I've been wanting to experiment with CD/waveguide combinations for awhile now, and I've been wanting to hear a pair of PR170M0s per side as well. So, on the way to an OB system, I put together some modular components to hear both. The 170s are in a slightly overdamped (Qtc ~.65) sealed box with false walls filled with 45 pounds of clumping kitty litter. I couldn't find any Playsand locally and the basic construction sand had iron in it when I dragged a magnet thru it. I just filled in around the connections to the binding posts, so I kinda thought iron might be problematic. The waveguide is a DDS ENG90 and the comp driver is a B&C DE250 (8ohm).
I used a bi-wire set of binding posts and a coupla short jumpers for the Audax drivers so I could quickly change from parallel to series and to make it easier to insert passive components if needed. The system is all active 3-way, but I usually end up adding passive baffle step or something to the mess. In this case, it was a smart move, as the double Audax doesn't act like a simply more efficient single. There's a definite increase in midrange energy (maybe 500hz to 1khz?) that doesn't seem to be proportional to the rest and I'll probably need to roll one of them off to get some better balance. I ran them series, parallel, and one at a time, and parallel is most to my liking if I can drain off a little of the extra midrange. Overall, the liveliness is pretty addictive.
The star of the show is the CD/waveguide - I really wish I would've looked into these earlier. I've been very surprised at the quality of the combination. Extremely clear and smooth presentation with no hint of running out of steam at any volume level. The headroom from these things is just plain relaxing and un-constipated...like I've been living in an audio coffin all my life and I can finally breathe.
I'm still waiting for a set of XT1086 WGs and a pair of BMS 4540 drivers so I'll have something else to compare to, but in the meantime I'll do some tweaking on this setup to try and get a better understanding of what's going on. No measurements of anything yet, but that'll be coming soon.
Anyway, this was a very cool experiment and this type of presentation is probably what I've been looking for all my life. As much as I've tried to resist, I just know I'm gonna end up with horns in here eventually.
An externally hosted image should be here but it was not working when we last tested it.
I used a bi-wire set of binding posts and a coupla short jumpers for the Audax drivers so I could quickly change from parallel to series and to make it easier to insert passive components if needed. The system is all active 3-way, but I usually end up adding passive baffle step or something to the mess. In this case, it was a smart move, as the double Audax doesn't act like a simply more efficient single. There's a definite increase in midrange energy (maybe 500hz to 1khz?) that doesn't seem to be proportional to the rest and I'll probably need to roll one of them off to get some better balance. I ran them series, parallel, and one at a time, and parallel is most to my liking if I can drain off a little of the extra midrange. Overall, the liveliness is pretty addictive.
The star of the show is the CD/waveguide - I really wish I would've looked into these earlier. I've been very surprised at the quality of the combination. Extremely clear and smooth presentation with no hint of running out of steam at any volume level. The headroom from these things is just plain relaxing and un-constipated...like I've been living in an audio coffin all my life and I can finally breathe.
I'm still waiting for a set of XT1086 WGs and a pair of BMS 4540 drivers so I'll have something else to compare to, but in the meantime I'll do some tweaking on this setup to try and get a better understanding of what's going on. No measurements of anything yet, but that'll be coming soon.Anyway, this was a very cool experiment and this type of presentation is probably what I've been looking for all my life. As much as I've tried to resist, I just know I'm gonna end up with horns in here eventually.
"...add five or six tens a side for the bass."
I hear ya Mike about the bass. These things do fine for a less efficient system, but it was immediately obvious that they're not gonna cut it for this one. I'm a little cramped for space here and the 18s in these boxes do double duty as subs thru lower midrange so they're a nice compromise. I've been mulling over 4-6 12 inchers per side or possibly 4 15s per side for a year now, so that'll probably be the next big build. My biggest problem is that I'm an extension bass junkie - I like it to go to 20hz - and the current boxes do that rather easily. I may need to go 4-way but I don't know where to put dedicated subs.
I'll figure it out if I have to I'm sure.
I hear ya Mike about the bass. These things do fine for a less efficient system, but it was immediately obvious that they're not gonna cut it for this one. I'm a little cramped for space here and the 18s in these boxes do double duty as subs thru lower midrange so they're a nice compromise. I've been mulling over 4-6 12 inchers per side or possibly 4 15s per side for a year now, so that'll probably be the next big build. My biggest problem is that I'm an extension bass junkie - I like it to go to 20hz - and the current boxes do that rather easily. I may need to go 4-way but I don't know where to put dedicated subs.
I'll figure it out if I have to I'm sure.
ttan98,
1. what model of Audax driver you are using?
