Can you elaborate on that, Wayne? A cap bypassed resistor is a textbook shelf filter. Where would a rising response with no flat shelf come from?
Ray
Zilch's AK Design Collaborative - Econowave Speaker
- Thread starter Zilch
- Start date
Can you elaborate on that, Wayne? A cap bypassed resistor is a textbook shelf filter. Where would a rising response with no flat shelf come from?
Ray
Last time anyone checked in Canada, the distributer wanted 4X the price w/8-week leadtime.
The Michigan group is using the Pyle equivalent:
http://audiokarma.org/forums/showthread.php?p=1949398&highlight=Pyle#post1949398
I believe MCM DOES ship to Canada.... :yes:
Wayne Parham
Active Member
6dB/octave augmentation
If you use a series resistor bypassed with a capacitor, the transfer characteristic is essentially a 6dB/octave diagonal line from maximum attenuation until you reach approximately 3dB attenuation. At that point, the filter is no longer a filter but instead approaches a short circuit. In this sense, you're right that there's a shelf, but it's not useful to us because we want the 6dB/octave slope for CD equalization. That's why passive equalization requires at least 10dB attenuation, any less and you don't have enough attenuation to remove before you reach 20kHz. At 10dB, if you start bringing in augmentation around 5kHz, you have just less than 2 octaves of useful augmentation you can provide at 6dB/octave, and that's just about right.
There's a bit more to it than that. For one thing the high-pass filter that is used as the "core" of the tweeter circuit is designed for a specific load resistance. Less than that and it will be overdamped, and greater than that and it will be underdamped. So a single series resistor large enough to provide audible attenuation will likely shift the filter heavily towards being underdamped, and that would cause a large peak near the crossover frequency. Also, the driver isn't a pure resistance but is a complex reactive load. Those things are discussed in more detail in the links below, handouts from the "Crossover Electronic 101" seminars that I do at the various audio shows. It's also a big part of my Crossover Document linked earlier in this thread.
What we want for CD compensation, is an initial shelf that's flat, followed by rising response to compensate for the falling power response of the driver. The capacitor bypassed resistor provides the rising response part. What we need is something to bump up the lowest frequencies, from the crossover frequency up to about 5kHz. One way to do this is to slightly underdamp the frequency-splitter high-pass filter, the "core" filter of the crossover. By underdamping it slightly, you lift the bottom of the diagonal line, providing a curve that looks like this:
If you use a series resistor bypassed with a capacitor, the transfer characteristic is essentially a 6dB/octave diagonal line from maximum attenuation until you reach approximately 3dB attenuation. At that point, the filter is no longer a filter but instead approaches a short circuit. In this sense, you're right that there's a shelf, but it's not useful to us because we want the 6dB/octave slope for CD equalization. That's why passive equalization requires at least 10dB attenuation, any less and you don't have enough attenuation to remove before you reach 20kHz. At 10dB, if you start bringing in augmentation around 5kHz, you have just less than 2 octaves of useful augmentation you can provide at 6dB/octave, and that's just about right.
There's a bit more to it than that. For one thing the high-pass filter that is used as the "core" of the tweeter circuit is designed for a specific load resistance. Less than that and it will be overdamped, and greater than that and it will be underdamped. So a single series resistor large enough to provide audible attenuation will likely shift the filter heavily towards being underdamped, and that would cause a large peak near the crossover frequency. Also, the driver isn't a pure resistance but is a complex reactive load. Those things are discussed in more detail in the links below, handouts from the "Crossover Electronic 101" seminars that I do at the various audio shows. It's also a big part of my Crossover Document linked earlier in this thread.
What we want for CD compensation, is an initial shelf that's flat, followed by rising response to compensate for the falling power response of the driver. The capacitor bypassed resistor provides the rising response part. What we need is something to bump up the lowest frequencies, from the crossover frequency up to about 5kHz. One way to do this is to slightly underdamp the frequency-splitter high-pass filter, the "core" filter of the crossover. By underdamping it slightly, you lift the bottom of the diagonal line, providing a curve that looks like this:
Hi Z, I am going to take the crossovers apart and measure all values. I am getting different values on the assembles crossovers, one from the other and that tells me something is amiss. I hope the loud one is not the bad one, as the soft side runs out of steam before it fills the room. Cheers.
canadian waveguides
Zilch: thanks for the info.
MCM does ship to Canada, I have ordered from them.
BTW, the picture I found on Sound craft site did not match the picture of JBL
and they had only a single 1 inch waveguide. They also had their own numbering scheme (to protect the guilty:thumbsdn
.
I do have fallback plan:my daughter in Idaho can receive from JBL and send on to me. Probably about same cost.
Does anyone know for sure if Pyle econo performs equivalently to JBL econo?
I know a number were bought but I did not find any finished project stories.
Thanks
Sheldon
Zilch: thanks for the info.
MCM does ship to Canada, I have ordered from them.
