I dont know the Orion, and I have not heard it either. But - in my opinion there are compromizes. The XO frequency between the mid and tweeter is too high for the mid (should be no higher than 1 kHz because distortion rises dramatically above 1 kHz), and too low for the tweeter (distortion again). And with that baffle width, the polar pattern from 1k and up should look nasty... but since there are no published measurements of this we dont know for sure. I also expect that front/rear radiation is not perfectly the same for Orion.
The good thing with RD-75 is that front/rear radiation is very similar, so the dipole pattern is more or less the same front/rear. An other good thing is that it is line-source in the vertical plane, and thus there is almost no sound outside the vertical range of the line. Horizontally, it is not perfect. Without baffle (the way I use it), it behaves like a true dipole up to about 1 kHz, where you get a small dipole peak and wider dispersion. Above some 2 kHz, it behaves more like a dipole again. Above 5 kHz, the dispersion starts to narrow, and from 10 kHz there is obvious beaming.
Sorry, I have no measurements of this that I saved ....
The good thing with RD-75 is that front/rear radiation is very similar, so the dipole pattern is more or less the same front/rear. An other good thing is that it is line-source in the vertical plane, and thus there is almost no sound outside the vertical range of the line. Horizontally, it is not perfect. Without baffle (the way I use it), it behaves like a true dipole up to about 1 kHz, where you get a small dipole peak and wider dispersion. Above some 2 kHz, it behaves more like a dipole again. Above 5 kHz, the dispersion starts to narrow, and from 10 kHz there is obvious beaming.
Sorry, I have no measurements of this that I saved ....
thanks for the swift reply, I agree, the compromise with the Orion is the 3 way assignement, a 4 way with the W15 would have been better but SL ruled it out from the start. Gainphile is trying such an arrangment in Oz, looks like it's a clear improvement. One could also imagine something like the Grand Beethoven in a different combo, 2xW22, 2xW15 and the millenium tweeter "a la D'appolito", with a separated tall array of H frame big woofers.
beaming at 10k is not so important I think, no dome tweeter is small enough back to back to give perfect dipole radiation at these frequencies anyway..
If you manage to keep almost true dipole radiation up to 5k, you are into something! Would love to hear your system one day...
cheers
beaming at 10k is not so important I think, no dome tweeter is small enough back to back to give perfect dipole radiation at these frequencies anyway..
If you manage to keep almost true dipole radiation up to 5k, you are into something! Would love to hear your system one day...
cheers
Last edited:
Hi,
I actually built such a speaker:
An externally hosted image should be here but it was not working when we last tested it.
I have made some measurements on horisontal dispersion for two different tweeters.
27TDFC:
An externally hosted image should be here but it was not working when we last tested it.
27TBCD/GB-DXT:
An externally hosted image should be here but it was not working when we last tested it.
Top one is on-axis. Below that (Offset -5dB) is 30 degrees. At the bottom (Offset -10dB) is 60 degrees. Measurement window is 2ms. Crossover is 2.5kHz. I do prefer the DXT tweeter and that is the one I have playing at the moment. Please note that the DXT-tweeter is not even flush-mounted (GASP). Still it is quite smooth off-axis. It would be interesting to hear what Stig-Erik (or others) thinks about this DXT lense. Maybe you should create something similar around your RD-75?
regards,
Øyvin
Hi Øyvin,
looks like Norway is the place to go!
did you try the millenium tweeter too before going 4ways? how do you cross the medium, have you kept SL analog crossover and added a stage?
Cheers
Laurent
Hi,
I have not tested the millenium tweeter. I have rear-mounted tweeters and thought the price for four milleniums was too high. Besides that I have listened to a few other implementations with the milleniums and I really like them (I have never listened to the original Orions). I am using a pc with an EMU-1820M soundcard and VST-plugins for crossover. This is going to be replaced with the miniDSP 4x10 Hd that I just received. I borrowed a minidsp from a friend last year and it surprised me that it was a lot better than my soundcard in the mid+treble. I also plan to test the Eton ER-4 Air Motion Tweeter that I have had in a drawer for some time. It will be interesting to see the off-axis response with that combo.
sorry for the OT
Øyvin
PS! Have you considered the Seas Magnum(T29MF001) for your Orions? It has a lot more cone-travel(180% more) and slightly larger piston-area(14% more) than the Milleniums. I guess it should be a better candidate for crossing over that low.
Most manufactors are way too optimistic about the sensitivity of their speakers. Some even use the 8 ohms spec even if the speakers are 4 ohm, give an extra 3 dB. Manufactors of dipole speaker often relate their specification to the listening position, the calcutlate "backwards" to one meter. Real life sensitivity above 90 dB for 2.83 V in 8ohm are rare.
Roger
is it the difference in hardware (what source of signal was used with miniDSP? have you tried EMU soundcard as source?) or is it the actual DSP implementation that is better with miniDSP?
do you use linear phase plugins? I am myself using vst plugin based crossover with linear phase filters and was wondering whether mini dsp could be an upgrade..
thanks!
martin
Hi,
I do not want to stray too much off topic so I sent you a PM about this.
regards,
Øyvin
Yes I did. Its simply hung from a beam going across the room. The beam can be moved back and forth to make it easier to change the placement of the speaker. The chains are attached to a smaller piece of wood, that is easy to move across the beam, and it can be rotated for easy adjustments of toe-in angle. This is really very simple, I guess it took me less than half an hour to build it.