They're the PR170M0.
2. x-over freq. between waveguide and Audax?
I haven't settled on the frequency yet. I've been listening to them between 1.2khz and 2khz so far and either the waveguide isn't large enough or the B&C drivers don't like it that low, but 1.2khz sounds worse than 2khz. Keep in mind this is all purely subjective and without taking some realistic measurements, I really don't know what's going on with them yet. My feeling at this point is that 1.5khz is probably a solid number (see #3)
3. what order of filter from 2.?
I'm using an Ashly XR2001 active XO so all I have to work with is LR4. Acoustically of course, it's going to be somewhat different.
1. what model of Audax driver you are using?
They're the PR170M0.
2. x-over freq. between waveguide and Audax?
I haven't settled on the frequency yet. I've been listening to them between 1.2khz and 2khz so far and either the waveguide isn't large enough or the B&C drivers don't like it that low, but 1.2khz sounds worse than 2khz. Keep in mind this is all purely subjective and without taking some realistic measurements, I really don't know what's going on with them yet. My feeling at this point is that 1.5khz is probably a solid number (see #3)
3. what order of filter from 2.?
I'm using an Ashly XR2001 active XO so all I have to work with is LR4. Acoustically of course, it's going to be somewhat different.
AJ said:
No expert in this field. What I read from this site, DE250 is recommend to cross around 1.6kHz.
http://www.usspeaker.com/B&C-DE250-1.htm
Maybe Beyma CP380 is a better candidate? It is also a bit more expensive.
http://www.usspeaker.com/beyma CP380M-1.htm
btw... really like what you are doing as PR170M0 is what I have in mind. I wish I can start buying and building but too many project to complete.... a fact of life
Have fun
"What I read from this site, DE250 is recommend to cross around 1.6kHz."
Right. 1.6khz, 2nd order. I'm doing 4th order @ 1.2khz so my guess is that they'll both be down 12db at 800hz either way. Everyone seems to like that Beyma so maybe I'll give it a shot after I mess around with the BMS and B&C.
"How do you find his driver? Magnetar likes it a lot."
I like it alot too.
Right. 1.6khz, 2nd order. I'm doing 4th order @ 1.2khz so my guess is that they'll both be down 12db at 800hz either way. Everyone seems to like that Beyma so maybe I'll give it a shot after I mess around with the BMS and B&C.
"How do you find his driver? Magnetar likes it a lot."
I like it alot too.
I don't know enough about the two setups to be sure of apples-to-apples, but if yours is comparable to Dr. Geddes I believe the waveguide should allow for a lower XO than mfr spec. It may also require a brick wall HP to cross where phase response is a good match. Can you cascade the Ashly LR4s and just make a single channel to audition? Feel free to ignore my rambling, I just haven't posted for a while so this is pretty superficial.
Hi AJ,
I notice there's a WG on the floor in front of the bass cabinet, and it looks like this:
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=270-310
(Dayton has several sizes in this series, 6~12in mouths. )
Is it any good? (or bad, since it's abandoned and put aside)
I notice there's a WG on the floor in front of the bass cabinet, and it looks like this:
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=270-310
(Dayton has several sizes in this series, 6~12in mouths. )
Is it any good? (or bad, since it's abandoned and put aside)
Hi Boydon
"I don't know enough about the two setups to be sure of apples-to-apples, but if yours is comparable to Dr. Geddes I believe the waveguide should allow for a lower XO than mfr spec. It may also require a brick wall HP to cross where phase response is a good match. Can you cascade the Ashly LR4s and just make a single channel to audition?"
I'm not 100% sure either, so take this FWIW. The ENG90 had a throat radius, a straight conical section, and a large mouth radius. From what I've read in the Geddes threads (sorry ) it's visually close to how his WGs are constructed. There's no attempt on my part to match the exit/entry angles of the CD and the wave guides, so there's a definite departure at that point. Everything else is completely new to me so I'm the wrong guy to ask techy questions of about his own system. Until i spend some time with this stuff, I'm pretty much in the dark about what's happening with them. I like your idea of cascading the Ashly and just looking closely at one WG; I never thought of doing that but it makes sense.
"Feel free to ignore my rambling, I just haven't posted for a while so this is pretty superficial."
No sweat Boydon. I do superficial as well as anyone here.
CLS,
"I notice there's a WG on the floor in front of the bass cabinet...Is it any good? (or bad, since it's abandoned and put aside)"
Just because it's on the floor doesn't mean it's abandoned. I'm just a lousy housekeeper and being single, I don't have a wife to pick up after me.
