Well with a deep horn like the 1505, 1005 or even deeper 803, the compression driver does sit a little ways behind the woofer. Of course the magnet of the woofer is practically touching the back of the cabinet, so the offset isn't huge.
With DSP it was no problem to delay the woofer a little. With my passive crossover it took some physical movement and crossover tricks to get the phase right. Remember that the woofer's low pass filter actually shifts the woofer back some on the Z axis, which is handy.
With DSP it was no problem to delay the woofer a little. With my passive crossover it took some physical movement and crossover tricks to get the phase right. Remember that the woofer's low pass filter actually shifts the woofer back some on the Z axis, which is handy.
Greets!
You're welcome!
'Correctly'? Nothing but SOTA electronic test gear for me!
I used Harry Olson's? 'click' [impulse] test: Click Test | GM210 | Flickr
I learned most of what I know from studying ['pestering' some opined] the pioneers and one the 'gems' is the Eleanor Powell dancing on the tabletop 'double tap' [echo] story where they kept moving the HF horn backwards til it was a sharp, single tap, so figured if it worked for them it ought to work good enough for me.
Like I keep 'reminding' folks, 'those that don't learn from history are doomed to repeat it'.
Altec had told me that the acoustic center of compression horn drivers 'set' on the face of the phase plug and at the low XO points they used that the VC coil/diaphragm joint was near enough the acoustic center of their woofers [Can anybody confirm this? I've never had a proper measuring system], so knowing from Altec Tech Letter no. 214 about basic time delay calculation, I wired the XOs in phase, calculated a starting point, then 'clicked n' slid' the HF horn around till I got a 'sharp', single click.
Correctly? Up to a point, but now it can be dialed in to a laser point, though have to wonder if anyone can tell even just a perceived [inaudible] difference in a proper blind test assuming of course whoever did the alignment had the necessary keen hearing.
GM
+1
There's a local that has a mishmash of compression horns + dual REL electronically controlled subs in an acoustic disaster of a room [single seat system] and with XILICA DSP has dialed it in to a flat phase/frequency/group delay response, i.e. can reproduce a square wave, the requirement for truly accurate reproduction.
Says he can't hear the acoustically [some really] large ctc, timing, spacings, etc., just super big 'full-range' speakers. Forgot to ask if it's a 'head in vice' situation, but assume it is.
Anyway, he's not too far away as the 'crow flies', but metro Atlanta traffic has gotten so dangerous, grid locked enough that I'm in no hurry to make the trek.
GM
45 Hz is very low for a pretty manageable horn (if other horn loudspeakers are your point of reference LOL).
Has anyone tried something like a coax or a duplex in a VOTT enclosure? 55 Hz exponential doesn't sound like it will be a great mid/fullrange front horn, but who knows.
I am modifying the Voigt Home Constructor's Horn for my Fane 15 inch fullrange drivers. It gets so short, that there is really not much benefit to a curved horn. I could fit the straight version in the designated corner spaces. It would not sit flush, which is why I appreciate this information about the baffle wings.
Back to Hornresp, see what kind of results I can get. The Fane has a fairly high Qts. I think I either need a really large rear sealed enclosure, or damp the waves from the back of the driver to get a roll off that can give low end extension into the twenties. Obviously not EV Patrician-like horn-like performance, but it will probably carry the horn loaded part of the spectrum nicely.
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Altec originally offered the A6, a considerably larger A7 type cab years before the A800 and me and some others have tried 604s in A7s plus one person built a huge HT conical WG system with it, though can't remember how low or where he posted it, though assume either at AUB or HE forum and he was the only one that really liked these versions.
Well, keep in mind it only loads from ~135-400 Hz to blend to classic horn drivers (guitar amp type FRs), so with modern drivers it's an odd/unpleasant sounding speaker to me, including the 604s, though some around the world seem fine with it and of course it can be EQ'd out, but then why bother using such a complex cab design?
