I am wondering whether there are any major improvemnets in ths sound quality by adding a tweeter to a full range driver.
An example would be Fostex FE167E, Fostex suggests in their phamplet of adding their own Fostex tweeter. Does this prove benefitial?
I am sure some of you out there have tried this combination. If you have found it to improve the sound quality then let us know what type of tweeter you picked and why.
thanks.
An example would be Fostex FE167E, Fostex suggests in their phamplet of adding their own Fostex tweeter. Does this prove benefitial?
I am sure some of you out there have tried this combination. If you have found it to improve the sound quality then let us know what type of tweeter you picked and why.
thanks.
Adding a tweeter can help to bring some more air and detail to the sound. It's not as easy as it might seem though. While you whil certainly get more detail there's also the chnge that the coherence in the sound get's lost a bit. The whole sound spectrum can shift upwards, wich means that you will probably start noticing that your full-range driver has limited bass output as well.
I have had pretty good resulst with tweeters like the Beyma CP21, the Fostex FT66A. Don not get tempted to try a dome tweeter, most won't integrate wich fullrange drivers, totally different dynamic character.
I have had pretty good resulst with tweeters like the Beyma CP21, the Fostex FT66A. Don not get tempted to try a dome tweeter, most won't integrate wich fullrange drivers, totally different dynamic character.
Yup, time coherence is the problem here. By adding a tweeter you have the same problems you have with any other multipath - horror to fullrange fans.
Not digging deep into that problem here, there are threads galore dealing with this - it's the "first wave front" problem. Your brain uses transients to determine location of the sound source, thus getting able to reassemble the signal. If your FR and tweet are not time coherent that means your grey matter has a hard job - two disagreeing infos competing.
The trick with adding a tweeter to a fullrange is pushing it out of the detection time window, which is only ~20 milliseconds wide. Have the screecher beam upwards and/or backwards. Sounds crude, but works fine. The additional "airiness, detailing" or whatever you want to call it is there, but it doesn't spoil your FR's performance.
Cheers,
Pit
Not digging deep into that problem here, there are threads galore dealing with this - it's the "first wave front" problem. Your brain uses transients to determine location of the sound source, thus getting able to reassemble the signal. If your FR and tweet are not time coherent that means your grey matter has a hard job - two disagreeing infos competing.
The trick with adding a tweeter to a fullrange is pushing it out of the detection time window, which is only ~20 milliseconds wide. Have the screecher beam upwards and/or backwards. Sounds crude, but works fine. The additional "airiness, detailing" or whatever you want to call it is there, but it doesn't spoil your FR's performance.
Cheers,
Pit
Pit Hinder said:
I don't disagree that a rearwards fireing tweeter sounds as you describe. But I don't understand how your figures adds up. If the detecion window is 20ms and the speed of sound is 330m/s, then the tweeter would have to be 6.6 meters away to be outside the dection window.
Best regards
Peter
Peter,
you got me there - trying a quick-and-dirty explanation always means you expect people are as lazy as you and accept without thinking.
Let me try it this way: the detour via rear wall - ceiling - side walls arrives plenty late within the "time window", and it arrives several times, so it is smeared, no longer a sharply defined transient. Do you have measuring equipment? (ARTA is free, and quite good) Try measuring step response with too wide a time window, allowing wall-bounced sound in. Add a pair of piezo tweeters aimed backwards/upwards and try to tell their influence from general room influence. No good explanation, I know...do you by now know why I never tried to become a teacher?
Pit
you got me there - trying a quick-and-dirty explanation always means you expect people are as lazy as you and accept without thinking.
Let me try it this way: the detour via rear wall - ceiling - side walls arrives plenty late within the "time window", and it arrives several times, so it is smeared, no longer a sharply defined transient. Do you have measuring equipment? (ARTA is free, and quite good) Try measuring step response with too wide a time window, allowing wall-bounced sound in. Add a pair of piezo tweeters aimed backwards/upwards and try to tell their influence from general room influence. No good explanation, I know...do you by now know why I never tried to become a teacher?
Pit
Looking beyond the technical side, the easy way is to get a cheap tweeter like a piezo and try it forward, backward and to the side. See what you like, the option is yours regardless of what a machine tells you is good or bad. The ears are the only instrument that really matters in the long run. If you like the effect, consider getting a better tweeter. Room placement is a huge factor. In some cases you won't like it and in others you'll wonder why everyone doesn't do it.
ttan98 said:
I tried a piezo ($1.50 /each at PE) on the new metronome with L-pad and put it in the rear of the cabinet see it here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=97048
It is worthwhile since I do notice airy sparkle that can be adjusted. I recommend it (one can always turn it off)
gychang
Hi all,
generally if you "help" your wideranger at the top you will most likely need to "help" it as well at the bottom or your basically just cranking the treble knob like in the 70's when we had treble knobs....my opinion anyway.
Pointing the tweeter to the back is worth trying it gives interesting results in some cases.
Putting a tweeter on top of the box is a challenge to time align and also to match the output volumes of the 2 drivers.
cheers
paba
generally if you "help" your wideranger at the top you will most likely need to "help" it as well at the bottom or your basically just cranking the treble knob like in the 70's when we had treble knobs....my opinion anyway.