Actually, I bought 4 of them when they went on sale and haven't done anything with them. They're screw on types and I don't have an adapter for the B&C drivers. I bought screw-on to bolt-on adapters for the 4540s I ordered so I could use them with the ENG90 and the XT1086s. I'll plug the BMS drivers in the PE when they get here and have a listen.
BTW, they are NOT Geddes style waveguides. They don't have a conical section, just on continous, unknown profile that may be just a large radius for all I can tell. Hard to say how they were conceived.
"I don't know enough about the two setups to be sure of apples-to-apples, but if yours is comparable to Dr. Geddes I believe the waveguide should allow for a lower XO than mfr spec. It may also require a brick wall HP to cross where phase response is a good match. Can you cascade the Ashly LR4s and just make a single channel to audition?"
I'm not 100% sure either, so take this FWIW. The ENG90 had a throat radius, a straight conical section, and a large mouth radius. From what I've read in the Geddes threads (sorry
) it's visually close to how his WGs are constructed. There's no attempt on my part to match the exit/entry angles of the CD and the wave guides, so there's a definite departure at that point. Everything else is completely new to me so I'm the wrong guy to ask techy questions of about his own system. Until i spend some time with this stuff, I'm pretty much in the dark about what's happening with them. I like your idea of cascading the Ashly and just looking closely at one WG; I never thought of doing that but it makes sense. "Feel free to ignore my rambling, I just haven't posted for a while so this is pretty superficial."
No sweat Boydon. I do superficial as well as anyone here.
CLS,
"I notice there's a WG on the floor in front of the bass cabinet...Is it any good? (or bad, since it's abandoned and put aside)"
Just because it's on the floor doesn't mean it's abandoned. I'm just a lousy housekeeper and being single, I don't have a wife to pick up after me.
Actually, I bought 4 of them when they went on sale and haven't done anything with them. They're screw on types and I don't have an adapter for the B&C drivers. I bought screw-on to bolt-on adapters for the 4540s I ordered so I could use them with the ENG90 and the XT1086s. I'll plug the BMS drivers in the PE when they get here and have a listen.
BTW, they are NOT Geddes style waveguides. They don't have a conical section, just on continous, unknown profile that may be just a large radius for all I can tell. Hard to say how they were conceived.
Re: Re: Another PR170M0/Waveguide experiment
Told you so.AJ said:The star of the show is the CD/waveguide - I really wish I would've looked into these earlier. I've been very surprised at the quality of the combination. Extremely clear and smooth presentation with no hint of running out of steam at any volume level. The headroom from these things is just plain relaxing and un-constipated...like I've been living in an audio coffin all my life and I can finally breathe.
Anyway, this was a very cool experiment and this type of presentation is probably what I've been looking for all my life. As much as I've tried to resist, I just know I'm gonna end up with horns in here eventually.
Al, remember the comments at the Annex recently on this subject?Magnetar said:
Their distortion will start to rise at the bottom of their range, and that's probably what you're hearing.AJ said:
Hey Brett
"Told you so."
Yeah, I think I've heard that once or twice from you.
"Al, remember the comments at the Annex recently on this subject?"
That was before I began to appreciate fine hornery. Time to seriously look into it I guess. One thing that's encouraging is that a mid horn doesn't have to be all that large and space is at a premium here.
"Their distortion will start to rise at the bottom of their range, and that's probably what you're hearing."
That's why I need to do some real measuring of this stuff. I can't tell if it's the driver or the waveguide and without any previous experience, I can't even make an educated guess. I can tune it by ear only so far.
On the upside Brett, these things play some serious music. After tweaking out that overbearing midrange, I've been running thru all my favorite test cds at stupid loud levels; there's so little distortion at those insane levels, it would be pretty easy to go stone deaf with a smile on my face. I like where this is going.
"Told you so."
Yeah, I think I've heard that once or twice from you.
"Al, remember the comments at the Annex recently on this subject?"
That was before I began to appreciate fine hornery.
Time to seriously look into it I guess. One thing that's encouraging is that a mid horn doesn't have to be all that large and space is at a premium here."Their distortion will start to rise at the bottom of their range, and that's probably what you're hearing."
That's why I need to do some real measuring of this stuff. I can't tell if it's the driver or the waveguide and without any previous experience, I can't even make an educated guess. I can tune it by ear only so far.
On the upside Brett, these things play some serious music. After tweaking out that overbearing midrange, I've been running thru all my favorite test cds at stupid loud levels; there's so little distortion at those insane levels, it would be pretty easy to go stone deaf with a smile on my face. I like where this is going.
