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View Full Version : Should I change back my 2245's from 2240 or maybe 2242 kit?



colofan
07-11-2014, 10:02 AM
I have a couple of drivers that were originally 2245. I broke one over driving and the guy doing the rebuilt suggested changing to 2240 instead. My DIY box I re-tuned to match the 2240 and had my other sub changed as well (not broken). Okay I am now admitting that might not have been the best plan. Sure I can't hit the Xmech since the suspension is stiffer and I have not changed the amplifiers (at least yet).

Here is the question. Should I change them back? Should I use the 2242 kit?

I have a full test and simulation capability (LMS and Leap) the question is has someone done this here? I hate to spend the money and then wish I had not done this.

I will be putting in a sub-sonic filter to make sure the Xmech doesn't happen again.

Ideas suggestions?

grumpy
07-11-2014, 12:02 PM
Subsonic filter on a bass reflex box that has a good chance of being sent high power signals below the tuned resonance is always a good idea. Doesn't mean you need to leave it on all the time.

between 2245 and 40, that's up to you and your application.

Lee in Montreal
07-11-2014, 01:11 PM
2242 recone kit is not for the 2240/2245 baskets.

You forgot to let us know what you do with your bass cabinets.

Mr. Widget
07-11-2014, 07:27 PM
Here is the question. Should I use the 2242 kit?
As Lee said, the 2242 is not a compatible woofer design.



Should I change them back?
I would... If you need great SPL at low frequencies you may need a steep filter below resonance as Grumpy says and possibly additional drivers or modern drivers with greater Xmax.


Widget

Lee in Montreal
07-11-2014, 08:33 PM
For greater SPL, yould also multiply your bass bins.

Four 2245 should sound pretty good in a room. Definitely the wrong woofer though for PA as you don't get the punch.

As an exemple, I have criticized the 2226 to be weak in bass. But now that I know how to eq it, I find it sounds deep enough, can kick hard and sustain high power. Its 18" equivalent would be the 2242. Nothing beats testing. Get a set of 2242 and play with them. You have no idea what a 6 to 9db bandpass boost at 40Hz with Q=1.0 can do ;-)

Allanvh5150
07-11-2014, 09:04 PM
I always found the 2245 great for PA. You just had to use more of them.

Allan.

colofan
07-14-2014, 01:45 PM
Most home theater is the application.

I didn't think I could put the 2242 kit in.

Sounds like change back to 2245 and add the sub-sonic filter should be good to go....

Thanks for the input.

Val
07-14-2014, 08:27 PM
I handled the sub-sonic roll off on my 2245 sub that I use for HT and music by using the DSP in the Crown XTi1000. I also gave it the recommended 3db bump using the DSP.

colofan
07-17-2014, 08:51 AM
What about the clone kits ?:
http://www.simplyspeakers.com/jbl-recone-kit-aftermarket-jbl-2245H-RK-JBL2245-8.html

Since I am using in the low frequency range and I can used my electronic crossover to adjust. Is this a bad idea? The cost difference is about $200 /driver.

I read the thread about the Mckenzie (sp?) recone kit and that looks bad......

I would like to get the kit myself and just do it. yes I have a lot of test gear to check it afterwards...Ideas?

Lee in Montreal
07-17-2014, 09:38 AM
I read the thread about the Mckenzie (sp?) recone kit and that looks bad......

Why do you say it looks bad? Nobody has measured and compared. I have a set of 2226 Mckenzie recones and am very satisfied. if you are using the 2245 for the bottom octave, I'd say give them a try. It's only $79.00. Sure it is not a JBL recone kit but who said it will not sound the same? some people have even mentionned that some aftermarket recones sounded "better" to their ears. It may not have measured the same, but he pleasure was there... :D

grumpy
07-17-2014, 10:15 AM
Lot's of opinions on this one.

I've heard a B460 with a non-JBL cone kit and identified it almost immediately.
No A/B test, just a look, a listen, and a tap. Done. Wasn't privy to the kit mfg.

Not sure that ripping out a -working- 2240 kit to put in a non-aquaplassed aftermarket
kit is a worthwhile endeavor, but again ... just my opinion. Everyone's situation and
needs are different. Hope this turns out well for you, however it goes.

ivica
07-17-2014, 10:24 AM
What about the clone kits ?:
http://www.simplyspeakers.com/jbl-recone-kit-aftermarket-jbl-2245H-RK-JBL2245-8.html

Since I am using in the low frequency range and I can used my electronic crossover to adjust. Is this a bad idea? The cost difference is about $200 /driver.

I read the thread about the Mckenzie (sp?) recone kit and that looks bad......

I would like to get the kit myself and just do it. yes I have a lot of test gear to check it afterwards...Ideas?

Hi colofan,

please, inform us about the results.
I believe that Fs, and Qt will not be near the original, but may be the sound character would remain.

regards
ivica

colofan
07-18-2014, 07:24 AM
I will give a full set of test results back to the forum. Thanks for the help.

FE3T
07-20-2014, 12:58 PM
If you plan to rip out a 2240 kit and reinstall a non oem 2245 kit, why not try a middle way?
Cut off the fabric edge of the 2240 kit and replace it with one of Rick Cobb`s 2245 foams.
It migth not be to close to real 2245 behaviour afterwards, but maybe just as close as a non oem kit.
Besides, If the result are not pleasing, you have only wasted the cost of a foam.

colofan
08-02-2014, 09:35 AM
If I re-foam would I not also want to add the mass ring ? Does anyone know how close the cone masses are between 2245 and 2240?

ivica
08-02-2014, 09:40 AM
If I re-foam would I not also want to add the mass ring ? Does anyone know how close the cone masses are between 2245 and 2240?

about 20gr differences including VC weight

ivica

colofan
01-07-2015, 12:19 PM
Still tossing this around. I am now thinking of adding the mass ring (If I can find 2). The voice coils are of different length so maybe not a bad comprise.

Anyone know where I can buy the rings? The surrounds are in really good shape. Just hate the thought of taking a knife to them :)

The slow down in response is i bought a pair of Stereo Integrity drivers and swapped out. However the home theater is still lacking so since I have the drivers I would build a new box for them.

Ideas? What would you do? I don't mind spending money but I am a DIY kind of guy so wanting to experiment.

ivica
01-09-2015, 01:38 AM
Still tossing this around. I am now thinking of adding the mass ring (If I can find 2). The voice coils are of different length so maybe not a bad comprise.

Anyone know where I can buy the rings? The surrounds are in really good shape. Just hate the thought of taking a knife to them :)

The slow down in response is i bought a pair of Stereo Integrity drivers and swapped out. However the home theater is still lacking so since I have the drivers I would build a new box for them.

Ideas? What would you do? I don't mind spending money but I am a DIY kind of guy so wanting to experiment.

Hi colofan,

I would not suggest You to use "mass-ring". If You decide to re-foam (only) 2440 kit, I think that You will not get any difference to the 2440 original, as most of the today foams are fare from the original one.

First I think that you have to use subsonic filter (for under say 30 Hz, to protect your drivers)

regards
ivica