A preliminary search did not return any useful result on this topic so...
Is there any argument to be made in favour of utilising a an internal soundwave diffuser within an enclosure to break up standing waves or to any other benefit? Just to be clear, a diffuser role is understood not to absorb soundwaves, but merely change or sufficiently randomize their angle of reflection to break-up standing waves and resonant frequencies. In a studio or theatre environment, the panels can be quite large and cover a significant area. Lower frequency waves are longer than the longest dimension of most any speaker enclosure, but what of the mid to high frequencies, or harmonics – could these be addressed by an internal diffuser, or, as mentioned, could there be, any other possible benefits?
Is there any argument to be made in favour of utilising a an internal soundwave diffuser within an enclosure to break up standing waves or to any other benefit? Just to be clear, a diffuser role is understood not to absorb soundwaves, but merely change or sufficiently randomize their angle of reflection to break-up standing waves and resonant frequencies. In a studio or theatre environment, the panels can be quite large and cover a significant area. Lower frequency waves are longer than the longest dimension of most any speaker enclosure, but what of the mid to high frequencies, or harmonics – could these be addressed by an internal diffuser, or, as mentioned, could there be, any other possible benefits?
I tried all kind of diffusers inside speaker enclosures and the effect is minimal. Damping material is much more efficient. I put only that amount of damping material inside so that the small blimps in the phase of the impedance curve disappear.
In closed boxes for subwoofer use i stuff more because you can get an effective virtual doubling of the internal volume. Here glass wool or rock wool is most efficient.
In closed boxes for subwoofer use i stuff more because you can get an effective virtual doubling of the internal volume. Here glass wool or rock wool is most efficient.
Yes, I'm familiar with the benefits of damping material, and a diffuser would not be intended as a substitute for this. The absorption likely obviates any need for a diffuser. The case where I'm speculating whether a diffuser would have any benefit, would be in an enclosure where one wishes to use very little damping material to control standing waves and perhaps resonant peaks.
Then you need a funnel like the B&W solution or something like a Venturi Tube.
You could also make the inside cabinet from a lot of small cabinets connected with small holes. I think even B&W Matrix is too " open " to show a big effect. Bigger holes with damping ( say, closing the holes with felt ) could do the trick too.
I also tried a lot of outer shapes, round, triangulate, pyramid etc. again with minimal effect. Of cause the outer shape has an effect on radiation pattern and diffraction.
You could also make the inside cabinet from a lot of small cabinets connected with small holes. I think even B&W Matrix is too " open " to show a big effect. Bigger holes with damping ( say, closing the holes with felt ) could do the trick too.
I also tried a lot of outer shapes, round, triangulate, pyramid etc. again with minimal effect. Of cause the outer shape has an effect on radiation pattern and diffraction.
i think if you are going to allow the standing waves, the best you can do is get it all mashed up into one sound, compared to many different sounds without any effort.
but a standing wave is still there.
the difference is if you want to hear it from a port,
or
if you want to use the standing wave in the mechanical aspect of the speaker design's character.
it's like basically siting down to some math that says.. okay this speaker needs ____ size box.
but if you don't compensate for compression, then the compression is going to stretch or shrink the 'perceived' box size to the speaker's view.
so when you are mashing up the insides, all you are doing is getting one box size throughout the entire frequency response.
in the end, it is a trick (or effort) to get the speaker to perform in the shallow environment that it is specified to work in .. instead of allowing the compression to stretch and shrink the environment.
but a standing wave is still there.
the difference is if you want to hear it from a port,
or
if you want to use the standing wave in the mechanical aspect of the speaker design's character.
it's like basically siting down to some math that says.. okay this speaker needs ____ size box.
but if you don't compensate for compression, then the compression is going to stretch or shrink the 'perceived' box size to the speaker's view.
so when you are mashing up the insides, all you are doing is getting one box size throughout the entire frequency response.
in the end, it is a trick (or effort) to get the speaker to perform in the shallow environment that it is specified to work in .. instead of allowing the compression to stretch and shrink the environment.
Wow, this is a complex philosophy.
There is mostly only one standing wave in a closed enclosure of medium size, say 40 liters. It is the longest size, mostly around 200 to 300Hz.
Under that frequency is only pressure, over that frequency is chaos.
There is mostly only one standing wave in a closed enclosure of medium size, say 40 liters. It is the longest size, mostly around 200 to 300Hz.
Under that frequency is only pressure, over that frequency is chaos.
it is a bit complex.. why say there is only one wave after saying something about complex?!
ripples are when the soundwaves are small enough to fit into the box and they hit a reflection, then the reflection goes over the original soundwave to cause the ripples.
that is one problem, not necessarily a standing wave.. but yes a standing wave.
the soundwaves that are supposedly too large for the box are generalized as 'orders'
dumb is thinking the soundwave won't fit in the box, yet the speaker cone is only move 4mm to produce the soundwave .. thus the soundwave can be created within the 4mm of distance.
and as long as the speaker box is at least the same size as the cone (it absolutely has to be because the back of the speaker fits the cutout hole) then there is room for the soundwave equally no matter what portion (or all) of the cone it came from.
a perfectly designed diffuser will simply smear all the reflections to the same exact phase and timing.
but the problem with that is, the design is totally based on a specific amount of cone travel.
if you turn it down, the result changes.
if you turn it up, the result changes.
if the dynamic peak causes more cone movement, the result changes.
