AVS Forum banner

JBL 2242H Build Thread

36K views 92 replies 31 participants last post by  LTD02 
#1 ·
I have a pair of JBL 2242H drivers that I plan on building enclosures for. I am thinking of 12 cu ft net for each driver. Ported and tuned to 22 hertz.


JBL's cut sheet recommends anything from 5-12 cu ft for the driver. They also recommend a high pass filter set to 20 hertz for the larger cabinet sizes as the driver runs out of xmax rather quickly below tuning. I am not too concerned about the content below 20 hertz for the application that I plan on using it for.


I am looking forward to how they will sound in a larger cabinet as they get rave reviews all over the internet. The cabinets will be placed under my entertainment center and will be used for both music and movies.

 
See less See more
1
#5 ·
Why not build something like this:

http://www.jblsynthesis.com/Products/Details/110


JBL Synthesis S1S-EX Clone...


6.5 cu.ft tuned to 25Hz


Adding B6 Filter (6db Boost@20hz Q=2) will get you an F3 around 24hz as long as you apply a high pass filter 12db/octave or better at 20Hz. This design will also offer much better group delay than a 12cu.ft box.


Just my 2 cents.
 
#6 ·

Quote:
Originally Posted by atomicmist /forum/post/21020362


Why not build something like this:

http://www.jblsynthesis.com/Products/Details/110


JBL Synthesis S1S-EX Clone...


6.5 cu.ft tuned to 25Hz


Adding B6 Filter (6db Boost@20hz Q=2) will get you an F3 around 24hz as long as you apply a high pass filter 12db/octave or better at 20Hz. This design will also offer much better group delay than a 12cu.ft box.


Just my 2 cents.

Once you apply the B6 filter the smaller box actually has slightly worse group delay although group delay at 20hz is pretty meaningless.


By going with the 6.5 cu ft box, you give up about 5-6db of excursion limited headroom which IMO trumps anything group delay related.


That's not to say the 6.5 cu ft boosted box is bad, but if you have the room, the 12 cu ft is without question better. I've heard the S1S and it is very nice, but JBL only goes the smaller route because most people don't have room for 12 cu ft boxes.


And if you don't already own the 2242H, you would be better off with the TD18H which models basically the same as the 2242H but with 5mm more xmax, probably lower distortion if you run them high enough to care, and a lower price (about half the price with the AE group buy).
 
#7 ·

Quote:
Originally Posted by coctostan /forum/post/21020567


Once you apply the B6 filter the smaller box actually has slightly worse group delay although group delay at 20hz is pretty meaningless.


By going with the 6.5 cu ft box, you give up about 5-6db of excursion limited headroom which IMO trumps anything group delay related.


That's not to say the 6.5 cu ft boosted box is bad, but if you have the room, the 12 cu ft is without question better. I've heard the S1S and it is very nice, but JBL only goes the smaller route because most people don't have room for 12 cu ft boxes.


And if you don't already own the 2242H, you would be better off with the TD18H which models basically the same as the 2242H but with 5mm more xmax, probably lower distortion if you run them high enough to care, and a lower price (about half the price with the AE group buy).



True.. GD goes up with eq and even with the high pass. I should have worded it differently. I meant low GD with the smaller enclosure. Of course if he has the room for the larger box, he will gain max output for the lowest octave but lose some as well higher up where this driver really shines.
 
#8 ·
that sounds like a fun build. if you have the space, the 12 cubic foot option is a good choice at 22hz. other than placement issues and the sub 20hz stuff, i'm not really sure what more one could ask for. they are efficient, clean, and durable. a 3rd order butterworth at 20hz will pretty much keep the excursion below tuning to the same as above tuning (i.e., the excursion will be symmetric around the tuning frequency with an equal signal). what are you thinking about for portage?


jbl uses them in their 4645c commercial theater sub. i think it has a 1x6" port but don't quote me on that. with your lower tuning a 1x8" might be a little better.


