Port Tubes 4518

[rlove59]

Hello Everyone, I have recently joined the site and had a couple of questions that I can't seem to get an answer to or even an opinion. 1.Does anyone know the size and length of the port tubes in the 4518. 2. Anyone know what the sonic difference one could expect between the 2240 vs the E155 if used in this box

[SMKSoundPro]

2240 better for low end program material aka: music Re-producer

E155 better for bass guitar aka: music producer

4518 port length not on the top of my bald head right now. Box works very well with 2240 or 2245. Seems a little tubby for bass guitar to me.

Scotty.

[rlove59]

Thanks Scotty,
the dreaded tubby sound is exactly what I (as probably does everyone) want to avoid. I am thinking back in history to the cabaret and k series when often you would have the musical instrument speakers used in PA systems and as subs such as the 4695 which used the 155. I was thinking that it is possible that the MI speakers may provide more punch or snap than the LF versions which could make them a preferable choice especially in a small combo of bass,drum and guitar. I have 155s but have never tried them but the 2240s did sound good in a large (10ft) box tuned to 30hz. I have some 8ft boxes tuned to 40hz so I guess what I am thinking is build the 8ft box tuned to 30hz (4518) and hope for the same general performance as the 10ft box or see if the 155s would provide a sound that would work without extensive eq. You seem to have considerable experience with both speakers so input is deeply appreicated.
Rob

[SMKSoundPro]

Dear Rob,

I do dance floors and pro (PA) sound, mainly with the main focus lately being drag shows. It is a mix of humpin' and bumpin' dance music for the drag queens to lip sync to, and then in the middle of the show I have a few good live singers. The point is that I have to have a sound rig that is fairly flexible for the genre of music. My rigs are 80% music program playback and 20% live musicians.

I find that I like the boxes tuned to 40hz with 2240, 0r 2241, better than tuned to 30hz.

That being said, let me explain:
In all of the low frequency cabinets I build, I am thinking of the above music genre uses. The double 18 subs I built were clones of the SR4719's. Two 2241's in an enclosure measuring 48"x30"24"= 34,560 cubic inches; divided by 1728, which is exactly 20 cubic feet. Let me tell you that these boxes are perfect for my use, and am now building 4 more.

I built single sub cabs in 1990 which house one 2240-18", that are tuned to 40hz also, that are NO WAY NEAR the accoustic output or tone of the doubles. I have tried to make alot of these single subs work in our little dance floor room, and I have to tell you that there is NO way these single boxes (with the same driver installed and both tuned to 40hz) are making the grade. Both boxes are being driven by the same Crown macro 2400 amps. Same style of program. Same mixers, eq's and dbx 234 crossovers in both the large ballroom and the small dance floor at my nightclub.

The bottom line:

I can't imagine for my purposes tuning a box to 30hz. I have an extra double 18" 4719 box that I built as a prototype for the other 4, that is upstairs in my shop with two 2245's installed. same port size and duct length as the other 4. But with the 2245's installed, it is the most amazing subwoofer box for the hi-fi shop stereo from 80hz and down. And it's tubby. Not what I want for the dance floors, but I love it for the shop stereo! (Please see chart #12 in the link pasted below)

I am not sure if I am answering your questions? Please let me know more about your personal uses for these cabinets.

I re-read your posts, and recommend this link: http://www.jblpro.com/catalog/suppor...=219&doctype=3

I used these recomendations for many cabinets and have been happy with the information provided.

See chart #13 for a single 18"(2240, 2241 and 2242) tuned to 40hz for general low frequency duty. Maybe have the E155 reconed as 2240s, as that's what I am doing with them.

Scott.

[SMKSoundPro]

check this thread:
http://www.audioheritage.org/vbullet...highlight=e155

scotty.

[4313B]

drag queens

In Alaska?

[Doc Mark]

Morning, Scott,

MAN, that is some system you've created!!!! HOLY MOLY!! Great photo of your standing in front of your "Baby", too! I assume you made all the cabinets? Did you use MDF, or high density particle board? I've never played with MDF, but that seems to be what folks like to use these days. I've made all my Hi-Fi boxes with heavily braced HDPB, and am comfortable working with that stuff. Again, very nice system, and it's easy to see how proud you are of it, and rightly so!! Thanks for sharing, and God Bless!

