Hi all,
I picked up a JL audio 13w7 in need of a new surround for a song and am wondering what to do with it.
The system in my car is already loud and good enough and so I don’t really want to mess with it.
I also have a fit for purpose home cinema system and so have no particular role for this sub to fill.
This leads me to want to experiment and build something out of the usual sealed and ported box for it.
Given its T/S parameters and with box size being no object (within reason, it has to get through an internal door for example) what would be a cool and fun thing to build with it?
REcOMMENDED cONTINUOUS (RMS) POWER RANGE fOR ONE SUBWOOfER DRIVER:
500W 750W 1000W 1500W 2000W
Amplifier Recommendation: 1000/1v2
13W7-D1.5
free Air Resonance (fs): 23.5 Hz
Electrical “Q” (Qes): 0.476
Mechanical “Q” (Qms): 7.517
Total Speaker “Q” (Qts): 0.448
Equivalent compliance (Vas): 3.68 cu. ft. (104.3 ltrs)
One-Way, Linear Excursion (Xmax)*: 1.25 in. (32 mm)
Thermal Power Handling (Pt): 1500 Watts Continuous
Reference Efficiency (no): 0.269 %
Efficiency (SPL @ 1W/1m): 86.3 dB
Dc Resistance (Re): 2.41Ω
Effective Piston Area (Sd): 107.35 sq. in. (0.0693 sq. m)
Nominal Impedance (Znom): Dual 1.5Ω
I picked up a JL audio 13w7 in need of a new surround for a song and am wondering what to do with it.
The system in my car is already loud and good enough and so I don’t really want to mess with it.
I also have a fit for purpose home cinema system and so have no particular role for this sub to fill.
This leads me to want to experiment and build something out of the usual sealed and ported box for it.
Given its T/S parameters and with box size being no object (within reason, it has to get through an internal door for example) what would be a cool and fun thing to build with it?
REcOMMENDED cONTINUOUS (RMS) POWER RANGE fOR ONE SUBWOOfER DRIVER:
500W 750W 1000W 1500W 2000W
Amplifier Recommendation: 1000/1v2
13W7-D1.5
free Air Resonance (fs): 23.5 Hz
Electrical “Q” (Qes): 0.476
Mechanical “Q” (Qms): 7.517
Total Speaker “Q” (Qts): 0.448
Equivalent compliance (Vas): 3.68 cu. ft. (104.3 ltrs)
One-Way, Linear Excursion (Xmax)*: 1.25 in. (32 mm)
Thermal Power Handling (Pt): 1500 Watts Continuous
Reference Efficiency (no): 0.269 %
Efficiency (SPL @ 1W/1m): 86.3 dB
Dc Resistance (Re): 2.41Ω
Effective Piston Area (Sd): 107.35 sq. in. (0.0693 sq. m)
Nominal Impedance (Znom): Dual 1.5Ω
Here is a large but easy to build and rationally designed "HROAR"/ 6th order BP with mixed quarter wave first resonator and Helmholtz front chamber.
I can´t promise that it will sound any good since I have never used a JL-Audio 13W7 driver. It does have a quite high Qts and Vas with lots of Mms so it behaves a bit strange in Hornresp compared to the drivers I am used to.
It would be 1200 x 1200 x 522 mm for a rational use of standard 18 mm plywood (double layer in both front and back).
Layout as the first build in this thread:
ROAR with Helmholtz front resonator
I can´t promise that it will sound any good since I have never used a JL-Audio 13W7 driver. It does have a quite high Qts and Vas with lots of Mms so it behaves a bit strange in Hornresp compared to the drivers I am used to.
It would be 1200 x 1200 x 522 mm for a rational use of standard 18 mm plywood (double layer in both front and back).
Layout as the first build in this thread:
ROAR with Helmholtz front resonator
Attachments
Thank you circlomanen, that’s a very interesting design.
I am particuLry impressed with what seems to be the low group delay for a band pass box.
I have to confess to ring a sealed box man after GM reccomended I build ported and sealed boxes with the same driver and. Compare them. From my ISD simulations it seemed that the group delay was main factor different between them.
The xmax is genuine for the JL w7, the realistic continuous power handling is also closer to 750-1000 watts depending on the type of material played.
