Re: notch filters...
Essentially a variation on the BSC filter... check Martin King's site
12" is an estimated 380 Hz BS -3dB.
dave
AudioGeek said:
Essentially a variation on the BSC filter... check Martin King's site
12" is an estimated 380 Hz BS -3dB.
dave
diffuser???
I want to build a HF diffuser on the back.... something to reflect the HF sound a bit equally everywhere.
How would I do this???
Something like this:
|< shape on the back? with the point close to the center of the driver and tapered out to the edge of the driver.
hope this makes sense.
I want to build a HF diffuser on the back.... something to reflect the HF sound a bit equally everywhere.
How would I do this???
Something like this:
|< shape on the back? with the point close to the center of the driver and tapered out to the edge of the driver.
hope this makes sense.
Re: Re: ahh...
a single jx53 with a single jx125 will represent a point source more closely than a jx125 PP mated to a jx53 4-in-line. however the jx125PP + jx53 4-in-line would have considerably more SPL capability.
the reason i chose 300Hz is because most music has 50% of it's energy above 300hz and 50% below. Also I wanted as much of the vocal range to be managed by one driver. However maybe a XO at about 400hz might also suit me since my proposed baffle would be about 8.25" wide (210mm) and have a "lip" of about 1" (25mm) to simulate a baffle of about 10.25" (260mm).
the -3db step for baffle step would be about 440Hz.
BTW are the JX53 and JX125 that good. what about the Fostex FE83 and FW168N? Should that combo or any other also be considered?
planet10 said:
a single jx53 with a single jx125 will represent a point source more closely than a jx125 PP mated to a jx53 4-in-line. however the jx125PP + jx53 4-in-line would have considerably more SPL capability.
the reason i chose 300Hz is because most music has 50% of it's energy above 300hz and 50% below. Also I wanted as much of the vocal range to be managed by one driver. However maybe a XO at about 400hz might also suit me since my proposed baffle would be about 8.25" wide (210mm) and have a "lip" of about 1" (25mm) to simulate a baffle of about 10.25" (260mm).
the -3db step for baffle step would be about 440Hz.
BTW are the JX53 and JX125 that good. what about the Fostex FE83 and FW168N? Should that combo or any other also be considered?
Re: Re: Re: ahh...
I haven't unleased my JX150s yet, so don't talk from personal experience, but i have reports that even FR the JX125 & 150 will outdo a JX92 -- no mean feat.
The FW168HP would be very interesting... with something smaller than the FE83. I don't have an opinion on the FW168N, but it looks good...
dave
navin said:
I haven't unleased my JX150s yet, so don't talk from personal experience, but i have reports that even FR the JX125 & 150 will outdo a JX92 -- no mean feat.
The FW168HP would be very interesting... with something smaller than the FE83. I don't have an opinion on the FW168N, but it looks good...
dave
Re: Re: Re: Re: ahh...
i could not access any data on the 168HP from the fostex site. i guess the question is....
which combo is better...
Jx 53 with a JX125
or Fe83 (does fostex make a widerange that is smaller?) with a 168HP?
if either the jx53 of fe83 requires some hf help (which i doubt given that there are enough out there that are happy with a jx 92's hf) does adding a rear facing piezo make any sense.
planet10 said:
i could not access any data on the 168HP from the fostex site. i guess the question is....
which combo is better...
Jx 53 with a JX125
or Fe83 (does fostex make a widerange that is smaller?) with a 168HP?
if either the jx53 of fe83 requires some hf help (which i doubt given that there are enough out there that are happy with a jx 92's hf) does adding a rear facing piezo make any sense.
Although the mid is great, I found the top end of the JX92 lacked a bit of openness, especially on orchestral strings & cymbals.
I am now using them with Fountek JP3 ribbons crossed over 1st order at about 6K and the result is much better. The Aurum Cantus ribbons/JX92 combination I've heard sounds better still - but at a price.
There was an interesting contribution on the JX92 impedance from member 6010 a couple of months back and I'm going to try his Zobel and redo the xover.
I am now using them with Fountek JP3 ribbons crossed over 1st order at about 6K and the result is much better. The Aurum Cantus ribbons/JX92 combination I've heard sounds better still - but at a price.
There was an interesting contribution on the JX92 impedance from member 6010 a couple of months back and I'm going to try his Zobel and redo the xover.