the price of this thing has gone through the roof. i wonder if it is because the price of neodymium has shot up and they didn't want all their customers leaving the 2268.


as for quality of the 2242 vs 2268 asked earlier, that is a tough one. the lower q of the 2242
http://www.jblpro.com/pub/components/2242.pdf

is certainly attractive for a ported cab. the 2268
http://www.audioheritage.org/vbullet...hp?11346-2268H

isn't a bad driver though. the non-linear parameters and the distortion plots don't look too bad. it sure would make for an interesting shootout, 2242 2268 td18. :)
 
#9 ·

Quote:
Originally Posted by LTD02 /forum/post/21022525


that sounds like a fun build. if you have the space, the 12 cubic foot option is a good choice at 22hz. other than placement issues and the sub 20hz stuff, i'm not really sure what more one could ask for. they are efficient, clean, and durable. a 3rd order butterworth at 20hz will pretty much keep the excursion below tuning to the same as above tuning (i.e., the excursion will be symmetric around the tuning frequency with an equal signal). what are you thinking about for portage?


jbl uses them in their 4645c commercial theater sub. i think it has a 1x6" port but don't quote me on that. with your lower tuning a 1x8" might be a little better.


the price of this thing has gone through the roof. i wonder if it is because the price of neodymium has shot up and they didn't want all their customers leaving the 2268.


as for quality of the 2242 vs 2268 asked earlier, that is a tough one. the lower q of the 2242 is certainly attractive for a ported cab. the 2268 isn't a bad driver though. measurements here: http://www.audioheritage.org/vbullet...hp?11346-2268H

the non-linear parameters and the distortion plots don't look too bad. it sure would make for an interesting shootout, 2242 2268 td18. :)

I don't know how interesting it would be. The TD18 would slaughter the others...and you can get them for half the price right now. That's saying something because you could probably say that about the 2242H prior to the TD18 coming on the market. About the only thing I'd like to compare to the TD18 in this kind of setup would be the B&C 21SW152/115.
 
#11 ·

Quote:
Originally Posted by atomicmist /forum/post/21020362


Why not build something like this:

http://www.jblsynthesis.com/Products/Details/110


JBL Synthesis S1S-EX Clone...


6.5 cu.ft tuned to 25Hz


Adding B6 Filter (6db Boost@20hz Q=2) will get you an F3 around 24hz as long as you apply a high pass filter 12db/octave or better at 20Hz. This design will also offer much better group delay than a 12cu.ft box.


Just my 2 cents.

The attached simulations show the frequency response difference between a 8 and 12 cu ft enclosure. By going with the 12 cu ft enclosure I gain 6 dB down low. I have the space for the enclosures but I am dreading moving these things into position. They are going to be heavy!


I bought the mdf this evening so I should be able to start cutting wood this weekend.
 
#12 ·

Quote:
Originally Posted by LTD02 /forum/post/21022525


that sounds like a fun build. if you have the space, the 12 cubic foot option is a good choice at 22hz. other than placement issues and the sub 20hz stuff, i'm not really sure what more one could ask for. they are efficient, clean, and durable. a 3rd order butterworth at 20hz will pretty much keep the excursion below tuning to the same as above tuning (i.e., the excursion will be symmetric around the tuning frequency with an equal signal). what are you thinking about for portage?


jbl uses them in their 4645c commercial theater sub. i think it has a 1x6" port but don't quote me on that. with your lower tuning a 1x8" might be a little better.


the price of this thing has gone through the roof. i wonder if it is because the price of neodymium has shot up and they didn't want all their customers leaving the 2268.


as for quality of the 2242 vs 2268 asked earlier, that is a tough one. the lower q of the 2242
http://www.jblpro.com/pub/components/2242.pdf

is certainly attractive for a ported cab. the 2268
http://www.audioheritage.org/vbullet...hp?11346-2268H

isn't a bad driver though. the non-linear parameters and the distortion plots don't look too bad. it sure would make for an interesting shootout, 2242 2268 td18. :)

I am constrained to 20" in length for the port due to box dimensions and where I want the port to exit. So, I am thinking I will do three 4" diameter ports that are 14.5" long. No flares, just simple round ports.
 
