If you have not heard an IB, you have to. Since there is no box tuned to a certain frequency, it is free to reproduce the most perfect bass you can imagine.
The below is a post from Chrisbee at the Cult of the Infinitely Baffled on my thread, page 7. He explains why not only an IB sounds so good, but how it makes the rest of your speakers sound better as well.
May 13, 2010, 11:30am, pmcneil wrote:No, there is more to it than that. We both had subs taking that load before we built the IB, and my crossover frequency is unchanged.
But maybe the key is not 'taking the workload' but 'good' sub.
I'm wondering what in this case explains the 'good'?
The absence of distortion from the IB allows the fundamental to be clearly exposed rather than obscured by false harmonics. No single low frequency tone is ever involved in the reproduction of sound so the false harmonics (of other subwoofers) are as complex as the input signal itself.
The absence of these complex "muddy" upper bass harmonics (from the IB) prevents the speaker's output from being masked. Masking is a very common form of deafness which denies the listener the ability to effortlessly decode the underlying "message" in the signal. Speech quickly becomes unintelligible when masked by background or foreground noise. The brain lacks the ability to automatically filter the wanted signal from the "crud". This makes listening very hard work instead of the natural pastime we take for granted in everyday life.
The IB frees the listener of the heavy computational workload of decoding the hash. Listening becomes easier because it is so effortless to hear the message against the greatly reduced, wideband noise floor reaching our ears.
Despite the subwoofer handling only a couple of lower octaves it affects the entire frequency response of the speaker system. False harmonics combine with other false frequencies to produce yet more complex tones both above and below the original signal.
We learn from birth to recognise sounds and instruments from their harmonic structure. It used to have survival value but now it is mostly for our entertainment, for its emotional stimulus leading to enjoyment.
When denied a true harmonic "signature" to every note the brain becomes confused. It cannot instantly recognise a saxophone from a clarinet or an oboe from a bassoon. The expected harmonic structure is so badly distorted that we waste brain computing time trying to recognise sounds. Like a person learning a new language cannot keep up with fast speech as they have to try and interpret every syllable and inflection into their own, native language. Understanding is easily lost in the race to comprehend meaning by heavy number crunching.
The unwanted and artificial hash produced by most subwoofers has its own frequency response and phase superimposed on the speaker's output. The greater the clarity of the subwoofer the greater the sense of realism because nothing is added which wasn't in the original signal.
If any proof were needed of the IB's greater clarity, realism and low distortion then one only needs to listen to the great pipes of the organ being reproduced.
Where tones are at the limit of audibility (and beyond) the slightest low frequency distortion will rob the listener of the amazing subtlety and clarity of their interplay and means of vocal expression. The way they speak. The leading edge, sustain and decay are all laid bare by the IB. It can play these low notes with breathtaking clarity. Devoid of the masking additions so common to other subwoofers. No two pipes speak alike. Only the IB can reproduce this so effortlessly that we can hear it without overloading the brain's audio analysis into computational reading errors. The pipes become nimble and articulate. Clearly exposing the skills of the organist. Or lack of.