the Speaker in the Room – by Charlie Santmire

Why spend hours doing speaker-room integration when you could just use a little DSP chip and a microphone and be done with it. Don’t kid yourself. Read on.

This article started as a response to the introduction of yet another program that purports to fix bass in rooms. Many powered subwoofers and AVP/AVR have similar programs imbedded in their hardware. This article has morphed into an exposition of the importance of the interface between the speaker and the room. We are calling this Speaker-Room-Integration, SRI™. TSE has long promoted the importance of getting that integration “right”. We keep getting better at it. Without it, the best system is not worth the money.

What we have called speaker setup in the past is for us this integration of speaker and room. For us, speaker setup means fine adjustment of speaker placement in a room to achieve best possible music reproduction we can for that speaker in that room. It is a process unique to each speaker in each room. I like to think of it as integration. It is the final step and the most important one in achieving accurate music reproduction. The quality of the components that make up the system and the synergistic performance of those components come to naught if this final step is not taken and done well. Read Doug’s article, “What’s Possible?” about the ALEXX setup HERE. The work that Todd and Gale did with that system validates its half-million-dollar cost. Without that work, It is not a high-value system. 

Recently a new digital program has been promoted that purports to be able to distribute bass evenly across a room. This DSP program/chip is being offered for sale as an add on in some new electronic packages. Even distribution of bass across a room cannot be done.

Room modes cannot be eliminated by any equalization/time-alignment electronic system. Modes are a consequence of the room dimensions. Bass notes that relate in wave length to those dimensions will be decreased or increased due to that relationship at specific locations in the room that vary with frequency. It is not possible to make bass uniform throughout a room with electronic manipulation. You can, by careful placement of speakers and woofers in a room produce generally satisfying bass in the listening area. If this is done properly a bass run on a bass guitar will have equal intensity for each note in the run if that is what the performer does. 

Small, stiff rooms are very difficult to deal with at low frequencies. These stiff rooms make the amplitude of the reinforcing and diminishing modes greater. Small rooms make these modes higher in frequency so that they can influence the music in the important bass octave (40-80Hz). Stiff would be a concrete box but even a normal drywall room is fairly stiff. 

The best that can be done to ameliorate this situation is to use stereo subwoofers and through placement and phase alignment make them coincident with the main speakers for the primary listening area. If this is done correctly the subwoofers will integrate with the main speakers and produce a seamless sound that can extend bass reach and impact and convey the sense of space of the recording if the recording was made in a space. If it is not in your budget to add woofers it can be done later. In the meantime, exacting placement of your main speakers is what we would do. 

Room modes in small rooms can also be ameliorated with acoustic treatment that focuses on low frequencies. It is expensive to do acoustic treatment that is effective below 80 Hz. Most so-called bass traps have little effect at those frequencies. The octave between 40Hz and 80Hz can be improved in linearity for the primary listening area in the room with acoustic treatment or careful speaker placement. We do not recommend acoustic treatment focused on this octave.

40Hz to 80Hz is the range from E1 (open E on a normally tuned bass guitar or upright bass which is 41.2Hz where A4 is 440Hz (normal tuning in current western music) to E2. Deep bass (below 40 Hz such as found in organ or electronic music cannot be effectively reproduced in a small room. What is a small room? An example of a small room would be one that is 8′ by 12′ by 15′. Small rooms are helped by large openings into other rooms.

My listening/living room is roughly 22′ by 31′ with a ceiling that varies from 8′ to 12′. The room is lossy. Lossy means there are large openings and some walls are not very rigid. As a result, the bass modes are low in frequency and not very high in intensity. It is a good sounding room with extended bass.

You must start with speakers having reasonably accurate bass response. The response must be well controlled (able to start and stop motion quickly as demanded by the program material). It must have low harmonic distortion at reasonably high levels. Such a speaker, if properly integrated with the room, can be made to give reasonably even bass response in this octave for the listening area. Such a speaker will also give you the impact so important to satisfying reproduction of congas, toms, kick drum. 

Accurate reproduction of an orchestral bass drum (40″ diameter is usual) on the other hand is difficult and expensive. You must move a great deal of air to feel the impact. Typically, the peak impact level live in a concert hall will reach 106db in the seating area. You will feel the compression of your chest. That said, we have achieved remarkable reproduction of such drums in reasonably sized rooms such as our West room in Omaha which is 19′ by 16′ by 9′. For instance, Sonus faber Olympica II, a $10,000 a pair speaker, has produced surprisingly good bass impact from an orchestral bass drum in a system of other components that allow this to happen. 

Tuned drums such as the Tympani are a different animal. The lowest frequency of the largest (32″) Tympani is D2 (73.42 Hz) and is therefore not of consequence in this discussion.

Placement of the speakers to achieve good integration is difficult. It requires great experience and is time-consuming. Proper cables, amplification power conditioning, and component isolation are essential to achieve good results. There is no magic bullet from an electronic chip in your amplifier. Our charge for this service is $1,000 to $2,000 depending on the speakers. The charge would have an offsetting credit towards purchase of speakers and is included with purchase of speakers from us. Integration is only applicable to speakers at and above a certain level of capability to reproduce music. At the very high end, this is a process that takes our most skilled team four to six hours of time and a wealth of experience to accomplish. It is like building a great violin.

We have evolved techniques to position speakers that can achieve great, musically accurate results. It is time-consuming and exacting, requiring a good ear and careful movement of each speaker, ultimately in only small fractions of an inch. You must start knowing what acoustic music sounds like live. We do.  

If you are building a room or are remodeling we can help you achieve smoother more accurate bass response with good impact. The answers are somewhat counter-intuitive, complex, and relate to your particular circumstances. Our charge for this service is $500 to $1,500 depending on the situation. The charge would have an offsetting credit to be used for acoustic treatment or equipment purchases from us. Start with us early in your process. Room size and construction makes a difference. Let us help you. 

I seem to have made this a long article but all of these elements relate and I felt compelled to tell the larger story. The Sound Environment has learned over the years that integration of speaker and room is critical to get your money’s worth out of an audio system. There is no magic bullet to achieve this, just hard work based on knowledge and wisdom carefully acquired by doing hundreds of projects involving modest to very high-performance stereo and multi-channel (home theater) systems all over the United States from Florida to Hawaii.

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