Printable View
I'm designing some smallish cabinets that I plan to have built to hold a 15" LF and a compression HF driver and some small horn lens.
Anyway, since the speakers will serve as the front channels for my HT, they need to fit behind the TV in a moderate-sized room. The approximate demensions of the new boxes will be 18" x 26" x 15"
With such a small box, is there any advantage to using a sealed box?
Thanks...
In general a ported box will have an extended frequency response to the lows compared to a closed box when designed properly.
When designing an enclosure the volume for a given speaker is defined under consideration of the frequency response. These calculations can easily be done by an appropriate computer program.
It is easiest to follow the manufacturers recommendations for a given speaker.
____________
Peter
You've got to get down to the fundamentals. The driver parameters dictate whether it is better suited to closed or vented alignments.
In either case, there are not a lot of 15" woofers that will play competently high enough to mate with a small horn such as you suggest you'd like to use. Additionally, you're not going to get much in the way of bass out of a driver that size in so small a box.
Not that having extended bass response matters all that much in HT when used with a sub.
Also, I'm not getting what "They've got to fit behind the TV" means. Are you talking perforated screen here?
Small?? That's 4 cubic ft. Any reason they have to be 15"s??
Rob:)
Hello DavidQuote:
Since poster references space available I doubt those are internal dimensions
Didn't think they were. If you think a 4 cubic ft box is small well what can I say. Looks big to me, I have a pair sitting right in front of me. Larger than a 4425,4412,4311 and so on. L20T/4406 is small to me.
If space is at premium you can fit one hell of a lot of drivers, many in boxes smaller than that to fit the bill for acceptable lowend for HT for LRC duty with a sub. That was my point you don't need to do 4 cubic ft, you can do less and potentially still get what you want.
Hello Robert
You need to work out the efficiency and what horn you are going to use.
Rob:)
3.16 gross internal cuft.
LE14H-3, 2452H-SL on PT-F95HF, ... done.
Well, except for the crossover.... ;)
For the original question in the context of this forum . . . what traditional JBL 15" drivers will work properly in a sealed box for home hi-fi use?
Okay, so maybe there's something newer in the automotive line . . . but pretty much for this application, with JBL, plan on a ported box.
OK, Thx
Drivers:
2226H (LF 15)
2426H (HF)
Horn:
http://www.partsexpress.com/pe/showd...number=290-550 [eminence 295H, 12W x 6H x 4D]
or.
JBL 2370A
*****
Why would the horn size impact the optimum cabinet size; do you mean the compression driver size or horn lens size?
The TV is a big flat screen and is placed in 15'x30' room. I have about 18 inches on each side of the TV for speakers.
I suppose I could re-design the cabs and make them much taller and a tad deeper????
You're designing PA gear.
Think towers, Robert. Towers.... :yes:
Didn't someone just ask a very similar question a few days ago? :hmm:
http://www.jblproservice.com/pdf/SR-Series/SR4725A.pdf
Could go lower w/ different cabinet size/tuning, but there are tradeoffs.
Play with a box-tuning program (e.g., WinISD, which is free), to get an idea
of what those tradeoffs might be.
I know this is contrary to almost all of the JBL Studio Monitors, but I have found that putting my JBLs in narrower and deeper cabinets (that are heavily braced with hardwood) always sound better.Quote:
Originally Posted by robertbartsch
Widget
I finally found a thread of yours that has components. Do you actually *have* them or are in the process of getting them?? Aside from the altec ceiling speakers, what do you have?
Anyways:
Go the tower route - since floor space is at a premium. Look at robh3606's avatar to see how he incorporated the components. A very similar cab could be made with the 2342 horn ( 9"wide ) rather than the $$ lens.
If you don't have a woofer yet, look for the 14" models - they are actually 12.75 wide and fit a LOT easier than the 15.25" cones and the cone area is almost identical. LE14H-2 or -3 is the best choice. Porting is a must.
I have these speakers that I made 6 years ago from some stripped and abused L220's - 2344/2425H/LE14H-2/PR15D ( mirror imaged ) with the factory 4430 crossover. 20" wide by 48 tall with 5 coats poly. Make me an offer..:o)
sub
Hamilton built LE14 towers:
http://audioheritage.org/vbulletin/a...1&d=1135372878
John W built LE14 towers:
http://audioheritage.org/vbulletin/a...1&d=1142870606
Zilch built LE14 towers:
Horn: [eminence 295H, 12W x 6H x 4D]
TV is a big flat screen
Hi,
Why not use the 1" RCF100? It works fabulous in "Constant Directivity", very smooth and goes down to 800Hz if You mean to. It's about 40$ in Europe. From the specs and my measurements it would outperform some bigger vintage biradial designs but with lesser sexyness, though.
The spacing between drivers should be minimum. In that some of the mentioned homegrown boxes come a little bit short. With what reason?
If the screen is flat, why not making the boxes as deep as the screen, e/g with the RCF100 one foot or so? One should be aware that toeing the boxes (the front baffles == the horn) in by 30° .. 45° is a must. A triangular or trapezoid (??) shape could help to minimize the "felt" room consumption.
At least the volume doesn't mean to much with reasonable energized drivers. If You tune a reflex enclosure to 35Hz to 40Hz it will work. The bigger the volume the more efficient the speaker will be at the tuning frequency. As a rule of thumb a 15" (2226) will be a little bit on the low side with 70Litres @ 40Hz (~ -6dB) or on the other a little bit boomy with 210Litres @ 40HZ. There is no use in closed boxes, if the bandwith of the programm is limited to 35Hz .. 40Hz as it is with nearly all DVDs/CDs - and - if the drivers are of sound quality.
Hope this helps