Adding an additional HF to either the JX53 or the JX92 is a personal thing. I find the HF of the JX53 is very good and the lack of additional drivers and crossovers over 500Hz makes for a very natural, coherent sound, more like an ESL than a traditional moving coil speaker and totally removed from the sound of a dome tweeter. It's worth getting the 53 and 125/150 drivers as close as possible, though, as the first order crossover recommended by Ted Jordan means there is a considerable overlap.
An earlier version of the JX125 was used in a Townsend design, crossed over to a ribbon tweeter at around 5kHz. It got good comments on the stereo imagery though I suspect that was mostly the contribution of running the JX125 so high. As an experiment, I tried running the JX125 full range but things got a bit hard at the top end (they aren't really designed as a full range).
Re Jordans vs Fostex - there are comments on the sound of these at the zHorn site. A recent posting by the designer on the Konus site says he prefers the sound of the JX92 in the Essence-style enclosure.
Regarding using two JX92s in one enclosure, the VTL on the Jordan website would make a good starting point for this. The easiest way to roll off the HF of the rear driver (assuming you need to - it would depend on room and reflections) would be to put some sound absorbent material over the driver and let it run full range (no crossover to worry about). Another route would be to mount the second driver on the top, firing upwards. There have been a few designs using this approach and reviews seem split on whether it results in a more natural soundstage or simply messes up the imaging.
Alternatively, the Essence/ VTL design using one driver is supposed to work quite well against a wall.
Colin
An earlier version of the JX125 was used in a Townsend design, crossed over to a ribbon tweeter at around 5kHz. It got good comments on the stereo imagery though I suspect that was mostly the contribution of running the JX125 so high. As an experiment, I tried running the JX125 full range but things got a bit hard at the top end (they aren't really designed as a full range).
Re Jordans vs Fostex - there are comments on the sound of these at the zHorn site. A recent posting by the designer on the Konus site says he prefers the sound of the JX92 in the Essence-style enclosure.
Regarding using two JX92s in one enclosure, the VTL on the Jordan website would make a good starting point for this. The easiest way to roll off the HF of the rear driver (assuming you need to - it would depend on room and reflections) would be to put some sound absorbent material over the driver and let it run full range (no crossover to worry about). Another route would be to mount the second driver on the top, firing upwards. There have been a few designs using this approach and reviews seem split on whether it results in a more natural soundstage or simply messes up the imaging.
Alternatively, the Essence/ VTL design using one driver is supposed to work quite well against a wall.
Colin
Tsk tsk - I should have provided those.
zHorn is at http://audio-resolution.com/zhorn
The Essence site is http://sakurasystems.com/products/essence.html
The comments I mentioned on the VTL design are on the Sakura site at
http://www.sakurasystems.com/show/tom.html
There is also an interesting interview with the Essence enclosure designer at
http://www.6moons.com/industryfeatures/sead/seadlejlic.html
6moons also has a review of the Essence at http://www.6moons.com/audioreviews/47lab/shigaraki3.html which is pretty interesting (especially on single vs multiple drivers debate).
Ted Jordan's site has more on the linear array idea in the systems section at http://www.ejjordan.co.uk/systems_frameset2.htm
Colin
zHorn is at http://audio-resolution.com/zhorn
The Essence site is http://sakurasystems.com/products/essence.html
The comments I mentioned on the VTL design are on the Sakura site at
http://www.sakurasystems.com/show/tom.html
There is also an interesting interview with the Essence enclosure designer at
http://www.6moons.com/industryfeatures/sead/seadlejlic.html
6moons also has a review of the Essence at http://www.6moons.com/audioreviews/47lab/shigaraki3.html which is pretty interesting (especially on single vs multiple drivers debate).
Ted Jordan's site has more on the linear array idea in the systems section at http://www.ejjordan.co.uk/systems_frameset2.htm
Colin
I've been considering using a Jordan line array with 5 drivers instead of 4, in an MTM arrangement. The top and bottom pairs would be connected the same as a 4 driver line array, and crossed over at high frequencies to a single driver in the middle of the array. I thought that this would help increase the power response at high frequencies, and get some sparkle back, while still keeping the imaging qualities of the line array. Has anyone tried this?
