And "Official" it is; Badmusician is E'Waver #63! 
http://audiokarma.org/forums/showthread.php?p=2260584#post2260584
http://audiokarma.org/forums/showthread.php?p=2260584#post2260584
Zilch's AK Design Collaborative - Econowave Speaker
- Thread starter Zilch
- Start date
DE250 is bolt-on, so you have to use throat adapters, requiring a tweak of the filter, which nobody has worked through yet.
Yes, DE250 is smoother sounding than D220Ti.... :yes:
jackgiff
Well-Known Member
Trying the low efficiency crossover (<95 dB), a difference between the Selenium D220Ti and the B&C DE250 becomes apparent. The Selenium exhibits a good amount of overshoot at around 2 KHz, which was flattened by moving the hi pass frequency up to 3 KHz. This lowered the overshoot, so that the HF and LF blended seamlessly at around 1.6 KHz.
The B&C DE250 doesn't have this overshoot, and theoretically doesn't need as high a pass frequency as the Selenium. It didn't show itself on the high efficiency crossover, for whatever reason, but does show up when more attenuation is needed. The resulting FR's are shown in the panoramic first picture. The top FR is that of the JBL/Selenium combo, and the bottom is of the QSC/B&C combo. Also the FR's of the woofer, the Selenium, and the B&C drivers are shown, in that order.
It appears that the hi pass frequency of the B&C will need to be lowered to smooth the crossover region. The B&C also appears to have a bit higher output on this waveguide than the Selenium does on the JBL. I was willing to ignore the 1-2 dB difference, since the L-Pad has a much greater range of adjustment, but as long as the crossover frequencies are being changed, the HF attenuation and compensation resistors will also be looked at again.
So we are not done yet with the DE250/QSC crossover. It will be close to the standard EconoWave, but parts values will surely differ. More to come.
The B&C DE250 doesn't have this overshoot, and theoretically doesn't need as high a pass frequency as the Selenium. It didn't show itself on the high efficiency crossover, for whatever reason, but does show up when more attenuation is needed. The resulting FR's are shown in the panoramic first picture. The top FR is that of the JBL/Selenium combo, and the bottom is of the QSC/B&C combo. Also the FR's of the woofer, the Selenium, and the B&C drivers are shown, in that order.
It appears that the hi pass frequency of the B&C will need to be lowered to smooth the crossover region. The B&C also appears to have a bit higher output on this waveguide than the Selenium does on the JBL. I was willing to ignore the 1-2 dB difference, since the L-Pad has a much greater range of adjustment, but as long as the crossover frequencies are being changed, the HF attenuation and compensation resistors will also be looked at again.
So we are not done yet with the DE250/QSC crossover. It will be close to the standard EconoWave, but parts values will surely differ. More to come.
Attachments
Russellc
Addicted Member
Well I am assembling parts for my second Ewave project, the first went to a happy friend in town.
The first time around I used the D220ti/LE14A combo and I would like to supersize it this time with a high quality 15" woofer and perhaps the B&C driver you guys are testing. It doesn't seem like that 250 goes low enough to mate with most 15" drivers, or am I wrong? I have just ordered the QSC waveguide to try something new in this project. Maybe a JBL 2225/B&C combo?
P.S. I just realized that a 15" woofer is going to also increase the distance between the drivers centers even more than the increased size of the QSC waveguide, better to stick with a 12"?
I've done it with both 2225H and 2235H in the 5 cu ft JBL 4507 box. This is what I have ewaved with since the begining, and with smashing results! The directivity of the woofer that is 15 inches in diameter is definately starting to collapse around 1000, but it works out great in a two way as a slight stretch.....JBL 4430, which throws a large image uses the 2235H 2 way, and has been around for decades. I believe a pair resides with Mr Zilch
in fact.
I hope to eventually solve this "stretch" by installing one of Wayne's Mid horns with JBL 2123H in between......one of many projects.:sigh:
Russellc
What Jack's doing?
