Cal also uses Altec drivers on his Altec horns.
I tend to think of those two horns this way:
811 for indoors
511 for outdoors
Or if you're really crazy like me you use the 511 for mids and 811 for highs. Whatever works.
I'm liking this. So far, we've one vote for 811, one vote for the 10 x 14 QSC Waveguide. I agree we don't need no steenking baffle for the horn. WAF is no longer an issue (thank God).
I'm definitely going to get the Selenium driver (unless someone will sell me an Altec for $40), so it boils down to the horn. The 811 definitely will look cooler and match the vintage cab, but SQ is more important. Does the Waveguide sound significantly better? I'm not taking into account that the Waveguide will be half the price of the 811, that's not a big deal.
Cal. I like the indoor/outdoor analogy. What do you think about the Waveguide?
I'm definitely going to get the Selenium driver (unless someone will sell me an Altec for $40), so it boils down to the horn. The 811 definitely will look cooler and match the vintage cab, but SQ is more important. Does the Waveguide sound significantly better? I'm not taking into account that the Waveguide will be half the price of the 811, that's not a big deal.
Cal. I like the indoor/outdoor analogy. What do you think about the Waveguide?
Good point. $14 hardly gets you a decent 12 pack of beer these days. Getting both the QSC and the 811 hardly breaks the bank. Maybe I'll just go ahead and nab a QSC, and then I can wait to get the 811 when I find a real bargain on one.
Next, I will be bugging you guys about crossovers, about which I know next to nothing, except for the fact that they will make or break a multi-way speaker. I also think I'll be needing an L-pad, because the JBL woofer is rated 101 db, and the Selenium is 109, if I recall correctly.
This site is great, you guys have really been helpful! Thanks again.
You need to get everything measured before any XO or Lpad discussion can start. The waveguide will flatten out losing 8 or 9 dB so you may not need much of an Lpad.
Bare horns are ugly..wife and girlfriends are right about that stuff
Also why do you say the baffle isnt meaningful. A nicely rounded baffle will help extend the waveguide out smoothly won't it??
Beyond the aesthetic issue of whether or not bare horns are ugly (they can be, or they can look cool, it depends), it seems to me that in live PA setups, I always see them without cabs, or am I remembering wrong? Been awhile since I went to a concert and paid any attention to the sound system.
you guys are the experts. Don't cabs add their own thing (resonances, unwanted sound gremlins, maybe good stuff) to a horn just as they do to a paper driver? I know that nothing is coming from behind since the driver is screwed or bolted onto the horn, but in front? I don't know, therefore I ask.
Maybe it's because I'm old school, but this is what I think of with these kind of systems.
you guys are the experts. Don't cabs add their own thing (resonances, unwanted sound gremlins, maybe good stuff) to a horn just as they do to a paper driver? I know that nothing is coming from behind since the driver is screwed or bolted onto the horn, but in front? I don't know, therefore I ask.
Maybe it's because I'm old school, but this is what I think of with these kind of systems.
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A box around the waveguide isnt going have resonance since the waveguide has no rear sound wave. I learned the hard way that isolating the waveguide from the woofer is also a good idea. I just finished new boxes where my waveguide is isolated from the woofer rear wave.
I still believe the rounding of the box around the waveguide/horn continues the smooth exit of the sound wave. Any diffraction (ie. sharp corners) will create ripples in the sound wave, no? I know Geddes has commented on using large round overs to smooth out the transition from the mouth of the horn to the corners of the speakers.
Its also one of the reasons LeCleach horns (sp?) have incredible SQ and measurements.
I see no reason to argue that sort of common sense from those guys.
I still believe the rounding of the box around the waveguide/horn continues the smooth exit of the sound wave. Any diffraction (ie. sharp corners) will create ripples in the sound wave, no? I know Geddes has commented on using large round overs to smooth out the transition from the mouth of the horn to the corners of the speakers.
Its also one of the reasons LeCleach horns (sp?) have incredible SQ and measurements.
I see no reason to argue that sort of common sense from those guys.
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Example of what Im talking about with sharp corners.
vs something with round over
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vs something with round over
An externally hosted image should be here but it was not working when we last tested it.
Agreed in that the 511 loads to a lower frequency, ergo controls directivity better with the trade-off being it beams more up high. Still, I much prefer it sonically to the 811 overall once EQ'd plus it has more tuning flexibility same as a large Vs merely adequate, size bass bin.
Crazy like a Fox!
absolutely!
GM
True, though this has been changing in recent years as PA sound in general has improved, particularly in cinema sound.
Correct, and it's what WGs and mouth round overs address. Note that the horn in the picture was designed for high speech intelligibility in the 'telephone' BW with a well defined power response, whether it be located up on a pole, behind a cinema screen or in a HIFI app with the latter being a very limited BW circa 1950 when it was released. Still, cutting out the vane welds and bridging the gap with silicone helps with mouth resonances as does adding a thick insulation 'baffle' around it.
Mounting it to a rigid baffle is a 'mixed bag' in that it helps to mechanically damp the horn and complete its truncated mouth, but also adds strong notches in its response if its edges aren't well damped, so ideally you want to mount it to at least a ~30.5" wide x 21.56" tall well braced/damped baffle to ensure that the XO has rolled it off enough that there's no eigenmodes worthy of the name being generated to reflect back to the horn's throat.
GM
Depends on the horn's physical properties and whether or not it's damped externally.
Yes, but...... if the horn mouth is already large enough to support its 1/2 WL XO LF corner frequency such as the 511, 811 has, then any edge diffraction will be quite high in frequency, ergo of very low amplitude and while out-of-phase it adds a bit to its HF polar response up where our phase hearing acuity is ~non-existent. Altec chose to add the vanes as reflectors to both deal with HF beaming and intensifying this diffraction, so the downside to the damped baffle in my previous response is a loss of HF, especially off axis and if a super tweeter is used, then the throat needs damping to flatten its power response.
Anyway, while these horns work well for what they were designed for and can be tweaked enough to work well enough for many folks in the 'digital age', they belong in a period correct app for best performance and let true WGs have their time now that power is plentiful and digital delay is no longer a 'pipe dream'.
GM
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