2225 to 2235 refoam xmax question

[Artcore87]

Well, it's your money, try it and see.

Enclosure volume/tuning is only a tiny aspect of getting a system to play at its potential. I don't know what exactly you plan to use for other drivers to mate to the 15" woofer, but you are over simplifying the task by at least one order of magnitude.

Just a few things to consider, you need to consider the individual SPL levels for each driver, their frequency responses, where you choose the crossover points, type of slopes, impedances, off axis responses of each driver at the crossover points, baffle step, and a host of other factors if you want to get reasonable sound.

It is folly to take an outstanding woofer and mate it with second rate components or a poorly designed system or expect a totally different woofer to play in a different system with the existing crossover. It's also folly to take a perfectly good high end woofer and modify it without a detailed understanding of what you are doing and how all the factors impact each other.

I'm not trying to be hostile, just trying to save you money and grief with your project, but in the end it is your money and time. I've said all I need to say. Good luck.

And I greatly appreciate the input don't get me wrong. I know there are many factors the volume was just one example of how the parameter should be close but does not need to be exact. Quality of sound is better than flatness of frequency response IMO, if for no other reason than I can EQ them flat with my 31 band Alesis EQ, but the sound character will remain the same and is thus more important.

One of the reasons I wanted these JBL's is because they have higher sensitivity than the RTR woofers in there now, which do NOT play as loudly as the midrange horns above them... and I know this is obviously not ideal! I have to EQ for this difference in output much more than I want to. The JBL woofer will match the horn level much better. Plus, I could buy a variable l-pad to put on the horn, to precisely match the levels of the 3 drivers. My speakers are in another house ATM so I can't take them apart but unfortunately I don't know what the mids and tweeters are. I realize this is slightly ridiculous. However I'm confident that they are rather good, for a couple reasons (one being how they sound). And for curiosities sake I will figure out what they are so I can know the exact specs. But the speakers were designed and built by a hi-fi enthusiast who was an engineer by trade... he had about 6 other complete systems (amps/speakers) in his home most of which costing 5 or 10 grand... this was a side project of his. So I highly doubt he made crappy speakers (apart from the rtr woofers like i said, which i suspect he put in there to sell them). He was selling most of his large gear because he was moving to a different state. He said that he specifically chose the mid and HF drivers for their specs and his previous experience with them... he said it was actually hard for him to find the tweeters he wanted and had to order them from Japan. Right now the speakers' weak point is below 1khz... the rest of the range sounds absolutely fantastic though the horn needs some EQ'ing... mainly as a level adjustment. Doing the PVC edge roll termination of the horns (maybe 120-150 degrees of the circle... whatever follows the contour) and maybe some foam or applied felt or EnABL'ing of the horns should smooth them out and reduce the need for EQ'ing. I have not heard a better tweeter.

Eventually I will build new cabs for the speakers because they COULD be better... the drivers are mounted right in the center of the baffle which is not ideal. Also I want less resonance.... its 3/4" 7-ply birch with mdf front and rear (1" up front, 3/4" rear). The vertical spacing seems good based on listening, and hoping the engineer got it right. There's also rounded wood trim that runs around the entire baffle that sticks out about 1", and I can't be sure what this is causing in terms of diffraction.

I believe the woofer low pass is 6db, horn (1" exit) high pass 6db, tweeter high pass is either 12db or 18db... I think recall him saying 3rd order, but i could be wrong... I'd have to look at it and google some values. It is a ribbon so I believe it needs the protection.... but maybe it's not a true ribbon... still need to find out.


So... can anyone recone these for me (not for free of course)... or sell me recone kits?

[Artcore87]

Artcore, I agree with your point - building a speaker is a matter of juggling many variables, and the decision to use one woofer over another often is not validated until after you've purchased, installed, and measured/listened to the woofer, often followed by re-listing it on Ebay. Other than -3db point and bass roll off, it's difficult to predict how a woofer will sound and transition to a midrange without lots of modeling with expensive software tools, usually still followed by prototyping it. I'm glad you're having fun with your project, and are willing to try anything. Personally, I've been wanting to experiment with TAD drivers, but wow! Talk about needing some serious coin - it will have to wait...

In the interest of budget, I would really consider leaving your 2225's stock while they still have resale value. If they don't turn out to be the right speaker, resell them and buy 2235's. Spending $175 reconing 2225's as 2235's leaves you with a woofer that is worth $150. I would also consider buying a cheap electronic crossover so that you can play with your woofer/mid transition - maybe a JBL M552 or equivalent on Ebay.

