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JuniorJBL
05-15-2005, 10:51 AM
Hi All

I am going to start building my cabs for my 2242's and would like some input.

A starting size and design for me would be (internal size):

Any input would be helpful:D

JuniorJBL
05-15-2005, 11:38 AM
I would also like to keep these cabs as light as possible.
Suggestions?:hmm:
Shane

spkrman57
05-15-2005, 11:55 AM
http://audioheritage.csdco.com/vbulletin/showthread.php?t=4845&highlight=2242

Hope that helps

Ron

4313B
05-15-2005, 11:55 AM
I wouldn't get real crazy. I'd just build them similar to a 4645C.

*****

I think spkrman57 has these now.

These are 1.25:1.00:0.80 style.

spkrman57
05-15-2005, 12:06 PM
And it is hard to believe how light they are considering the size and the substantial bracing inside.

Well built cabinets for sure!

Ron

4313B
05-15-2005, 12:09 PM
And it is hard to believe how light they are considering the size and the substantial bracing inside.Plywood as opposed to MDF.
The original owner wanted them light for mobile purposes.
Mine were MDF and heavy as hell.

JuniorJBL
05-15-2005, 12:45 PM
I curently have about a 10 cu ft cab for my first 2242 and it really gets things moving. It is just the wrong size for my space of were to put them. I will have a 80" screen this week and will be puting them on each side. I was wanting to make a smooth finnish box to do a piano black finnish on them. I thought that a taller cab would look better in this application.

There are pics of the HT and were the 2242's will go here:
http://www.audioheritage.org/vbulletin/showthread.php?t=5815&page=2&pp=15

Would plywood would require more bracing than MDF? (Birch or Oak ply):hmm:

4313B
05-15-2005, 12:50 PM
I'd use MDF for a totally static installation. Mount the 2242 closer to one end if only so you can play around with boundary reinforcement. Make the enclosure so it can be turned "woofer up" or "woofer down" depending on room response.

R Beardsley
05-15-2005, 01:05 PM
Besides being better acoustically, MDF is far better for a smooth black finish. MDF is dynamite for paint.

JuniorJBL
05-15-2005, 01:25 PM
Besides being better acoustically, MDF is far better for a smooth black finish. MDF is dynamite for paint.
You are right:D

I did realize what I had said after my post. I just dread hefting MDF around by myself.:blink:
Shane

R Beardsley
05-15-2005, 02:15 PM
The edges suck up paint like crazy, so I block sand smooth, then brush some thin epoxy (like West system). If you make sure there isn't any excess gobbed on, you will never tell there are edges overlapped. This is a BIG SECRET........DON'T TELL ANYONE ELSE HERE!!!http://audioheritage.org/vbulletin/images/smilies/rotfl.gif http://audioheritage.org/vbulletin/images/smilies/rotfl.gif http://audioheritage.org/vbulletin/images/smilies/rotfl.gif

JuniorJBL
05-15-2005, 02:20 PM
Thanks Bear!:bouncy:

JuniorJBL
05-15-2005, 06:12 PM
I came up with what looks to be a better design.
The new size is:
30 hX30 wX25d
These are outside dimensions. It is about 11.2 cu ft this should compensate for bracing and driver displacement and be a more versatile design. I will post pics as the job goes on.:bouncy:
Shane

4313B
05-16-2005, 05:42 AM
two 6" diameter ports x 17.25" ducts

JuniorJBL
05-16-2005, 07:14 AM
Thanks Giskard:D

Did you look at the new dimenstions?
Shane

4313B
05-16-2005, 07:48 AM
No. What are the new inside dimensions?

JuniorJBL
05-16-2005, 07:54 AM
-1.5" of the outside.
Driver will be in the middle to one side, ports on the other side in each corner.

4313B
05-16-2005, 09:08 AM
What is the crossover frequency and slope?

JuniorJBL
05-16-2005, 09:20 AM
I will use an Ashley 1001 most likely at about 80Hz 24db. I also have an Ashley PQX572 for eq.

4313B
05-16-2005, 09:53 AM
With 80 Hz 24 dB / octave.

4313B
05-16-2005, 09:55 AM
With 1 dB EQ at 25 Hz

JuniorJBL
05-16-2005, 10:08 AM
For the -6db on the chart. Is it possible to get it to 0db?:hmm:

4313B
05-16-2005, 10:14 AM
No, to get the 2242H to behave like a 2245H requires bandwidth limiting. So, loaded like a 2245H you loose ~ 6 dB of efficiency. Don't worry, it works plenty fine. ;)

Red is 2242H, green is 2245H.

4313B
05-16-2005, 10:20 AM
No bandwidth limiting.

For sub use the 2242H is an evolutionary improvement and replaces the 2245H. It is NOT a direct replacement for a 2245H in a 4345 Studio Monitor.

JuniorJBL
05-16-2005, 10:47 AM
I will post pics very soon:applaud:

spkrman57
05-16-2005, 02:25 PM
Giskard, you said:

"For sub use the 2242H is an evolutionary improvement and replaces the 2245H. It is NOT a direct replacement for a 2245H in a 4345 Studio Monitor"


Is that because of the subwoofer use requires LP at 80hz or under for proper subwoofer use.

Crossing over any higher the mid-bass and midrange efficiency takes over and the bass response is barely heard compared to the rest?

Just wondering if I have a clue here????