#13 ·

Quote:
Originally Posted by coctostan /forum/post/21022725


I don't know how interesting it would be. The TD18 would slaughter the others...and you can get them for half the price right now. That's saying something because you could probably say that about the 2242H prior to the TD18 coming on the market. About the only thing I'd like to compare to the TD18 in this kind of setup would be the B&C 21SW152/115.


The TD18 looks like an excellent driver. Only problem is...availability. I have seen some folks waiting close to a year for their AE drivers to be built.


The 2242H drivers are readily available and I will have no concerns about parts availability if I ever have to recone it.
 
#14 ·

Quote:
Originally Posted by nichol1997 /forum/post/21023566


The TD18 looks like an excellent driver. Only problem is...availability. I have seen some folks waiting close to a year for their AE drivers to be built.


The 2242H drivers are readily available and I will have no concerns about parts availability if I ever have to recone it.

...and the 2242H is a killer driver. I recently heard a setup with 4 S1S's and it was impressive to say the least. I run 4 2245Hs which are old school 2242Hs.


We are talking about "best" and "slightly better than best".
 
#16 ·

Quote:
Originally Posted by atomicmist /forum/post/21020362


Why not build something like this:

http://www.jblsynthesis.com/Products/Details/110


JBL Synthesis S1S-EX Clone...


6.5 cu.ft tuned to 25Hz


Adding B6 Filter (6db Boost@20hz Q=2) will get you an F3 around 24hz as long as you apply a high pass filter 12db/octave or better at 20Hz. This design will also offer much better group delay than a 12cu.ft box.


Just my 2 cents.

6th order for a 2242 is 90L with a Q=2 HPF at 32Hz.

For a 2241 it is 205L at 26Hz.
 
#17 ·

Quote:
Originally Posted by nichol1997 /forum/post/21023566


The TD18 looks like an excellent driver. Only problem is...availability. I have seen some folks waiting close to a year for their AE drivers to be built.


The 2242H drivers are readily available and I will have no concerns about parts availability if I ever have to recone it.

There is a difference between the supply of TD series woofers that are used in main speakers vs AV series subwoofers. There was a major supply issue with the AV series but the TD series has never had one year delays, atleast nothing I have read about.


FWIW, John has indicated that the group buy TD series will have shipping times about 1 month or so after the large shipment of materials arrive sometime in November.


If I was search for a driver in the TD18 class, I wouldn't bother with any other choice, its simply unmatched in terms of measured performance. Yep, Im a Fanboy



Saying all that,

I doubt you will find real audible differences in the performance of either choice in your room.
 
#19 ·

Quote:
Originally Posted by coctostan /forum/post/21022725


I don't know how interesting it would be. The TD18 would slaughter the others..

I don't know about slaughter, I have both and both have their pluses and minuses. The Jbl has a larger voice coil, the TD has more x-max.They sound more similar than different Imo.


I paid close to 500 dollars for my TD, at 313 or whatever the group buy nets, its the value leader here.

The TD is beautifully made and was worth the money at list price.


2242s fetch good money on the bay, its possible to sell them, buy TDs and come out ahead, but that's a lot of work.


I found 8 cubic feet or so to be the best compromise of size and extension for ME. I'm sure 12 feet will work fine but if you haven't cut that MDF yet, you may want to return it for some nice ply. Thing is going to be HEAVY.


I have to build out a couple 2242s by Halloween to DJ my sister in laws party. I'm going to blow their masks off



Good luck with the build.
 
#20 ·
Ricci- re TD measurements -


Fs: 29Hz

Qms: 5.9

Vas: 390L

Cms: .185

Mms: 165g

RmsL 5

Xmax: 14mm

Xmech: 18mm

Sd: 1220sqcm

Vd: 3.4L P-P

Qes: .23

Re: 5.6ohm

Le: .41

Z: 8ohm

Bl: 27Tm

Pe: 1000W

Qts: .22

1WSPL: 98.2dB

2.83V: 99.8dB



That was as of 3-09 so I don't know if anything has changed since.
 