While it seems you have put the aftermarket kit question to rest, one final comment. When you purchase a JBL Recone kit, everything is pre-assembled for the frame you are using, so that installation is highly reliable and repeatable. Have you read the simplyspeakers kit's instructions? Holy crap! There are many extra steps to this kit, all of which are critical to performance, including "set the voice coil height according to original voice coil setting." and gluing the voicecoil to both the cone and they spider. I do not question that there are pros on this forum who have used these kits and are able to to assemble them with some uniformity, but I am not one. Even with the test equipment I have, if you had me assemble and install the kit, how many would I have to build until I got a pair that matched as well as a pre-built JBL kit? I'm guessing 5 if sober, maybe 4 if not (steadier hands). I think to assure any quality, a good professional would need to assemble and install these, and that good professional is going to charge a premium for all the extra steps needed (glue voicecoil to cone, wait at least 1hr, etc), and that extra time is going to cost money. I'd like to get one of the pro's opinion on how much extra they'd charge versus the factory kit, but I don't see how the aftermarket kit is practical. Just my 2 cents, feel free to ignore...

-John

HSCGuy thank you for your input. You're probably dead-on about leaving these 2225's alone for now. I'll simply EQ for bass response and see how I like them. I couldn't find any 2235's which is why I bought them... so as for reslisting them and buying 2235's... not sure if that's doable. Plus money wise... I'd probably have to sell them first and then buy the 2235's which leaves me with no speakers for a while :'(. If the VC, and the spider, and the mass, AND the surround are all different between the 25 and the 35, then just going to foam surround on the 2225 and adding mass won't get me the extension I want (though maybe part of it)... and you're right my skills as far as refoaming them may or may not be sufficient to achieve uniformity and linearity.

As for the cone mass though... instead of modpodge (irreversible, not good for resale), what if i hot-glued some lead bb's inside at the VC/cone junction... that would be removable and unnoticeable afterwards. Could drop Fs a few hz, yes?

[Allanvh5150]

HSCGuy thank you for your input. You're probably dead-on about leaving these 2225's alone for now. I'll simply EQ for bass response and see how I like them. I couldn't find any 2235's which is why I bought them... so as for reslisting them and buying 2235's... not sure if that's doable. Plus money wise... I'd probably have to sell them first and then buy the 2235's which leaves me with no speakers for a while :'(. If the VC, and the spider, and the mass, AND the surround are all different between the 25 and the 35, then just going to foam surround on the 2225 and adding mass won't get me the extension I want (though maybe part of it)... and you're right my skills as far as refoaming them may or may not be sufficient to achieve uniformity and linearity.

As for the cone mass though... instead of modpodge (irreversible, not good for resale), what if i hot-glued some lead bb's inside at the VC/cone junction... that would be removable and unnoticeable afterwards. Could drop Fs a few hz, yes?

To be perfectly honest your are better saving up the cash to get 2235 cones dropped into your 2225 baskets. 2235 are like rockinghorse poo.

Allan.

[Artcore87]

To be perfectly honest your are better saving up the cash to get 2235 cones dropped into your 2225 baskets. 2235 are like rockinghorse poo.

Allan.

That's probably what I'll do. It would be sweet if someone here on the boards could do it or have someone they know do it at somewhat of a discount..... anyone?

[HCSGuy]

Patience, patience - 2235's come up all the time. I've passed on several on Craigslist in my area at $175-200 each over the past year. Watch Ebay and Craigslist and something will come up.

Regarding adding weight to your 2225's, add it to the edge of the dustcap, with a small gap between the weight and the glue edge. It's very easy to cut out and replace the dustcap later. I'm not sure you could get hot glued BB's off the cone without pulling the cone apart, but I'm not going to experiment.

-John

[4313B]

It would be sweet if someone here on the boards could do it or have someone they know do it at somewhat of a discount..... anyone?

What would be sweet is if you'd take your drivers to a reconer, get it done and leave us out of the loop...

[grumpy]

... and here I thought -I- was grumpy...

[Artcore87]

What would be sweet is if you'd take your drivers to a reconer, get it done and leave us out of the loop...

generally I've always found hobbyist forums are full of exceptionally helpful, nice, and willing people, such as on the diy audio forums and many others. 4313b if that isn't you then you don't have to respond to my request. Personally if I had the connections, time, knowhow, and enjoyed working with something, I'd be more than happy to help someone out with something like this. Regarding my tripath amp thankfully there are such people out there to help in various ways, such as building custom amps and selling them for barely over parts cost.

I'll continue to search for 2235s. If anyone wants so
e 2225s at cost let me know =)

[4313B]

Whatever...

[grumpy]

I think you might be -really- surprised at how much help can be leveraged here
(albeit with a full range of experiences, that often need filtering).

I believe your original question was eventually answered in much detail
with time investment from several very experienced folks.

It -is- hard (and frustrating) to help when the helpee has painted his/her-self
into a corner and refuses the helper ... no wants to suffer that kind of query.
(ok, not many of us).

[timc]

generally I've always found hobbyist forums are full of exceptionally helpful, nice, and willing people, such as on the diy audio forums and many others. 4313b if that isn't you then you don't have to respond to my request. Personally if I had the connections, time, knowhow, and enjoyed working with something, I'd be more than happy to help someone out with something like this. Regarding my tripath amp thankfully there are such people out there to help in various ways, such as building custom amps and selling them for barely over parts cost.

I'll continue to search for 2235s. If anyone wants so
e 2225s at cost let me know =)

Perhaps....But how would you feel after xxxxxxx BS requests?


