Russellc
Addicted Member
15 inch and 5 cu. ft. eh? Sounds like you need JBL 2235H! I can not say enough good about the pair I put in my E'waves! ( 2225H at 40 hz aint bad either for that matter.:thmbsp:
russellc
Zilch's AK Design Collaborative - Econowave Speaker
- Thread starter Zilch
- Start date
15 inch and 5 cu. ft. eh? Sounds like you need JBL 2235H! I can not say enough good about the pair I put in my E'waves! ( 2225H at 40 hz aint bad either for that matter.:thmbsp:
russellc
Russellc
Addicted Member
I hauled home the JBL 4647 boxes Zilch found for me on CL in a Mitsubishi Galant! Talk about a tight fit with my fat ass in there.
Russellc
Bauhausler
Rational Subjectivist
I hauled home the JBL 4647 boxes Zilch found for me on CL in a Mitsubishi Galant! Talk about a tight fit with my fat ass in there.
Russellc
The only speakers I've found that I couldn't fit a pair of in the CRV:
Valencias
Model 19s
Klipschorns
A5s
all of those required 2 trips. From Detroit to Columbus, in the case of the A5s.
A pair of Cornwalls fits just fine. A pair of 7' tall Acoustat 1+1's has to hang out the back window.
On the woofer issue, I think a 2225 or 2235 would be wasted playing only from 300 hz down.
I fired up Unibox and plugged in the specs for the Dayton Classic 15" ($65 each). The sensitivity is a good match for the LE10 at around 90 db. I don't really know most of the features of Unibox and something more sophisticated will be necessary to get the port tuning right but it confirms that the Dayton will put out solid response down to 30 or so in that 5.5' box.
A system sensitivity of 90 dbs leaves me plenty of headroom for the CD compensation on the horn while allowing the system to be run by low powered amps if necessary. I love these Linn Isobariks I've been listening to but in this 900 sf room a 50W amp is a minimum and 200 is comfortable.
I toyed with the idea of mounting the LE10 and the waveguide side by side in the horn enclosure at the top of the cab. Physically, that would be a good fit and it would look neat. I'd still try it if I could satisfy myself that the crossover nulls wouldn't cause strange things in the lateral response. Turning that crossover transition 90 degrees means that the nulls that appear above and below the sweet spot in the conventional vertical configuration appear to the sides of the coverage pattern now.
With the horn and midwoofer placed laterally the minimum center-to-center distance for the drivers is 10.6". I'll have to work out whether that places the crossover nulls inside the horn's coverage pattern and which side it's worse on. It might be made tolerable by fooling with the mounting depth/time alignment of the drivers. It would be a bonus to get all 3 drivers inside the cabinet.
Now I gotta find that arcsin calculation of Wayne's.
**************** EDIT
As I suspected, the 10.6" lateral c-to-c distance kills the lateral dispersion of the waveguide. The 50 X 90 pattern becomes a 50 X 50 pattern when the crossover nulls are figured in. One of the things I like most about the ewave is the lateral coverage of the WG. Still, with correct alignment and positioning of the 2 drivers you could come up with a listening position in the middle of the sweet spot (horn pattern skewed toward the middle) with the nulls appearing 25 degrees off axis on both sides if that's what's desired. If I recall the drpths of the waveguide/driver and the LE10 correctly, this would require placing the LE10 at the 'outside' and the waveguide at the 'inside' since the waveguide's VC is at a greater depth than the dome of the LE10. That's less desirable, since in this room I have reduced lateral spacing and I'd prefer to have the waveguide at the outside edge to maximize stereo spread.
Drawing board, here I come...
Bauhausler
Rational Subjectivist
Tnx. I found it and did the math above.
The illustrations Rob just posted indicate why HF comp won't work with the JBL exponential horns and diffraction lens: even if you get the frequency response playing flat to 20 kHz, the vertical beamwidth narrows to become a mere slit. :thumbsdn:
Footnote: Page 300. The E'Wave thread has become a textbook of loudspeaker design....
Footnote: Page 300. The E'Wave thread has become a textbook of loudspeaker design....