I have some more detailed pics below, taken before I put on the curved foam edges.
Attachments
See the pic below.
The woofer towers are delayed to get the same arrival time as the ribbon. Impulse response of this system is pretty clean if you ask me. Will try to find a measurement ... if I bothered to save any measurements....
This is NOT how the room looks now, but the speaker arrangement is the same.
The woofer towers are delayed to get the same arrival time as the ribbon. Impulse response of this system is pretty clean if you ask me. Will try to find a measurement ... if I bothered to save any measurements....
This is NOT how the room looks now, but the speaker arrangement is the same.
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
thanks. 1.5m is close, and you absorb the rear wave.. that is give you a sort of "giant headphone" feeling with lips 2m large on female voices? I myself listen fairly close, around 2m from the dipoles. I do loose a little bit on pinpointing abilities but I am just drawn into the music, it's addictive! but I also have a recessed soundstage due to the Orions 3.1 revision.
Last edited:
No, its not like headphones. Maybe when it comes to clarity and lack of coloration it is, but the soundstage is in front of you, and not inside your head like with headphones. You also loose the depth perspective with headphones, which is not lost here. With headphones there you can't feel the sound physically either, with my setup you can (if playing loud enough...).
Soundstage in my setup is spacious in depth and width, but also very precise. Pin-pointing can be ultra-sharp if the music is recorded that way.
And its very addictive to be kind of "transported" into the music and the acoustics of the recording. I wouldn't want to have it any other way than this!
Soundstage in my setup is spacious in depth and width, but also very precise. Pin-pointing can be ultra-sharp if the music is recorded that way.
And its very addictive to be kind of "transported" into the music and the acoustics of the recording. I wouldn't want to have it any other way than this!
I'd like to say a little more about my room acoustics ...
Some of the reason people love dipoles is that you can use the room reflections to create a very large and spacious soundstage. It can sound very cool I admit, but the problem with this approach is that different recordings will start to sound the same. What you hear is mainly the "signature" of your own room, and not so much the acoustics that is on your recordings.
I prefer to remove the listening room from my listening experience. A complete removal is not possible, but it is possible to bring the room reflections down to a level where they are inaudible with music signal. A very short listening distance and proper room treatment makes it possible to get room reflections 30 dB or more below the direct sound, which I have achieved.
What you get with this approach is the ability to hear everything that is on your records, and I mean everything. It's like being transported into the music rather than have the music appear in your room, if you get my analogy.
One guy that visited me, who is a classical musician and hifi-enthusiast, said he had never ever felt like actually being in the concert hall with a stereo system, but with mine he did. I think that's a very nice compliment!
I listen to all kinds of music, and I think that my approach to listening room acoustics pays justice to all music styles and types of recordings. I think its better to let everything come through rather than put an other layer of acoustics (the listening room) on top of everything.
Some of the reason people love dipoles is that you can use the room reflections to create a very large and spacious soundstage. It can sound very cool I admit, but the problem with this approach is that different recordings will start to sound the same. What you hear is mainly the "signature" of your own room, and not so much the acoustics that is on your recordings.
I prefer to remove the listening room from my listening experience. A complete removal is not possible, but it is possible to bring the room reflections down to a level where they are inaudible with music signal. A very short listening distance and proper room treatment makes it possible to get room reflections 30 dB or more below the direct sound, which I have achieved.
What you get with this approach is the ability to hear everything that is on your records, and I mean everything. It's like being transported into the music rather than have the music appear in your room, if you get my analogy.
One guy that visited me, who is a classical musician and hifi-enthusiast, said he had never ever felt like actually being in the concert hall with a stereo system, but with mine he did. I think that's a very nice compliment!
I listen to all kinds of music, and I think that my approach to listening room acoustics pays justice to all music styles and types of recordings. I think its better to let everything come through rather than put an other layer of acoustics (the listening room) on top of everything.
Last edited:
Stig Erik,
I agree to a certain point with your last post. But I also disagree. Dipoles do not all flatten out the record to a massively spread auditory scene, at least my Orions don't. When I listen to a rock record, or jazz, in a tight and dead space, I hear it, so do I hear the difference between the concertgebouw, and the scala.. maybe not to such extent to what you experience, but, the difference is very easy to spot, really obvious to anyone. At least for the ones properly recorded with only a few mics.
You made me even more curious now!
I agree to a certain point with your last post. But I also disagree. Dipoles do not all flatten out the record to a massively spread auditory scene, at least my Orions don't. When I listen to a rock record, or jazz, in a tight and dead space, I hear it, so do I hear the difference between the concertgebouw, and the scala.. maybe not to such extent to what you experience, but, the difference is very easy to spot, really obvious to anyone. At least for the ones properly recorded with only a few mics.
You made me even more curious now!
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.