BAH! Can't upload FRDs; they're 19.6 Kb with minimum phase, 512 pts. Shall I strip the phase or redo them with lower (256 pt.) resolution? Strip readings below 100 Hz? Zip them? (Never done that.)
Here they are as image:
ZMAs below.
C/C distance 10.5"
HF front plate ~2" behind LF
Drivers measured via windowed MLS (185 Hz min resolution) on-axis @ 44", 1/6 octave smoothed.
Is this on the tweeter-axis for both plots? Or separates?
Then you would also need to measure offsets, cab-size, edge-treatments, etc and post those too.
I have a few other ones to sim first...
Later,
Wolf
"Wolf, you shall now be known as "King of the Zip ties." -Pete00t "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith "We don't just make a crossover, we make a statement!" - Lawrence Fishburne for Cadillac
They are separates, but I can redo with both at any desired forward axis. On tweeter axis tilts the forward lobe upward arctan 5.25/44 = 6.80° if that is to be the design axis and we approximate the vertical center between drivers as the midpoint between them.
I thought about this, and grabbing FRDs from published curves assumes separates, so I did the same. Did both, actually, but separates seemed to produce a better result. PCD does not model constant directivity waveguides that I have found. Point source is possibly that over a limited range.
As we are discussing elsewhere in this forum, cab edge treatments are a non-issue, though I admit it takes some courage to ignore the all-around 1.125" overhang present here. The waveguide pattern is 90° x 50° (-6 dB). The opening of the recessed woofer does seem to be showing up in the curves, and we'll likely address that by rounding it over and hope it helps.
BAH! Can't upload FRDs; they're 19.6 Kb with minimum phase, 512 pts. Shall I strip the phase or redo them with lower (256 pt.) resolution? Strip readings below 100 Hz? Zip them? (Never done that.)
Here they are as image:
ZMAs below.
C/C distance 10.5"
HF front plate ~2" behind LF
Drivers measured via windowed MLS (185 Hz min resolution) on-axis @ 44", 1/6 octave smoothed.
Target: 1.5 kHz acoustic.
Need more info?
You show yours and I'll show mine.
[Y'all go first.... ]
You can upload the FRDs. you just need to compress them into a ZIP file first.
R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
I had already converted them to text for uploading, so have to rename .frd to use them, maybe?
Do they yield the curves as posted in the image above?
Hmm ... looks like I could have zipped the folder instead of individual files, without renaming them. Does that work?
Q: Is the formula bar supposed to be open? I can't save sessions with the values and files intact, but don't want to bug Jeff about that 'til I figure out if I'm doing something stupid. The saved session files are <1Kb, and I have to input everything manually each time I shut down....
I had already converted them to text for uploading, so have to rename .frd to use them, maybe?
Do they yield the curves as posted in the image above?
Hmm ... looks like I could have zipped the folder instead of individual files, without renaming them. Does that work?
Q: Is the formula bar supposed to be open? I can't save sessions with the values and files intact, but don't want to bug Jeff about that 'til I figure out if I'm doing something stupid. The saved session files are <1Kb, and I have to input everything manually each time I shut down....
Yeah, you didn't have to rename them to txt files before adding them to the zip, and yes, you could have zipped the folder.
Would you say that the acoustic centers are pretty close (about the same depth from the baffle?
I'll get back to you shortly. let me play with these for a bit.
R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
I had already converted them to text for uploading, so have to rename .frd to use them, maybe?
Do they yield the curves as posted in the image above?
Hmm ... looks like I could have zipped the folder instead of individual files, without renaming them. Does that work?
Q: Is the formula bar supposed to be open? I can't save sessions with the values and files intact, but don't want to bug Jeff about that 'til I figure out if I'm doing something stupid. The saved session files are <1Kb, so I have to input everything manually each time I shut down....
The file is programmed to not allow you to save it with anything in it. It is a much larger file than you might think. However, if you save out your session. Then the next time you need to load the frd, zma, and csp files and everything will be back where it was - no need to enter everything manually beyond that. The program has always worked this way for a number of reasons. I may consider changing that for the final edition someday.....
BAH! Can't upload FRDs; they're 19.6 Kb with minimum phase, 512 pts. Shall I strip the phase or redo them with lower (256 pt.) resolution? Strip readings below 100 Hz? Zip them? (Never done that.)
Here they are as image:
ZMAs below.
C/C distance 10.5"
HF front plate ~2" behind LF
Drivers measured via windowed MLS (185 Hz min resolution) on-axis @ 44", 1/6 octave smoothed.