BTW, the picture I found on Sound craft site did not match the picture of JBL
and they had only a single 1 inch waveguide. They also had their own numbering scheme (to protect the guilty:thumbsdn
.I do have fallback plan:my daughter in Idaho can receive from JBL and send on to me. Probably about same cost.
Does anyone know for sure if Pyle econo performs equivalently to JBL econo?
I know a number were bought but I did not find any finished project stories.
Thanks
Sheldon
Hit "Search this Thread" at the top, and put in "Pyle." Jackgiff did the comparison, and deemed them "Worthy."
Kegger, Andyman, Bauhausler, and Djnagle's projects are using them.... :thmbsp:
Kegger
R.I.P. 1/12/1966 - 6/1/2017
Nice Wayne,
Perfect timing for all this, as this is the area I've been playing with lately.
After getting my bass cabs where I want them I dropped the top end to the lower
output version and have been experimenting with R1, R2, and C3, now running 31
15 and .33uf, it seems to of bought the shelf out further and helps with sibilance.
Perfect timing for all this, as this is the area I've been playing with lately.
After getting my bass cabs where I want them I dropped the top end to the lower
output version and have been experimenting with R1, R2, and C3, now running 31
15 and .33uf, it seems to of bought the shelf out further and helps with sibilance.
Hi Sheldon, the pics in this link show my ESS EWGs using Pyle lenzes. I think they sound great.
http://www.audiokarma.org/forums/showpost.php?p=2178684&postcount=1651
http://www.audiokarma.org/forums/showpost.php?p=2178684&postcount=1651
canadian waveguides
Zilch: thanks for the info.
MCM does ship to Canada, I have ordered from them.
BTW, the picture I found on Sound craft site did not match the picture of JBL
and they had only a single 1 inch waveguide. They also had their own numbering scheme (to protect the guilty:thumbsdn.
I do have fallback plan:my daughter in Idaho can receive from JBL and send on to me. Probably about same cost.
Does anyone know for sure if Pyle econo performs equivalently to JBL econo?
I know a number were bought but I did not find any finished project stories.
Thanks
Sheldon
Zilch: thanks for the info.
MCM does ship to Canada, I have ordered from them.
BTW, the picture I found on Sound craft site did not match the picture of JBL
and they had only a single 1 inch waveguide. They also had their own numbering scheme (to protect the guilty:thumbsdn
.I do have fallback plan:my daughter in Idaho can receive from JBL and send on to me. Probably about same cost.
Does anyone know for sure if Pyle econo performs equivalently to JBL econo?
I know a number were bought but I did not find any finished project stories.
Thanks
Sheldon
6dB/octave augmentation
Ok Wayne. I'm with you now. You're mainly using the transition section of the curve and pushing the flat top part higher (cap=short). You're also not using a log scale on your plot, which threw me.
I'm not a horn guy so I'm a little slow catching up.
Ray
Ok Wayne. I'm with you now. You're mainly using the transition section of the curve and pushing the flat top part higher (cap=short). You're also not using a log scale on your plot, which threw me.
I'm not a horn guy so I'm a little slow catching up.
Ray
jackgiff
Well-Known Member
Sheldon, you won't be able to tell any difference between the two systems. The Pyle waveguide is a very nice equivalent to the JBL, but it doesn't have the JBL name on the outside.
The Baronet clones that had the volume of 1.6 Cu' were finished with JBL LE10H's and the Pyle waveguides. They are quite nice. In fact, another pair of "keepers."
Kegger
R.I.P. 1/12/1966 - 6/1/2017
Thanks Zilch, nice to see the verification.
Probably if the Drivers were a bit better sounding/mellower to start with then I'd op for a
.47uf cap but I just have this thing with hot vocals that make me cringe when I hear um.
Alright back to clip leads and wire nuts! (when I'm done I'll post the final on the KPM thread)
Probably if the Drivers were a bit better sounding/mellower to start with then I'd op for a
.47uf cap but I just have this thing with hot vocals that make me cringe when I hear um.
Alright back to clip leads and wire nuts! (when I'm done I'll post the final on the KPM thread)
Hey Keg, I have been listening for a couple hours now and really like what I hear. The female volcals are a bit harsh, but turning up the woof amp just a bit killed the harshness. Overall, very impressed. You gotta stop by......I also have the .47 for you. Cheers.
I've got some Pioneer CS63's that I'm thinking of using for an econowave. I believe they are just over 4 cubic feet volume. At this time I only have a pair of L100 drivers to rob from (which I hate to do). I have not been able to find any specs on the 15" woofer in the CS63 cab. Would the installed woofer work with the econowave and one of the crossovers referenced here? I absolutely HAVE to build one of these babies. I am looking for some LE14's but I'll rob the L100's if I have to. Hoping the 15" woofers in the CS63's are workable though.
Yeah I know the 15's are tough but reading through this thread...a few times.....it looked there were a couple that could. I was looking at some Altec 3127's possibly. Wish I had some test equip to test those CS63 woofers. I haven't pulled them but I'm gussing they are 16 ohm. They super efficient, about twice as loud as the L100's at the same volume setting. But high up they go I don't know.