Was looking around in the shed and found halve of a panel i made, 6 years back. in this thread http://www.diyaudio.com/forums/planars-exotics/145184-poor-mans-magneplanar-tweeters.html?highlight=wrinex+poor
well we came a long ways since then we can etch a foil now and use a cnc for the rest. thought since i kind of wanted to refine the etching of aluminium a bit more , i thought ill make one quick like the panels back then, so i can practice etching a bit more. i used the foil from bandsei. magnets used rubber magnet strip from magnepan cut in halves. only uses like 1 of the magnets of an smga in total. this one is not yet push pull, and i must get resistance a bit down its 5.6 ohm right now so losing some efficiency. want to make it 4 ohm. aah wel its just for fun and giggles. will do the backside tomorrow
Must say it does sound rather nice, and i know in push pull they sound even better. efficiency is rather low. not yet compared to another speaker yet. will do when then backside is in place.
Red curve is at 1 meter
Green curve is at 30 cm.
one thing i do notice it does not extend to 20khz. could be weight of the foil, or there is something wrong with my measurement laptop, ive seen serveral measurement now with this kind of curve. must reall really make a loop tomorrow.
i found out the positioning the foil over the spacers is hard, first time the traces where incredible off, so i had to reaplly the foil, thats the reason why it looks a bit crappy. still a wonder i could get it tensioned and reposition it again by hand with the tape still attached
The poor mans tweeter will have a comeback this is such a small panel i can imagine you could make a very nice sounding lines array with such panel. efficiency will be good to. adding the backside should give +6dB getting the resistance down to 4 ohm will increase another 2 db or so. using 2 in series will increase power handling by 2 adding another 2 in paralel wil increase spl again by 6dB. welll would cost a major 8 meter of rubber magnet.....
well we came a long ways since then we can etch a foil now and use a cnc for the rest. thought since i kind of wanted to refine the etching of aluminium a bit more , i thought ill make one quick like the panels back then, so i can practice etching a bit more. i used the foil from bandsei. magnets used rubber magnet strip from magnepan cut in halves. only uses like 1 of the magnets of an smga in total. this one is not yet push pull, and i must get resistance a bit down its 5.6 ohm right now so losing some efficiency. want to make it 4 ohm. aah wel its just for fun and giggles. will do the backside tomorrow
Must say it does sound rather nice, and i know in push pull they sound even better. efficiency is rather low. not yet compared to another speaker yet. will do when then backside is in place.
Red curve is at 1 meter
Green curve is at 30 cm.
one thing i do notice it does not extend to 20khz. could be weight of the foil, or there is something wrong with my measurement laptop, ive seen serveral measurement now with this kind of curve. must reall really make a loop tomorrow.
i found out the positioning the foil over the spacers is hard, first time the traces where incredible off, so i had to reaplly the foil, thats the reason why it looks a bit crappy. still a wonder i could get it tensioned and reposition it again by hand with the tape still attached
The poor mans tweeter will have a comeback
this is such a small panel i can imagine you could make a very nice sounding lines array with such panel. efficiency will be good to. adding the backside should give +6dB getting the resistance down to 4 ohm will increase another 2 db or so. using 2 in series will increase power handling by 2 adding another 2 in paralel wil increase spl again by 6dB. welll would cost a major 8 meter of rubber magnet.....Attachments
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yes you could, as long as you create a barrier between froint and back by the cup or foam between your head and the panel you can almost go as low as you would please.
i use an solid ink printer from xerox and coppersulfate with salt to etch
there is when you would put them against your head like a normal headphone with foam etc.
well added the backplate. biggest problem is cutting the magnets in 2, and align them well. first i made a backplate where the magnets where not aligned as well as i wanted and gained almost nothing in spl terms, only in distortion. so working accurate is a big issue. second try i gained around 5-6 db so almost perfect. still i am pretty sure if magnets where aligning beter with each other and the traces more could be gained. its playing with soem eq to counter dipole behavior from 600hz to 20khz. i like the simplicity. no transformers no expensive magnets etc
hmm reaplied the second membrane that measured 4ohm to the former backplate of speaker one. i now run them on top of each other in paralel to see hat happened. with some eq from 2500 hz to compensate low roll off a bit, it can be crossed at 450 hz. pretty nice. i think it would be usefull to make the menbrame area on the side of the traces a bit larger. just to lower resonance. since this is not an esl stability is not an issue. instead of magnets there will be felt in these regions.
of course running them parallel is not ideal since its a 2.3 ohm load now.. but it does sound nice
i am pretty stoked as you already noticed. love not having a extreme complicated system. no High voltage no shocks no expensive transformers ..... i notice i grab the panels still with allot of care and only at the spacers etc.... i think this is because of my former experiments with all the ESL's. You wil learn to be careful in time (and shocks)
of course running them parallel is not ideal since its a 2.3 ohm load now.. but it does sound nice
i am pretty stoked as you already noticed.
love not having a extreme complicated system. no High voltage no shocks no expensive transformers ..... i notice i grab the panels still with allot of care and only at the spacers etc.... i think this is because of my former experiments with all the ESL's. You wil learn to be careful in time (and shocks)
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