**edit**
well i guess if the phase from the speaker is constant no matter if the excursion is high or low, then the phase adjustments will remain valid.
but the timing calculations would prove to be different.
and it is the phase result that people ever begin such an endeavor in the very first place.
**edit again**
it is because the speaker sees the inside of the speaker box as the perfect weather to enjoy freedom of motion.
it allows the speaker to output the absolute maximum amount of slew possible, where some speakers need it and other speakers sound worse going all the way to maximum.
ripples are when the soundwaves are small enough to fit into the box and they hit a reflection, then the reflection goes over the original soundwave to cause the ripples.
that is one problem, not necessarily a standing wave.. but yes a standing wave.
the soundwaves that are supposedly too large for the box are generalized as 'orders'
dumb is thinking the soundwave won't fit in the box, yet the speaker cone is only move 4mm to produce the soundwave .. thus the soundwave can be created within the 4mm of distance.
and as long as the speaker box is at least the same size as the cone (it absolutely has to be because the back of the speaker fits the cutout hole) then there is room for the soundwave equally no matter what portion (or all) of the cone it came from.
a perfectly designed diffuser will simply smear all the reflections to the same exact phase and timing.
but the problem with that is, the design is totally based on a specific amount of cone travel.
if you turn it down, the result changes.
if you turn it up, the result changes.
if the dynamic peak causes more cone movement, the result changes.
**edit**
well i guess if the phase from the speaker is constant no matter if the excursion is high or low, then the phase adjustments will remain valid.
but the timing calculations would prove to be different.
and it is the phase result that people ever begin such an endeavor in the very first place.
**edit again**
it is because the speaker sees the inside of the speaker box as the perfect weather to enjoy freedom of motion.
it allows the speaker to output the absolute maximum amount of slew possible, where some speakers need it and other speakers sound worse going all the way to maximum.
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A 3 way speaker makes that more easy. The other option is no box at all. aka dipole and siblings.
but chaos can be declared in as little as ONE addition.
some say chaos might be 3
some say 4
some say 6
same say 12
some say 100
it isn't chaos if you can count the details individually.
i think it is expensive learning sometimes, and then with the information learned.. people either take it with them to their death or they share it.
this internal diffuser would be one of those times where you build something and learn, perhaps you went to maximum & the reward was less.
or maybe you learn it doesn't matter much if you choose the phase for the speaker's happiness , or if you are adjusting the speaker's phase to match the room it is in.
there is a whole bunch to life that can be seen as if it fits on math paper (grid paper).
but diving into such a realm is costly, not only financially.. but time, mentality, & emotions are all taxed negatively & positively all in a lump sum.
perhaps computer modeling has made it easier on time, which should translate to mentality & emotions.
but it should also translate to doing more, for when i said the difference between making the speaker perfectly happy or finding a compromise for the room the speaker is in.
as far as math goes.. there is more room for K than there is I
yet just like two legs are needed to walk, they go together much better compared to when they are constantly fighting eachother.
some say chaos might be 3
some say 4
some say 6
same say 12
some say 100
it isn't chaos if you can count the details individually.
i think it is expensive learning sometimes, and then with the information learned.. people either take it with them to their death or they share it.
this internal diffuser would be one of those times where you build something and learn, perhaps you went to maximum & the reward was less.
or maybe you learn it doesn't matter much if you choose the phase for the speaker's happiness , or if you are adjusting the speaker's phase to match the room it is in.
there is a whole bunch to life that can be seen as if it fits on math paper (grid paper).
but diving into such a realm is costly, not only financially.. but time, mentality, & emotions are all taxed negatively & positively all in a lump sum.
perhaps computer modeling has made it easier on time, which should translate to mentality & emotions.
but it should also translate to doing more, for when i said the difference between making the speaker perfectly happy or finding a compromise for the room the speaker is in.
as far as math goes.. there is more room for K than there is I
yet just like two legs are needed to walk, they go together much better compared to when they are constantly fighting eachother.
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The conversation appears to be pursuing various related ideas to what I had originally intended to enquire about. Imagine please the walls of the enclosure, which is curved, not rectangular, with a surface resembling a vastly scaled down version of the studio image below.
What could the effect of a such a randomized surface with relatively small peaks and valleys be?
What could the effect of a such a randomized surface with relatively small peaks and valleys be?
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He should try harder. The tweeter mounting is the absolute worst possible case for diffraction.
Yes, the decoupling is nice to see. The use of cardboard is also not without interest; how effective it is compared to other methods I wouldn't like to hazard without trying though.
You're misunderstanding the context- he's saying the same thing, that the logic saying "a wave of X size can't fit within the box so the box can't create it" is flawed.
Of course, below some frequency it's really more of a periodic pressure than a wave, but nevertheless, you don't need a wavelength with an acoustic source or enclosure to get response.
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