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Hi guys!
I'm considering building a subwoofer using two JBL 2241H drivers in one of these type enclosures:
-- Nelson Pass' slotted subwoofer
-- Linkwitz H dipole subwoofer
-- ripole subwoofer
Here's the info I could find about the 2241H drivers:
Product Specifications
Nominal Diameter 18"
Power Handling (RMS)600 Watts (max)1200 Watts
Impedance 8 ohms
Frequency Response 30 to 3,000 Hz
Sensitivity 98 dB 1W/1m (this matches my fullrange very closely)
Voice Coil Diameter 4"
Thiele-Small Parameters
Resonant Frequency (Fs)35 Hz
DC Resistance (Re)2.5 ohms
Voice Coil Inductance (Le)0.86 mH
Mechanical Q (Qms)5.7
Electromagnetic Q (Qes)0.43
Total Q (Qts)0.4
Compliance Equivalent Volume (Vas)11 ft.³
Maximum Linear Excursion (Xmax)7.6 mm
Surface Area of Cone (Sd)1241.29 cm²
As most know here I'm very naïve about driver specs and how they're used to help decide what type enclosure it's best suited for. So I really need your help here. Plus I have these two 18" 2241H drivers sitting around and really want to put them to use, rather than purchasing another set of drivers. I look forward to the input I receive from those who choose to help me...
I'm listening to: Dreamland by Yellowjackets
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
Follow Ups:
From the specs, the driver is intended (optimized) for a ported box at around 30-35Hz and around 10 cubic feet per driver. (Also the DC resistance indicates a 4 ohm driver, not 8 ohms - so re-check the specs! Many JBLs are available in more than one impedance ...)
What will you drive it with? SET/P-P/solid state? Asking because unless the amp has a lot of feedback, the optimum design may be quite different.
If you have two drivers, why would you build ONE woofer cab? Build two, and cross at 80-150 Hz. Don't be afraid of having great sound!
:)
Hi Inmate! All three of those subwoofer types I mentioned require the use of at least two of the same woofer! I was considering one for that reason and because I'm not sure I have the space for two large subwoofers in this room...
I'm listening to: Clear Approach by Trillion
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
"I'm not sure I have the space for two large subwoofers in this room..."The cabinet size of the TH is largely a function of how low you want it to go, and the Sd of the woofers. With the 18 the cabinet will be huge.
A single 10 in a TH will more than keep up with your system.
A TH in 1Pi with this driver will be about 95dB, and a fraction of the size the JBL would need to be. The JBL would be capable of about 1.6dB more maximum output based on the coil overhang (5.5mm vs 18.4mm) times Sd.
Edits: 09/18/15
From reading many threads seems to me that a tapped horn with 10" woofer for 30hz looks to be a good compromise.
Yes, it looks real good.
The 20hz design I posted could be revised for a higher cut-off and a smaller size.
That XBL^2 woofer with its underhung design would be just the ticket for a powerful tapped horn.
Then you should do something else, cabinet-wise. One 18" driver is plenty for one channel. Do the math: One quarter of an acoustic watt will be easy for an 18, and will put you outdoors to save your hearing.
TWO subs - not one.
Cross an octave above where your "fullrange" starts to crap out.
(And, add an appropriate tweeter on each side. ;) )
Then, you'll have a "full range" speaker.
You heard it here first.
:)
Hi Inmate!
Presently I'm using Dayton PS220-8 drivers that have had their cones treated by Mike Rispoli. Running these Dayton PS220-8 drivers " fullrange " in my Sachiko double-back-loaded horns, they literally smoked Fostex FE206e, FE206es-r and FE208es-r, as well as a Lowther DX4 drivers ---{ with the exception of the FE208es-r all the other cones were treated exactly like the PS220-8 was }--- and they easily cover from approx. 35Hz to 18Khz. I have a pair of Fostex T900a tweeters that come in at 8KHz and extend out to 35KHz. Except for the deep lows it does everything quite well. Hence the need for subwoofers...
I'm listening to: A Trick of the Tale by Genesis
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
Might be a option not a fan of the others the best being the S.L.O.B..
Hi John!
If I knew how to design a tapped horn with the correct dimensions for the JBL 2241H woofer I'd give one a try for sure!
I'm listening to: Clear Approach by Trillion
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
Join diyaudio and ask for help. There are a few people who are quite good with Hornresp.
Meanwhile there is this thread which might be of interest:
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