Hello, I am also of the opinion that driver material is not nearly as important as the over all finished product.
For instance, aluminum might be fine if the speaker is of an electrostatic design. Or even some other exotic design.
When I evaluate the finished product, measurements don't matter. It is only the end product that matters.
Of course in the design phase I may make different choices.
For instance, aluminum might be fine if the speaker is of an electrostatic design. Or even some other exotic design.
When I evaluate the finished product, measurements don't matter. It is only the end product that matters.
Of course in the design phase I may make different choices.
myhrrhleine, if you only measure a response curve, high "Q" resonances in the cabinet may be missed, yet add a lot of coloration to the sound.
Yes, the overall finished product is what's important, but measurements do help determine what the overall product is, and cabinet resonances is part of that, as are driver resonances.
Yes, the overall finished product is what's important, but measurements do help determine what the overall product is, and cabinet resonances is part of that, as are driver resonances.
The Krell sub uses a somewhat small overall cabinet that pushes any panel resonance well above its useful range at low frequencys only.
Try 400hz at 120DB or 600 hz etc. and now you might excite a panel enough to hear it.
A thick aluminum enclose is not needed here and a waste of money
Regards
David
Try 400hz at 120DB or 600 hz etc. and now you might excite a panel enough to hear it.
A thick aluminum enclose is not needed here and a waste of money
Regards
David
just to recap metal will ring metal isnt damping at least most. You need to incorporate damping, stiffness, and isolation. some special materials have both stiffness and damping like Panzer which is a great unobtanium material. Damping can be applied in levels as seen in the q of thiele parameters. Isolation should carry with it damping and care in calculation needs to be applied in this. The ultimate speaker a " perfect replicator" should produce the "exact" electronic signal and not apply to it any changes. One widely argued case is radiation pattern. as I see it there are two extremes which would work theoretically about equally. That is to be unbiased operation in the room. Those two patterns are a laser beam or omni. as they are completely unbiased or dont even interact with the room. True omni speakers will produce a delay in time for reflection but this is actually not a problem. damping is not robbing energy it is merely riding the speaker of the waste think if a sealed sub vs a ported some one is "dampened" which is more accurate?
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Especially if you combine readily available ingredients. EPDM, linoleum, sand, aluminum, lead, plywood...
There's a lot out there. I bet one of the smart guys could come up with the best combination.
There's a lot out there. I bet one of the smart guys could come up with the best combination.
I don't think that I agree -- until you demonstrate that there is no perceptible effect. If you can measure a difference, there is a difference.
You can DIY laser interferometry, it's no longer rocket science -- a small mirror affixed to one of the 6 panels -- but to correlate measurements with pleasurable listening experience is a very daunting task.
Hi and thanks and of course this is a test that can be carried out not cheaply
And i have to trust some reviews that i read for instance about Krell speakers line. They look a little extreme to me and i think that maybe a right selection of different materials can achieve similar results at lower price
But my main thought was about whay makes the sound to be "boxy"
Basically i think we hear what vibrates, like a driver.
So in my mind if the box does not vibrate we should not hear it.
And moreover it is clear to me that the contribution of the front baffle must be so much more decisive of all the other panels
The right solution could be a very stiff cabinet strategically damped or a damped cabinet strategically stiffened.
I am going to try this last way putting some metal plates screwed to the inside of the front baffle and listen for any improvement.
Much safer than using lead.
I have already a speaker that could be used.
The front panel is quite thin
Thanks a lot indeed for your valuable advice but i will not touch lead again
I read that is very toxic.
Actually i am also concerned about some sort of toxic release in the room.
I will move them to the cellar i think
Anyway i have a sincere interest in this topic because the ability to reach an out of the box sound is what really intrigues me.
Sometimes when the effect is good the speakers seem even not connected to the stereo.
Thanks a lot indeed again
Kind regards, gino
Hello and i do not agree with the fact the vibration of the front panel is good
For me it is very very bad.
I think it is all about focus.
Just think to read a newspaper moving it back and forth ... you will get easily and headache because you will try to focus something that is moving
I think that the front panel must stay perfectly still, much more of all the other panels
And actually some speakers that image well have very thick and dampen front baffle.
I agree and to make things easier i would avoid dipoles and omnidirectional speakers.
About omni i had the opportunity to listen quietly to a very high level omni
The transparency was very very good. The purity of tones was spectacular.
The image was simply not esistent. I could not locate the singer at all.
The voice was coming from all around like in a cave.
I did not like at all.
I like when you get the feeling of an almost physical presence of singers and instruments in the room .. that is very wonderful experience.