AJ said:
I guess that Dayton WG is also used on this:
http://www.emeraldphysics.com/intro.htm
They look the same on the photos.
I remember Lynn once mentioned this on the RMAF thread...
AJ said:Hi CLS
"They look the same on the photos."
Yes they do. And they're cheap. It'll be interesting to compare them to the ENG90s, which are not so cheap. Who knows, maybe they're giant killers.
I have the smallest and largest ones. They are in fact a good sounding horn for almost nothing. They are conical horns, so they don't load very low but otherwise are pretty free from coloration.
"They are in fact a good sounding horn for almost nothing."
That's good to hear Mike. I didn't know what to think of them when I first saw them.
BTW, that cap on the second driver did alot more than just clean up the midrange. It allowed the bass boxes to gell alot better too. I've got about 8db gain on them over the mids and CD, and the sytem as a whole is frankly, astounding me. I'll work for a coupla hours, take a break, throw in another cd, go thru the usual expectation of hearing something grossly wrong, and it just ain't happening. I can't believe the lack of distortion at extreme volumes; I honestly have never heard anything like this.
I don't want to measure them, I just wanna listen to them.
That's good to hear Mike. I didn't know what to think of them when I first saw them.
BTW, that cap on the second driver did alot more than just clean up the midrange. It allowed the bass boxes to gell alot better too. I've got about 8db gain on them over the mids and CD, and the sytem as a whole is frankly, astounding me. I'll work for a coupla hours, take a break, throw in another cd, go thru the usual expectation of hearing something grossly wrong, and it just ain't happening. I can't believe the lack of distortion at extreme volumes; I honestly have never heard anything like this.
I don't want to measure them, I just wanna listen to them.
AJ said:
The star of the show is the CD/waveguide - I really wish I would've looked into these earlier. I've been very surprised at the quality of the combination. Extremely clear and smooth presentation with no hint of running out of steam at any volume level. The headroom from these things is just plain relaxing and un-constipated...like I've been living in an audio coffin all my life and I can finally breathe.
Anyway, this was a very cool experiment and this type of presentation is probably what I've been looking for all my life. As much as I've tried to resist, I just know I'm gonna end up with horns in here eventually.
Hi AJ,
Any update on the XT1086 WGs and BMS 4540?
Hi Sam
I still haven't got the XT1086s yet. They were supoosed to arrive Loudspeakersplus mid November, but I still haven't seen them. I got the BMS drivers in and plugged them into ENG90 first.
These drivers are quite a bit different than the B&C. I've got a 1.5uF cap on them to get some flatter response and they're kinda-sorta +- 3db between 2khz and 10khz now. Not bad overall, but they're a little less full bodied than the B&C and bit edgier. The B&C are pretty smooth throughout their range and it's probably because they start with a much flatter FR. A better attempt at EQing the BMS would probably help, but I could live with them the way they are.
I have the BMS in the PE wave guides right now (I'm running out of scrap wood for baffles )
There's a substantial difference in the presentation between the PE and the DDS waveguides. The PE seem to give a larger sweet spot and a more open sound, but it's more ragged than the DDS. Almost spitty if that's the right word. I haven't had time to analyze it any further but I'll take a closer look this weekend.
Bottom line, the BMS drivers probably need more attention to fine tune, but I like them enough to keep them. Compared to the B&C drivers, I'd keep the B&C long before the BMS though. These are just some subjective observations, so YMMV as always.
I still haven't got the XT1086s yet. They were supoosed to arrive Loudspeakersplus mid November, but I still haven't seen them. I got the BMS drivers in and plugged them into ENG90 first.
These drivers are quite a bit different than the B&C. I've got a 1.5uF cap on them to get some flatter response and they're kinda-sorta +- 3db between 2khz and 10khz now. Not bad overall, but they're a little less full bodied than the B&C and bit edgier. The B&C are pretty smooth throughout their range and it's probably because they start with a much flatter FR. A better attempt at EQing the BMS would probably help, but I could live with them the way they are.
I have the BMS in the PE wave guides right now (I'm running out of scrap wood for baffles
) An externally hosted image should be here but it was not working when we last tested it.
There's a substantial difference in the presentation between the PE and the DDS waveguides. The PE seem to give a larger sweet spot and a more open sound, but it's more ragged than the DDS. Almost spitty if that's the right word. I haven't had time to analyze it any further but I'll take a closer look this weekend.
Bottom line, the BMS drivers probably need more attention to fine tune, but I like them enough to keep them. Compared to the B&C drivers, I'd keep the B&C long before the BMS though. These are just some subjective observations, so YMMV as always.
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