John,
Interesting, I was just perusing the Mirage site, but I didn't see the model in your picture; which one is it?
Thanks
Interesting, I was just perusing the Mirage site, but I didn't see the model in your picture; which one is it?
Thanks
Oh yea, I have the Omni 50s as my current speakers. They are discontinued. Their new series are really nice they now have reference grade omnipolar loudspeakers. My speakers are pretty nice the only complaint is that they can be a bit on the bright side occasionally. Soundstaging is huge and aslong as they are more or less equidistant from side walls the image the doesn't skew to one side. A pair on Ebay should be a good price. I bought mine for $200 oddly enough at The Great Indoors, a furniture store as they were being discontinued.
drawing
As promised a drawing of dispersion cone. The advantage of this design that it reflects sound good. The cone on the Mirage omni speakers reflect too much back to the dome, because its too flat. This gives interference errors.
The cone works as a phase plug too. Another fact: when i first placed the tweeter vertical on box, it was very obvious to hear a sort of "doppler effect" when i moved speaker from front to back. With the tweeter mounted horizontal with dispersion dome, i could not hear allmost any difference in sound with moving! So i placed tweeter in the best position it would be when it is mounted vertical: baseplate 1 cm from edge box.
Its advisable to search a tweeter which has about 3dB more efficiency then woofer, because its radiating around and fills allmost whole room with high tones. But tweeters have usual a lot more efficiency then woofers.
The radius in the concave is about 33mm. For a bigger tweeter(this cone is for a tweeter of 20mm diameter) it can be enlarged. Mounted it just above dome, 1 mm away from it. The tip has a small convex curve of about 0.6 mm radius.
As promised a drawing of dispersion cone. The advantage of this design that it reflects sound good. The cone on the Mirage omni speakers reflect too much back to the dome, because its too flat. This gives interference errors.
The cone works as a phase plug too. Another fact: when i first placed the tweeter vertical on box, it was very obvious to hear a sort of "doppler effect" when i moved speaker from front to back. With the tweeter mounted horizontal with dispersion dome, i could not hear allmost any difference in sound with moving! So i placed tweeter in the best position it would be when it is mounted vertical: baseplate 1 cm from edge box.
Its advisable to search a tweeter which has about 3dB more efficiency then woofer, because its radiating around and fills allmost whole room with high tones. But tweeters have usual a lot more efficiency then woofers.
The radius in the concave is about 33mm. For a bigger tweeter(this cone is for a tweeter of 20mm diameter) it can be enlarged. Mounted it just above dome, 1 mm away from it. The tip has a small convex curve of about 0.6 mm radius.
Attachments
Yea, the omnis would make amazing surrounds, I'm going to put them to that use once i finish building my new speakers.
Interesting point on the mirage omni cone reflecting too much sound back into the dome. I never really thought of that, but the omniguide is designed to have a bias to radiate sound to the front. Tubee, does your design exagerrate the soundstage too much?
Interesting point on the mirage omni cone reflecting too much sound back into the dome. I never really thought of that, but the omniguide is designed to have a bias to radiate sound to the front. Tubee, does your design exagerrate the soundstage too much?
Angsuman, i listened to them in stereo, to compare sound. The soundstage is in a good proportion, even considering the cheap tweeters.
At some points they outperform my normal stereo speakers. (series filtered 2 way ML-TQWP's with 20 cm Audax bextrene woofer, and heavily modified but good-old Focal T120K tweeter.)
I have dampened the focal myself, mounted a bigger volume (had to drill pole!) + small phase plug like the titanium T120's have of Focal. But still this tweeter can sound sometimes a bit sharp, the cheap CRB40 from Monacor has a silky sound, and is not dampened on the rear of dome, it has only some ferrofluid.
At some points they outperform my normal stereo speakers. (series filtered 2 way ML-TQWP's with 20 cm Audax bextrene woofer, and heavily modified but good-old Focal T120K tweeter.)
I have dampened the focal myself, mounted a bigger volume (had to drill pole!) + small phase plug like the titanium T120's have of Focal. But still this tweeter can sound sometimes a bit sharp, the cheap CRB40 from Monacor has a silky sound, and is not dampened on the rear of dome, it has only some ferrofluid.
stands ready
Finished the stands, simple made from MDF and PVC rain drainage tube. They will be filled with dry sand. In back tube is a small pipe to put speaker wiring through.
http://img529.imageshack.us/img529/4443/surrmetstand2ux8.jpg
Finished the stands, simple made from MDF and PVC rain drainage tube. They will be filled with dry sand. In back tube is a small pipe to put speaker wiring through.
http://img529.imageshack.us/img529/4443/surrmetstand2ux8.jpg
Anyone know how well this would work with the ApexJr ribbon tweeter? If I'm not mistaken, this would lower the efficiency, but eliminate the "beaming" commonly found with ribbons. Seeing as how they're very efficient and cheap, this might work pretty well.
I'm tempted to try making some of these - I, however, would use lost-wax casting instead. Much easier to make multiples.
I'm tempted to try making some of these - I, however, would use lost-wax casting instead. Much easier to make multiples.
Nice this cheap ribbon Spasticteapot! Its a pitty i don't live in the us, otherwise would try some.
This ribbon is constructed circular, so horizontal placed and a dispersion cone above it should give same results as with a dome i assume. For the price i would simply give it a try.
For a new main speaker i am thinking of a BG Neo 3 and with a cone on the back, working as dipole. Working with 2 long cone excusion paper woofers in d'Appolito in an ML TQWT, don't know the make, but from Canada. Series filtered. As we say in Holland: All this keeps you from the street!
This ribbon is constructed circular, so horizontal placed and a dispersion cone above it should give same results as with a dome i assume. For the price i would simply give it a try.
For a new main speaker i am thinking of a BG Neo 3 and with a cone on the back, working as dipole. Working with 2 long cone excusion paper woofers in d'Appolito in an ML TQWT, don't know the make, but from Canada. Series filtered. As we say in Holland: All this keeps you from the street!
Here is the canadian speaker ment.
http://www.creativesound.ca/details.php?model=WR125S
Small, so good midrange, and special voice coil construction for larger cone excursion.
http://www.creativesound.ca/details.php?model=WR125S
Small, so good midrange, and special voice coil construction for larger cone excursion.
Hi Spasticteapot
This speaker has relative high Qts of 0.61, so a small bookshelf speaker is not very suitable to build with this unit.
A small cabinet (+/- 7 litre) is possible though with a coupling cap of specific capacity before unit
More ideal a bigger cabinet and Transmission line (lower f -3dB) I just read an article about this unit in Hobby Hifi, a german magazine.
This speaker has relative high Qts of 0.61, so a small bookshelf speaker is not very suitable to build with this unit.
A small cabinet (+/- 7 litre) is possible though with a coupling cap of specific capacity before unit
More ideal a bigger cabinet and Transmission line (lower f -3dB) I just read an article about this unit in Hobby Hifi, a german magazine.
A perfect tweeter for this task is the new Dayton ND20FA-6
http://www.partsexpress.com/pe/showdetl.cfm?Partnumber=275-030
I had to lathe the tweeter i used (Monacor car audio tweeters)
For the Dayton it is not neccesary anymore. (But Dayton's dome is slightly recessed in a small horn compared to my used tweeters)
http://www.partsexpress.com/pe/showdetl.cfm?Partnumber=275-030
I had to lathe the tweeter i used (Monacor car audio tweeters)
For the Dayton it is not neccesary anymore. (But Dayton's dome is slightly recessed in a small horn compared to my used tweeters)
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