serenechaos said:
Buried in here
http://www.diyaudio.com/forums/showthread.php?s=&threadid=98834
dave
As stated in an earlier post I am a firm convert to open baffles with speakers mounted on isolated frames but I have played a lot with regular boxes and made some pretty serious attempts to kill cabinet resonances.
My reasoning is that a lot of what most listeners hear in a speaker is actually colouration from the box not the music from the drivers, anyhow.......
A few things I discovered might help.
1) The best resonance free results I obtained were from cabinets with sandwiched construction, in other words the walls were made of different layers of different, (3 different materials on the best ones I built) materials.
2) Weight/mass and lots of it helps, the best sounding set had heavy concrete paving blocks glued top and bottom, I know it sounds like it would look rough but actually it looks good in a sandstone finish
3) Lots of internal bracing helps a heap, even if the bracing materials are fairly thin.
4) Really thick/stiff baffles are much better even with smallish drivers
5) Extra mounting screws/bolts on the drivers helps, I had some 6.5 inch drivers with four screws, drilling an extra 8 holes and torque/mounting them evenly all round with a nice gasket made for a much tighter sound. This one really surprised me.
6) Covering the front baffle with a neoprene mesh materials made for cleaner more focused sound.
Well there you go, I'm not totally anti box, I just choose the alternative.
None of the above though will deal with the problem of sound coming back through the thin membrane of the single drivers cone, which also adds a fair bit of colouration in my mind.
Cheers
Zero One.
My reasoning is that a lot of what most listeners hear in a speaker is actually colouration from the box not the music from the drivers, anyhow.......
A few things I discovered might help.
1) The best resonance free results I obtained were from cabinets with sandwiched construction, in other words the walls were made of different layers of different, (3 different materials on the best ones I built) materials.
2) Weight/mass and lots of it helps, the best sounding set had heavy concrete paving blocks glued top and bottom, I know it sounds like it would look rough but actually it looks good in a sandstone finish
3) Lots of internal bracing helps a heap, even if the bracing materials are fairly thin.
4) Really thick/stiff baffles are much better even with smallish drivers
5) Extra mounting screws/bolts on the drivers helps, I had some 6.5 inch drivers with four screws, drilling an extra 8 holes and torque/mounting them evenly all round with a nice gasket made for a much tighter sound. This one really surprised me.
6) Covering the front baffle with a neoprene mesh materials made for cleaner more focused sound.
Well there you go, I'm not totally anti box, I just choose the alternative.
None of the above though will deal with the problem of sound coming back through the thin membrane of the single drivers cone, which also adds a fair bit of colouration in my mind.
Cheers
Zero One.
yes indeed!
these are some great suggestions. as I mentioned, i use linseed oil. which has seemed to do the trick. I have ABed wax, laquer, tung oil, poly, and linseed oil.
the linseed wins out. I will certainly try the inside of the swan thingey. hell, the inside of everything thingey.
thanks again for all the suggestions.
I did hear the micropure speakers. they were stunning. a benchmark for single driver performance.
sukuji and I hung out a bunch at RMAF. I was there representing cain and cain, and tri amps (the same ones for micropure) lent us our amps. so we all had dinner several times, etc.
the best was sukuji waking Jason flannary (cain and cain owner) and I up at like 6 AM and teaching us all about driver mounting screw torque. my own stuff since (after incorporating his techniques) has not sounded the same...to say the least...
If I did not know how to build my own speakers, and I wanted small ones, his would be the TOP of the list.
I think that between the swan and his speakers, it is a tossup. but the cabinet size difference is certainly there. though the swans tend to go a little lower. a little...
there is alot to learn from people like sukuji.
he IS building a musical instrument. the freaking things weighed like 7 ppounds! WTF!!!! I wanna hear his big stuff.
I guess I consider for instance the whole debate over hifi definitions ot be simply bunk. the term becomes meaningless if we extend the definition of it enough, so why not let it become meaningless. yes, none of us are in fact building pianos. but if you consider electronic music, for instance, then all the sudden we have a problem. the speaker IS in the chain of the musical instruments. It turns a virtual event into an actual one. same way a pianist given instructions (sheet music) will put their pwn interpretation on the piece when played. same as the stereo playing electronic music is putting its own interpretation on the saw tooth waves.
so our lovely distinctions break down. also, if you look at the way stereos are used nowadays, it is not unlike the pianos and pianists playing parlor music. the only missing link is the person actually playing the music being gone. not the musical instrument itself...
so I think that a stereo is a musical instrument. like it or not.
but we are splitting hairs afterall, and I just promised not to do that.
Clark
these are some great suggestions. as I mentioned, i use linseed oil. which has seemed to do the trick. I have ABed wax, laquer, tung oil, poly, and linseed oil.
the linseed wins out. I will certainly try the inside of the swan thingey. hell, the inside of everything thingey.
thanks again for all the suggestions.
