It should be pointed out that the remainder of drivers in a system may not necessarily have McKenzie kits that differ to the same degree.
It should be pointed out that the remainder of drivers in a system may not necessarily have McKenzie kits that differ to the same degree.
True. And this is what was explained in the test. People running active won't mind 1db difference. In my case I have a stack of power amps and a digital crossover. Therefore, I don't mind if my 2445 compressoer are at least 18db more efficient. I just correct the difference in the crossover. Same applies with the woofers.Originally Posted by gasfan
Right, I didn't miss that. I was referring to the advice to recone an entire passive system. It may turn out that one anomaly is still preferable to possibly skewing the whole system.
Probably not an issue in a domestic setting but most of the failures I see with non JBL kits are 10-15 rounds of the bottom of the voice coil loose and in the bottom of the motor.
Also that real high Z at resonance as compared to all the other drivers is odd. It would be intersting to observe the "geezer" test speaker with a strobe light. I can usually tell of a coil or spider or some part of the suspension is disconnected or a diaphragm is broken via a high impeadance peak. Something isn't peachy.
Barry.
If we knew what the hell we were doing, we wouldn't call it research would we.
I used one of the 2245 kits from mackenzie for the sub I built for my brother about two years ago. It did not have the aquaplas on the cone and did not appear to weigh enough to meet the JBL moving-mass spec for the 2245. I expected this from what I had read in this thread so I simply painted duratex (hillbilly aquaplas?) on to the rear of the cone and kept weighing it until I got it in the ball park. Cosmetically it is a dead ringer for my JBL 2245 in the B460. I was using a blown 2240 driver so I didn't have an old 2245 cone to use as a reference for the weight. Obviously a real JBL kit is (was?) the way to go but it wasn't in the budget for this build. Two years later the low-budget recone is working fine.
Don
I know of a place that is doing a pretty good job of reproducing JBL recone kits that are no longer manufactured by JBL, and I just received a report from a caller that the facility south of the border is not living up to the legacy quality that the brand has been known for.
My kits seem to be being well received by users on a few different continents...and for that I am truly honored.
Some key ingredients are missing from aftermarket recone kits that make JBL perform they way they do. Details matter. If you don't pay attention to the details, the sound will clearly reveal it.
Shameless plug. Please forgive me.
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
Plug away! It's not like you're some fly-by-night dude.
Warren
DIY Array, 2242 sub, 4408, 4208, Control 8SR, E120 Guitar cab, Control 1, LSR305.
Hey Ken, don't be modest. Someone has to have the guts and wherewithal to keep doing good work. Haven't been up your way now for a couple of years since I retired, but hope you're doing well. I assume you're doing your work out of a streamlined work area now? Hope work is still coming your way.
Regards,
Bart
When faced with another JBL find, Good mech986 says
, JBL Fan mech986 says
You are 100% correct when mentioning that a repro will never be the exact same thing as the original. At least the way the original used to be built. Would I use a repro 2245 (per exemple) in the exact same configuration as originally, certainly not. But, I would see no problem using such recone for a sub with a limited pass band or for test projects where $80.00usd makes more sense to me than $300.00usd... Sound might be different (maybe more or less upward extension, different sensitivity), but hey, sub has its own amp, and DQX are there for a reason ;-)
Mackenzie is just another option that seems to "work".
I can't speak for McKenzie kits, but I have a set of 2235s that are all MWA parts. Actually they are 2234s because I didn't want the mass ring. I use them in my L300s. I wanted to compare the sound to the OEM woofers that I have (136a reconed with JBL 2235h kits). I must say, they sound pretty much the same, except for the fact that now, I no longer have the mass ring kissing the back plate when I get a little over zealous with the volume
Without the mass ring they shouldn't "sound pretty much the same". There should be more mid band coming from the woofers.I can't speak for McKenzie kits, but I have a set of 2235s that are all MWA parts. Actually they are 2234s because I didn't want the mass ring. I use them in my L300s. I wanted to compare the sound to the OEM woofers that I have (136a reconed with JBL 2235h kits). I must say, they sound pretty much the same, except for the fact that now, I no longer have the mass ring kissing the back plate when I get a little over zealous with the volume
Widget
I do have my system going through a parametric EQ. If I were running it without any type of tone controls, I'm sure the "more mid band" would be obvious to my ears. My point, IMHO, the MWA cone kits sound pretty damn good vs the OEM. Now, I've only had them for 6 months or so, only time will tell whether they're as durable as the OEM. As I stated before, I'm just so tickled not to hear that God awful sound of the mass ring kissing the backplate......maybe I should do more critical listening
And maybe turn it down a bit?I'm just so tickled not to hear that God awful sound of the mass ring kissing the backplate......maybe I should do more critical listening
Actually in in all seriousness, if you are boosting the VLF you might be pushing the speakers harder than you think. I too have heard the slapping of 2235H mass rings against the top plate, but in my experience the output is quite significant.
Widget
There is a way to keep the moving mass of a 2235H style kit...or for that matter, a genuine JBL 2235H...and eliminate the smackage of the mass ring.I do have my system going through a parametric EQ. If I were running it without any type of tone controls, I'm sure the "more mid band" would be obvious to my ears. My point, IMHO, the MWA cone kits sound pretty damn good vs the OEM. Now, I've only had them for 6 months or so, only time will tell whether they're as durable as the OEM. As I stated before, I'm just so tickled not to hear that God awful sound of the mass ring kissing the backplate......maybe I should do more critical listening
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
I totally understand the concept of saving money to make a speaker "work". The part that really angers and frustrates the hell out of me is when the seller claims that the recone kit is "just as good as" or "the same as" the factory version or a faithful reproduction and sells the item to an unsuspecting buyer who thinks he/she is buying the OEM equivalent...when they clearly are being lied to. I think this practice is actually illegal without a disclaimer. A 2245H kit...or any other kit, for that matter...cannot possibly perform the same as or even close to OEM JBL without having Aquaplas applied to the cone in an amount that closely matches the engineering standard. Of course, this is for models that were originally produced with Aquaplas.
What you have is an 18" woofer with a 4" edgewound, 8 ohm voice coil, and a cast aluminum frame. What you cannot call it is a JBL 2245H...because it is incomplete. Making it complete takes time and effort.
That said...I'm glad you're satisfied with the results for the amount spent. That's an objective "value" call.
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
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