General question...
What happens if a driver, say a woofer crossed at 200Hz, has an opening in the baffle that is smaller than the driver?
The driver would be set back about 6" from the opening, with a cabinet construction that "funnels" to the opening.
So, say you were dealing with a 12" driver, but the opening in the front face of the cabinet was 6" h x 12" w?
What about if the total opening size remained the same, but was a different shape. So instead of 12"x12", it was 6"x24"?
Lastly, what happens if only the front of the driver has this reshaping, but the rear is kept fully open?
Thanks.
What happens if a driver, say a woofer crossed at 200Hz, has an opening in the baffle that is smaller than the driver?
The driver would be set back about 6" from the opening, with a cabinet construction that "funnels" to the opening.
So, say you were dealing with a 12" driver, but the opening in the front face of the cabinet was 6" h x 12" w?
What about if the total opening size remained the same, but was a different shape. So instead of 12"x12", it was 6"x24"?
Lastly, what happens if only the front of the driver has this reshaping, but the rear is kept fully open?
Thanks.
There are a bunch of questions here, each with distinct answers. Can you draw a picture or give a description and describe what its purpose is?
Its purpose is to make the overall height of an open baffle speaker shorter for use as a center channel.
The mid/tweet would still be fully open and at the front face of the baffle.
By setting the woofer back 6" in depth and funneling its output out a smaller opening, I can reduce the height of the speaker quite a bit. The opening area would be near the same size as the driver the surface, with the bottom 2/3 of the driver having a straight shot outwards. Only the top 1/3 would be routed downwards.
The "funnel" area would have sides.
I could also flip the woofer around so that the magnet pointed towards the listener. That would improve timing, but output balance may be less.
Setback-Funnel — ImgBB
The mid/tweet would still be fully open and at the front face of the baffle.
By setting the woofer back 6" in depth and funneling its output out a smaller opening, I can reduce the height of the speaker quite a bit. The opening area would be near the same size as the driver the surface, with the bottom 2/3 of the driver having a straight shot outwards. Only the top 1/3 would be routed downwards.
The "funnel" area would have sides.
I could also flip the woofer around so that the magnet pointed towards the listener. That would improve timing, but output balance may be less.
Setback-Funnel — ImgBB
Are you concerned about dipole behaviour, directivity?
Such a tunnel could create a resonance around 500Hz.
Such a tunnel could create a resonance around 500Hz.
To the "sound"?
OK, how about "muffled" as the highs get mixed up in the front space, or "peaky" at that resonance, also the reflections are bound to take on a different tone.
Do you plan to measure it and see what has happened.. By your drawing it doesn't look too drastic, especially for lower frequencies.
OK, how about "muffled" as the highs get mixed up in the front space, or "peaky" at that resonance, also the reflections are bound to take on a different tone.
Do you plan to measure it and see what has happened.. By your drawing it doesn't look too drastic, especially for lower frequencies.
That is along my thinking. I wouldn't try it for upper frequencies, but 200Hz and lower might be unnoticeable.
Have a look at Karlson or Karlsonator speakers, may give you some clues what is possible.
What are the acoustic principles behind a Karlson/Karlsonator speaker?
What are the acoustic principles behind a Karlson/Karlsonator speaker?
"The volume of the compression chamber works like a low-pass filter (6 dB/oct.), the higher the frequency the higher the attenuation. The crossover point (-3 dB) can be calculated with formula" - near the bottom of the page here:
BD-Design - Bass Horn Design
BD-Design - Bass Horn Design