Every Good Wish,
Doc

[jbl4ever]

3 ports total length 8 1/2'' long and 4 1/8'' diameter

[rlove59]

Thank you JBL4ever,
it It is amazing how tough it is to get information that one would think would be easily available. would I be correct to assume that the 8 1/2 total length refers to the length of each port including the baffle and the 4 1/8 refers to inside diameter of the tube. Again thanks for your assistance.
Rob

[rlove59]

Scotty,
Thank you once again. the information you get from folks who are actually out using the stuff is usually much more benificial than data and spec sheets. One of the main reasons for wanting to construct the 4518 is that I have a pair of 4508s and since the two boxes are exactly the same dimention wise I thought that it would be easier to transport and set up if the bass boxes were the same. as for the tuning I thought that the 30hz tuning may afford better low end. (I would rebuild the 4508s out of plywood due to the weight and fraigilty of partical board). I however could be completly wrong and was hoping that you would explain the advantages of the 40hz tuning. If I told you my initial intended use for the 2240s you would think me a bit over the edge but they did work nicely.Now what I am trying to do is put together a sound system for a three or four peice band that is compact enough to do smaller rooms and possibly added to for larger rooms. My primary concern is getting a good well mixed sound at reasonable volumes. I would be using 12s for mids leaving the horns solely for the high end. I figure if it really took off and I had to do jobs that took a lot of power it would make more sense to hire out sound from someone such as yourself who knows what they are doing. Your system is great and it must really thump if you are doing those kind of shows. I don't think I would be anyway near that tough on a sound system but I would like to get the punch on the bass drum and the snap on the snare that I hear on systems like yours but at a volume that would not get me thrown out the door as I have seen happen to many guys.Thanks again
Rob
ps are you double 18s the no.12 on the chart

[AltecLansingFan]

Dear Rob,



Scott.

Hi Rob,
I don't know when, but I think I come by, just to drink a beer (Heineken ?).:dont-know

[rlove59]

Hi Rob,
I don't know when, but I think I come by, just to drink a beer (Heineken ?).:dont-know

that's good for me or maybe a Spaten.

[SMKSoundPro]

Yes, I used #12 as a good start for my double subs cabs. I also cloned the SR4719a model. I borrowed a pair from a friend, wired them up in the big ballroom and ran them off a Crown macro 2400. Driven from 80hz down as a sub driver. The carpeted 4719 rattled and buzzed like a bid dog. It had been bounced around by stoned roadies and it sounded like it!

Lisa and I agreed to build our own version of the 4719 using voidless plywood and with a greater attention to detail in the joinery. The box sounds good for its intended purpose and has no rattles or buzzes.

I also have EN8 enclosures that are exactly the same as 4508 double 15 boxes. They are built from 3/4" particle board and perfect for install work, but definetly not for multiple gigs.

I gotta tell you though, I am really considering a double 15 cab for your purposes. A 4508 cab loaded with two 2226H's yields a 4 ohm box that can give a warm and yet punchy bottom up to about 250-300 hz, and then into a pair of 2206- 12"s mids upto a 2" driver from 1.2K up.

This sounds like a SR4715 bottom and SR4732 top box combo.
see link: http://www.jblpro.com/pub/obsolete/sreries.pdf

For a 5 piece lesbian rock and roll band, I put together a 4718 and 4722 combo. I biamped in the beginning and all was fine. Then when the band broke up, and I got all of the gear back, I triamped it. WOW what a difference! I took this same 4718/4722 and Crown amp rack to Fairbanks in the back of my Town & Country, and it sounded pretty dog-gone good for the venue! The crossover points were around 250 and 1.2K. It offered everything I needed for the performance and was compact. It is easily added on for a larger venue, and had a pretty good snap in the snare.

ALL in ALL...
There are MANY choices to make in this sound reinforcement world and as always there are many considerations in the area of finance, portability and upgrade-abilty. Choose wisely, grasshopper.

AND: Go with what you know!

Scotty K.

[jbl4ever]

Roy, the overall length is 8 1/2". If your baffle is 1" thick then 7 1/2"
On the 4518's there is 1/2'' of baffle before the 8" tube
Hope this helps