I did hear the micropure speakers. they were stunning. a benchmark for single driver performance.
sukuji and I hung out a bunch at RMAF. I was there representing cain and cain, and tri amps (the same ones for micropure) lent us our amps. so we all had dinner several times, etc.
the best was sukuji waking Jason flannary (cain and cain owner) and I up at like 6 AM and teaching us all about driver mounting screw torque. my own stuff since (after incorporating his techniques) has not sounded the same...to say the least...
If I did not know how to build my own speakers, and I wanted small ones, his would be the TOP of the list.
I think that between the swan and his speakers, it is a tossup. but the cabinet size difference is certainly there. though the swans tend to go a little lower. a little...
there is alot to learn from people like sukuji.
he IS building a musical instrument. the freaking things weighed like 7 ppounds! WTF!!!! I wanna hear his big stuff.
I guess I consider for instance the whole debate over hifi definitions ot be simply bunk. the term becomes meaningless if we extend the definition of it enough, so why not let it become meaningless. yes, none of us are in fact building pianos. but if you consider electronic music, for instance, then all the sudden we have a problem. the speaker IS in the chain of the musical instruments. It turns a virtual event into an actual one. same way a pianist given instructions (sheet music) will put their pwn interpretation on the piece when played. same as the stereo playing electronic music is putting its own interpretation on the saw tooth waves.
so our lovely distinctions break down. also, if you look at the way stereos are used nowadays, it is not unlike the pianos and pianists playing parlor music. the only missing link is the person actually playing the music being gone. not the musical instrument itself...
so I think that a stereo is a musical instrument. like it or not.
but we are splitting hairs afterall, and I just promised not to do that.
Clark
I like linseed for the outside, or a first coat under shellac.
Have you tried shellac? French polish technique like on a good guitar?
So what did sukuji have to say about driver mounting, and torquing? I didn't really get the details from him. Just that it was more like the bridge on a violin than trying to damp the driver.
Listening to Swans as i write this, and yes, they go lower, but he easily had the best little speakers I've ever heard.
Unreal for their size.
Back on sukuji's "magic";
why do we think using the sound produced by
tuned cabinet volumes, TL lengths, front & back horns, ports, etc
is "good", scientific, the "right thing to do",
but,
when someone figures out how to tune cabinet resonances,
that's "colouration from the box", "distortion", etc.
It sure sounded right, a lot" more right" than most anything I heard that weekend.
Robert
Have you tried shellac? French polish technique like on a good guitar?
So what did sukuji have to say about driver mounting, and torquing? I didn't really get the details from him. Just that it was more like the bridge on a violin than trying to damp the driver.
Listening to Swans as i write this, and yes, they go lower, but he easily had the best little speakers I've ever heard.
Unreal for their size.
Back on sukuji's "magic";
why do we think using the sound produced by
tuned cabinet volumes, TL lengths, front & back horns, ports, etc
is "good", scientific, the "right thing to do",
but,
when someone figures out how to tune cabinet resonances,
that's "colouration from the box", "distortion", etc.
It sure sounded right, a lot" more right" than most anything I heard that weekend.
Robert
serenechaos said:It sure sounded right, a lot" more right" than most anything I heard that weekend.
Robert
darn tootin. the rooms I spent time in? the serious stereo room, where I was brought to tears listening to everything but the girl,
cogent room, despite its problems.
the cain and cain room (obviously), but in the end, despite of my alliances, I felt that it represented a good middle ground. the fostex full rangers in general, for that matter.
and of course, the micropure room.
for my friend who came to visit. knew not a ton about audio, I brought him to these four rooms. he was stunned in each. was also nearly brought to tears by the serious stereo room as well, but his standout was definitely the micropure room.
you know, those boxes REALLY are something. I am not sure how much sukuji would want me to repeat about the specifics, but I can assure you, that you are on the right thought train there.
he tunes every part of the box to be desirably active. it IS a musical instrument speaker if I ever saw one.
the thing is, he thinks just as literally about distortion as we all do. that it is harmful, etc. like me, and like alot of my philisophically closer colleagues, he also thinks alot about dynamic compression, and the root causes of it.
the only way to get zero compression is to not damp whatsoever. or to use enough power which is equally unlikely to have happen perfectly.
he thinks like an engineer, about the internal stress that overtightened screws cause. he also dempnstrated to me the VERY audible sonic differences between screws too tight, loose, and just right. I can now do this by ear as well (though not as quickly as him to be sure).
basically, you want to drill the right size hole for the shaft of the screw to clear and the threads to cut. thread lock can be important. screw tension should be enough to hold the washer in place against a fingernail pushing it around. that is prettymuch it. you want to watch the driver frame being pulled air tight against the wood to a degree. nothing in excess, simply.
there is simply so much to it all. when you operate in a musical and intellectual vacuum that is high end audio too much, you get rather depressed. meeting him, learning about the MYRIAD of considerations we must make in building a great speaker, I am only recharged on my own never ending personal pursuit of refinement.
while he is in japan and I am in the US, and his english is not awesome, nor is my google japanese translator (or my human one) very reliable, I look forward to working with him in the future, no doubt.
