Hi Chalkandtalk,
The size you are thinking about 8' x 1.25' will be too unstable especially at that width, the one I am building now 6.5' x 23" required 2 angle iron bracers on the back, otherwise there is a chance the MDF could fold especially 8' long. the most stable length with that width would be about 3'. If you want to make it 8'. You will need angle iron on the back to give it stability, especially if you want to put some stands on it . Otherwise it would take about 3 persons to move it safely. At8' x 3' you would need well over 1300 magnets for each speaker. The foil doesn't come in that length, I will have to join mine even at 6.5' x 23" size. Best of luck Henry.
The size you are thinking about 8' x 1.25' will be too unstable especially at that width, the one I am building now 6.5' x 23" required 2 angle iron bracers on the back, otherwise there is a chance the MDF could fold especially 8' long. the most stable length with that width would be about 3'. If you want to make it 8'. You will need angle iron on the back to give it stability, especially if you want to put some stands on it . Otherwise it would take about 3 persons to move it safely. At8' x 3' you would need well over 1300 magnets for each speaker. The foil doesn't come in that length, I will have to join mine even at 6.5' x 23" size. Best of luck Henry.
Why aren't you guys trying to build something closer to the Raven R3.2 MMX?
I've seen that you like to build longer ones instead.
How much do you think the magnets would cost to get something close to the Raven?
(I've checked this thread a little bit fast, I admit.)
I've seen that you like to build longer ones instead.
How much do you think the magnets would cost to get something close to the Raven?
(I've checked this thread a little bit fast, I admit.)
Hi Horus,
I think you have got the wrong end of the stick! We are building full range planar speakers. The Raven R3.2 MMX is a tweeter, and you have to incorporate it with midrange and bass speakers using complicated and power wasting crossovers. Whereas I build full range planars which cover the full frequency range (10khz - 20khz.) Which don't require any crossover and difficult suspension. So I am not interested in tweeters.
Regards Anthony.🙂
I think you have got the wrong end of the stick! We are building full range planar speakers. The Raven R3.2 MMX is a tweeter, and you have to incorporate it with midrange and bass speakers using complicated and power wasting crossovers. Whereas I build full range planars which cover the full frequency range (10khz - 20khz.) Which don't require any crossover and difficult suspension. So I am not interested in tweeters.
Regards Anthony.🙂
JAMESBOS, the name of the topic is DIY Ribbon....this includes tweeters as well. I actually saw a few pics with DIY ribbon tweeters in this topic, but not as much as I hoped.
60" ribbon tend to be pretty expensive, but the sound is very pleasing. I am thinking that building a smaller ribbon and combining it with a good midwoofer, could maintain some of the advantages of ribbons but at a much lower cost.
60" ribbon tend to be pretty expensive, but the sound is very pleasing. I am thinking that building a smaller ribbon and combining it with a good midwoofer, could maintain some of the advantages of ribbons but at a much lower cost.
Sorry Horus,
Keep forgetting that the replies are not for the last link listed. The neos I use are 50 x 12.7 x 3mm, so you shouldn't need many for a tweeter the size of the Raven. I have some spair ones if you are interested!! Regards Anthony.
😱
Keep forgetting that the replies are not for the last link listed. The neos I use are 50 x 12.7 x 3mm, so you shouldn't need many for a tweeter the size of the Raven. I have some spair ones if you are interested!! Regards Anthony.
😱
JAMESBOS, thank you for your offer, but I don't think I'm the right person for testing ribbon designs, though I would be able to follow a tested design. 😎
"....powered by huge magnets that beam almost 1 Tesla of force into a 20mm wide air gap."
Some pictures with the Raven R3.2 MMX:
Some pictures with the Raven R3.2 MMX:
An externally hosted image should be here but it was not working when we last tested it.
LineSource said:
Hey 🙂
I`m building a 180cm high ribbon, 18mm wide and about .8 mY thick alu. My class D amp can handle about 1-2 ohm without any problem.
Instead of a transformer, would it be a better idea to use a resistor made by a cut of aluminium at about 1.3 ohm glued to at big piece of paper in series with the ribbon?
Yes I know I burning a lot of power off here, but what about the sound quality?
I don`t need a high sound pressure.
Jan Jensen
blaaberg said:
Hi Jan,
A non-inductive resistor will sound much better than a transformer. You can easily buy or make one. I have made non-inductive resistors by contact cementing 25 micron cooking aluminum foil to plexiglass and cutting a serpentine resistor pattern, using brass screws drilled into the plexiglas and washers for end connectors. Forces from the high AC currents in this foil will cause audio vibrations. Paper may not be the best substrate.
I have big Krell amps that are made to drive very low impedance loads, but I got the best sound when I resistor padded the load up to 1.5-2 ohms. If your amp has enough power, you might want to try 1.5-2-ohms first and reduce this if the SPL is too low.
planar loudspeaker
Hi Henry,
could you please, provide some information about the aluminium tape, like width and thickness as well as where do you buy it?
I guess very thin wire could be used as well, like the one magnepan uses? I believe I am not the only one who is interested in your latest fullrange planar loudspeaker and would be glad if you could post the details (photos, etc) in a dedicated thread. I have an old article by Ole Thofte from the Speaker Builder magazine entitled "Kitchen Bench Ribbon", which I guess is similar to the one you mentioned. Do you feel there is a more overdamped bass quality when using neo magnets as oppose to the ferrite ones?
