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Author Topic: Jbl 2245 in project  (Read 10712 times)

Jeff Bankston

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Re: Jbl 2245 in project
« Reply #10 on: May 22, 2015, 04:35:53 PM »

winisd is not very accurate. Eminence cabinet design software is very accurate. its all manual like winisd.

http://www.usspeaker.com/cabinetsoftware-1.htm
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Stephen Kirby

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Re: Jbl 2245 in project
« Reply #11 on: May 22, 2015, 05:21:04 PM »

It sounds to me like they unloaded below fs and overran their Xmax.  You said you had a HP at 30 but not if the tuning was set above that, or by how much.
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Jacob Shaw

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Re: Jbl 2245 in project
« Reply #12 on: May 22, 2015, 05:47:39 PM »

The cabinet is tuned to have an f3 around 30hz per win isd instructions, and the cabinet does produce it well as verified by a tone sweep.  I cut the amp all the way down as soon as I heard the rattle.  I have seen a few cases where I heard some crap coming out of a double loaded cab and later verified an open circuit on one of the drivers.  If the current cannot control the cone then the air inside the enclosure does it (poorly).  But we will see when I get that one open.  As for the one that I did pull, I will be cutting it open tonight.  I appreciate the insight that a short should not open the circuits.
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Stephen Kirby

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Re: Jbl 2245 in project
« Reply #13 on: May 22, 2015, 07:11:12 PM »

Did you run an Xmax plot in WinISD?  Trying to remember if you can do that.  30Hz sounds pretty low for an SR sub.  It might go there at low levels, but cranking it will run out of excursion pretty quick.  The rattle was probably hitting the back plate.

I made the mistake of trying to do this many years ago with some EVM drivers I pulled out of T18s.  After reconeing a few, I upgraded to better drivers and retuned the cabs higher up.  f3 around 50Hz.  Eventually I built new boxes that have a bump around 60 after noticing that SRXs sounded "louder" than otherwise flat boxes with bands playing through them.  These get high passed at 40, 18dB/octave.  Higher if I'm really leaning on them outdoors.  Yes, I know a 5 string bass goes below that.  I have one.  Very few people use those bottom 4-5 notes as the pitch is pretty unintelligible though most bass amps.  50-60 is that kick drum thump most people think of as low end.  To put out a lot below that involves more and larger boxes than I want to carry these days.
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Jacob Shaw

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Re: Jbl 2245 in project
« Reply #14 on: May 26, 2015, 03:27:30 PM »

Yea, the whole point is that these are the biggest damn reflex cabinets that I have ever seen and 6" ports, it seems it would be a shame to do anything less than an infra cabinet.  I do Edm shows, so is plenty going on in the subsonic range if your bighpass lets it through.
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Bob Leonard

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Re: Jbl 2245 in project
« Reply #15 on: May 26, 2015, 03:47:59 PM »

Jacob,
If you're doing EDM then you've chosen the wrong driver. As a matter of fact the 2245 was never designed or intended for use within a pro sound environment. The 2245, with it's foam surround and 600 watt PROGRAM rating, was specifically designed by JBL for use in studio monitors. If you want good subs then you need to use the correct driver in a box that's properly ported. I don't think anyone here would find anything wrong with using a 2242 or 2268 for this purpose, and if you need to copy a design, then copy any of the single or dual 18" cabinets JBL sells for pro sound.
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BOSTON STRONG........
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Tim McCulloch

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Re: Jbl 2245 in project
« Reply #16 on: May 26, 2015, 05:00:42 PM »

Jacob,
If you're doing EDM then you've chosen the wrong driver. As a matter of fact the 2245 was never designed or intended for use within a pro sound environment. The 2245, with it's foam surround and 600 watt PROGRAM rating, was specifically designed by JBL for use in studio monitors. If you want good subs then you need to use the correct driver in a box that's properly ported. I don't think anyone here would find anything wrong with using a 2242 or 2268 for this purpose, and if you need to copy a design, then copy any of the single or dual 18" cabinets JBL sells for pro sound.

This.  Right.  Here.

I'll add that there are scores of sub plans from speaker manufacturers and some of them end up sounding pretty good.  Some of them have been discussed in the PSW Subwoofer forum and in the diyspeakerplans forum.

If you want to make your own sawdust I suggest you look at some of the things Art Welter has designed and built.  He's been doing this a long time and is well grounded in both principles and practicality.
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"If you're passing on your way, from Palm Springs to L.A., Give a wave to good ol' Dave, Say hello to progress and goodbye to the Moonlight Motor Inn." - Steve Spurgin, Moonlight Motor Inn

Jacob Shaw

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Re: Jbl 2245 in project
« Reply #17 on: May 26, 2015, 10:23:27 PM »

I have no interest in becoming a consumer of lumber (I'm a tree hugger), but if I did I would build usbs and labs.  I do believe that I can find a suitable driver for these cabinets.  I got into the first cabinet that I believe had the short.  It was not bottomed out. the only evidence I could find other than the infinite resistance was a pair of charred streaks where a pair of shiny streaks also where.  I think this recone was slightly missaligned and it shorted when it rubbed through the coating.  I took a picture but I am not forum savey enough to know how to post it.
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Jacob Shaw

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Re: Jbl 2245 in project
« Reply #18 on: May 26, 2015, 10:38:24 PM »

I bought the driver on e-bay so there is no telling who reconed it.
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Bob Leonard

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Re: Jbl 2245 in project
« Reply #19 on: May 27, 2015, 07:13:25 AM »

The wrong driver re-coned or not is still the wrong driver. Use the same driver and you'll be feeding strawberries to the hogs, then all of your work won't amount to a piss hole in the snow.
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BOSTON STRONG........
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I did a gig for Otis Elevator once. Like every job, it had it's ups and downs.

ProSoundWeb Community

Re: Jbl 2245 in project
« Reply #19 on: May 27, 2015, 07:13:25 AM »


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