Here it is next to a “normal” sub capable of around 13mm of xmax.🙂
I am particuLry impressed with what seems to be the low group delay for a band pass box.
I have to confess to ring a sealed box man after GM reccomended I build ported and sealed boxes with the same driver and. Compare them. From my ISD simulations it seemed that the group delay was main factor different between them.
The xmax is genuine for the JL w7, the realistic continuous power handling is also closer to 750-1000 watts depending on the type of material played.
Here it is next to a “normal” sub capable of around 13mm of xmax.🙂
Attachments
A simple sketch of the layout.
Internal depth is 450 mm.
The port is 400 mm in diameter for 1256 cm2 port cross section and a max port air particle velocity of 12 m/s.
60 ms GD @ 17 Hz is quite low.
Very nice looking driver! Seems quite capable for some serious HT-use. 🙂
Internal depth is 450 mm.
The port is 400 mm in diameter for 1256 cm2 port cross section and a max port air particle velocity of 12 m/s.
60 ms GD @ 17 Hz is quite low.
Very nice looking driver! Seems quite capable for some serious HT-use. 🙂
Attachments
IMO take a page from JL Audio's home subwoofer line and build a sealed box and drive it with lots of power and DSP to get the response that you want. Vented, maybe, if it's an offset TL type of arrangement. I wouldn't consider any higher-order designs for that driver.
Home Audio - Powered Subwoofers
Home Audio - Powered Subwoofers
Thanks again, I am giving your design serious consideration but its a big beast to sneak past the Better Half! 😀
The driver is a good one, its very expensive and so it doesn't get much attention outside car audio "elite" circles, certainly not worth double over an Adire Brahma for example, but they weren't available for years and years whereas the JLs were...
I researched this line of enquiry and it seems that the home series of subwoofer use different drivers with different parameters.
The design of the drivers themselves differ radically, have a read of this thread on partsexpress:
Unusual JL subwoofer driver -
Techtalk Speaker Building, Audio, Video Discussion Forum
This is the HT version:
The W7:
Given that the W7s are thought of as being over priced, those HT drivers must cost a bomb.
Ok, Ive just about managed to get Hornresp to import them, I still need to learn how to use the software properly... 😀
I like these designs, low GD, play loud, nice passband width.
Incidentally, I built those two experimental boxes as you advised on my last thread on subs.
One sealed, one ported both braced to excess and experimented with stuffing.
Interesting results, taking into consideration the many, many factors that were apparent from listening to music, I prefer sealed for drums and ported for about everything else... 🙄😀
thanks for the suggestions as always GM.
Well, for one thing, the design of that driver does not allow for rear-mounting, which basically negates its use in any design that calls for a low S2, unless you make an access panel at that point, which is probably the worst place you want to put an access panel in any high-order build because it can cause considerable losses.
Plus, given the technical capabilities of this driver, it really does not need a high-order design to get considerable output from it.
That's for one series of their home subs, and, while it looks cool, that driver is actually less capable (excursion-wise) than the W7.
Cool! 
One of a very few [AFAIK] that's bothered! 🙁
Pretty typical, though if tuned low, i.e. extended bass shelf [EBS] alignment, I believe you'd love drums with vented. Got to get tuning down for organ reproduction to do drums any justice.
You're welcome!
GM
One of a very few [AFAIK] that's bothered! 🙁Pretty typical, though if tuned low, i.e. extended bass shelf [EBS] alignment, I believe you'd love drums with vented. Got to get tuning down for organ reproduction to do drums any justice.
You're welcome!
GM
Tell us more, tell us more! As for the JL, I noted the Fs and Q and "transmission line" popped into my head. Though the high Mms someone mentioned is maybe not tops for that? Maybe you could find some 15" gigantic stiff rubber hose, coil it into a kind of snake form, brace the whole thing. That would be unique!
The driver you show for the home series, is not that of the Fathom/Gotham line. That was another line that I don't know I've seen for a few years. It may not be available anymore. The Fathom/Gotham line use the W7-style drivers, even if the parameters have been changed for application.
Later,
Wolf
Later,
Wolf
A question if I may sir, why did you choose that power level to model it with?
I have the sub in a sealed box for now, have just built a ported box to test and will be building your design next. I run it with 1.5kW of amplification, would that make any difference to optimising your design?
Thank you. 🙂