Thanks and regards, gino
"But my main thought was about whay makes the sound to be "boxy"
Probably most boxes sound boxy due to not enough panel bracing and acoustic stuffing inside. You would be surprised at the difference an adequate amount of fiber stuffing (polyester/wool) makes to the sound of a speaker. Maybe that's why most mids sound best in either an open baffle or closed box that is filled with fiber stuffing.
Probably most boxes sound boxy due to not enough panel bracing and acoustic stuffing inside. You would be surprised at the difference an adequate amount of fiber stuffing (polyester/wool) makes to the sound of a speaker. Maybe that's why most mids sound best in either an open baffle or closed box that is filled with fiber stuffing.
Gino,
The work I have done on enclosures has been in molded polyurethane rigid foam materials. I don't bring this up in most discussions because it is beyond most people to do, it is not something that can be done simply and requires a large investment in tooling. It has the properties of high internal damping and high stiffness to weight. An advantage is that it can be molded into shapes that would be difficult to impossible with most other materials. Most plastic type enclosures sound fairly poor and are made with very thing cross-sections due to molding constraints and also to keep down costs.
In a more traditional wooden enclosure there are things that you can do. A fairly good material you can use is Baltic birch plywood. This again has a very high stiffness to weight ratio and for the front panel you can easily laminate two 18 or 24 mm sheets together with nothing but normal wood glue. Side walls can be single layers and you can use the same material for internal stiffening ribs that attach the walls together like the Matrix enclosures without getting as extreme as those enclosures. Just make panels that reach all panels in one piece and cut sections out of the panels so they are not solid but are continuous pieces. One area you need to look at to remove some of the boxy signature is to round all corners with as large a radius as possible to limit the diffraction from sharp edges. Solid wood corners can be used for this, I have even seen round corners done with quarter sections of plastic pipe, I would prefer a wood section though as you can still stay with the wood glue for assembly and could use solid spruce or something similar to create these details. You just have to get a little creative with your wood working skills.
Another option is to make extremely narrow front baffles that are only as large as necessary to mount the drivers to limit the front reflective surface area, There are as many ways to do this as your imagination. With a very narrow front baffle it will also have a higher stiffness than a wide baffle that has more area that can flex.
I hope this helps a little on your quest. You can always PM me and I will help you where I can. My Icon is actually a molded polyurethane horn loaded enclosure following the concepts that I am talking about.
The work I have done on enclosures has been in molded polyurethane rigid foam materials. I don't bring this up in most discussions because it is beyond most people to do, it is not something that can be done simply and requires a large investment in tooling. It has the properties of high internal damping and high stiffness to weight. An advantage is that it can be molded into shapes that would be difficult to impossible with most other materials. Most plastic type enclosures sound fairly poor and are made with very thing cross-sections due to molding constraints and also to keep down costs.
In a more traditional wooden enclosure there are things that you can do. A fairly good material you can use is Baltic birch plywood. This again has a very high stiffness to weight ratio and for the front panel you can easily laminate two 18 or 24 mm sheets together with nothing but normal wood glue. Side walls can be single layers and you can use the same material for internal stiffening ribs that attach the walls together like the Matrix enclosures without getting as extreme as those enclosures. Just make panels that reach all panels in one piece and cut sections out of the panels so they are not solid but are continuous pieces. One area you need to look at to remove some of the boxy signature is to round all corners with as large a radius as possible to limit the diffraction from sharp edges. Solid wood corners can be used for this, I have even seen round corners done with quarter sections of plastic pipe, I would prefer a wood section though as you can still stay with the wood glue for assembly and could use solid spruce or something similar to create these details. You just have to get a little creative with your wood working skills.
Another option is to make extremely narrow front baffles that are only as large as necessary to mount the drivers to limit the front reflective surface area, There are as many ways to do this as your imagination. With a very narrow front baffle it will also have a higher stiffness than a wide baffle that has more area that can flex.
I hope this helps a little on your quest. You can always PM me and I will help you where I can. My Icon is actually a molded polyurethane horn loaded enclosure following the concepts that I am talking about.
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Have you tried 3-D Printing yet? There are some really, really interesting resins and fillers making it into the market.
For your amusement, Jay Leno shows off the FARO Laser measurement tool, AutoDesk CAD and his 3-D Printing:
Jay Leno's Garage: Faro 3D Laser Scanner - YouTube
They make an intake manifold for a Merlin engine.
Jack,
I actually supervised an aerospace tooling department and the Faro arms were part of the inspection department that I managed. The only problem with most of the 3d printers is the limitation of size until you have a very expensive sized machine. Jay can afford whatever he wants. He actually comes to a live steam train club I am a member of with some of his steam powered cars. I can make inexpensive temporary tooling if that is something that I need to use to mold a part. One of my skills is as a pattern maker and mold maker.
ps. There are no moldable foamed plastics that I know of at this time. Perhaps someday. Many of the older plastics we used that were 3d molded were not UV stable and would only have a 6 months life expectancy if not coated.
