from approximately 150Hz.-300Hz. and female vocals from 200Hz.-400Hz. If we have a dip or trough in the frequency response in this range we lose information. If we can not hear this vocal range because of speaker design issues or room interaction response issues we are doomed if we are going to seek an emotional connection to the music, which has to be our goal.

Bass and Low Frequency
We have the same issues occurring with low frequency or bass energy. Bass notes have long attack and decay modes. It is in this attack and decay process that the true beauty of the bass instruments can shine through. As a bass note is played and is still present in the room, that note will begin to decay. The decay from the first note must be allowed to decay on its own volition and the room response must allow for this decay to unwind on its own and not blur and smear our presentation. Now, a second note follows and the process begins again. It is this attack and decay process that produces a layered bass foundation to our musical presentation where every note is heard in its entirety. The room must be designed to allow this process to occur or we get muddled and confusing bass sounds and we all know what those sound and feel like.


In order to allow for a tight layered bass response we need a large room. Unfortunately, most people do not have the ability to have a room at least 30′ long to allow for natural bass energy room response to occur. Acoustic product manufacturers claim that end users must “live” with the bass issues and focus on the middle and high frequencies for product design and acoustic control which are much easier to design for. This is nonsense also. Products can be designed to control bass energy attack and decay ratios, so the bass has a tight and layered presentation and we do not need to tear down walls and make the room larger. We also do not need numerous free standing bass absorbers placed throughout the room. In fact, one can take the opposite approach and physically make the room smaller if the bass absorbing technology is designed correctly.


I am a structural engineer as well as a master furniture maker. I design cabinets for low frequency, activated carbon absorbers. Connect with me on Google+

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