Help me complete the subwoofer ~ automobile analogy.. - AVS Forum | Home Theater Discussions And Reviews
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Old 07-07-2014, 02:27 PM - Thread Starter
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Help me complete the subwoofer ~ automobile analogy..

Let's say you want to explain a speaker or subwoofer to someone who knows a lot about cars but nothing about the mechanics or physics of speakers. Naturally you will use an analogy between the two. Since my knowledge about either is very incomplete, help me fill out this analogy. So far, here is what I can think of:

Frequency response = handling
burst output = 0 to 60 mph
long term max output = top speed
bl^2/re (force factor) = torque (or maybe ground pressure?)
sensitivity = fuel efficiency
vd (displacement) = horsepower (iffy on this one)
group delay/overhang = braking distance
system Q = optimal engine efficiency (speed for best mpg) (?)
MMS = drag coefficient (?, really not sure about this one)

Where would you say I am on the wrong track here, and what would be better? What else can be added? Another thing, at what point do you think the analogy breaks down, ie the two are too functionally different to be compared? Any thoughts are welcome.
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Old 07-07-2014, 03:09 PM
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Originally Posted by shadyJ View Post
Where would you say I am on the wrong track here, and what would be better?
A main is a Mazda Miata. A sub is a Ford Super Duty F250. The main error made by most is having a size/power mismatch between mains and subs. It all comes down to wavelengths. The size/power of a speaker is proportional to the wavelengths passed. The longest wavelength passed by a main is 14 feet, that by a sub 56 feet. The size and power relationships of the mains versus subs must reflect that. Car analogy is that a Miata need only have room for 2 people and suitcases, an F250 needs a two ton capacity.
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Bill Fitzmaurice Loudspeaker Design

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