Russellc
Addicted Member
Well for one thing its bolt on rather than screw on, the adapter was giving some response anomalies with the JBL guide.
Russellc
Zilch's AK Design Collaborative - Econowave Speaker
- Thread starter Zilch
- Start date
Well for one thing its bolt on rather than screw on, the adapter was giving some response anomalies with the JBL guide.
Russellc
Can't get boost passively without losing the equivalent efficiency throughout the rest of the bandwidth, so, active. I'm doing it using a Behringer DEQ2496 parametric (PEQ) right now, plus a highpass in its FBD just below 30 Hz. I have other options available, but this was the simplest way for me to get there since it's always in the test system chain here.
In a fully active system, it's a cinch to program in the lowpass of DCX2496 or similar.
I see threads with others using FBQ2496 doing similar stand-alone for subs, but I'm unfamiliar with that device.
Sidebar:
Using high-efficiency midwoofers implicitly offers the potential for better midrange performance than the extended-bass woofers we often use in building full-range EconoWaves. Typically, they must be augmented with subs to cover the full spectrum, however. That's not an issue for home theater and sound reinforcement applications, as subs are a "given."
Look at the specs for KappaLite 3012 HO vs. LF:
http://www.parts-express.com/pdf/290-589s.pdf
http://www.parts-express.com/pdf/290-590s.pdf
The HO has higher efficiency, 100.5 dB vs. LF's 95.5 dB 1W/1m with essentially the same Re, 5.5 and 5.6 Ohms, respectively. Both are significantly higher efficiency than the 85 - 90 dB woofers we typically use, and hugely more power handling as well.
Mms tells us HO has a lighter cone, 46.9g vs. 72.4g, but LF has an effectively more powerful motor, BL = 16.7 T-M vs. 15.9 T-M for HO. These and other design differences combine to yield Fs of 51.5 Hz vs. 37.02 Hz, favoring LF for bass response, but sacrificing 5 dB of efficiency and a full octave of frequency response at the high end.
Noting that LF also has greater linear excursion (Xmax) of 9.1mm vs 6.2mm, I modeled LF in assisted alignments and found that it could be "pushed" to play extended bass at modest levels for home use, if desired. For our purposes, do we care that it won't play to 4 kHz like HO does? Only to the extent that its midrange performance is compromised in achieving this.
Comments from those who actually KNOW something about this are welcome, 'cause Zilch don't....
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I thought that JBL guide + D220Ti were compatible, screw-on to screw-on...
What I meant to ask was: Has anyone compared 3012LF + QSC waveguide to 3012LF + JBL Waveguide (standard E-Wave)?
Basically, what does the QSC guide offer that the JBL guide doesn't?
I was thinking of 3012HO with the standard E-Wave guide (JBL + D220Ti), unless there are significant advantages to the QSC waveguide...
JSS
Russellc
Addicted Member
The testing going on here is with the B&C DE 250, which is bolt on. The QSC came along b/c of similarities to the JBL guide pattern wise, and it allowed the B&C to be used with out an adapter, which caused some response problems. The JBL guide and the 220 ti are both screw on.....
Sorry for any confusion,
Russellc
We A/B'd Advent eWave vs. KDT/3012/QSC/DE250 yesterday. The HF's were remarkably similar; the LFs, not so....
ROSSO
Active Member
So - may we consider the HF section of the XO and PL posted over on the PE-TT site to be specific to the DE250-QSC combo, or does it contain some compromise to accomodate the Eminence LF driver?
It's all optimized for that specific combo, was just developed yesterday, and nobody has a clue whether or how well it will work with anything else.
We're talking two resistors and a cap here. Anyone with measurement capability can make this determination.... :yes:
Thanks for digging these up.
These really give me perspective of how these PE Trap enclosures can be dressed up. I am guessing the standard ply supplied by PE isn't finish grade where you could apply a nice stain to it?
Worst case I finish them with Duratex to match my THT sub I guess.
donprice
Wound up workin' at a gas station....
FR curves and XO testing
So here's my first shot at posting FR plots. Not sure if it is going to be legible.
Blue = standard HE XO (left speaker)
Purple = LE14 HE XO (left speaker)
Green - standard HE XO (right speaker)
Eminence Kappalite 3015 & Pyle 612/D220Ti
Measured at 39.5" from horn centerline
Problems - L/R response not consistent using same XO configuration; FR falls off cliff between 1500 & 2000 Hz...
