TBI s' MYTHS AND FACTS
Myth - The current technology for subwoofers is the best solution for audio and home theater applications.
Fact - The current methods employed cannot succeed in general applications to improve audio or home theater because of the many idiosyncratic behaviors associated with conventional bass sound reproduction. Room interaction, resonance based sensitivity, dimensions and other phenomena associated with typical subwoofers prevent objective behavior and general acceptance. One only has to observe the adjustments, costs and subjectivity associated with a high-end subwoofer installation for two channel audio. Mass oriented consumers simply buy what is sold to them and use it.
Myth - Subwoofers have been around for ages so with all of the hoop-hoola and money spent by the majors it would appear that the solution would have been found by now.
Fact - The current technology employed for all subwoofers is outdated and is the main reason that the costs are so high. One should be able to purchase a subwoofer that makes our sound as clear as the video is to watch and it shouldn't cost a fortune. The term subwoofer has been given a bad rap especially in high-end audio because of the tendency to associate boom with it. Whether home theater or high quality two-channel audio the subwoofers job is to present low frequency audio to the system that is not there and do so in a non intrusive manner. The idea is to recreate the event as a natural facsimile of the production including the special effects.
Myth - More amplifier power is better when purchasing a subwoofer.
Fact - You always want enough amplifier power to prevent clipping but the goal is to only play the woofer at a level that blends with and without effects and prevents its audio signature from being apparent at any level. The resonance associated with making bass the conventional way prevents the woofer from using its power effectively especially in a music system. This resonance signature can't be eliminated with a equalizer or other types of processors so the sub dominates the sound field at low or high levels. Two different resonating diaphragms can never be in sync regardless of electronic manipulation of the signal and in the case of your mains woofer and the subwoofer it is like trying to get the turn signals in two different cars to blink together. They might do it every now and then but in that case who really cares. The only real common denominator between the two drivers is the signal itself and this is the link that TBI uses to sync the sub driver with the main bass driver.
Myth - There must be a digital algorithm or process that can correct for such problems in real time. Digital electronics has proven to be the savior for so many sound related problems and its cheaper now.
Fact - The electrical and acoustical domains are entirely different. Whereas electricity travels at a rate of 186000 mi/sec and encounters little resistance as we know it while sound travels at the rate of 1100 ft/sec and is encumbered by many natural and man made mazes before it actually reaches our ears. Once the electrical source signal enters the world of the loudspeaker crossover, driver, air masses and room acoustics the battle is lost and the integrity of the sound is lost forever. Audiophiles will pay a heavy premium to attempt to maintain integrity but the rest of the world will not. It is a good idea to preserve the signal as much as possible just in case a solution is found to allow the average Joe to enjoy the well-preserved sound.
Myth - It is always best to crossover to the woofer at the lowest possible frequency to avoid the sonic signature of the subwoofer.
Fact - In actuality the statement above is a fact but not a reality at least not now. The main speaker capable of going pretty low is always easier to match with a subwoofer as opposed to the smaller speakers that most people own. Why? It all goes back to resonance and having more than one associated with reproducing the bass frequencies. If we crossover as low as possible it avoids stimulating the driver near its resonance frequency therefore leaving only the mains as the dominate and necessary resonance contributor. With TBI bass extension modules the drivers operating resonance is high and de-emphasized (acoustic low pass function) while the port resonant feature is eliminated. The acoustic low pass function and a resonance stable driver allow the crossover to be seamless at any crossover point within the bass extenders operating range.
Myth - Sound has to be played loud to sound natural. This is the way it is according to the founding fathers of sound research.
Fact - Again this myth has truth in fact but a solution is now available making it invalid. The F-M curves generated back in the 1930's has always governed the psychoacoustics' phenomena associated with loudness and the ability to enjoy sound especially reproduced music at low volume levels. TBI bass extension has proven this myth to be false as the low frequency reproduction governed by the ETL™ technology enhances the clarity and realism of the entire presentation even at low volumes. The signal based low frequency reproduction allows complete synchronization of overlapping fundamentals and harmonics while preserving low frequency integrity and coherence so you hear detail without high volumes.
Myth - The corner is the best place to locate a subwoofer.
Fact - The corner stimulates the room modes all of them. If the loudest volume is your goal then you would be crazy not to place the sub in the corner. The sub can actually becomes an oscillator as the driver is affected by so many modal reflections including those at its resonant frequency. If however quality is the major concern then the corner is the worse place. This of course all depends on the quality of the system and the need to preserve the integrity over the volume but audiophiles are concerned about quality so the corner is out. TBI audiophile subwoofer applications generally benefit from a centrally location equal distance from the loudspeakers or the use of two units, one for each channel, whether stereo or mono.
Myth - Smaller subwoofers are better than large ones and certainly easier to place.
Fact - Larger subwoofers perform in a physically normal manner by having a larger cone for more efficient operation. Larger subwoofers are hampered by the rooms' acoustics and resonance. Large drivers make efficient receptors of low frequency sound, as the cone area is large causing the larger subwoofer to easily overload the room by becoming oscillatory. The efficient large sub maintains a resonant signature regardless of electronic signal processing especially in smaller rooms. Large rooms are much easier to get smooth bass with large subs but that doesn't affect the two-resonance paradox that always exists. Small subwoofers require too much mass and too much cone travel to ever become a resonating partner for a music system. You can make some that measure good frequency response.
Myth - There has been plenty of reviews lately in popular audio magazines that hold several subwoofer brands with high regards. It seems that they have this subwoofer thing under control.
Fact - If you read the reviews of subwoofers in specialty audio magazines there will always be a sonic limitation preventing overall class A recommendation. Something always goes wrong to prevent the sub from becoming a permanent part of the reviewers system even though they may recommend it to you with these caveats. Read the reviews on even the most popular brands and you will always find a reason for not including it in your system. Read TBI s reviews and you see the reviewer purchasing the product as a first time experience with subwoofers. You will see the same reaction in subsequent reviews even though everything is different each time. Video magazines will always scream over how loud it gets and never seem to understand the link between a subwoofer and musical rhythm.