It's the eWave crossover, with HF comp based upon and derivative of Wayne Parham's Pi-Speaker teachings.... :yes:
jackgiff
Well-Known Member
How much does Spice want the value of L1 reduced and the value of C1 increased? Could save me some time doing math.
I had the Bode plots all set to post before I realized the action is at 3 kHz, whereas the issue is at 1.6. We don't need more Q at 3 kHz, rather, down where the acoustic crossing occurs.
Nevermind.
[Carry on....
]
jackgiff
Well-Known Member
Here is the crossover action with the hi pass lowered to 2.5 KHz. First FR is with L-Pad set to listen level. Second is set at Max (attenuation resistor shorted out). Third is Selenium at listen, and shows the bump at 2 Khz that required its hi pass set to 3 KHz.
Much cleaner bandpass at crossover, and lowering the L-Pad to almost nothing shows no dip in response at 1.6 KHz. Now it needs to be checked with high efficiency version, but I don't expect any more surprises.
Tomorrow, I will tackle the attenuation and compensation components. I may also try the hi pass at 2.2 KHz, just to be sure it is optimized.
Much cleaner bandpass at crossover, and lowering the L-Pad to almost nothing shows no dip in response at 1.6 KHz. Now it needs to be checked with high efficiency version, but I don't expect any more surprises.
Tomorrow, I will tackle the attenuation and compensation components. I may also try the hi pass at 2.2 KHz, just to be sure it is optimized.
Attachments
Rightbrained
New Member
I finished a pair of "ewaves" today (except for the veneer).
I am using the standard crossover for the less than 95 db sensitivity woofer , 220ti paired with the DC300.
For the cost of entry , this is a good value to say the least. However , My ears have grown fond of ribbons I suppose . The 220ti seems to play nicely (the L-pad is at mid-point and mounted to the back). The DC300 has a nice warm sound with good extension in the 30 hz tuned 3.0 cubic foot enclosure rear ported with dual 2 inch ports.
After 5 hours of listening with A/B comparisons I find that I prefer my 3.5 ways with the ribbons. This is in no way an attempt to criticize the design at all.
I have decided I am going to sell the waveguides , 220ti's and the DC300's.
I bought 5 of the JBL waveguides in case I fell in love so I could build a 5 channel set.
If anyone wants these parts I will take a 15 percent loss on them.
I am using the standard crossover for the less than 95 db sensitivity woofer , 220ti paired with the DC300.
For the cost of entry , this is a good value to say the least. However , My ears have grown fond of ribbons I suppose . The 220ti seems to play nicely (the L-pad is at mid-point and mounted to the back). The DC300 has a nice warm sound with good extension in the 30 hz tuned 3.0 cubic foot enclosure rear ported with dual 2 inch ports.
After 5 hours of listening with A/B comparisons I find that I prefer my 3.5 ways with the ribbons. This is in no way an attempt to criticize the design at all.
I have decided I am going to sell the waveguides , 220ti's and the DC300's.
I bought 5 of the JBL waveguides in case I fell in love so I could build a 5 channel set.
If anyone wants these parts I will take a 15 percent loss on them.
mcmurma
Active Member
Ok all you econo waveguide guru folks, I'm about ready to take this plunge... sort of... with a few significant variations. Surely it's nothing others have not done before, but please pardon me for not reading through nearly 500 pages of previous threads to check 
I plan on implementing this thing with an active crossover in a 3 way configuration utilizing the Selenium D220Ti paired with a 6" - 8" midbass in a pair of satellites, and either a 12"-15" DVC sub, or a full-on two-driver sub.
While I have been following this thread for the past few days I have not seen much on the waveguide I'd like to use, which is a 8" to 10" rounded waveguide. I want the satellites to retain the ability to be placed on a horizontal axis (high on a bookshelf) with fewer concerns about coverage than you would have with a more traditional horn shape. I know I've seen info on this posted!
