argo said:
i have been following this discussion eagerly. my goal is to build a speaker that is small enough to have 5 without getting thrown out of my apt. (by my wife).
4 thin tall cylinders each holding a JX92 and Esg seem like a nice idea. given that the XO for this system is around 5k and 1st octave there would some ammount of lobing. how does this affect the sound. will putting the JX92 and Esg close together help?
Definitely if mid and tweet can be made closer to each other, lobbing will decrease. I would even modify the faceplate of ribbon for closer mounting to mid.
Another thought - with JX92S very thin cone in not so deep boxes I have got impression that the back wave from the speaker cone bouncing back from back wall may interfere with the sound from the front of the speaker cone. So I am leaning more and more to very deep (1/4 of the lowest wavelength) sealed boxes or open back (stuffed) boxes. Minding the aesthetics and WAF achieving this becomes problematic. On the other hand looking at Ted Jordan’s own designs he doesn’t seem to care much about the free room behind his drivers. So go figure? I haven’t done any testing on this but hopefully will make some comparisons soon.
Also I have found out that single JX92S driver per channel is insufficient for getting live performance experience playing large orchestra music with low power amps (Gainclone, Class A) so two driver MMT or MTM is what I am considering now. Actually I’ll planning to make it three way so here I am sliding away from “slimmer is better” concept.
Oh yeah one more thing with Esg2 and ribbons generally - their frequency response is very sensitive to baffle shape and size changes due to diffraction effect – very large edge radii is highly beneficial.
Argo
Another thought - with JX92S very thin cone in not so deep boxes I have got impression that the back wave from the speaker cone bouncing back from back wall may interfere with the sound from the front of the speaker cone. So I am leaning more and more to very deep (1/4 of the lowest wavelength) sealed boxes or open back (stuffed) boxes. Minding the aesthetics and WAF achieving this becomes problematic. On the other hand looking at Ted Jordan’s own designs he doesn’t seem to care much about the free room behind his drivers. So go figure? I haven’t done any testing on this but hopefully will make some comparisons soon.
Also I have found out that single JX92S driver per channel is insufficient for getting live performance experience playing large orchestra music with low power amps (Gainclone, Class A) so two driver MMT or MTM is what I am considering now. Actually I’ll planning to make it three way so here I am sliding away from “slimmer is better” concept.
Oh yeah one more thing with Esg2 and ribbons generally - their frequency response is very sensitive to baffle shape and size changes due to diffraction effect – very large edge radii is highly beneficial.
Argo
The inside of these cabinets is a transmission line. There is no parallel wall inside; it is angled and I added felt dampening over what Ronnie at Carolina Audio supplies.
I personally have built MTM designs in the past and do not like them. The tend to simply lobe in different directions and I don't believe the imaging is as good; more diffuse. Less is better. I've mentioned previously the dynamic range that I've measured; it is vastly superior to planar speakers. Now that I've made a surround system of them, the sound pressure level is even better with SACD surround. I've built amplifiers that supply in the neighborhood of 350W/8ohms and these control each speaker very well.
When I was originally measuring the driver combination, I played with height of ribbon above the JX92 cabinet as well as the fore/aft positioning. Both sonically and aesthetically, the height I chose worked out well. The optimum displacement posteriorly is about 20 mm (front baffle of ribbon to front baffle of JX92).
Regards, Robert
I personally have built MTM designs in the past and do not like them. The tend to simply lobe in different directions and I don't believe the imaging is as good; more diffuse. Less is better. I've mentioned previously the dynamic range that I've measured; it is vastly superior to planar speakers. Now that I've made a surround system of them, the sound pressure level is even better with SACD surround. I've built amplifiers that supply in the neighborhood of 350W/8ohms and these control each speaker very well.
When I was originally measuring the driver combination, I played with height of ribbon above the JX92 cabinet as well as the fore/aft positioning. Both sonically and aesthetically, the height I chose worked out well. The optimum displacement posteriorly is about 20 mm (front baffle of ribbon to front baffle of JX92).
Regards, Robert
I'm also coming to concluson that MTM designs don't sound that well, although it seems like the flagship model from all major companies is MTM after all (Dynaudio, JM Labs, Wilson, Burmeister, to name just a few). I guess the crossover has to be at least in 2k range for the system to sound well.
