This line of questions is geared towards PA, although could apply to home appliances too.
To begin I've got a case (qty:12) of sealed back 6" midrange drivers. I've been wanting to build them into 3-way PA cabs. I've been envisioning 4 per cab, slot-loaded on the vertical plane. Series/parallel for 8Ohms.
So here's my questions:
(1.) The slot loading was to lessen the lobing these large'ish for bandwidth drivers will normally produce. Would a very short rectangular, sharp-edged waveguide produce good horizontal dispersion via diffraction, or would a vertical line flare be better?
(2.) Looking at UnityHorn designs, the mids always fire through offset equal-distant holes. Could this be adapted to the above so as to create a virtually smaller center-to-center driver spacing? That cfg may be highly contingent on horn loading to properly couple the compressed (via holes) drivers?
It seems like this should be viable, but those of you more versed with horn loading may shoot it down as impractical?
Thanks in advance for any input on this concept!
To begin I've got a case (qty:12) of sealed back 6" midrange drivers. I've been wanting to build them into 3-way PA cabs. I've been envisioning 4 per cab, slot-loaded on the vertical plane. Series/parallel for 8Ohms.
So here's my questions:
(1.) The slot loading was to lessen the lobing these large'ish for bandwidth drivers will normally produce. Would a very short rectangular, sharp-edged waveguide produce good horizontal dispersion via diffraction, or would a vertical line flare be better?
(2.) Looking at UnityHorn designs, the mids always fire through offset equal-distant holes. Could this be adapted to the above so as to create a virtually smaller center-to-center driver spacing? That cfg may be highly contingent on horn loading to properly couple the compressed (via holes) drivers?
It seems like this should be viable, but those of you more versed with horn loading may shoot it down as impractical?
Thanks in advance for any input on this concept!
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What frequency range are you targeting?
2) If your talking about using the 4 drivers in an offset driver conical horn without a tweeter (unity horn without tweeter) this will work almost the same as if the tweeter was there. You could also play around with making S1-S2 shorter/longer to change the cancellation notch frequency. Typically the bandwidth is quite narrow, may be able to extend it if S1-S2 shorter.
2) If your talking about using the 4 drivers in an offset driver conical horn without a tweeter (unity horn without tweeter) this will work almost the same as if the tweeter was there. You could also play around with making S1-S2 shorter/longer to change the cancellation notch frequency. Typically the bandwidth is quite narrow, may be able to extend it if S1-S2 shorter.
Hi kipman725,
As far as bandwidth I'm looking for 700-6KHz, well into comb filtering/lobing territory.
Not looking to depth horn load these mids. The UnityHorns are awesome but take up quite a bit of room.
What I was thinking with these sealed back mids is to mount 4 vertically. Linear or stagered vertically. This array would be integrated via either a narrow vertical slot/waveguide, or feeding a vertical shallow flare (think JBL VerTec).
Alternatively, I was thinking the (UnityHorn like) offset dual hole per driver arrangement might work even better on the above slot/flare? The theory behind the dual offset holes is, not only does it accomplish compression but of even more importance is the virtually much smaller center-to-center dimension this creates.
IE, further reduction of comb filtering/lobing.
As far as bandwidth I'm looking for 700-6KHz, well into comb filtering/lobing territory.
Not looking to depth horn load these mids. The UnityHorns are awesome but take up quite a bit of room.
What I was thinking with these sealed back mids is to mount 4 vertically. Linear or stagered vertically. This array would be integrated via either a narrow vertical slot/waveguide, or feeding a vertical shallow flare (think JBL VerTec).
Alternatively, I was thinking the (UnityHorn like) offset dual hole per driver arrangement might work even better on the above slot/flare? The theory behind the dual offset holes is, not only does it accomplish compression but of even more importance is the virtually much smaller center-to-center dimension this creates.
IE, further reduction of comb filtering/lobing.
kipman725,
Getting back to the economical driver subject, take a look at the midrange MCM 55-1595. Super cheap in qty, think PA line array. Not the smoothest curve, but the specs look really good for PA applications!
Getting back to the economical driver subject, take a look at the midrange MCM 55-1595. Super cheap in qty, think PA line array. Not the smoothest curve, but the specs look really good for PA applications!
I'm not an expert but your asking for more than 3 octaves of bandwidth which is always considered difficult from a single horn. Also I think you will need a phase plug @ 6kHz to avoid acoustic cancellation as your driver is large. The phase plug will then have to be too far from the cone and cause low pass filtering, this is usually solved using a compression driver where the phase plug is closer to the dome.
I think I have seen the vertical slot short horn before used of a double 12" midbass like the attached image. Why not have a play in hornresp?
This is another interesting cheap driver as its sealed back, saving a lot of work (I'm currently sealing the backs of 8 drivers its a pain):
https://www.newark.com/pyle/pdmw5/mid-bass-woofer-8ohm-200w/dp/88C6353
(also available on Farnell)
I think I have seen the vertical slot short horn before used of a double 12" midbass like the attached image. Why not have a play in hornresp?
This is another interesting cheap driver as its sealed back, saving a lot of work (I'm currently sealing the backs of 8 drivers its a pain):
https://www.newark.com/pyle/pdmw5/mid-bass-woofer-8ohm-200w/dp/88C6353
(also available on Farnell)
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