I already run horns, cheap ones, in an identical setup to what I'm proposing for this new setup. So has this not already been done? and does it not work out well?
-mac
I plan on implementing this thing with an active crossover in a 3 way configuration utilizing the Selenium D220Ti paired with a 6" - 8" midbass in a pair of satellites, and either a 12"-15" DVC sub, or a full-on two-driver sub.
While I have been following this thread for the past few days I have not seen much on the waveguide I'd like to use, which is a 8" to 10" rounded waveguide. I want the satellites to retain the ability to be placed on a horizontal axis (high on a bookshelf) with fewer concerns about coverage than you would have with a more traditional horn shape. I know I've seen info on this posted!
I already run horns, cheap ones, in an identical setup to what I'm proposing for this new setup. So has this not already been done? and does it not work out well?
-mac
Very nice cabs, Rightbrained!
I just finished mine today also. The speakers still need some time to break in, but so far I like what I hear. Maybe a little too crisp on the top end, but I think I read somewhere in this thread that the 220Ti begins to sweeten up as it breaks in. The Dayton 12" Classic really surprised me. I didn't think I could get such a nice bass response out of these little cabs but it somehow works!
Anyway, here's a pic of the speakers and also one of the crossovers.
Thanks to all of you who contributed to this project. I'm elated that they turned out sounding so good. With a little more breakin time and a few final tweaks, I think these are definately keepers!
I just finished mine today also. The speakers still need some time to break in, but so far I like what I hear. Maybe a little too crisp on the top end, but I think I read somewhere in this thread that the 220Ti begins to sweeten up as it breaks in. The Dayton 12" Classic really surprised me. I didn't think I could get such a nice bass response out of these little cabs but it somehow works!
Anyway, here's a pic of the speakers and also one of the crossovers.
Thanks to all of you who contributed to this project. I'm elated that they turned out sounding so good. With a little more breakin time and a few final tweaks, I think these are definately keepers!
Attachments
Rightbrained's round-edge eWaves earn "Official" standing #64. :yes:
And Normster's converted CS-77As make him "E'Waver #65...!"
http://audiokarma.org/forums/showthread.php?p=2260584#post2260584
And Normster's converted CS-77As make him "E'Waver #65...!"
http://audiokarma.org/forums/showthread.php?p=2260584#post2260584
Last edited:
skywave-rider
Slumming in Akihabara
Mac,
I am sure the gurus will kick into gear shortly, but to me, what you propose doesn't sound econo in price or spirit of the design. I do have a suggestion, however. Use the 6-8" midwoofer with the JBL 6x6 waveguide. It has a 90 degree horiz and vertical dispersion, and I'm sure with some tilt down you can make it work high on a bookshelf. And by all means...subs. I use the Dayton Classic 8" in a .9 cu ft ported box.
http://audiokarma.org/forums/showthread.php?p=1856214#post1856214
Rightbrained
New Member
Thanks Normster , yours look good too !
I was surprised by the Dayton classic 12 as well .
The combo sounds damned good for the money invested for sure.
I was surprised by the Dayton classic 12 as well .
The combo sounds damned good for the money invested for sure.
There are issues, specifically associated with the two drivers generating off-axis interference nulls, total cancellations, in fact, which impinge upon the dispersion pattern. In the normal vertical orientation with the drivers above or below each other, and employing waveguides having asymmetric directivity, the design may position these outside the vertical pattern, or near its edges to augment the forward lobe, but deployed horizontally the nulls occur within the normal listening window, as the angles are fairly narrow, in the range of +/- 20°. Round waveguides force a larger center-to-center distance, narrowing the lobe, as does the higher crossover frequency necessitated by smaller waveguide dimensions.
Scroll down to the end of this description to see the location of the null "eyes" about the axis at the 2kHz crossover frequency in the vertical polar map of this optimized 8" design using an asymmetric waveguide. They would be even closer using a round one:
http://www.eighteensound.com/staticContent/applications/kits/18Sound_kit8.pdf