Ron

4313B
05-16-2005, 02:40 PM
Crossing over any higher the mid-bass and midrange efficiency takes over and the bass response is barely heard compared to the rest?Yes, poor balance. If you want to use the 2242H "full range" it is probably best to tune it up quite a bit in order to balance out its response. See what Wayne Parham is doing with the 2242H these days (I don't know). I've put them in 5 cubic footers tuned to 40 Hz and they crank. Usable response only goes to mid thirties in that config though.

Or you can just EQ them, they can certainly take it. :p

JuniorJBL
05-17-2005, 01:59 PM
two 6" diameter ports x 17.25" ducts

What material do you use for your ports, PVC, Cardboard?

Shane:bouncy:

4313B
05-17-2005, 02:04 PM
https://www.nyli.com/secure/mailingtubes/catalog.html

Sorry, but I'm not into "modern" port materials. :p

Four 6-inchers should run about $25.
Use whatever is left over for LE5/104 subenclosures.

JuniorJBL
05-17-2005, 02:47 PM
What does your box program say for 2 7-3/8" tubes?

4313B
05-17-2005, 02:52 PM
Two would be too much.
Use a single 7-3/8 x 10-1/8.

JuniorJBL
05-17-2005, 02:55 PM
Thanks Giskard!:applaud:

JuniorJBL
05-21-2005, 09:21 AM
Does anybody have a rule of thumb for dacron in a cabinet?:blink:

JuniorJBL
05-21-2005, 09:32 AM
Here are some pics of the box:D
BTW This is 80oz of stuffing.

JuniorJBL
05-22-2005, 12:47 PM
I have finished the constuction part and I have been listening to it today.
There is nothing quite like 18" bass!:applaud:
Time to build another

spkrman57
05-22-2005, 02:19 PM
I am running a pair of 2242's with sub plate amp 1 kw that has adjustable eq on it. I guess I forgot some basics when I started out blocking one of the ports and applied eq at 20hz.

Well, sound was not good at all. 1st problem was boomy on some bass notes, then not at all on others. After I settled down and quit being pissed off I did some tests and found out I had my right chnl 2242 out of phase with the 2242 on the left chnl. :banghead: :banghead: :banghead: DUH!!!!!!!!!


Next problem was after phase was corrected, I had one of my audio friends stop by and listen, he told me bass was too heavy, so I cut the eq altogether and things started sounding better.:applaud: :applaud: :applaud:


Sometimes when I work a new project, I am too anxious to check out all the different checklist items(like double-check my work), so when I find my mistakes and become humbled(need that to happen more often), I often find the simple basics work best than trying to tweak too soon.

Learn to crawl before walking!!!!


With my smallish room size, I will drop down to a single 2242 sub and find a use for the other one later. But pipe organ music sound killer with this sub.


Main system for this session: Yamamoto 45 SET amp 2 wpc driving JBL D123/075 N2400(hz) crossover. I simply put these on top of the 2242 cabs.

Yes, the 2 wpc Yamamoto has plenty of drive with at least 95db/watt speakers

Next possible setup will be E130 reconed to 2225 mounted in Peavey FH-1 folded horn (alleged 60hz to 400hz), midrange handled by Great Plains 399 driver(modern 288K) on 311-60 horn with 075 for top octave. All using 1st order crossover to start with.

That will happen in a week or two, holiday weekend coming up and GF complaining about "quality time" :blah: :blah: :blah:


Just wanted to throw my results in to the mix, Thanks for listening,

Ron;)

JuniorJBL
05-22-2005, 06:31 PM
It is nice to hear others response to thier undertakings.

I have had a single 2242 before in a 14cu ft cab and it pretty much tore down walls. It is an awesome driver if you have the acreage to acomadate it.:D

I do love my sub1500's and I am not sure that I would give them up or not.

I still need to fine tune my newest box but right off the bat it sounded good.:D

I am using an ashley crossover and PEQ.

The 18's seem to have a natural low freq response that other drivers can not come close to like pipe organs, string bass :blah:

Thanks for your comments
Shane

Jakob
06-18-2005, 02:50 AM
Aahh... 2242's, Id like a pair of those!

Could anyone tell me what response You would get if you put one of those in an 130 l cabinet? Or is that to little volume for that driver?
According to my calculations You would get -6dB at 40 Hz if tuned to 30 Hz. Could that be right?

Regards: Jakob

Earl K
06-21-2005, 06:46 AM
Hi Jakob,


According to my calculations You would get -6dB at 40 Hz if tuned to 30 Hz. Could that be right?

- According to my software ( MacSpeakerZ ) , a tuning of 40hz gives a 6 db down point of about 41 hz .

- Moving the tuning down to 32 hz moves that 6 db (down) point about 45 or 46 hz

- Moving the tuning down to 30 hz moves that 6 db (down) point to about 48 or 49 hz.

- I've posted some relevant reading links in the other thread you started on this. Look closely at the one about creating a passive line level Low-Pass filter to create a reasonable looking curve ( for the B212 ) . This is exactly what you would need to do if you stuffed this 2242 into 5 cu'. You'd need to lowpass the VLF at around 50 hz to create a useful , musical curved response .

- Do you have any Simulation Software ? If not, you should download some of the free stuff. There is a link to WinISD embedded within one of the thread links ( this was posted in your most recent thread ) .


:cheers:

spkrman57
08-23-2005, 07:39 AM
Earl,
I am in awe of the results of lowering the port tuning actually raised the rolloff frequency.

What would the results be with a tuning of 45hz and 50hz, sorry my curiousity is getting the better of me.

Ron