Good luck with your latest project!
regards
fivestring
JAMESBOS said:Hi,
It is not aluminium sheet, it is aluminium tape which you place on the membrane in one continous strip between the rows of magnets . Leave sufficient tape at each end so you can trap both ends under 2 washers held with 5mm screws, one at the top + and the other screw and washer at the bottom - impedance should be about 4 ohms if you build the 4' x 2' sized wooden surround, no need to glue the magnets. They stick like glue anyway on the perforated steel sheet. I am listening to my newly built 4' x 2' x 3" full rangers burning in my new chinese EL 34 B P/P Amp, just arrived today. Plenty of volume at the 4 ohms or 8 ohms setting. Also burning in the speakers as well. Well worth the trapped fingers and backache, the sound is so open and the bass is really tight. They are also very revealing so you need a good source and amp to drive them. Crap in and you certainly get crap out. Be very careful with the magnets they jump quite well and can trap the fingers. All the best Henry.
Hi Henry,
could you please, provide some information about the aluminium tape, like width and thickness as well as where do you buy it?
I guess very thin wire could be used as well, like the one magnepan uses? I believe I am not the only one who is interested in your latest fullrange planar loudspeaker and would be glad if you could post the details (photos, etc) in a dedicated thread. I have an old article by Ole Thofte from the Speaker Builder magazine entitled "Kitchen Bench Ribbon", which I guess is similar to the one you mentioned. Do you feel there is a more overdamped bass quality when using neo magnets as oppose to the ferrite ones?
Good luck with your latest project!
regards
fivestring
Hi Fivestring,
I get my alu tape from CPC it is for security on windows, it comes in rolls 45 mtrs x 9mm and is 5 hundreths of a mm thick it already comes glued so is easily stuck on the membrane it costs about£2.00 so is very cheap. I used to use thick black bin liners for the diaphragm membrane but I use transparent plastic on a roll. It is easier to use as you can see the position of the magnets underneath, which makes it easier to mark out the position of the tape on the membrane. This platic roll is 10 hundreths of a mm thick.
The Ole Thoft article which appeared in the HI-FI NEWS started me off,and I have been building full range planars ever since. To see some photos go to post 445, Michael saw them with these directions.
Using Neo magnets increases the sensitivity and also opens out the upper frquencies. The ferrite planars are more mid rangey and mellow and are not as sensitive. These would work better with transistor amps, especially if the are hard sounding.
The taughtness of the membrane is very important especially if you use Neos. The membrane must be fairly taught or you will get funny noises if the bass is quite strong on the music, but will be very clean with no boom whatsoever!!
When the speaker has been running for quite awhile you must check the taugtness of the membrane, and tighten it up as necessary. If you trap the membrane either side between 2 pieces of wood, this wood can be repositioned and tightened by using elongated holes in the wood surround. Keeping the membrane taught at all times as the membrane stretches with hard use.
The smaller 21" x 24" x 2 1/2" planar using neos is more sensitive than a larger 78" x 24" 2 12" planar using ferrite magnets!!!
My smaller planars are in the sunroom suspended from 2 net curtain wires aqs they only wegh about 5 KG each. I also have 3 more of a smaller size for the centre and surround speakers running off a 5.1 Amp.
I hope this is of some use regards Anthony.
I still have the original ferrite planar I built over 20yrs ago and its still going strong.
I forgot to mention that these full range planars don't use crossovers or transformers, which makes them easy to build.
I get my alu tape from CPC it is for security on windows, it comes in rolls 45 mtrs x 9mm and is 5 hundreths of a mm thick it already comes glued so is easily stuck on the membrane it costs about£2.00 so is very cheap. I used to use thick black bin liners for the diaphragm membrane but I use transparent plastic on a roll. It is easier to use as you can see the position of the magnets underneath, which makes it easier to mark out the position of the tape on the membrane. This platic roll is 10 hundreths of a mm thick.
The Ole Thoft article which appeared in the HI-FI NEWS started me off,and I have been building full range planars ever since. To see some photos go to post 445, Michael saw them with these directions.
Using Neo magnets increases the sensitivity and also opens out the upper frquencies. The ferrite planars are more mid rangey and mellow and are not as sensitive. These would work better with transistor amps, especially if the are hard sounding.
The taughtness of the membrane is very important especially if you use Neos. The membrane must be fairly taught or you will get funny noises if the bass is quite strong on the music, but will be very clean with no boom whatsoever!!
When the speaker has been running for quite awhile you must check the taugtness of the membrane, and tighten it up as necessary. If you trap the membrane either side between 2 pieces of wood, this wood can be repositioned and tightened by using elongated holes in the wood surround. Keeping the membrane taught at all times as the membrane stretches with hard use.
The smaller 21" x 24" x 2 1/2" planar using neos is more sensitive than a larger 78" x 24" 2 12" planar using ferrite magnets!!!
My smaller planars are in the sunroom suspended from 2 net curtain wires aqs they only wegh about 5 KG each. I also have 3 more of a smaller size for the centre and surround speakers running off a 5.1 Amp.
I hope this is of some use regards Anthony.
I still have the original ferrite planar I built over 20yrs ago and its still going strong.
I forgot to mention that these full range planars don't use crossovers or transformers, which makes them easy to build.
Thanks very much Henry, now I have all the necessary informations,
I believe. Good luck with your future projects.
Best regards
fivestring
I believe. Good luck with your future projects.
Best regards
fivestring
JAMESBOS said:
JamesBos,
I tracked down the photos on your project and found the pics a bit lacking. Could you possibly post more detailed pics .
Regards,
A.Wayne
Or could be like this, to save on magnets and size...less work
Being smaller(narrow) it could be crossed higher
magnet "poleplates" would be made from maybe 5mm steel plate
Either a mate could have them lazer cut...or I would do it myself with drill and jigsaw, but a lot of work
Being smaller(narrow) it could be crossed higher
magnet "poleplates" would be made from maybe 5mm steel plate
Either a mate could have them lazer cut...or I would do it myself with drill and jigsaw, but a lot of work