#21 ·
"Here is someone who compared the two subjectively"


nice review. i wonder why the difference doesn't seem to show up in the measurements. eyeballing the charts is a little tricky, but knowing that distortion scales roughly twice as fast as spl, the 2242 looks a little cleaner, but i would have expected to see more difference in the measurements given how different they seem to have performed subjectively. both use techniquest to linearize inductance, so that leaves the much lower qe as the only thing that i can see that would explain the difference.


just thinking out loud, is it possible that distortion (or something in the frequency ressponse) has a time property that is not captured in a simple frequency sweep? qe is a damping property and damping is across time. if this were true, than it would explain how two drivers with equal measured frequency response and distortion, could sound subjective "fast" or "slow", with fast simply being the one with the lower qe.
 
#22 ·

Quote:
Originally Posted by Tack /forum/post/21025681


I don't know about slaughter, I have both and both have their pluses and minuses. The Jbl has a larger voice coil, the TD has more x-max.They sound more similar than different Imo.


I paid close to 500 dollars for my TD, at 313 or whatever the group buy nets, its the value leader here.

The TD is beautifully made and was worth the money at list price.


2242s fetch good money on the bay, its possible to sell them, buy TDs and come out ahead, but that's a lot of work.


I found 8 cubic feet or so to be the best compromise of size and extension for ME. I'm sure 12 feet will work fine but if you haven't cut that MDF yet, you may want to return it for some nice ply. Thing is going to be HEAVY.


I have to build out a couple 2242s by Halloween to DJ my sister in laws party. I'm going to blow their masks off



Good luck with the build.

I should have just said they have a significant advantage in output headroom. Whether that translates into an audible difference, that probably depends on how much output you are using. As far as the JBL SVG vs AE Lambda motor, I'll take the Lambda. I haven't seen any measurements on the TD18 specifically, but assuming it performs in line with the TD15, IMO it is superior. Of course, once again it is questionably audible, especially when used as a subwoofer on an LFE channel.


They should sound pretty much the same...they model to almost the same FR.


Nobody is going to complain about either driver.
 
#23 ·
"They should sound pretty much the same...they model to almost the same FR."


are those two separate claims, or a claim and the evidence?


"I should have just said they have a significant advantage in output headroom."


which one? like you said, they model pretty much the same watt for watt. they use different methods to cool the coils. are you saying that the td will slaughter the jbl for power handling/output headroom or did you just speak too quickly on this one?


btw, from what i've seen, for a home system, i'd go with the td, so this isn't a fanboy question.
 
#24 ·
nichol, just in case you are curious, here is 2242 in 12 c.f. and 8 c.f.


in a typical room, you are going to get some boost under about 30hz, so consider that.


a filter on the orange line of +3db, q=2, f=22hz matches them up. personally, i'd go with the smaller enclosure, but if you have the space, larger is more efficient, which is always good.
 
#25 ·

Quote:
Originally Posted by Ricci /forum/post/21024633


Doug do you have any links to TD18 measurements? I can't really remember seeing any.


To the OP where are you located? I have a couple of 4645c cabs you could have if you happen to be near me.

I am located in Virginia so a little too far to come and get the cabinets. Thanks for the offer though.
 
#26 ·

Quote:
Originally Posted by LTD02 /forum/post/21027113


nichol, just in case you are curious, here is 2242 in 12 c.f. and 8 c.f.


in a typical room, you are going to get some boost under about 30hz, so consider that.


a filter on the orange line of +3db, q=2, f=22hz matches them up. personally, i'd go with the smaller enclosure, but if you have the space, larger is more efficient, which is always good.

I have the space so the free output down low looks very appealing to me. The cabinets will be part of my entertainment center.


It rained all day today and more rain is expected tomorrow so no cutting mdf for me this weekend.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top