How deep low I can go with a JBL 2215H in a sealed sub? - diyAudio
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Old 15th February 2013, 12:35 AM   #1
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Default How deep low I can go with a JBL 2215H in a sealed sub?

I have a pair of JBL 2215H in my basement, are they suited to subwoofer use?
the T/S parameters are:
fs = 20 Hz,
Qt = 0.21,
Vas = 736 ltr,
Qm = 5.5,
Qe = 0.22,
Re = 5.7 Ohms
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Old 15th February 2013, 12:52 AM   #2
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Other than running a simulation of the box and seeing the response, checking the SPL vs. Power (or xmax), and then taking into account placement in the room, and possible "room lift", there's no way to know for sure how low it will go.

Otoh, if you have enough sensitivity and the SPL vs. Power vs. Excursion part is favorable, you can do the EBS thing, which EQs the lower freqs and uses an enclosure that is somewhat smaller, and an amp that is somewhat larger.

High power amps for bass are pretty inexpensive today.

How low do you think you need or want to go, and how loud?

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Old 15th February 2013, 07:33 AM   #3
djk is offline djk
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Qts is too low for good bass.
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Old 15th February 2013, 12:34 PM   #4
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Quote:
Originally Posted by bear View Post
Other than running a simulation of the box and seeing the response, checking the SPL vs. Power (or xmax), and then taking into account placement in the room, and possible "room lift", there's no way to know for sure how low it will go.

Otoh, if you have enough sensitivity and the SPL vs. Power vs. Excursion part is favorable, you can do the EBS thing, which EQs the lower freqs and uses an enclosure that is somewhat smaller, and an amp that is somewhat larger.

High power amps for bass are pretty inexpensive today.

How low do you think you need or want to go, and how loud?

_-_-bear
Sorry, but I think you've got your definitions mixed up.

EBS is an oversized ported cabinet, tuned low. This gives a LF shelf before final rolloff, which is lower in frequency than the usual optimally flat response.

What you describe is simply sealed with Linkwitz Transform.

If the drivers have plenty of power handling, you can put them in tiny boxes, throw power in and still drive to Xmax, giving the same maxSPL as a bigger cabinet (whose SPL will be displacement limited)

Chris
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Old 15th February 2013, 03:07 PM   #5
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Quote:
Originally Posted by murillollirum View Post
I have a pair of JBL 2215H in my basement, are they suited to subwoofer use?
Anyway, NO.
They are good for BR and horn.
What best project to do with these drivers?
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Old 15th February 2013, 03:26 PM   #6
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Time for a FYI:

b
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File Type: jpg JBL-2215H_Quarter-Wave-Subs.jpg (502.7 KB, 77 views)

Last edited by bjorno; 15th February 2013 at 03:43 PM.
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Old 15th February 2013, 05:51 PM   #7
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bjorno, you always come up with something funny...
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