Stage issues. Help!

Re: Stage issues. Help!

Bennett Prescott said:
If I knew, I would tell you! That assumes several things: Your subwoofers and mains are equalized flat, they are equal gain to begin with, they have the same acoustic crossover slope (unlikely), they are time aligned (maybe, to where?).
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My subs and mains are both qualized flat with both gains set to 32db the slopes are Sub LP24 and Highs HP24.

Were the delay specs you gave in the previous post refering to my setup with a 7db increase in sub bandpass gain?
 
Re: Stage issues. Help!

Jonathan Betts said:
My subs and mains are both qualized flat with both gains set to 32db the slopes are Sub LP24 and Highs HP24.

Were the delay specs you gave in the previous post refering to my setup with a 7db increase in sub bandpass gain?
Click to expand...

I'll be back a little later, but very quickly, I wanted to mention that I'm pretty impressed you went from "What's that muddy sound?" to "Won't changing the gain of the bandpass change the crossover point?" in 24 hours. :)
 
Re: Stage issues. Help!

Jonathan Betts said:
My subs and mains are both qualized flat with both gains set to 32db the slopes are Sub LP24 and Highs HP24.

Were the delay specs you gave in the previous post refering to my setup with a 7db increase in sub bandpass gain?
Click to expand...
Sorry, I was referring to final acoustic gain. If your subs are already 6dB hot acoustically then your crossover point is already wrong... hard to say without taking a measurement. The delay specs I gave you will probably work for a 100Hz HPF on your tops and an 80Hz LPF on your subs. You could probably change the HPF on your tops to LR12 and be a lot closer to being matched up, slope and phase shift wise, between your subs and tops at crossover... but that depends on how low your tops go.
 
Re: Stage issues. Help!

My tops are rated down to 50hz. Would it make more sense to match the sub LPF and top HPF around 85hz or is there a benefit to setting 100hz tops 80hz subs. This has been recommended by some. On the other hand I have read that you should try to match your LPF and HPF. Does anyone have experience running the 515 and 718 together? I have not been able to find any threads with this setup, especially using an ITECH and aux fed subs.

Again, thanks for all your help! Without you guys I would be lost in the dark.
 
Re: Stage issues. Help!

Should I be doing something else to adjust the level of bass in the system so I don't mess up the crossover point? Would setting different gain sensitivities on each channel say 32db for subs and 26db tops be a better way to go?
 
Re: Stage issues. Help!

LP of 80 hz on the sub and 100hz HP on the tops
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That is "the half octave split between the crossover points"
As McCarthy says in his chapter on "Acoustic Crossovers" - it's a lot easier to integrate when the the split and response curve and performance aspects are symmetrical.
 
Re: Stage issues. Help!

I find it easier to think in terms of the acoustic crossover (eyes on the prize) rather than focusing on the electrical crossovers.
 
Re: Stage issues. Help!

That's it:
With the signal level being attenuated ( already down @ chosen xover points ) and the curves in steep decline on both parts the response drop is significant the further from the xovers point.
A 6db down on both parts at the same xover will sum and transition flat* ; with that much of a gap a potential hole exists between the 2 points.
I've seen gaping done but it's tricky and often as compensation ( like Kentucky Windage, not SOP )

* variables to be dealt with
 
Re: Stage issues. Help!

Yep. Sorry guys, was doing too many things at the same time and didn't realize I'd spit out a thought fragment.

1/2 octave is a rough guide to how much space to have between HP and LP using L/R filters (defined at -6dB points) and 10dB more final, acoustic gain on the subs than the tops. This assumes that subs are equalized flat for at least an octave past that crossover point. The tops behavior below XO is much less critical.

There is no "gap", this is not "kentucky windage", these are the electrical settings required to get the proper crossover in the air, which is all that matters. If you think your loudspeakers behave like your crossover you need to spend some time with Smaart.
 
Re: Stage issues. Help!

Ahem...
Apparently my attempt to greatly simply summation doesn't set well.
Sorry for the input (distraction) on this thread.
 
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Re: Stage issues. Help!

Bennett Prescott said:
If you think your loudspeakers behave like your crossover you need to spend some time with Smaart.
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Sorry for the sidetrack, but you should know that Robert is very well aware of this, probably even to a greater degree than most posters here. Perhaps there is some communication gap between folks in the last few posts.... I can say with certainty he's one of the brighter minds here and is no slouch. Please go easy.
 
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Re: Stage issues. Help!

I have been messing around with SA and my settings visually don't look good.

Channel 1:

But 18 HP frequency 31hz
LR 24 LP frequecny 80hz

Channel 2:

LR 24 HP frequency 80hz

When I raise the bandpass gain 8db on channnel 1 the crossover changes to (100hz -6db). The HP on channel 1 is +5db!. Should I move the HP on channel 1 up to 43hz to compensate or go with a steeper Butterworth slope?

Bennett, I could not find a LR 12 for my HP(mains) in SA.
 
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Re: Stage issues. Help!

Jonathan Betts said:
I have been messing around with SA and my settings visually don't look good.
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I wouldn't expect them to.

Which crossover changes? What do you mean by the HP is +5dB? The HPF on channel one, which I assume is your subwoofer, shouldn't have anything to do with it. We're talking about the relationship between the LPF on channel one, and the HPF on channel two.

Bummer that they don't give you LR12. Do they give you LR36? You could use that on the subs, add phase shift instead of taking it away and get the same effect of equal slopes.
 
Re: Stage issues. Help!

Bennett Prescott said:
I wouldn't expect them to.

Which crossover changes? What do you mean by the HP is +5dB? The HPF on channel one, which I assume is your subwoofer, shouldn't have anything to do with it. We're talking about the relationship between the LPF on channel one, and the HPF on channel two.

Bummer that they don't give you LR12. Do they give you LR36? You could use that on the subs, add phase shift instead of taking it away and get the same effect of equal slopes.
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The HP on the sub goes from -3db to +5db when the bandpass is raised to +7db. Doesn't this defeat the purpose of the sub HP? I do believe there is a LR36.

Silas just made me a custom preset. I can't wait to try it out!
 
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