And you think $70 for a genuine JBL recone kit is expensive? Here in norway the recone kit for the 12" 2213 costs $300 EACH!

I do have a little trouble where you are going with your project. If you are planning on putting the 2225/2235 into an existing system, you will have to rework the woofer AND midsection of the crossover. That is unless you are very lucky. In wich case i would recommend buying a lottery ticket


-Tim

[Loren42]

I think you might be -really- surprised at how much help can be leveraged here
(albeit with a full range of experiences, that often need filtering).

I believe your original question was eventually answered in much detail
with time investment from several very experienced folks.

It -is- hard (and frustrating) to help when the helpee has painted his/her-self
into a corner and refuses the helper ... no wants to suffer that kind of query.
(ok, not many of us).

-grumpy (was "scratchy" taken?)

+1

I agree. It is frustrating when you ask a question, get sage advice, but you already had your mind made up. You were just looking for support to do things your way (because you already bought the wrong woofers). When that didn't come you "sorta" "kinda" concede you possibly may change your mind.

Nonetheless, all of us here keep coming back to try to make your project succeed.

[Artcore87]

+1

I agree. It is frustrating when you ask a question, get sage advice, but you already had your mind made up. You were just looking for support to do things your way (because you already bought the wrong woofers). When that didn't come you "sorta" "kinda" concede you possibly may change your mind.

Nonetheless, all of us here keep coming back to try to make your project succeed.

Fair enough, I didn't mean to come across that way, so I apologize. I probably shouldn't have interpreted some others' posts the way I did which prompted my remarks. I DO appreciate the help that I have received in this thread, and never denied receiving it, so thank you all. I admit I was too impatient to wait for 2235h's to pop up, and underestimated the differences and complexity of changing a 2225 into a 2235 or something close (which I've learned may or may not be a good idea depending on the factors discussed and expressed here).

I will enjoy the 2225's for now as is, with EQ'ing. They'll be in an apartment so the bass levels achievable should be adequate for my listening level. This is certainly not going to be my last speaker project, so please understand the lack of perfectionism on my part in wanting to just get a GOOD speaker together. The next ones will be of more epic proportions, when finances allow for it.

I've been browsing for electronic crossovers and am seriously considering a Behringer DCX2496. Does anyone have any experience with or knowledge of this product and it's quality? I'm currently using an older Alesis 31 band stereo EQ also, which I may upgrade to something of higher quality, but I really haven't researched this component or how good it may be (or has the potential to be with some capacitor mods etc.). My source is my computer, which has a VIA Envy 24HT sound card (wolfson DAC 2ch 24/96 output), which has upgraded capacitors, and my music is played in Foobar, and I don't like the character of the foobar EQ, and it doesn't have enough bands, but there are some plugin EQs supposedly of higher quality that I still have to try.

I will let you know how the woofers work out in my current system with the existing crossovers. I'm a bit limited in x-over values (if i'm thinking about it correctly), because the mid horns drop off probably around 800-1khz, which is about the upper limit of the woofers... so please enlighten me as to why i'll have to modify a crossover that seems to be at the right frequency... that is, based on the lower limit of the midrange driver. The woofer should be relatively flat up to that point, no?

[1audiohack]

Disclaimer! This is not directed at anyone!!! OK;

I don't think people tinker (explore) enough, many read read read and puzzle but,,,

A 2225 is the 80's Chevy truck of the JBL line, I would be surprised if there is another 15 they made in larger quantities. I wouldn't discourage anyone from modifying either one.

So tune the box to 20Hz and see what you get, it won't be flat but what have you got to lose? Add some weight to the cone and see what you get. If you have the power and EQ what's the worst thing that could happen, pissed neighbors and or re-cone? 2225's are not in short supply.

Have some fun and see what you can learn.

Somewhere I once read, "Scientists are explorers, Engineers are pioneers, Philosophers are tourists."

You would probably not believe what I have run through a bandsaw over the years just to see whats inside. As a side note, every speaker that I have thrown in the trash since I was a kid got connected directly to the national power grid on the way out, I guess I will never grow up.

Have fun,
Barry.

[HCSGuy]

Artcore,
Here are JBL's frequency response curves for the two woofers. As you can see, the 2225 is very predictable and has a rising response between 1k and 2k. the 2235 gets really hairy after 1k. I have never built with either of these woofers (Except the 2235 as subwoofers), so I will defer to the experts, but my opinion is that the 2235 will work better with a higher slope crossover at a lower frequency (600-800hz) so that the output is pretty low by the time those lumps hit. The 2225, however, is nice and predictable up high - more friendly with different crossovers. This is the reason you see 2225's used in DIY 2 ways with 2" horn drivers, while the 2235 is more often used in 4 ways or with mids that will go lower.

I think you can also see that inserting both drivers in your existing crossover will give very different performance at the crossover point to the midrange, hence the suggestion that you will need to modify the crossover.

I don't know what your other drivers or your crossover are, but I think you might find the 2225 blends better at the top of its range. Maybe keeping your 2225's and building a sub for the first octave is a consideration?
-John