Bauhausler
Rational Subjectivist
The illustrations Rob just posted indicate why HF comp won't work with the JBL exponential horns and diffraction lens: even if you get the frequency response playing flat to 20 kHz, the vertical beamwidth narrows to become a mere slit. :thumbsdn:
Footnote: Page 300. The E'Wave thread has become a textbook of loudspeaker design....
For the permanent loudspeaker design textbook record, which JBL horns are you referring to, by model or family?
2307 is used in many 43xx Studio Monitors, and the consumer edition, H91, in S7 and L200, for example. It's why L200B's HF comp didn't effectively extended VHF, and that knowledge may have been the impetus for Keele's development of the the Biradial horn, as documented in that paper.
I would expect the same result with the longer variant of the exponential horn and the same lens in L300, et. al, as well, though I've never looked at that specifically.
Wherever you see that lens technology, it's a good bet VHF extension is similarly compromised, until proven otherwise.... :yes:
Bauhausler
Rational Subjectivist
OMG, you weren't kidding about the G-D logo. Eerie...
Hello Drewman
You would be surprised directly on the horns axis they can sound great. You really need to have the horn at ear height and toed-in, stand-up out of the sweet spot, and forget it. Off the vertical axis you can hear it plain as day. That's one of the nice things about CD type waveguides and horns. Much better polar and power response. It's nice being able to move around the room and not loose that last octave.
I have a set-up with that type of horn and lense with a slot and a PT system in the same room. It's hoot going from one to the other. The PT remains consistant off axis over a much wider area. The older exponential horn changes until you get in the "zone". Only then does the older system sound balanced in the last octave or so.
There is one plus no floor or ceiling bounce to worry about.
Rob
Bauhausler
Rational Subjectivist
Hello Drewman
You would be surprised directly on the horns axis they can sound great. You really need to have the horn at ear height and toed-in, stand-up out of the sweet spot, and forget it. Off the vertical axis you can hear it plain as day. That's one of the nice things about CD type waveguides and horns. Much better polar and power response. It's nice being able to move around the room and not loose that last octave.
I have a set-up with that type of horn and lense with a slot and a PT system in the same room. It's hoot going from one to the other. The PT remains consistant off axis over a much wider area. The older exponential horn changes until you get in the "zone". Only then does the older system sound balanced in the last octave or so.
There is one plus no floor or ceiling bounce to worry about.
Rob
Totally agree. After having Model 19s, Valencias and all manner of classic Klipsch in this system I was astonished at the evenness of the dispersion of the Econowave. that was the big surprise for me, and why after doing a vintage conversion 2-way I'm aiming for a more sensitive 3-way design.
It all makes sense; those radial horns are an exponential profile rotated horizontally, and they beam in the vertical.
Altec went MantaRay CD, Klipsch went Tractrix, and JBL, Biradial, and now, PT.... :yes:
Bauhausler
Rational Subjectivist
BTW, after a little research, it seems as if their soundman was responsible for the idea behind that logo....makes me wonder if there isn't really a connection, now.
I think you're giving the Grateful Dead's sound man too much credit, although I could be wrong.
Russellc
Addicted Member
I have often thought of the three way as well, and I'm considering one of Wayne's Mid horns, with the wave guide on top...one day.:sigh:
russellc
Bauhausler
Rational Subjectivist
3-way Ewaves from Valencias:
I've figured out that if I remove the existing horn enclosure from the cabinet and make a new full baffle I can get a 15", the LE10 and the waveguide all on the baffle. The mounting positions are somewhat staggered, so I probably can't get the LE10 directly centered under the waveguide, but it's only an irrelevant 2" offset. To know for sure I'll have to make full size cutouts of all of the parts and push them around to see what fits. My wife is the CAD designer in the family. I still do it all on paper.
I've figured out that if I remove the existing horn enclosure from the cabinet and make a new full baffle I can get a 15", the LE10 and the waveguide all on the baffle. The mounting positions are somewhat staggered, so I probably can't get the LE10 directly centered under the waveguide, but it's only an irrelevant 2" offset. To know for sure I'll have to make full size cutouts of all of the parts and push them around to see what fits. My wife is the CAD designer in the family. I still do it all on paper.