I high quality two way can make real magic provided the tone of instruments and voices are correct. They can totally disappear creating a very seamless and coherent sound space. With no sound sticking to the speaker. Maybe surround sound is trying to do this. But not any I have listen too. It sounds really fake to me. The major flaw with almost all speakers is that they sound like speakers. Meaning you can tell the sound is coming from the speaker. The sound does not float in space and melt the walls of the room away. The bigger they are and the more drivers the worse it tends to get. There is no reason a two way can not play loud and clear too. Or go down low enough for most music. It will not happen if the recording is bad. With all the sound jamed into the left or right channel. Sadly most recordings are bad. And the better your equipment the less you want to listen to those.
my goal is to build a system that proves to my family and friends that one does need to give up sound quality to make speaker more WAF friendly.
hence the front L & R will be thin tall (max dim. 40"H x 6"W x 10" D) spires the center a short (under 6"), wide (about 30") unit that can sit over a 29-34" TV, the rears will be small boxes outer dim. 9"x6"x6" (about teh size of the JBL control 1). I am planning to use 6mm thick aluminum extrusion for this.
hence the front L & R will be thin tall (max dim. 40"H x 6"W x 10" D) spires the center a short (under 6"), wide (about 30") unit that can sit over a 29-34" TV, the rears will be small boxes outer dim. 9"x6"x6" (about teh size of the JBL control 1). I am planning to use 6mm thick aluminum extrusion for this.
MTM or MMT - there are tradeoffs with either one but if you need to have two mids then you basically only have those two major configurations. Theoretically MTM creates more uniform radiation pattern and MMT could cause some lobbing in higher frequencies but at the end it all comes down which order and cutoff rate the crossover has with chosen driver configuration. Di - pole and Bi - pole are another animals with their own caveats where I cannot advise.
For surround duties (I mean watching movies and stuff) I have found single JX92S without tweeter for Center (provided it has adjusted for same level as mains) and Rears can provide all the needed enjoyment.
Now I must eat my words about box deepness importance. I still haven’t done any test but looking at the JX92S driver I can see that all of the driver’s smallish cone back area is hindered by the driver’s spider and huge magnet assembly anyhow so providing more space behind it seems to make no sense. So I quess the deep box is unnecessary.
For surround duties (I mean watching movies and stuff) I have found single JX92S without tweeter for Center (provided it has adjusted for same level as mains) and Rears can provide all the needed enjoyment.
Now I must eat my words about box deepness importance. I still haven’t done any test but looking at the JX92S driver I can see that all of the driver’s smallish cone back area is hindered by the driver’s spider and huge magnet assembly anyhow so providing more space behind it seems to make no sense. So I quess the deep box is unnecessary.
I built the JX92S minimonitors designed by Jim Griffin and found that stripping all the foam out and using a Deflex panel on the rear wall and a Deflex ring on the back of the driver improved clarity substantially. I chamfered the driver cutout too. They seem to like air around them.
I'm keen to try a tweeter with this design. Anyone have any experience of doing this?
I'm keen to try a tweeter with this design. Anyone have any experience of doing this?
Sealed or closed? F3 of 80Hz -sure you need to ad the sub anyhow.navin said:
navin said:
I cannot imagine how adding a tweeter to any woofer could add SPL to the speaker as whole.
To passively add SPL (actually to not lose it) to single woofer can be done by getting rid of the baffle step compensating circuit. That means you need to mount the speaker in or on wall.
Jordan’s rated sensitivity is 88dB. Baffle step loss depending on speaker location from the back wall falls into –3 to –6 dB range. Adding second driver in parallel should raise SPL +6dB, in case both woofers are in close proximity i.e. their acoustic outputs are coupled. For push - push I don’t have a clue.
argo said:
Efficiency wise push-push just eliminates a full baffle-step (ie 6 dB). As such it will need a bit more room behind to breath, or if rolled off (as in an x.5-way, you may need to roll off the bottom (or use a low Q alignment) as room lift causes a rise in the output at lower frequencies... this would give you more headroom at the bottom.
dave
BrianGT said:
is the R2 cheaper than teh Esg? anyone used both?
argo said:
F3 of 80 is enough for rear and center. any lower F3 and the box gets too big - big enough for me to get thrown out of the house. my wife barely tolerates the JBL Control 1 (actually Pro III) I am usign for rear now. i dont think icna get away with a larger box.
for the front (L&R) I hope a thin tall speaker 40" tall, 6"W, 10"D might be the max I am allowed. even here is the box was 24"Hx6"Wx9"D and wall mounted it would be much appreciated. I perfer the the later box. it would be 12 liters and shared by 2 JX92 and a tweeter (R2, Esg etc..). is it big enough?
to manage this I intend to build the boxes out of 6mm thick aluminum sheet. Then I intend to layer the inner walls with fiberglass mating soaked in resin.
instead of a JX92 + Esg what about a 5" midbass XOed to a JX53 so similar combo...such as a MCM Al cone midabss mated to a 2, 3 or 4" TB. The 5" MCM could then provide BSC. given that the baffle width of such a speaker will be under 6" BSC will be in the range of 2500Hz to 120Hz.
