JBL K2 S9500/M9500...ish with 2226 and 2441

[Joe Alesi]

Hello All,

I hope this post finds you all happy and well. I am interested in your opinions about a K2 S9500 or M9500 look-alike or clone(???) made from four JBL 2226 drivers and two 2441 drivers I have. I also have 2461s with Titanium diaphrams (untested- maybe a 2421 like sound?). I also have two 2245 subs in B460 sized enclosures. I would make a wooden horn to suit the compression driver. I also have two 2402.

Any thoughts about my K2..ish project? Has anyone built something similar using non 1400 or LE14 drivers? These drivers as well as the 2235 are a little hard to find in Australia. I know the fs of the 2226 vs these other drivers is quite different, but the sensitivity and power handling are good.

Thanks in advance for your thoughts.

Best
JA

[speakerdave]

I am interested in your opinions about a K2 S9500 or M9500 look-alike or clone(???) made from four JBL 2226 drivers and two 2441 drivers I have. I also have 2461s with Titanium diaphrams (untested- maybe a 2421 like sound?). I also have two 2245 subs in B460 sized enclosures.

A clone is an EXACT replication.

I'm working on a plan using 1400nd's, but a different horn and driver, so I call them wannabes.

Not the ideal combination of drivers for that layout, but since you already have them, there's nothing to keep you from trying it. I would try to calculate the spread of the 2226's to bring in acoustic coupling at the frequency the bass is beginning to tail off in the enclosures you choose.

To me the advantage of the MTM layout is the vertical and horizontal symmetry of the driver interactions. Adding a tweeter changes that. I don't think it works, but others don't seem to mind it.

David

[sa660]

Joe,
This is a good example to follow.
Using the 2226 I recomend that you follow the cinema cabinet 4507 volume and vents port sizes. Deeper cabinet will alow you to build a full tower that will not be to high. Also Deeper cabinet may be able to cover the depth of the horns. I would recommed the smith design JBL 2397.
MR widget has a lot of experience and quality creation clones or better.
The 2441 is a very good driver and with a titanium diaphragm and aquaplas you will not need the 2402 making a 2way MTM ala K2 9800 a good looking beast.
Like speaker dave mentioned try to set the crossover near the roll off od the 2226.
If you are using the 2441 I would recommend 500Hz.
If you are using the 2461 I would recommend 800Hz.
You can always start with a simple 2 way like the 4430 and progress to the dual 15". But I am not sure if you will gain much for home application.
Good luck.

[Joe Alesi]

Hello David and SA660,

Thankyou for your kind replies.

David
I like the MTM arrrangement for the same reasons you stated and having heard this arrangement (albeit with much smaller non-JBL drivers ) on several occassions know that this is the way I would like to go with JBL. The increased power handling and reduced strain on the drivers in a 2 driver arrangement can only be another plus.

SA660,
I like the idea of the 2397, it would certainly be somewhat easier to make than a (for want of a better description) more fat lipped horn like a 2345 or 2350 shape. I suppose the only way to tell is try. I think I know of a Melbourne Australia Smith Horn based fan- Maybe I should beg him for a good listen? (If he is reading- consider this a beg.... )

I will research the 4507 size for my application and play around with the depth as you suggested.

One question the 2441 with a titanium diaphram what sort of HF extension are members achieving with these? Is HF EQ being used for 16kHz+ or is it straight out of the box with a 2445/2446 diaphram or dare I say it non-JBL diaphram?

Thanks again
Best
Joe Alesi

[speakerdave]

If you are going to use the coated titanium 4" diaphragm you might look at the crossover for the M9500 as a starting place (not that I can decode it for you).

I would like to mention also that in the lead up to Project May, we were advised to NOT use a linear driver in an MTM arrangement. In that case the 2234 was to be preferred over the 2235. I think the 2226 could be called a linear driver--in fact I think one of its design goals was to improve upon the bass of the 2225 and its RISING RESPONSE. I think the 2226 is as linear a driver as the 2235; it just has a much tighter suspension and therefore higher resonance.

At that time we also looked into the details of acoustic coupling and found two different (both respectable) sources--one saying that it occurs when the centers of the two drivers are one-half wave-length apart and the other saying one-quarter. My completely non-authoritative opinion is that the latter is correct for full effect, and that the onset is gradual between one-half and one-quarter. In other words, this effect takes place over the span of an octave; since the gain of acoustic coupling is 3 dB it will not be very useful in managing the 12-18 dB per octave fall-off of the typical bass reflex alignment. One thing that might help is to use staggered tuning for the two enclosures in a stack. With the 2226, if you make one box 20% larger than optimum and one 20% smaller, you will have a couple of really large boxes stacked up.

David

[Joe Alesi]

Hello David,

Yes I will have to do some rough calcs to cover the acoustic coupling issue you mentioned. Thanks for the info.

Best
Joe Alesi