Clark
I approached this screw torque idea with a bit of skepticism. I figured that it would make good sense to as closely couple the driver basket (something you don't want to move an resonate, etc) to the baffle (big heavy object) as tightly as possible. When I examined my own screw torque (big ol' Hemp BIB's, screws are cap head sockets in T-nuts, not wood screws in the baffle), I found that they weren't all that tight. I loosened 'em just a bit and listened. I cranked 'em down hard and listened. I carefully torqued to what I deemed the minimum necessary amount (and listened). Between my original torque and the slightly lighter torque, I can't a hear a huge difference. It is better. However, cranking them down really tight sounded awful. The midrange sounded tight and small. Voices and instruments lost their resonance. As you mentioned earlier Clark, it sounded kind of like the drivers were fresh out of the box again (but with a smoother high treble.)
It is frustrating to realize that such little things make a big difference. How many folks try fullrangers in general, or a particular driver, or a particular enclosure design and write off the entire idea, all because they had something as minor as the screw torque wrong? On the other hand, it is always fun to find great musical improvements without laying out any cash or effort.
My BIB's are still unfinished. I need to get that Tung oil on ASAP.
pj
It is frustrating to realize that such little things make a big difference. How many folks try fullrangers in general, or a particular driver, or a particular enclosure design and write off the entire idea, all because they had something as minor as the screw torque wrong? On the other hand, it is always fun to find great musical improvements without laying out any cash or effort.
My BIB's are still unfinished. I need to get that Tung oil on ASAP.
pj
Junichi roughly said it was like "string on bridge of violin."
I gave him that puzzled look, thinking this can't be right, and he gave me that japanese smile/nod/bow/smile and said yes.
it puzzled me all weekend, 'cuz I know drivers have to be tight, w/ damping between them & the front baffle!
--wasn't the first time I've been wrong about something I knew either!
Robert
I gave him that puzzled look, thinking this can't be right, and he gave me that japanese smile/nod/bow/smile and said yes.
it puzzled me all weekend, 'cuz I know drivers have to be tight, w/ damping between them & the front baffle!
--wasn't the first time I've been wrong about something I knew either!
Robert
The Spawn series designs recommend a rear brace against the magnet to couple the driver to front and rear baffles.....if I understand its function correctly. How should the brace design be coordinated with the recommendation to torque the driver only to that necessary to form an air tight seal?
Badwater said:
I'll be interested to see how this plays out. Conventional wisdom is that the cone should move but the frame should not. I personally follow this logic. I use multiple thicknesses for the baffle, mass load the cabinet and brace the whole thing together into as solid and heavy a mass as I can. The driver is bolted down to this mass.
Now, I realize the if it is intuitive, it is probably wrong, but I would like to understand why I should let the driver frame flop around, even it is isolated from the cabinet.
Should be a good discussion.
Bob
I personally feel that a brace against the back of the driver's magnet is a bad idea. The problem is that the two pieces are so hard it is difficult to build in any preload deflection. It only takes a microscopic motion to unload this joint. I measured a pair of cabinets a few years ago that a chatter could be seen in the impedance plot when a solid contact between the magnet and the support was not maintained at moderate volume levels. In my opinion the best place to support a driver is the outer edge of the frame, it is the stiffest part of the driver and has the greatest wheel base for clamping the driver to the front baffle. However, you do not want to twist the driver's frame so a sequence of tightening should be followed just like for an engine's head. I agree with Bob that a solid uniform tight connection of the driver to the baffle is the best approach.
MJK said:
That could well be, but if executed well, the increase in downward dynamic range is definitly noticable. I won't build a box that doesn't have a driver brace now. If you are worried about chatter, leave enuff space for a very thin neoprene "gasket"
If you have a front baffle/box that is not stiff enuff to keep a driver pressed against a holey brace then you have lots of other problems anyway.
dave
MJK said:
Couldn't agree more. We've actually had PA subs back for reconing where the only problem was uneven clamping causing the driver's VC to rub. I've only seen it this bad with 21" and larger drivers, but a lesser amount of distortion with smaller drivers unevenly tightened seems likely.
I have always felt that the driver should be very solidly mounted, but this whole idea intrigued me so I have done a bit of thinking (probably wrong) and some checking.
It seems to me it might just be possible that a less than tight fit might help if it prevents the input of HF movement into the box but allows some low input into the box which could then be reinforced by the resonances of the box. This I imagine could only work if the box were designed to be sympathetic to such an arrangement, a box made of lighter materials without flat surfaces may just qualify. I guess it would act as a sort of pass filter.
The idea that the cabinet should dissipate the vibrations as quick as possible seems good, but I feel that this would be very material dependent, going light would not be the answer in itself, it I think would need to be a fairly inert material, perhaps for example carbon fibre over foam with lots of bracing may just do the trick. Even then I think the type of weave and resin might have considerable impact. This interests me as I am building a monocoque tone arm in conjunction with my brother along these lines.
Now a little checking on the micropure seems to indicate the drivers are not "just loose" mounted but rather mounted on spikes of some sort with a very small air gap between the driver and case. In other words a bit like speaker box spikes, this probably would act like a pass filter of sorts without causing vibrational issues. The only problem might be air leakage but that could be dependent on the design and how big that gap is and I guess it is very small.
If the spikes are in fact used then the tension would need to be less as otherwise it would bed into the casework and work loose, so the right tension would be critical.
Certainly in the case of most light speakers the driver seems to put way too much energy into the box, which then is happy to resonate its flappy panels all to readily, but I am well aware that strength, stiffness and lightness are not actually mutually exclusive, otherwise most planes would just fall from the sky and more folk would die in bad car accidents.
In the end my feeling is still that there are many ways to musical nirvana, open baffle, horns, heavy boxes light boxes etc can all work very well indeed if the design is approached as a whole and all things work in sympathy (actually I think that applies to the whole system).
My experience is you can take some pretty basic drivers and create some nice magic and likewise you can take some great drivers and create rubbish, I guess that is what I really respect about Planet10s approach, he explores the boundaries rather than assuming that greatness is achieved by throwing money at a problem.
Another thing I have strong feelings about (alluded to by other in this thread) is that the devil is in the details, lots of little tiny changes add up to one massive difference, once again Dave seems to be the man that really explores those little things.
Anyhow if this mounting idea has value it could well be another great tool for our DIY audio arsenal, it is certainly worth some investigating. perhaps a place to start is by gluing a ring of 8 or so very small ball bearing to the back mounting face of the drivers then screwing them in a little lighter than with a very thin casket or none at all. It would probably be a good idea to use dome threadlock or PVA glue in the holes.
It seems to me it might just be possible that a less than tight fit might help if it prevents the input of HF movement into the box but allows some low input into the box which could then be reinforced by the resonances of the box. This I imagine could only work if the box were designed to be sympathetic to such an arrangement, a box made of lighter materials without flat surfaces may just qualify. I guess it would act as a sort of pass filter.
The idea that the cabinet should dissipate the vibrations as quick as possible seems good, but I feel that this would be very material dependent, going light would not be the answer in itself, it I think would need to be a fairly inert material, perhaps for example carbon fibre over foam with lots of bracing may just do the trick. Even then I think the type of weave and resin might have considerable impact. This interests me as I am building a monocoque tone arm in conjunction with my brother along these lines.
Now a little checking on the micropure seems to indicate the drivers are not "just loose" mounted but rather mounted on spikes of some sort with a very small air gap between the driver and case. In other words a bit like speaker box spikes, this probably would act like a pass filter of sorts without causing vibrational issues. The only problem might be air leakage but that could be dependent on the design and how big that gap is and I guess it is very small.
If the spikes are in fact used then the tension would need to be less as otherwise it would bed into the casework and work loose, so the right tension would be critical.
Certainly in the case of most light speakers the driver seems to put way too much energy into the box, which then is happy to resonate its flappy panels all to readily, but I am well aware that strength, stiffness and lightness are not actually mutually exclusive, otherwise most planes would just fall from the sky and more folk would die in bad car accidents.
In the end my feeling is still that there are many ways to musical nirvana, open baffle, horns, heavy boxes light boxes etc can all work very well indeed if the design is approached as a whole and all things work in sympathy (actually I think that applies to the whole system).
My experience is you can take some pretty basic drivers and create some nice magic and likewise you can take some great drivers and create rubbish, I guess that is what I really respect about Planet10s approach, he explores the boundaries rather than assuming that greatness is achieved by throwing money at a problem.
Another thing I have strong feelings about (alluded to by other in this thread) is that the devil is in the details, lots of little tiny changes add up to one massive difference, once again Dave seems to be the man that really explores those little things.
Anyhow if this mounting idea has value it could well be another great tool for our DIY audio arsenal, it is certainly worth some investigating. perhaps a place to start is by gluing a ring of 8 or so very small ball bearing to the back mounting face of the drivers then screwing them in a little lighter than with a very thin casket or none at all. It would probably be a good idea to use dome threadlock or PVA glue in the holes.
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