Right, as I indicated in the referenced post its high Qts leaves precious little loading BW, so can be a (segmented) parabolic WG like virtually all folded box horns for ease of construction purposes.
??? I thought the Voigt was a compound (front and rear) loaded horn.
Well, keep in mind it only loads from ~135-400 Hz to blend to classic horn drivers (guitar amp type FRs), so with modern drivers it's an odd/unpleasant sounding speaker to me, including the 604s, though some around the world seem fine with it and of course it can be EQ'd out, but then why bother using such a complex cab design?
Right, as I indicated in the referenced post its high Qts leaves precious little loading BW, so can be a (segmented) parabolic WG like virtually all folded box horns for ease of construction purposes.
??? I thought the Voigt was a compound (front and rear) loaded horn.
Yes, the Voigt is a compound loaded horn, but he was trying to squeeze a lot out of a 6 inch driver (the original driver size used). Initially, I figured I'd build the horn and see what it sounded like in the midrange and then decide if I wanted to go through the hassle of designing and tuning the rear horn/pipe. After some simulation in Hornresp, a simple sealed backchamber seemed to get me a lot of bass response below the fronthorn cut off. The backloaded horn/pipe is on hold now.
I have been reading Voigt's original patents and taking note of his design philosophy for fullrange front loaded horns. On more than one occasion, he describes them als baffles with some hornloading. He suggests either 1*Sd as the throat size, or to take the width of the driver (distance between sides, measured from the middle of the surrounds) and to make a square throat.
Essentially, the Fane frequency response is a lot like a Voigt/Lowther drivers' response, which is why I want to try hornloading with them. The very large throat makes for a relatively short horn, which reminds me of a VOTT.
I'll start another thread to discuss some Fane 15 inch and BIG fullrange front loaded horn simulations. Thanks for the additional information.
I have been reading Voigt's original patents and taking note of his design philosophy for fullrange front loaded horns. On more than one occasion, he describes them als baffles with some hornloading. He suggests either 1*Sd as the throat size, or to take the width of the driver (distance between sides, measured from the middle of the surrounds) and to make a square throat.
Essentially, the Fane frequency response is a lot like a Voigt/Lowther drivers' response, which is why I want to try hornloading with them. The very large throat makes for a relatively short horn, which reminds me of a VOTT.
I'll start another thread to discuss some Fane 15 inch and BIG fullrange front loaded horn simulations. Thanks for the additional information.
You're welcome!
Thanks!
Right, all the early point source driver horns I'm aware of were 1:1 CR max Vs Voigt's square ~1:0.78 with the Klipsch being the first compression (bass) horn IIRC, though due to the driver design limitations of the times (mid '50s) Altec recommended 1.52:1 CR Vs EV's 2:1 max.
But a multi-cone tri-ax, especially one with such a high Qt requires a horn/WG with at least a 1:1 IME and had to do much higher for several '50s mobile audio co-ax drivers for scaled Altec 210 cabs with single 6x9" oval where normally two 8" (1/4 scale), which taught me the hard way (the woodworking with only non powered hand tools was quite the chore for this 11 y.o.) that the smaller (weaker back then) the motor the less horn/baffle loading required.
Thanks!
Right, all the early point source driver horns I'm aware of were 1:1 CR max Vs Voigt's square ~1:0.78 with the Klipsch being the first compression (bass) horn IIRC, though due to the driver design limitations of the times (mid '50s) Altec recommended 1.52:1 CR Vs EV's 2:1 max.
But a multi-cone tri-ax, especially one with such a high Qt requires a horn/WG with at least a 1:1 IME and had to do much higher for several '50s mobile audio co-ax drivers for scaled Altec 210 cabs with single 6x9" oval where normally two 8" (1/4 scale), which taught me the hard way (the woodworking with only non powered hand tools was quite the chore for this 11 y.o.) that the smaller (weaker back then) the motor the less horn/baffle loading required.