@wesayso and whoever: Wayne Parham at Pi Speakers uses that very same JBL picture in one of his whitepapers (High-Fidelity Uniform-Directivity Loudspeaker). Found here: http://www.pispeakers.com/Pi_Speakers_Info.pdf .
Well worth reading, with info on some of the points Wesayso raised above in post #252. The picture is in the middle of that whitepaper.
Well worth reading, with info on some of the points Wesayso raised above in post #252. The picture is in the middle of that whitepaper.
@Adhoc1, nice find! I have read that paper some time ago but forgot all about that JBL picture.
A nice write-up with more to think about. Underlining some of the points I mentioned earlier about the Synergy/Unity concept from Tom Danley.
Drivers as close together as possible at the crossover frequency has it's merits. Within 1/4 wavelength is good, within 1/8 wavelength of the crossover frequency will be even better. Not always easy to do.
A nice write-up with more to think about. Underlining some of the points I mentioned earlier about the Synergy/Unity concept from Tom Danley.
Drivers as close together as possible at the crossover frequency has it's merits. Within 1/4 wavelength is good, within 1/8 wavelength of the crossover frequency will be even better. Not always easy to do.
400Hz crossover from Bass to Mid has a crossover frequency quarter wavelength of 212mm. Just about possible to get this C/C distance if one uses small drivers. Going down to 300Hz crossover makes it more possible with normal sized drivers.
2000Hz crossover from Mid to Treble has a crossover frequency quarter wavelength of 42mm. Just about impossible to get this C/C distance even if one uses tiny drivers.
I don't believe 1/8th wavelength spacing is worth chasing.
Coaxial designs are an alternative, but bring their own compromises.
2000Hz crossover from Mid to Treble has a crossover frequency quarter wavelength of 42mm. Just about impossible to get this C/C distance even if one uses tiny drivers.
I don't believe 1/8th wavelength spacing is worth chasing.
Coaxial designs are an alternative, but bring their own compromises.
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There are some exceptions, eg the null above and below the lobe produced with greater spacing coincides with planned floor/ceiling absorption, and/or the sources have limited inherent vertical directivity.
Just look at a Danley design to see a creative way to solve that problem
I'm not saying everyone should chase it... but it does make a lot of sense.
We as a DIY crowd can make sure our speakers will work within our room, so, yes... there will be exceptions too, worth chasing.
Being aware of what happens once we drag our speakers into a room can really help to get the sound we desire. Pick your own set of compromises.
But to do that, one should first be aware of them.
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