I'm not saying the same as Dave is. I'm assuming a perfect driver but a random baffle / crossover.
When in doubt, no-one will argue if you call it an open baffle, unless you are sure it is dipole
I hope this endeavour works out for you
Similar to a perfect wall reflection? I don't think error is the right word.
OB can introduce some directivity to low frequencies which would otherwise require big baffle or waveguide or some array setup? but the compromises are that lots of cone surface area and displacement required and they can't be positioned close to wall. Is there other benefits? Box sound, "ambient sound" and directivity can be achieved other ways. Bass directivity as well with corner placement. I haven't heard OB speakers, to me they seem to have a bit weird set of compromises. Easy to build though, couldn't be easier actually.
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OTOH the goal of accuracy that is of reproducing the recording as exactly intended by the recording producer is a red herring as well, perhaps even more.
Because while I know how a piano sounds in my room, basically no listener knows what the producer/engineer exactly heard in the studio, and intended, we are not in the studio and we don't have the studio gear - electronics and speaker monitors. Absolutely no point of reference.
So at the end of the day we're left with what we like or do not like when we hear it.
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It's ONLY IF the enslosure is big enough for a wave to form, therefore it is wise to keep the enclosure volume as small as possible so that the driver "sees" a spring at its back, not a cavity with waves bouncing back or even standing, in the worst scenario
I'm not saying the same as Dave is. I'm assuming a perfect driver but a random baffle / crossover.
When in doubt, no-one will argue if you call it an open baffle, unless you are sure it is dipole
I hope this endeavour works out for you
anyway, OB has many trade-offs as a loudspeaker design
No, potentially
Have you noticed that some of us use the word trade-off to mean a compromise which we ultimately settle, while others imply that it remains unsolved...
Yes indeed
...until we find a solution, theoretically we can find a way out of every trade-off situation in loudspeaker design, for many of them DSP offers solutions (with its own trade-off of necessary A/D/A conversion)
In my eyes in OBs trade-offs include positioning requirements (need more space at the back), power requirements (need more power in the bass), baffle size (trade-off in many rooms, also WAF etc.) or in case of more minimal baffle with midrange or midbass drivers (SL's or John K's styles) - time response (need higher order crossovers).
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It's interesting where this all went. Discussing the pros and cons of the various radiation patterns is pretty useless if you leave (again) the positioning and the room itself out of the equation. Any dipole in an acoustic nightmare performs poor whereas a good speaker with a lousy directivity pattern in a well treated room can sound pretty stunning. My starting point was that the practical limits of room adaptation brought me to the conclusion that the speaker only has to be good enough to not form the weakest link. An easy task in a lot of situations.
Ps.
and this:
also an obvious trade-off, an awful lot more of displacement for same SPL in the bass
SL's or John K's school OBs not that easy
and this:
also an obvious trade-off, an awful lot more of displacement for same SPL in the bass
SL's or John K's school OBs not that easy
interesting conclusion about the weakest link
But is it easy? Because most listening rooms are difficult, far from ideal. Too small, first of all, taking into accounts the common recommendations regarding early reflections.
first reflections calculator
How should a loudspeaker be designed so that it is not a weakest link in a room that is too small?
This was my point of departure when I have started the "Loudspeakers and room as a system" discussion, later renamed.
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graaf, constant directivity works for big and small rooms. Reduced sound radiation to directions outside the listening spot reducing the first reflections ratio to the direct sound. More importantly the frequency response is ideally the same on and off-axis so the reflections shouldn't change the sound much. This can be achieved with very good waveguide we've recently seen to finally get realized in the ATH thread. No diffraction, no "horn sound" or other issues one might associate with horns, just control. One can choose wide or narrow beamwidth and make it as big as you want.
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Controlled directivity
....
Anything controlled sounds bad from my POV
I mean, talkin' about the system
Electrically you raise the gain of the signal (preamp) and there are some LP/HP stages troughout till the power stage of amplification ( HP/LP brings some phase alterations too, right?). The signal appears at the binding posts ( bad, very bad! ) of the speakers ( imagine perfect speakers, but in the real world they are band limited and to work correctly, moreover, they need additional stages of filtering, which brings the usual tradeoofs of phase shift, but...luckily if they are out-of-band and well attenuated...) and at this point it has to be spread all around the room, no, pardon, it has to have a natural way of emitting the sound. The nature of the sound is [point source]and omnidirectional but...
The caption occurs (via microphone) usually in front of a venue...I mean, you are in front of a venue, etc etc. That's why also omni doesn't work ( sorry graaf)
....
Anything controlled sounds bad from my POV
I mean, talkin' about the system
Electrically you raise the gain of the signal (preamp) and there are some LP/HP stages troughout till the power stage of amplification ( HP/LP brings some phase alterations too, right?). The signal appears at the binding posts ( bad, very bad! ) of the speakers ( imagine perfect speakers, but in the real world they are band limited and to work correctly, moreover, they need additional stages of filtering, which brings the usual tradeoofs of phase shift, but...luckily if they are out-of-band and well attenuated...) and at this point it has to be spread all around the room, no, pardon, it has to have a natural way of emitting the sound. The nature of the sound is [point source]and omnidirectional but...
The caption occurs (via microphone) usually in front of a venue...I mean, you are in front of a venue, etc etc. That's why also omni doesn't work ( sorry graaf
)
Well, controlling directivity is the key. And while you of course could make that a very complex task, the various implementations including mid frequent cardioid designs are not really hard to construct.
Apart from that I meant that several loudspeaker issues, like quite a few distortion ones, quickly vanish in comparison with the room problems. All the pages and pages here about bass tuning of a speaker, forget about it. Group delay in low frequency ranges? Completely irrelevant. Cabinet wall construction? Well, when about every cup and closet in your room is trembling, who cares about a mere cabinet wall resonance? Ok, I might exaggerate, but in my humble opinion a lot of us could spend their cash wisely in pursuit of great sound.
Has anyone NOT done this once? That was about the first thing I did when I started this hobby...
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I do all my listening at home in the nearfield, any further distance and the sound dominates by the room
picowallspeaker: The constant directivity is the more important word here than the control, you don't need to control pulsating point of sound to get constant directivity but those don't exists (at least yet) so the control is currently required to reach constant directivity Just wanted to raise the ATH thread up since those waveguides presented by mabat and his remarkable piece of work are something that has not existed before. And it is free, available to anyone. Removes some trade-offs that have been associated with horns (waveguides) so it is relevant here.
Just wanted to raise the ATH thread up since those waveguides presented by mabat and his remarkable piece of work are something that has not existed before. And it is free, available to anyone. Removes some trade-offs that have been associated with horns (waveguides) so it is relevant here.
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