nzlowie Posted October 20, 2016 Posted October 20, 2016 Hi guys, Just playing around with location of my tweeters, how important is time alignment when these are used at really hi frequencies? These are crossed at 12khz so the wavelength is really short, does this make time alignment more or less critical? Thanks Sent from my Moto G (4) using Tapatalk
VanArn Posted October 20, 2016 Posted October 20, 2016 Yes,it is difficult to get this to work easily. There are other areas that need consideration ,other than physically shifting or time delaying the signal to the super tweeter. The wavelength at 12 kHz is approx. 28 mm and the proximity to the other tweeter presents an immediate problem if you are to avoid lobing and mutual interference causing dip and peak anomalies. The issue being that it is difficult to mount the H.F. drivers close enough together to obtain an integrated source in the crossover frequency range. The crossover type will also have a large influence on how the drivers will blend together. Perhaps resorting to measuring the end results with a calibrated microphone may be useful tactic.
georgehifi Posted October 20, 2016 Posted October 20, 2016 (edited) When I crossed my magnificent MP-02 Plasma tweeters at 12kHZ to my esl's and roll them off at 12khz it didn't seem to matter that much where I put them, but they are 360' radiation. Which reminds me I must put them up F/S one day as I don't use them. Edited October 20, 2016 by georgehifi
nzlowie Posted October 20, 2016 Author Posted October 20, 2016 To start with no other tweeters in the mix, mid horn rolls off at 12khz and this is where the tweeter picks up.I did have them back inline with the mid driver diaphragm.(had to be inside otherwise it would be against the wall.)Then moved them level with the face of the mid horn, think its better.I think there may have been reflection from the back of the horn which may have killed any advantage of time alignment.Sent from my Moto G (4) using Tapatalk 1
Upfront Posted October 20, 2016 Posted October 20, 2016 To start with no other tweeters in the mix, mid horn rolls off at 12khz and this is where the tweeter picks up.I did have them back inline with the mid driver diaphragm.(had to be inside otherwise it would be against the wall.)Then moved them level with the face of the mid horn, think its better.I think there may have been reflection from the back of the horn which may have killed any advantage of time alignment.Sent from my Moto G (4) using Tapatalk Ive been wanting to mount mine in the absolute centre of my 204hz horn. Might just have to give it a go you that you have me thinking.
nzlowie Posted October 20, 2016 Author Posted October 20, 2016 Also thought about in the middle of the horn..... Let me know how you get on. Sent from my Moto G (4) using Tapatalk
Upfront Posted October 20, 2016 Posted October 20, 2016 Also thought about in the middle of the horn..... Let me know how you get on. Sent from my Moto G (4) using Tapatalk Will do mate. Mounting it rigidly and transparently has been what has held me back. Its never as easy as it seams is it...
nzlowie Posted October 20, 2016 Author Posted October 20, 2016 Have a look at what the telescope guys do with the top mirror, the support legs wide but thin so invisible to light or sound in our case.Tried to attach a photo of what I'm talking about but everytime Tapatalk crashed!Check Google images.Sent from my SM-T800 using Tapatalk
Upfront Posted October 20, 2016 Posted October 20, 2016 Have a look at what the telescope guys do with the top mirror, the support legs wide but thin so invisible to light or sound in our case.Tried to attach a photo of what I'm talking about but everytime Tapatalk crashed!Check Google images.Sent from my SM-T800 using Tapatalk Ahhh! I get it. Might have to buy a sheet of 3mm ply for a mock up. Nice one mate!
jamesg11 Posted October 27, 2016 Posted October 27, 2016 On 20/10/2016 at 3:14 PM, georgehifi said: When I crossed my magnificent MP-02 Plasma tweeters at 12kHZ to my esl's and roll them off at 12khz it didn't seem to matter that much where I put them, but they are 360' radiation. Which reminds me I must put them up F/S one day as I don't use them. Hmm, wonder how these would compare to the Elac 4Pi.plus2 ...? Larger & heavier - no way they'd sit atop floorstanders.
georgehifi Posted October 27, 2016 Posted October 27, 2016 (edited) Quote 1 hour ago, jamesg11 said: Hmm, wonder how these would compare to the Elac 4Pi.plus2 ...? Larger & heavier - no way they'd sit atop floorstanders. The MP-02 Plasmas are not a super tweeter like the Elacs, even though they extend much higher, 150khz compared to the Elacs 53khz, but they also go much lower as well, the Elac I believe can only go down to 10khz, where the MP-02's go down to 4.5khz, so they are a just an exceptional tweeter. That's exactly what they were made for, to sit on top of speakers and take the place of the tweeter, and they radiate 360'. 30cmW x 26cmD x 9cmH weight approx 10kg. They ask big $$$ for them in EU http://www.ebay.com/itm/Magnat-Plasma-MP-02-ion-tweeter-massless-air-plasma-speaker-Plasmahochtoner-/281848982375?hash=item419f822b67:g:XksAAOSwuMFUk3AA And no that's not a misprint 4.5khz -150khz!!!! Cheers George Edited October 27, 2016 by georgehifi
Keith_W Posted October 27, 2016 Posted October 27, 2016 At 12kHz, it is VERY important to time align them. Your ears are very sensitive at this frequency - if not time aligned it will just sound wrong.
georgehifi Posted October 27, 2016 Posted October 27, 2016 (edited) When I used the MP-02's this was not critical, maybe because of the 360' radiation, you felt you could reach out and touch the highs in front of you, a bit like the big MBL's RadialStrahle, but they were so much more delicate on things like harpsicord, because it has no mass, the ironized air around the plasma flame is the tweeter diaphragm, no mass. This is why their frequency response goes out to 150khz!!!!!! Cheers George Edited October 27, 2016 by georgehifi 1
georgehifi Posted October 27, 2016 Posted October 27, 2016 I wouldn't used them for long periods in a small sealed up room, otherwise no problem. The current Lansche speakers are plasma, all owners are still alive and kicking. http://www.ultrahighendreview.com/lansche-speakers-have-plasma-tweeters/ We have Berilium drivers etc, hifi is far from being eco friendly. Cheers George
ENIGMA Posted October 27, 2016 Posted October 27, 2016 14 minutes ago, georgehifi said: I wouldn't used them for long periods in a small sealed up room, otherwise no problem. The current Lansche speakers are plasma, all owners are still alive and kicking. http://www.ultrahighendreview.com/lansche-speakers-have-plasma-tweeters/ We have Berilium drivers etc, hifi is far from being eco friendly. Cheers George Yes we are still alive because the Lansche has a CAT converter to treat the ozone. You can smell the ozone on start up and they are fine once running hot. It's also a good idea to have a window open or breeze in the room.
georgehifi Posted October 27, 2016 Posted October 27, 2016 (edited) Yes I noticed that you can smell it a little on start up, I think that's when the flame is orange and the Tungsten electrode rod is heating up, once it goes blue it much better. I also leave a window/door open for long periods of listening. But once heard, you realize that nothing can compete with them for sheer transparency and delicacy. Cheers George Edited October 27, 2016 by georgehifi 1
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