Target: 1.5 kHz acoustic.
Need more info?
You show yours and I'll show mine.
[Y'all go first.... ]
13 components, 5 on woofer, 8 on tweeter. 1KHz LR4. I finally saw the acoustic center info you mentioned.
R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
Would you say that the acoustic centers are pretty close (about the same depth from the baffle?
The HF front plate is ~2" behind the LF. Various iterations in PCD have given me different offsets with phase aligned on the known forward axis, but the current one is 62mm.
The file is programmed to not allow you to save it with anything in it. It is a much larger file than you might think. However, if you save out your session. Then the next time you need to load the frd, zma, and csp files and everything will be back where it was - no need to enter everything manually beyond that. The program has always worked this way for a number of reasons. I may consider changing that for the final edition someday.....
So I need either to save the current session as a new file, or delete the old one first? And reload ZMA and FRD each time?
I mention the formula bar because some values are not ending up in the correct fields on reloads. Sounds like I may be reloading an earlier screwup and need to start from scratch with the session files, maybe.
So I need either to save the current session as a new file, or delete the old one first? And reload ZMA and FRD each time?
I mention the formula bar because some values are not ending up in the correct fields on reloads. Sounds like I may be reloading an earlier screwup and need to start from scratch with the session files, maybe.
Give the session files different names - no need to delete any. I have dozens; the names tell me what they are for. Yes, reload the frd and zma each time. If you know where the files are then it is really pretty fast.
13 components, 5 on woofer, 8 on tweeter. 1KHz LR4. I finally saw the acoustic center info you mentioned.
Looks good, Pete! Where is the forward axis?
1KHz is likely too low for D220Ti, and this waveguide has lost vertical pattern control down there, as well. I'm at 1.8 KHz, 6 components, 2 on woofer, and 4 on tweeter, but I'd sure like to get down to ~1.5 KHz, with the forward axis just above the midpoint between the drivers.
Here's Geddes's vertical polars on this driver/waveguide combo, in 7.5° increments, i.e., light blue line is 30°:
1KHz is likely too low for D220Ti, and this waveguide has lost vertical pattern control down there, as well. I'm at 1.8 KHz, 6 components, 2 on woofer, and 4 on tweeter, but I'd sure like to get down to ~1.5 KHz, with the forward axis just above the midpoint between the drivers....
I was using tweeter axis.
Also, I was trying to avoid that nasty resonance area in the woofer if possible. I didn't know enough about the tweeter to know where to cross it and figured the lower, the better from an acoustic center perspective.
I'll move up the targets to 1500Hz and see what happens.
R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
Yes, and I'm too close to it; you've notched it down hard, looks like....
Well, I reset the targets and took another shot at it. I still have more components than you, mainly to take care of that resonance and give the woofer a smoother roll off. 4 on the woofer, 5 on the tweeter to do some shaping as well.
Also, the targets are no longer LR4, but some other setup. With the driver arrangement you are showing, tweeter under woofer and tweeter wired positive phase, there's a very wide lobe, forward and above the tweeter axis. Invert the tweeter polarity and the lobe is below, with almost no change to response on axis.
R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
Well, I reset the targets and took another shot at it. I still have more components than you, mainly to take care of that resonance and give the woofer a smoother roll off. 4 on the woofer, 5 on the tweeter to do some shaping as well.[/IMG]
We are very close, and have arrived at the same topology, looks like, as I'm 5 on the tweeter, not 4. I have PM'd you my values.
The speaker is upside-down in the pic for convenience in measuring, though it should work either way. When I said forward axis "above" the midpoint between drivers, I meant between there and the waveguide, actually. Sorry for that confusion.
Interestingly, there's a current thread about speakers for a HS bandroom. In that installation, they'd be mounted as in the pic, up high, with the forward axis aimed slightly downward.
We are very close, and have arrived at the same topology, looks like, as I'm 5 on the tweeter, not 4. I have PM'd you my values.
The speaker is upside-down in the pic for convenience in measuring, though it should work either way. When I said forward axis "above" the midpoint between drivers, I meant between there and the waveguide, actually. Sorry for that confusion.
Interestingly, there's a current thread about speakers for a HS bandroom. In that installation, they'd be mounted as in the pic, up high, with the forward axis aimed slightly downward.
It's beginning to lose vertical pattern control at 3 kHz, still usable at 2 kHz, but below that, we're relying upon the vertical nulls to augment the pattern per the teachings of Pi-Speakers' Wayne Parham. The horizontals reach nearly an octave lower with equivalent control. Load in separate tabs and click between them to view the difference in directivity....
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