I actually supervised an aerospace tooling department and the Faro arms were part of the inspection department that I managed. The only problem with most of the 3d printers is the limitation of size until you have a very expensive sized machine. Jay can afford whatever he wants. He actually comes to a live steam train club I am a member of with some of his steam powered cars. I can make inexpensive temporary tooling if that is something that I need to use to mold a part. One of my skills is as a pattern maker and mold maker.
ps. There are no moldable foamed plastics that I know of at this time. Perhaps someday. Many of the older plastics we used that were 3d molded were not UV stable and would only have a 6 months life expectancy if not coated.
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This confuses me- I'm familiar with lots of foamable molding materials and processes, from expandable microspheres to supercritical CO2, as well as conventional chemical and physical blowing agents. Am I misreading you?
Sy,
I mean in the 3d stereo lithography area. Not sure if you can use those materials in these machines but I suppose someone will figure that out. I only know of solid materials in those machines but it has been a couple of years and things change fast.
I mean in the 3d stereo lithography area. Not sure if you can use those materials in these machines but I suppose someone will figure that out. I only know of solid materials in those machines but it has been a couple of years and things change fast.
Sorry about that Sy. Of course we both know about plenty of foamed plastics, just not in the lithography realm as far as I know. The additive process also from what I know.
Hi thanks and i agree completely
And this could be also a reason why the mini monitors usually image very well
Because they have narrow and short front baffles, and maybe also thick
I have notice that cheap minimonitors image better than cheap towers, where the baffles are long and usually also thin and they tend to flex as you say.
Moreover towers have also the woofer on the baffle that transmits vibrations to the mid-high drivers.
This is a good point for a satellite plus woofer arrangement.
Of course the best sounding towers have exceptionally well constructed front baffle, like some Rockport speakers for instance, where the front baffle is a thick sheet of metal.
Thanks and regards, gino
Thats a fallacy , the best imaging speakers are not mini monitors , the best i have ever heard for imaging were large speakers some over 2M in height ...
Hi and thanks for the very valuable advice
I still have this fundamental question: why no measurements of vibrations on the most important panel of the enclosure that is the front baffle
I was thinking myself about damping.
Now i am not so sure about the importance of damping.
Damping in some way is wasting of energy.
So a very stiff front baffle could work perfectly
For me it is important to have a graph like this for the front baffle
Taken from Stereophile magazine
Rockport Technologies Antares loudspeaker Measurements | Stereophile.com
what i really not understand is that this graph is the "cumulative spectral-decay plot of accelerometer output fastened to rear panel above reflex port"
as i said they usually put accelerometer everywhere but where it counts immensely more, the front baffle.
If the front baffle moves/vibrates there is a microdisplacement of the tweeter position in space (especially) and this in my feeling is extremely detrimental for a good soundstage reproduction.
A very thick front baffle would tame this a lot indeed.
The front baffle execution is decisive for me.
Again about damping, if you damp the woofer with the enclosure you will loose energy
The energy from the woofer instead should be all transformed in acoustic energy.
So an extremely stiff enclosure without damping should work best.
You do not want to waste the energy from the transducers.
Thanks again and kind regards, gino
No , its not what you think , go ahead and actually measure a caninet for resonance , you will understand why and where the energy forces are located ....
I have to agree with A.Wayne here that you do indeed need damping in whatever material you do end up using. You also have to understand that there is a difference in types of damping. Internal damping in a material is different than adding a damping layer though they may get to a similar result.
Think about a metal piece such as a tube used for a chime or bell. You can divide this material into smaller and smaller sections but they will still ring, the only thing that happens is that the frequency moves up where resonance occurs, there is virtually no damping in a metallic tube by itself, that would be an extreme example but the same thing can happen with say an all aluminum solid enclosure. There would be a major difference between a machined aluminum plate enclosure and the same enclosure made of a cast aluminum material because of the damping that the cast material would have. Tap on a cast aluminum piece and then do that with a solid aluminum part and the difference would be very apparent.
Think about a metal piece such as a tube used for a chime or bell. You can divide this material into smaller and smaller sections but they will still ring, the only thing that happens is that the frequency moves up where resonance occurs, there is virtually no damping in a metallic tube by itself, that would be an extreme example but the same thing can happen with say an all aluminum solid enclosure. There would be a major difference between a machined aluminum plate enclosure and the same enclosure made of a cast aluminum material because of the damping that the cast material would have. Tap on a cast aluminum piece and then do that with a solid aluminum part and the difference would be very apparent.
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