Zilch,
Rather than bore the absolute crap out of us with all this conjecture how about setting up on real measurements at different power levels and EQ settings to actually prove what you are talking about.
There is not a lot of point to this thread otherwise .
ieIf you can shatter a diaphragm by forcing it as you refer to it would also least prove something.
He has 5db more attenuation at the 1k-2K range than the original filter. If you look at the measured response it looks to me like you can see it there. Could be just the way the curves were spliced. You should really ask him anyway they are his measurements and Voltage Plots.Help me, now. Where's Guido getting the 25 dB of headroom shown in his voltage drives?
Bottom line is, he is happy.
Frankly I don't understand what your point is.
Rob
These are considered medium format drivers...3" diaphragm.Originally Posted by Zilch
The 2425 has 110dB sensitivity...figure in that ball park, which is at least 15dB more than the woofer.
To my knowledge there is no published specs...but you should be able to get an idea with the instruments you have.
Vertec uses three drivers on a wave guide and they need to make lots of clean out put for concert venues.
They don't break a sweat in home use....unless you are completely deaf.
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
Seem to me that all of this talk is based on compensation for the compression driver. But what of the horn that it is mounted on? This will also have a profound impact on the HF, even on-axis.
When I did crossovers for the surrounds that use the W10GTI and 2425, the resistor values for the HF compensation on the P. Audio PH-230 horn were completely different than a similar driver on the JBL 2370 horn.
I believe my point is well made, Rob, and being once again advised to take my two-way crap elsewhere, I'll do that now....
I believe my point is well made, Rob, and being once again advised to take my two-way crap elsewhere, I'll do that now....
Who said your two-way stuff is crap? THE EVEREST II IS BASICALLY A TWO WAY WITH VLF AND UHF AUGMENTAION THAT THEY DON'T NEED TO MAKE GREAT MUSIC>>>> BUT IT WILL SELL MORE SPEAKERS!!!!
The problem lies with your explanation of virtual HF boost and the attenuation of midrange and differences between driver efficiencies and the need to CUT DOWN the output of these extremely sensitive compression drivers to balance out the speaker system through a PASSIVE network by attenuating energy.
You are having a hard time swallowing the fact that we are saying your explanation is convoluted and confusing by your spinning of your point of view.
Get over it....geez.
I'm done with this one...should have been a few post back.
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
Oh boys ...
____________________
Peter
Zilch what’s with you??I believe my point is well made, Rob, and being once again advised to take my two-way crap elsewhere, I'll do that now....
Now you are questioning the validity of the Voltage Drives??
Do you think LEAP is wrong?
The original drive is without the highpass. Do you know what the horns gain is from 1-2K?? Is there a bump there?? If so do you need to bring it down a bit?? That could be the reasons why the voltage drive is lower.
Rob
No, not at all. I am merely reading them.
To the nearest whole numbers:
1) How much compensation does Guido's filter provide between 1.8 kHz and 20 kHz? 21 dB. Do you agree?
2) How much compensation does the Timbers filter provide between those same frequencies? 13 dB
3) What is the difference between the amount of compensation Guido is using between those frequencies versus what Timbers uses? +8 dB
Stay with me now:
4) How much compensation does Guido's filter provide between 10 kHz and 20 kHz? 10 dB
5) How much compensation does the Timbers filter provide between the same frequencies? 4 dB
6) What is the difference between the amount of compensation Guido is using between those frequencies versus what Timbers uses? +6 dB
So, overall, above 1.8 kHz, Guido is applying 8 dB more compensation than Timbers, for the apparent (and stated) purpose of achieving a more full range response.
Of that, 6 dB (6.5 dB, actually) more is being applied in the last octave alone.
Now, back to my original statement quoted in Post #1 of this thread:
It's 8 dB, actually, overall, and more like 6.5 dB in the last octave.
I'm not saying that Guido or anybody else shouldn't do that, nor do I contest any observation anybody may have with respect to how that might sound. I am merely noting that it comprises a significant departure from what that filter's designer considered appropriate for use with essentially the same driver/horn combinaton....
*******
I think we really need to look at them as fixed points and plot them.
Here we go
Gregs Guido Difference
2K -19 -25 -6
5K -14 -19 -5
10k -11 -15 -4
20K -7 -4 +3
Guidos curve is below the average level compared to Gregs except the last octave. There is an 11db delta from 10-20k but he starts at a lower level. These are again negative numbers and you have to look at them systematically to see exactly whats going on. Looking at the total compensation as just whole numbers is misleading. What's important is where the delta's are and what they are doing.
It may be a departure but don't you think Greg would be one of the first to say tune it up the way you like it??I am merely noting that it comprises a significant departure from what that filter's designer considered appropriate for use with essentially the same driver/horn combinaton....
Just becasue it departs from the curve doesn't mean it's wrong. These drivers have to work in a real livingroom and they may sound just great that way depending on the acoustics.
Honestly we can stand here all day poking at each others systems looking at the graphs but what counts is what it sounds like. Unfortunately we can't just pull up a chair and have a listen in our collective livingrooms.
Rob
From your comparison, I'd say we've come to the same conclusion via different methods, Rob.
Note the quote I added to the post immediately above: Greg's using a different woofer (1200FE, not shown,) and is actively crossed. That explains why Guido starts lower, I believe.
[I think we're all actively crossed, actually....]
I'll throw some curves in here just for fun. The Maps tell what the curves are.
.
Greg's filter (2nd rev) for 476Be to replace the 435Be on H4338 horn (no longer applicable due to active bi-amping instead)
Note that the filter was applied to the 476Be on the H9800 horn fo these runs.
Modified Everest II filter (Giskard rev 1)
Plus or minus 1.7 dB from ~ 900 Hz to ~ 13 kHz on H9800
Modified Everest II filter (Giskard rev 2)
Plus or minus 1.9 dB from ~ 900 Hz to ~ 17 kHz on H9800
These curves are without any notch filters. I might be able to get to plus or minus 1.5 dB with a few notch filters. I'm not convinced yet that it would be worthwhile.
These are examples of what the Project May top end looks like.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote