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vernb
08-08-2011, 02:59 AM
Hi there
Can someone tell how deep a pair of JBL 2225 wil play in a 176litre vented/ported cabinet?
I have four 2225 driver and two 176litre cabinets.

They are to play with 2445 drivers on 2360 horns, and I just need to know from what frequency the sub is needed.
Thanks

Vern

Allanvh5150
08-08-2011, 03:20 AM
The 2225 was not really made to play super low. Usualy around 40hz

Allan.

vernb
08-08-2011, 03:22 AM
The 2225 was not really made to play super low. Usualy around 40hz

Allan.

Thanks for a quick reply.
But will the two 2225 really play down to 40hz in a 176 litre cabinet, or do they roll off higher. That's the question.

Allanvh5150
08-08-2011, 04:38 AM
Hi again, To give you more of an idea, 2 x 2225's in a 102L box with play flat down to 58hz. In 175L box tuned to 50Hz, they are 3db down at 55hz. Optimum box size for flatness is about 102L. Download WinISD and have a look at the numbers yourself. The 175L box is too big.

Allan.

Earl K
08-08-2011, 04:38 AM
Here ya go .

This is a 176 litre box ( with 4 ports ) tuned to 55hz ( holding both speakers ) .

Cross the sub in at around 50 to 55 hz .


<> Earl

Allanvh5150
08-08-2011, 04:52 AM
I must have been half asleep when I read the post. I did not see the mention of the 2445. EarlK's spot on but I would lift the crossover point to 80hz to take more bottom end out of the 2225's

Allan.

Eaulive
08-08-2011, 05:21 AM
I must have been half asleep when I read the post. I did not see the mention of the 2445. EarlK's spot on but I would lift the crossover point to 80hz to take more bottom end out of the 2225's

Allan.

But he wants bottom end! :dont-know:

Allanvh5150
08-08-2011, 05:50 AM
But he wants bottom end! :dont-know:

hmmmm......maybe I should go back to bed.....:)

P.S. I will then refer back to my earlier post.

spkrman57
08-08-2011, 05:58 AM
I just need to know from what frequency the sub is needed.
ThanksVern

Bring in the subs between 50hz - 60 hz and the 2225's should work well on up from there.

If I'm barking up the wrong tree be sure and ignore this...

Regards, Ron

vernb
08-08-2011, 12:12 PM
Thanks a lot guys. I got all the info I needed. No I didn't want the 2225's to play VLF. I just needed to know how low they would actually play in my already made 175 litre cabinets.
Best regards
Verner

Ruediger
08-08-2011, 12:27 PM
Thanks a lot guys. I got all the info I needed. No I didn't want the 2225's to play VLF. I just needed to know how low they would actually play in my already made 175 litre cabinets.
Best regards
Verner

The question is: what will be the frequency response if each driver is given 1/2 the volume, which results in 88 liters per driver. Mutual coupling between the drivers will improve things a bit. With an active setup this (the frequency response, not the coupling ) can easily be calculated, with a passive crossover things get more complicated and worse.

Can somebody please run his design program for a net volume of ca. 80 liters?

Ruediger

grumpy
08-08-2011, 01:28 PM
it appears that simulation -was- with 176l shared by two drivers.
both drivers in 80l is down 3dB at ~76Hz.

1audiohack
08-08-2011, 03:46 PM
Like this? The center is half space flush mount, the bottom is 1/4 space as in the pic.

Ruediger
08-09-2011, 11:17 AM
I do not understand what You are trying to achieve. Two bass drivers will yield a lobed response unless You bring in the 2nd only at very low freuencies (see the 4435).

Why not throw the cabinets away (or sell them :) and build proper ones for either just one driver per cabinet or two drivers in a 4435-like arrangement?

Ruediger

paragon
08-15-2011, 11:03 AM
I used a pair 2205A in a 225 L reflex enclosure like this. 35 Hz (-10 dB), 40 Hz (-3 dB)?