I figured that if I use 5 drivers, I could also experiment with connecting them up in an alternative array I read about. I'll be damned if I can remember the name of the array or the author of the article. I'll have to spend some time digging it up. Basically, the 5 driver array was connected up in various phase combinations which, in sum total, maintained a fairly constant dispersion pattern throughout its band. I think it did so vertically, also. This is the problem with a line array. At high frequencies, the vertical pattern collapses. I don't know about recent history, but in the distant past, when Transendental Audio distributed Jordans in the late seventies, they recommended rolling off a pair of in the array at high frequencies. I figured that using 5, and having a single Jordan at high frequencies, would be better, eliminating combing as well as increasing the power output in the upper treble range.
I figured that if I use 5 drivers, I could also experiment with connecting them up in an alternative array I read about. I'll be damned if I can remember the name of the array or the author of the article. I'll have to spend some time digging it up. Basically, the 5 driver array was connected up in various phase combinations which, in sum total, maintained a fairly constant dispersion pattern throughout its band. I think it did so vertically, also. This is the problem with a line array. At high frequencies, the vertical pattern collapses. I don't know about recent history, but in the distant past, when Transendental Audio distributed Jordans in the late seventies, they recommended rolling off a pair of in the array at high frequencies. I figured that using 5, and having a single Jordan at high frequencies, would be better, eliminating combing as well as increasing the power output in the upper treble range.
I don't think the baffle step comes into play, here (with the Jordans). XO would be pretty high. to be determined by the spacing between the upper and lower pair. I think I would use a first order series XO here. The impedances should be the same on the 4 drivers series/parallel combo and the single tweeter. They should blend perfectly, being the same drivers.
pooge said:
Of course baffle step would come into play, determined by the width of the cabinet.
For a passive XO, i'd try series 1st too... "identical drivers" makes getting it work a lot easier. You need to use the baffle step to your advantage to compensate for the xtra 6 dB of sensitivity of the series/parallel set.
dave
Oh, I got you now. I wasn't thinking of the sensitivity situation. However, regarding the baffle step, I think I would be crossing over to the tweeter well above the baffle step frequency to do what you suggest. I could pad differences in sensitivity. I want to get the 4-driver array well out of the power range to keep the single tweeter from overload.
One of the reasons I'm contemplating this arrangement is because I have drivers from different eras. My older ones are not as good at the top end as the newer ones. I though this would be a good way to use them all. They might not be identical at crossover, but would likely sound more alike than using other drivers. Using these in the alternative 5 driver circuit I mentioned may not be as idea as 5 identical drivers, though.
One of the reasons I'm contemplating this arrangement is because I have drivers from different eras. My older ones are not as good at the top end as the newer ones. I though this would be a good way to use them all. They might not be identical at crossover, but would likely sound more alike than using other drivers. Using these in the alternative 5 driver circuit I mentioned may not be as idea as 5 identical drivers, though.
planet10 said:
Are you sure about this? The series/parallel combination should make for the same sensitivity as a single driver, as they would be the same 8 ohm load. The mutual coupling at low frequencies might raise sensitivity there. Is this what you are talking about, vis-a-vis the baffle step? I'm rusty on the sensitivity of plural drivers, though. I'll have to dig up my info on this.
pooge said:
The XO at the BS should be between the 4 drivers & the single driver... you don't want to be padding your "bass" drivers.
pooge said:
everytime you double the number of drivers you gain 3 dB (ignoring differences, if any, of amplifier output into different impedances) so 4 drivers is 6 dB.
The confusion arises in that many, when talking about multiple driver sensitivity, will lump in an extra 3 dB for the (theroectical) increase in amp output (in actual fact this is rarely the case, and certainly not if you talk tube amps).
dave
planet10 said:
I loved the look of the essense. the box was a bit too wide but otherwise i like the slim look. I'd have to show it to my wife to get her approval though.
what i was thinking about was a similar looking box for the 125 with the front bafle extending on the top so teh JX53 could be open baffle.
Looking at the specs of the 125 however i noticed that it requires over 20 liters to work. EJJ actually recomends 25 liters (min 18 liters). This means I can only fit 1 JX125 in the box (intrenal dim. 24"Hx6"Wx12"D)
That is why I started investigating Fostex.
however i'd like to know what drivers you are using in the system described above. I like the idea of using 1st order PLLXO at baffle step.
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