Pointing the tweeter to the back is worth trying it gives interesting results in some cases.
Putting a tweeter on top of the box is a challenge to time align and also to match the output volumes of the 2 drivers.
cheers
paba
Cal, gychang (strictly in alphabetical order, to those who can read and are PC minded, ie stupid)...I wonder why people in a DIY forum shy away from things like piezo tweeters - they are affordable, so they must be bad? Fuggit, they are the easiest screechers to build a Xover for, and they cost next to nothing - try if your ideas work, costs you two bucks!
Pit
Pit
Here should be something about piezos, havent read it myself and personally I would use a ribbon
http://www.planet10-hifi.com/piezo-XO.html
http://www.planet10-hifi.com/piezo-XO.html
The www.zillaspeak.com page has info on piezos too... but i'm not sure it's up and working at this time. Internally, i cannnot access it.... try it and see. Click Speakers and scroll down for the article on piezos. There are freq charts too.
I am a BIG fan of piezos! Facing them backwards always sounds best to me. Use with resistor, cap and Lpad for excellent results.
I am a BIG fan of piezos! Facing them backwards always sounds best to me. Use with resistor, cap and Lpad for excellent results.
Yep....AC G2
Ran with a single 2uf cap & no padding, B200 is rolled @ 4250 with a single .22mH foil jobby....also 1st order high pass of 150hz on B200 & ribbon's tube amp. a single cap does that work..I really like the G2 with FR's..some times I tri-amp it, but really no need, I have a match & no resistors for padding needed..I am seriously addicted to ribbons &
FR's now.
Ran with a single 2uf cap & no padding, B200 is rolled @ 4250 with a single .22mH foil jobby....also 1st order high pass of 150hz on B200 & ribbon's tube amp. a single cap does that work..I really like the G2 with FR's..some times I tri-amp it, but really no need, I have a match & no resistors for padding needed..I am seriously addicted to ribbons &
FR's now.
Aurum Cantus G2, the rear pic doesn't show the ribbon connected. I just finished the driver install when pic's were tooken. I do have & tried Fountek Neocd3 & it is not as good as the AC G2 as I hear it. The bass drivers are Vifa m26wr-09-08's driven w/ BASH plates @ 150hz. I can also get very high spl's w/ this ribbon & I do not hear any distortion artifacts as in fatigue or anything remotelly nasty.I still retain the most of the FR magic with a much better top end. The G2 does not give itself away with previously stated above configuration.
Hi!
Just a question of the doomed dome.
How on earth, could a back firing dome, ruin the sound when transients are totally smeared via walls by this position?
I actually prefer to use tone controls nowadays
Blasfemi in audio, but early NAD tone controls were only working around 50hz
and over 10 Khz. Today models I have not a clue where the center freq. are.
Just my 2 cent
Cheers
Peter
Just a question of the doomed dome.
How on earth, could a back firing dome, ruin the sound when transients are totally smeared via walls by this position?
I actually prefer to use tone controls nowadays
Blasfemi in audio, but early NAD tone controls were only working around 50hzand over 10 Khz. Today models I have not a clue where the center freq. are.
Just my 2 cent
Cheers
Peter
sometime this year I will get another pair of G2's & try adding a rear fire ribbon to the mix, I gotta figure out how to wire it up though, parrallell doesn't seam cool, so I got to figure how to do it in series & still retain a 2uf cap for each ribbon. or use a tweeter amp which I have but, rather just slip it in passive..w/ no resistors after the amp at all.. gotta think this one out first..I am a newbie compared to most of you.
Don't overlook the good old cone tweeters. Some can give a good account of themselves.
I believe the trick with piezo horns is to use a crossover well above the resonance and use a parallel resistor across the driver. Also, I have noticed on a pair of Motorolas here, a moulding ridge on the mouth. If I ever hook these up, I'll radius the flair to the mounting plate.
Peter, to me, most domes spit at you. Softdomes from Peerless and Philips being some exceptions. So it doesn't matter which way they point.
I believe the trick with piezo horns is to use a crossover well above the resonance and use a parallel resistor across the driver. Also, I have noticed on a pair of Motorolas here, a moulding ridge on the mouth. If I ever hook these up, I'll radius the flair to the mounting plate.
Peter, to me, most domes spit at you. Softdomes from Peerless and Philips being some exceptions. So it doesn't matter which way they point.
Hi Geoff!
Well I'm not religious about domes. It doesn't matter if speakers are made of this and that as long they sound good.
Often people generalize saying this sound bad, this sound good.
A well constructed speaker sounds good with all the limitations one has to live with.
Take polypropylene cones as an example. Manufacturers claimed it was a step forward compared to paper cones. Truth was most probably, it was cheaper and more a rational way of production.
Still, poly cones can be good if blended with other materials.
OT maybe but...
Cheers
Peter
Well I'm not religious about domes. It doesn't matter if speakers are made of this and that as long they sound good.
Often people generalize saying this sound bad, this sound good.
A well constructed speaker sounds good with all the limitations one has to live with.
Take polypropylene cones as an example. Manufacturers claimed it was a step forward compared to paper cones. Truth was most probably, it was cheaper and more a rational way of production.
Still, poly cones can be good if blended with other materials.
OT maybe but...
Cheers
Peter
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