MCM midbass link:
http://mcm.newark.com/NewarkWebCommerce/mcm/en_US/support/catalog/productDetail.jsp?id=55-1870
T-B links
http://www.tb-speaker.com/detail/0414/W4-657SC.htm
http://www.tb-speaker.com/detail/tweeter/w3-315sc.asp
http://www.tb-speaker.com/detail/tweeter/w2-800sc.asp
MCM midbass link:
http://mcm.newark.com/NewarkWebCommerce/mcm/en_US/support/catalog/productDetail.jsp?id=55-1870
T-B links
http://www.tb-speaker.com/detail/0414/W4-657SC.htm
http://www.tb-speaker.com/detail/tweeter/w3-315sc.asp
http://www.tb-speaker.com/detail/tweeter/w2-800sc.asp
Doesn’t this create a need for new thread about TB drivers or something alike?
I am curious about those TB’s as well as there are always some cases where you need decent size fullrange with minimum cost like for computer monitors or cheap HT set-up. There has been lot of talks about TB’s in Madisound board some time ago but I am not sure are this discussions still in their archive. Cudos to diyaudio board archive –it has been preserved all the posts from the past unlike Madisound who stores posts no longeer than about 6 months.
Also check out new Aurasound fullrange drivers. While they have pretty low sensitivity they are very compact and inherently shielded due to using neodyn magnets.
As for mating Jordans with tweeters which wont broke your bank I have tried JX92s with Audax small metal domes. Not so refined sound as Esg2 it is still a viable option for HT use when budget must be kept low.
I am curious about those TB’s as well as there are always some cases where you need decent size fullrange with minimum cost like for computer monitors or cheap HT set-up. There has been lot of talks about TB’s in Madisound board some time ago but I am not sure are this discussions still in their archive. Cudos to diyaudio board archive –it has been preserved all the posts from the past unlike Madisound who stores posts no longeer than about 6 months.
Also check out new Aurasound fullrange drivers. While they have pretty low sensitivity they are very compact and inherently shielded due to using neodyn magnets.
As for mating Jordans with tweeters which wont broke your bank I have tried JX92s with Audax small metal domes. Not so refined sound as Esg2 it is still a viable option for HT use when budget must be kept low.
i am a budget audiophile ...anyone know how do the TB al cone drivers sound v/s the jordan, bandor, fostex, lowther et. al.
what i was thinking of (too keep things simple) is a 1.5 way (MCM+TB). this dodges 2 issues.
1. XO in the vocal range
2. XO where the C-C distance of the 2 drivers being XOed is larger than the wavelength - this phenomenon can cause lobing.
say you have a 10cm fullrnage and a 1" tweeter ona 3" face plate. the c-c distance is 3.5" (9cm). now if one was to XO at 5k you'd get lobing after 343/5000 m where 343m/s is speed of sound (in warmer climes like India in the US it is closer to 330m/s) which is if the c-c was more than about 7 cm.
one way out of this is use a 3" fullrange like the W3 871 or W3 315sc and a tweeter with no flange like the Vifa D26NC even then the c-c distance is about 6cm menaing that lobing could occur above 5700Hz or so.
what i was thinking of (too keep things simple) is a 1.5 way (MCM+TB). this dodges 2 issues.
1. XO in the vocal range
2. XO where the C-C distance of the 2 drivers being XOed is larger than the wavelength - this phenomenon can cause lobing.
say you have a 10cm fullrnage and a 1" tweeter ona 3" face plate. the c-c distance is 3.5" (9cm). now if one was to XO at 5k you'd get lobing after 343/5000 m where 343m/s is speed of sound (in warmer climes like India in the US it is closer to 330m/s) which is if the c-c was more than about 7 cm.
one way out of this is use a 3" fullrange like the W3 871 or W3 315sc and a tweeter with no flange like the Vifa D26NC even then the c-c distance is about 6cm menaing that lobing could occur above 5700Hz or so.
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