Concrete is my favorite material because the stiffness (less losses) brings more output from the reflex port.
However anyone heard of Hawaphon?
It's like sand but easier to use
Here is the producer
https://www.korff.ch/produkte/hawaphon/
They designed it to dampen conference or directors doors so nobody can listen through the door
However anyone heard of Hawaphon?
It's like sand but easier to use
Here is the producer
https://www.korff.ch/produkte/hawaphon/
They designed it to dampen conference or directors doors so nobody can listen through the door
Attachments
The sand filled panel is 1,5" (38mm) thick and not a lot better as D or E? Strange.
It should be compared to 38-50mm wood ... cause this also get's pretty good when you have the space.
Hi please excuse me but i missed which board they have measured I mean which side of the cabinet
I have a strong belief on this topic The only cabinet side that really matters is the front baffle
In all the tests i have seen they put accelerometers almost anywhere ... but not on the side that matters most
Maybe they will not like what they could see ?
I think that at B&W they did so in developing the matrix concept cabinets ?
P.S. by the way if you want to check how resonant is your speaker cabinet there is a very simple and cheap way
Just place one of this on one side and rotate the mechanism
https://m.media-amazon.com/images/I/41ADjLAtLtL.__AC_SY300_SX300_QL70_ML2_.jpg
if the cabinet does not resonate (good) you will hear a very tiny sound like when you rotate the mechanism in free air
And i think you can also test in the same way woods of different quality and thickness Of course in a complete speakers also bracing can block resonance a lot and damping materials and so on
my speakers cabinets resonate like an acoustic guitar 😢
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The whole box is important. The baffle is the weakest panel because you put big holes in it.
dave
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Hi yes i agre with you Therefore it is also the more critical And incidentally the drivers are mounted on it
i think that even small vibrations of the baffle could influence the tweeter emission (i.e. shifting the sound source point when the woofer shakes the baffle)
i think that even small vibrations of the baffle could influence the tweeter emission (i.e. shifting the sound source point when the woofer shakes the baffle)
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Finally remembered, Art Ludwig, a 'must read' site for beginners IMNSHO, but link is now only on the web archive, which is holding it ~hostage. 🙁
I tend not to use tweeters but the boxes i do create an “iBeam" structure to dramatically stiffen the baffle.
If you are worried asbout the tweeter moving decouple it from the box.
save
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Some good suggestions here. Also constrained layer damping for the baffle.
Hi thank you all very much for all the very kind and valuable advice
Just out of curiosity i have read that an Avalon Eclipse model has a 4.5" max thickness baffle I guess it's a Guinness record
Moreover i have read that the brand it's criticised for using MDF for cabinets
I think that the result is what counts
Just out of curiosity i have read that an Avalon Eclipse model has a 4.5" max thickness baffle I guess it's a Guinness record
Moreover i have read that the brand it's criticised for using MDF for cabinets
I think that the result is what counts
Sure. Although Avalon being Avalon, they're at least using MDF 'properly' (as in 'as well as realistic'). If memory serves, the thick front baffle is made up of 1/2in layers rather than 3/4in so you have more laminations and more boundary losses in there -arguably it may also be a bit stiffer, although that depends to a point on the adhesive etc. The rest of the box is, as I recall, made up of at least 1 1/8in panels, and heavily braced. The thick front baffle makes cutting the facates easier (assuming you have suitable tools -it can be done by hand but it's a swine for experienced woodworkers & completely beyond the likes of me), and gives the drivers a high mass, high rigidity 'sink' for their structural resonances, as well as a very inert platform for the expanding external wavefront / 'bubble'. It also gives the other panels, with the bracing, a similar high[ish] mass, high rigidity structure to key into. Strictly speaking it would probably be better if they used HDF / valchromat (I suspect their MDF isn't too far off HDF), panzerholtz, or preferably a quality void-free multiply e.g. Baltic birch, bamboo etc., especially at their kind of prices. But they're a business, and in fairness, if you're going to use MDF, they're one of the better examples of how to use it well.
