© Hybrid Audio Technologies, 2010
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believe
pure tones
in the vehicle are going to be difficult, if not impossible to localize. Finally,
most vehicles exhibit a Schroeder Frequency (Fs) between 50 at 125 Hz; the Fs (or cabin-gain
frequency) is vehicle dependent, and is the frequency at which resonances become so tightly
packed in frequency and space that the acoustical properties of the vehicle behave quite
uniformly.
2
Acoustic treatment can be very effective above 200 Hz, depending mostly on the polar
radiation pattern of the speaker. In the case of the Imagine midbass, the polar radiation
pattern is quite large at lower frequencies, with a narrowing of the radiation pattern
(“beaming”) at frequencies into the treble bandwidth.
Should the Imagine midbass be placed in the kick panel locations, one may find that a notable
improvement can be made by adding acoustical treatments, such as open-cell foam, into the
underside of the dashboard. Likewise, should the midbass, or in fact the I1 tweeter be placed
up high on a-pillars, or in the dashboard, where comb filtering (reflective summation and
cancellation off of a hard surface, such as a windscreen) may become an issue, a dashboard
“mat” or other soft furnishing may be a noticeable improvement. It will require trial and error
to get it right, but the learning is in the experimentation!
Advanced Installation Conclusions
Sadly, there are no rules in mobile audio, only several hypothesis and theorems that seem to
work for
most
vehicles. Your vehicle may be different, and defy everything we know, and
everything written in this manual. You may find that getting that rich, detailed sound that you
crave may require some experimentation and a lot of work to make it right. Or you might be
fortunate to have a vehicle that sounds excellent with minimal work. Have patience and work
through the issues; the result will be a rewarding musical experience in your vehicle! Just
remember, it is critical to get a reference, as detailed in Lesson 5. Go out and become a
student of music and audio, learn, and improve your audio system one step at a time. The
journey is exciting and rewarding!
What we have included above is only a very brief primer to the world of high-end mobile audio
systems. We invite you to read more by going to our
Downloads
web page.
2
As an aside, one significant benefit of car audio sound systems is that frequencies below the lowest room resonance increase at a theoretical
12 dB/octave…it’s no wonder car audio systems have such great bass!
