Don't you imagine that's a typo... 5 5/16"?Originally Posted by Zilch
Sounds like you have really underbraced cabs... those are quite large boxes to only have a couple of braces in the middle.
Other issues:
How much and what type of damping material is inside?
Only one 4" port for an 18" sub?! At any SPL above a whisper you will hear port noise at low frequencies.
My guess is that you have a very lossy cab that is tuned too low. You may also have room placement issues.
Widget
I tend to agree with The Widget.
While you recent measurments are more factual, I think my previous thoughts posted earlier about the tuning apply.
Gene, you mention something about the woofer supplier giving you the tuning. I think they have given you tuning based on an understanding/assumption that this was a sub woofer application.
There have been several articles written about this driver for sub woofers using 12 cu ft 3 enclosures. In each instance operation above 80 hz is NOT recommended. If my understanding is correct you are operating the woofer over a bandwidth up to 250hz. This really necessitates a different type of alignement.
All is not lost but it is most likely you will require alternative tunings as i explained earlier.
The closest tuning given the current enclosures is a Keele alignment of 292 lites (about 10.3 cu ft) tuned to 27.2 hz. The two 4 inch ports will need to be in the order of 4 1/4 inches in length. This assumes Ql=7 and normal filling in Bassbox 5.1 simulator.
You may wish to provide / collect more facts and this would be appreciated before deciding what course of action you will take.
Please note we cannot be responsible for incorrect advice where you have not provided complete or accurate information.
All the factors, room placement, tuning and associated equipment will effect the bass performance. But it should not sound crap in any instance.
From you picture the box appears near a wall/ floor juntion in a corner.
Please note the corner location is not the most ideal for the bass to sound best.
Please continue to provide more details.
Ian
Hello
Have you checked to be sure that the 18's are in phase. The simple battery test work, use just a 1 1/2 volt battery.
Sorry if this has already been tried or suggested.
Mike Caldwell
jbl 2245 H thread
Hello I just bought a jbl 2245 H woofer from vintage tube amp or uncle spot speaker repair. the problem I am having is the woofer look the same as the other one but the color is gray kind of orange -redish .the surround is not foam its the same surround thats on the 4312 woofer. what about the low end responce will this effect any thing
bo
"Indeed, not!!"
This may not be applicable but I once had a 2245 that looked like it had a 2241 cone (but with foam surround). It never did sound as good as the original 2245 that I have. The new re cone came from OCS. I decided to just sell it and would work on finding a different one. It would never play quite as low as my original and would pop all the time. I also tried to run a 30hz signal at about 10 watts for 30 hrs but that changed nothing.
Always fun learning more.......
from "D+S Sound Labs"
bo
"Indeed, not!!"
gene's crossover...
I think I see one crossover point worth reconsidering:
In the 4345, the 2245H is taken-up to 290Hz.
Asking the 2202H to go down so low (80Hz) - inside what should be a fairly small subenclosure - might be a great deal of the reason for a lack of bass response. You certainly would not get anything like the magnificent response the 2245H is capable of.
Here's the passive crossover points, and slopes, from the 4345 brochure (L) and 4355 (R, which uses the 2202H)...
bo
"Indeed, not!!"
I believe on jbl speakers terminals red is neg and black is pos. . good question but the drivers are hook up right speakers ports are 4 inch in dia and 5-5/6 in lenth the speaker has two ports per cab. 1-1/2 of fiberglass is use for insulation.. something call biscuit is use for bracing in each corner of the speaker. one speaker is in a corner box on the floor the other speaker is located right befor the patio glass door which that speaker is in the middle of the basement so there 10 ft to the left of the speaker which is a open area. i look in side my jbl L250 my cabs has more brace then the jbl L 250 IF that means any thing
Should that be 5-5/16 in?
bo
"Indeed, not!!"
I ask dan at dssound to leave me a message becuse I wanted from the start the xovers points to be 80hz 1200 and 5000. but after he did his thing he told me he had to bring up the low end xover point up to ethier 250hz or 290. so I waiting on his responce. but 1200 and 5000 is correct...... for those who wondering why I wanted 80hz.I got my info from gold sound kit 14 but they use a 2206 or 2226h for there midbass . so I knoe he change the crossovers points to 250 or 290hz
Are those values correct?? You have a 2mH on the 2245??? Ist order no cap and a first order bandpass on the midrange?? What is the phase on the midrange vs. the 2245?? You have the phase reversed??
That 2202 is sealed??? It's not ever going to get to 80Hz. Not sure what the crossover point is but its not 80Hz. Here is what the driver look like with the 2245 in 10cubic ft and the 2202 sealed in 1 cu ft with the crossover components added as listed.
Rob
did every body take a vacation. the only person is boputnam whos feeding me input for right now. I am like a kid waking up for christmas waiting on your responce so I can finally get this issue squared away and JAMMMMMMMMMMMMMM
Patience, man... This information has been a long time coming - and right now you are living with timezones differences, dinner hour, and fine wine time.
Get some more info on the internal cabinet detail. Specifically, what the bracing is like and the dimensions of the 2202H subenclosure. email me more pics...
gene - if you can, lay the cabinet on it's back and remove the 2245H and the 2202H. Take best possible pictures inside the 2245H opening.
Take best possible measurements inside the 2202H subenclosure.
This is critical info, pard'...
bo
"Indeed, not!!"
I am not asleep. I'm waiting for your response to post #30, 31, and 39.
I've spun out twice here so far; we need some TRACTION!
Also, we're all over the place regarding the size of these boxes, somewhere between 10 and 14 cuft., apparently.
What makes you think they're 12 cuft.? That's not what the dimensions you've provided calculate out to.
[The pic indeed scales to ~29" wide....]
Yep... kinda makes me loose interest.
...about the volume...
Based on the answers to the game of twenty questions, I'd bet it's in the neighborhood of 10 cu ft and not any larger than 12 cu ft... the gross internal volume is 14.6 cu ft before you subtract the dog house, any bracing, and the drivers.
Send up a balloon when you've figured it out.
Widget
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