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👍
Not too far off your (our) preferences when it comes to MDF rigidity. A bit of overkill for the front baffle -especially since you end up with a tunnel for the drivers that needs major relief. Still -I'd rather have excessive than not enough. 😉 What's the old adage from the track? If you're not 'cheating' you're not trying hard enough.
Not too far off your (our) preferences when it comes to MDF rigidity. A bit of overkill for the front baffle -especially since you end up with a tunnel for the drivers that needs major relief. Still -I'd rather have excessive than not enough. 😉 What's the old adage from the track? If you're not 'cheating' you're not trying hard enough.
Hi thanks a lot for the very valuable information So MDF can be perfectly ok It is just a matter of using it properly Good !
This confirms the idea that the front baffle is by far the most critical panel of the cabinet
Strangely enough i see accelerometers placed everywhere even on the rear panel but NEVER on the front baffle where the vibrations matter most 😉
I would like to see measurements of panel displacement when the speaker is driven at 100dB peak and 60Hz to pull numbers out of the air
Again even small shift of the baffle can cause (i read) some doppler effect ? 😳
i hope that the bracing reaches also the front baffle However 4" of thickness provides some guarantees
i think that the cuttings are superflous i think it is done more for look Avalon have a certain aestethic signature
Moreover the newer series have felts around the higher Hz drivers
What is the reason to cut edges that are not reached by the waves (the felt absorb the side emission of the drivers i guess)
I like the felt concept a lot Maybe it needs a fine tuning with measurements
this must be the perfect wood
Very important conclusion and thank you again for that Speaking of layered material (not interesting at all for DIYers unfortunately) i am always been surprised by the acoustic isolation provided by bulletproof glass If you knock on them the sound is very dead
They are layers or tempered glass (very stiff) alternated with layer of viscoelastic plastic that could stop some vibrations
I was in a bank and i could not hear the heavy traffic outside ... almost complete silence Very impressive
With would make the baffle 9-ply MDF plywood. One of the prime reasons for such a thick baffle is that is gives tham room for the big chamfers they use.
The 5-layer (dirt cheap MDF) plywood in the curved PE boxes was also better than straight MDF. I suspect that Avalon starts with a higher quality MDF.
They could probably get teh same stiffnes sout of 3” quality ply, but there would not be enuff room for the big chamfers
dave
It does make them look more dramatic but the big chamfers do a lot to decrease the loudspeaker’s diffraction signature which i would think is the prime reason. Cosmetics are a bonus.
The Avalon that most distrubs me is the one with the tweeter at teh tp and the woofer at the bottom. How do they get them to blend given the huge C-C.
dave
i cannot help but notice that in the more recent models they have also added felts around the upper drivers Maybe to increase the edges diffractions control ? the chamfers are still there But if great speakers can be done even without these difficult to make chamfers for me they have no reason to exist look aside of course But i like listen in the darkness Look is not important to me at all
I would experiment with felts first Much easier In the past they were more popular AR, Spica, Snell, Vandersteen and others used felts around the dome drivers at least
maybe the listening distance comes into play ? maybe at 10 feet and more the emissions of the two drivers will blend ?
Perhaps they've considered that the low woofer pushes it away from the ceiling by angle and distance, and pushes the floor bounce up in frequency.
Huge reduction in diffraction signature (partly after Olson). Personally I prefer the slightly less outre Vimberg configuration, but in fairness to Avalon, it does work.
They were crossing at 1KHz, LR4 acoustical & electrical with the old Eclipse, full impedance compensation for that MB Quart tweeter. A bit ambitious for that unit TBH, as it was starting to struggle, but some more recent tweeters can do it better assuming we're talking modest spaces & SPLs rather than 'ballroom & live Motorhead'. 😉 Spacing is within 1 wavelength so integration is reasonable; not as good as 1/4 wavelength, but there aren't a whole lot of speakers that can do that, & a lot better than most despite the large spacing, so they could get away with it. Predominantly it was about reduction of baffle diffraction for the individual units & to a lesser extent floor-bounce and the ability to use symmetrical electrical orders in the filter.