Todays rant.
Growing up, the two were quite different. How did we adopt the IB name to the sealed enclosure? An IB used to be a flat plane, large enough to prevent wave canellation down to 20Hz, and AC was any old sealed box.
Heck, I don't even hear the term acoustic suspension anymore. I suppose I should roll with the punches and get on with it but the whole thing rubs me the wrong way.
Never mind the 'sub' woofer thing
Growing up, the two were quite different. How did we adopt the IB name to the sealed enclosure? An IB used to be a flat plane, large enough to prevent wave canellation down to 20Hz, and AC was any old sealed box.
Heck, I don't even hear the term acoustic suspension anymore. I suppose I should roll with the punches and get on with it but the whole thing rubs me the wrong way.
Never mind the 'sub' woofer thing
Poobah, You're great.
Shin, Don't have to worry about the speed with my omni/multi/bi-directional speaker leads. They promise zero drag provided I elevate the amp above the speakers to not compromise the electron siphon effect.
Joules, I like it and I wonder if the speed of the bass changes with the choice of automobile?
Shin, Don't have to worry about the speed with my omni/multi/bi-directional speaker leads. They promise zero drag provided I elevate the amp above the speakers to not compromise the electron siphon effect.
Joules, I like it and I wonder if the speed of the bass changes with the choice of automobile?
ShinOBIWAN said:
Nope, red is.. as evidenced by the vast increase in speeding tickets over all other colors.
Cal.. I have the same peeves.. I don't know about IB vs. other methods.. But I have a STRONG feeling that Bose Marketing pegged the pathetic "subwoofer" bandwidth that is commonly referred to today.
Cal Weldon said:
An Infinite Baffle started out being a flat board of immense proportions, but then someone decided you can wrap the board around the speaker and if the resulting sealed box is large enough, it acts similarly to an infinitely large flat board.
That's the strict, strict, strict definition. When the sealed box is much smaller than Vas, the springiness of the air of the box has a far greater effect than the speaker's own suspension.richie00boy said:
When a speaker is put into a sealed box equal in volume to it's Vas, both the Fs and the Qts are raised 1.4 times. While that is a visible effect, it is nowhere near as much as if the box volume is much less than Vas.
As a result, for a long time the practical parlance was, for closed boxes, you have an Infinite Baffle if the sealed box volume is equal to or greater than the speaker's Vas; you have an acoustic suspension if the box volume is much less than the speaker's Vas.
However, even that compromise seems to falling by the wayside now, as the label Infinite Baffle seems to be applied to most any sealed box.
"You know that is interesting... purple speaker wires are claimed to be fast as well."
poobah,
Maybe you forgot one thing, not just the colour but also the wires should be straight(braided means more turns to negotiate).
Further, AC waveform follows the curves whereas DC will tend to crash on the bends..... Fast is infinitely perplexing.
Regards,
Francis
poobah,
Maybe you forgot one thing, not just the colour but also the wires should be straight(braided means more turns to negotiate).
Further, AC waveform follows the curves whereas DC will tend to crash on the bends..... Fast is infinitely perplexing.
Regards,
Francis
I haven't noticed IB being misused for sealed boxes.
I never much liked "acoustic suspension"; it's more marketing speak than a descriptive term.
"Air suspension" would be much more accurate.
"Acoustic suspension is when the Vas/Vb ratio is less than 3. Infinite baffle is when the ratio is 3 or above."
Are you sure it's not Vb/Vas?
Either way, I disagree. In science and engineering, "infinite" is used where increasing a value has no further significant effect.
Even at Vb = 3 Vas, the total stiffness is 3 parts from the air and 1 part from the driver, giving Fc = 1.15Fs.
To qualify as IB, I'd say Fc should be no more than 5% higher than Fs.
"foam surround is cheap suspension material and certainly has
limited lifetime"
Materials technology has progressed hugely in the last couple of decades, and foam is much more durable.
I never much liked "acoustic suspension"; it's more marketing speak than a descriptive term.
"Air suspension" would be much more accurate.
"Acoustic suspension is when the Vas/Vb ratio is less than 3. Infinite baffle is when the ratio is 3 or above."
Are you sure it's not Vb/Vas?
Either way, I disagree. In science and engineering, "infinite" is used where increasing a value has no further significant effect.
Even at Vb = 3 Vas, the total stiffness is 3 parts from the air and 1 part from the driver, giving Fc = 1.15Fs.
To qualify as IB, I'd say Fc should be no more than 5% higher than Fs.
"foam surround is cheap suspension material and certainly has
limited lifetime"
Materials technology has progressed hugely in the last couple of decades, and foam is much more durable.
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