ventilation holes ?

Speaker design is Paavo's special interest so post away.
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mflorio
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ventilation holes ?

Post by mflorio »

Hi - This may sound like a ridiculous question, but I can't find any info on it whatsoever...

I have a pair of JBL 4410's (positioned vertically w/ woofer on bottom). What side should the ventilation hole be on ??? Right now, as I have them, the holes are on the inside (see http://www.8thstreet.com/prod.asp?pid=11010 for a pic).

My problem is I seem to have an unusual dip at around 125hz and a spike at 300hz. My ceiling is only 7ft, so maybe there is some cancellation going on ? Or maybe the holes should be on the outside ???

Thanks for any insight,

Mike
har-bal
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Re: ventilation holes ?

Post by har-bal »

mflorio wrote:Hi - This may sound like a ridiculous question, but I can't find any info on it whatsoever...

I have a pair of JBL 4410's (positioned vertically w/ woofer on bottom). What side should the ventilation hole be on ??? Right now, as I have them, the holes are on the inside (see http://www.8thstreet.com/prod.asp?pid=11010 for a pic).

My problem is I seem to have an unusual dip at around 125hz and a spike at 300hz. My ceiling is only 7ft, so maybe there is some cancellation going on ? Or maybe the holes should be on the outside ???

Thanks for any insight,

Mike


Mike

Paavo is on vacation for three days. He will address your question when he returns.

Cheers

Earle
HarBal
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Post by HarBal »

Do they have the drivers axially aligned or are the tweeter and mid range units off to one side (4410A?). If they are off to one side then the polar response will likely be biased to one side or the other, in which case youi'd have to go with what JBL says is the left or right speaker. If axially aligned then it should have no affect on the imaging so just choose the best positioning to minimise bass problems.

You may find that the drivers are positioned too high off the floor but you may well have setup limitations restricting that (mixing desk?). I'd really recommend trying to get the best sound without other furniture constaints first and then from there try and figure out if it is possible to fit your gear into the space left over. The other way around can just impose too many limitations on sound optimisation.

Cheers,


Paavo.
mflorio
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Location: New York
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Post by mflorio »

The mid and tweeter are off to the side (and I have them positioned like in the picture - with the holes on the inside of the pair). JBL hasn't marked either as L or R, and the documentation I have doesn't specify that either. I think you're right, I'm going to have to experiment with positioning and room treatments.

Thanks,

Mike
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