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Posted By: sonicfox woofer measurement - 07/15/02 10:00 PM
Call me ignorant, but how is woofer size measured? I'm assuming it is the diameter of the woofer. The reason I ask is that my current speakers (Infinity RS-4's) claim to have 6 1/2 inch woofers. However, when I get the measuring tape out, it barely makes 6" and that's including the rubber surrounds. Maybe the opening for the woofer is 6 1/2" across, but certainly the woofer isn't. Is this normal for a speaker company to exaggerate woofer size?

Thanks...and sorry if this seems like a dumb question.

Mary
Posted By: chesseroo Re: woofer measurement - 07/15/02 11:40 PM
When i hear a length pronounced for a driver, i automatically picture it being the entire diameter of the driver and not just the cone, or the cone plus surrounds.
This means that the edge of the basket holding the cone and surrounds is also included in this measured length. In double checking the 6.25" drivers on my M60s, the cone plus surrounds is actually more like 6" with the basket edge taking up the last 0.25".

If none of this changes the fact that your Infinity drivers don't measure up to 6.5", then i would have to say that is false advertising, unless of course Infinity can define the length of their drivers in some other way (front to back perhaps?). But that would not make much sense.
Posted By: Randyman Re: woofer measurement - 07/16/02 03:18 AM
hmmmm..

Sound to me like the person at Infinity who "sized/named" the drivers was a man. Men are always exagerating the size of their woofers!(heh heh)

Well... perhaps it's like the sizing of TV sets and computer monitors. The actuals vary somewhat from the published specs. At least in monitors they usually state a viewing size (vs the actual tube size)

I think that in speakers, the stated size is nominal and usually includes measurement to the outside of the frame where the screws/bolts go. Check out a 6X9 or a 5X7 speaker for a car.

Randyman
Posted By: alan Re: woofer measurement - 07/16/02 03:29 PM
Hi Sonicfox,

I'm not aware of any specific standard, but of the several speakers that I checked, including Axioms and a Paradigm, the diameter to the outer edge of the metal frame was included.

Odd that you asked, because I'd always assumed it included the diameter to the outer edge of the rubber surround, but apparently not. It's to the outer rim of the speaker's frame.

Just be happy you don't have to deal with centimeters and millimeters (plus inches!), which I had to contend with when I edited equipment directories in Canada.

Regards,
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