Any suggestions on cleaning this up? Step one maybe finding a better way to post the damn graphs...
So here's my first shot at posting FR plots. Not sure if it is going to be legible.
Blue = standard HE XO (left speaker)
Purple = LE14 HE XO (left speaker)
Green - standard HE XO (right speaker)
Eminence Kappalite 3015 & Pyle 612/D220Ti
Measured at 39.5" from horn centerline
Problems - L/R response not consistent using same XO configuration; FR falls off cliff between 1500 & 2000 Hz...
Any suggestions on cleaning this up? Step one maybe finding a better way to post the damn graphs...
Attachments
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juniorJBL
SUB 1500 :)
alt-prtscrn paste to paint save as jpeg or gif. upload as file.
Edit here is a link for info.
http://www.seoconsultants.com/windows/print-screen/
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Alas, your image is not showing, and I don't know how to navigate the gallery to find it....Finally finished my E-waves with JBL 2235H woofers. Thanks to all of the members who worked on making this project possible. They sound awesome.
donprice
Wound up workin' at a gas station....
That's what I did...I just over-compressed it or whatever. The resposted version is much better.
The dip at 260 Hz is most likely room stuff; ignore 'til proven otherwise.
The rest isn't making a lot of sense unless you moved the speaker or the mic between the determinations.
What is the center distance between your waveguide and woofer?
donprice
Wound up workin' at a gas station....
It's only marginally legible. I can't read the legends or differentiate the colors.
In terms of smoothness, the curve that is different looks the best, assuming the one lower down was taken at a different SPL....
I've got the posting figured out...finally. Reposted above.
Yup, different SPL levels. Something sounded like it was clipping. Only noticed when testing right speaker, not left...
I need to run back through the files and double check which ones are which. TrueRTA does not work like I think so it may be confused on which curve is which. I'll try again tomorrow.
I do an inordinate amount of retesting. Each measurement, I'm asking myself, "Is this what I'm expecting?" If not, it's, "What's up with THAT?"
Overall, your results are reasonable. I would not characterize that as "Off a cliff;" you have a peak in the region just below, is all. "Off a cliff" happens when you forgot you had turned the L-pad to "Min."
The more of this you do, the more your confidence will build in the method and your protocol implementing it, and you'll become aware of the limitations. See if you get the same result tomorrow. I'm betting the smoother one is with the LE14 variant of the lowpass. If not, you're not in control yet. You should be able to replicate the results on different samples of the same speaker, or know the reason why they measure different.... :yes:
wianieq
Well-Known Member
Here a few pics of the 2035hpl barzilay cabs. The place is a huge mess, I've been working on five different projects at the same time. Bad practice for me. Yes, my floor has a pretty good slant in it. Anyway, I plan on making new baffles for these with the drivers and waveguides centered. I think I'm going to buy the 8" legs that I saw from Ikea.
Any type of wood better than others for the baffles? Is it better to have ports in front or back and Is there a certain size that is better than others for this combo. I like SRM51555's that he just posted, I may mimic that.
Thanks for any input.
Any type of wood better than others for the baffles? Is it better to have ports in front or back and Is there a certain size that is better than others for this combo. I like SRM51555's that he just posted, I may mimic that.
Thanks for any input.
Attachments
wingman65
Member
Finished Pair of Sony Junk Cab Ewaves
Maybe the ugliest pair of speakers, but without a doubt the best sounding pair of 2-way speakers I've ever owned. Wife is wondering why I'm bothering with them, she'll Know soon enough. I'm filling a 20' by 15' insulated room in the basement with superb, crystal clear sound from $300 worth of DIY goodness
To all of you who put the time and effort into this project, many thanks. I'm already thinking of the next iteration. Has to be wife approved for living room so woodworking is required:yes:
Been listening to remastered Beatles collection and for you rockers out there, Chickenfoot is a must:thmbsp:
Tony
Maybe the ugliest pair of speakers, but without a doubt the best sounding pair of 2-way speakers I've ever owned. Wife is wondering why I'm bothering with them, she'll Know soon enough. I'm filling a 20' by 15' insulated room in the basement with superb, crystal clear sound from $300 worth of DIY goodness
To all of you who put the time and effort into this project, many thanks. I'm already thinking of the next iteration. Has to be wife approved for living room so woodworking is required:yes:
Been listening to remastered Beatles collection and for you rockers out there, Chickenfoot is a must:thmbsp:
Tony
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