Ok, no worries, it's helpful regardless, I appreciate your time. 🙂
Found that software. Trying to use it. I think I got the circuit back together, with some changes based on what I'm seeing.
Though I can't seem to get the different driver shapes and sizes to load in the diffraction calculator (I assume this is the one to use?). Or should I use the enclosure tab to try to create that there?
Attached my file (with .txt at the end, just remove that)
Very best,
Enclosure is just for speaker enclosure alignments.
You will use diffraction tool to model position on the baffle.
The driver is rectangle SD is 34mm x 150mm
Diffraction Tool will also generate the proper off axis info.
In half space response tap, open the 0 degree FRD file from dayton.
Click full space.
The shape and baffle is up to you, in real time you will see the response created by the baffle.
It is also up to you to decide listening position. Since all other drivers will be placed at certain
distances from listening position for phase response to be correct.
There is 2 ways to establish the listening position.
1) Place mic over whatever driver to be listening position. Likely the GRS planar.
When you model the other drivers. Do not move microphone, only individual driver positions.
leave microphone at listening position
2) If you move the microphone centered over each driver you will have to calculate
The XYZ placement of each driver in the crossover.
Click directivity tap, click vertical angles, click negative response if wanted.
I set individual measurements to 10 degrees.
Click export, save it to a file you remember. It will generate FRD files for all off axis info.
In crossover designer, for specific driver FRD you will import all the FRD files created.
Or much easier in Diffraction Tool click Feed Speaker. In crossover tool Click driver you want to Feed.
Same thing click export, again designate a folder to save to, once done it automatically puts all FRD
files into the driver you highlighted.
I will try to make a screenshot which can vaguely make that confusion clear.
As you can see with everything clicked as said and both windows open. In drivers I created a driver named for the planar and it is highlighted.
Feed speaker is also clicked. Once I click export. I will name that file likely PT6816 so the frd files make sense and save to a file where i know is located.
obliviously click photo to enlarge
when I pressed export, I created a file I wanted to save too, created the name PT6816, I used the tap to save it as FRD. After clicking save.
Bloop like magic all the FRDs appeared into the driver I selected. Now when I wire straight to that in crossover.
You will see all the off axis information. Hopefully clear how feed speaker works. In the driver tap use the ZMA file for PT6816 from dayton
So impedance is also correct.
So obvious now the baffles size must be established, the driver positions must be established.
You will have to use FRD files for the woofers and use the SD size in the datasheet.
Those positions must be established, if you use 2 woofers both need full FRD for those positions.
Yes phase will be different from listening position, and it is a absolute waste of time to not model
correctly.
You will use diffraction tool to model position on the baffle.
The driver is rectangle SD is 34mm x 150mm
Diffraction Tool will also generate the proper off axis info.
In half space response tap, open the 0 degree FRD file from dayton.
Click full space.
The shape and baffle is up to you, in real time you will see the response created by the baffle.
It is also up to you to decide listening position. Since all other drivers will be placed at certain
distances from listening position for phase response to be correct.
There is 2 ways to establish the listening position.
1) Place mic over whatever driver to be listening position. Likely the GRS planar.
When you model the other drivers. Do not move microphone, only individual driver positions.
leave microphone at listening position
2) If you move the microphone centered over each driver you will have to calculate
The XYZ placement of each driver in the crossover.
Click directivity tap, click vertical angles, click negative response if wanted.
I set individual measurements to 10 degrees.
Click export, save it to a file you remember. It will generate FRD files for all off axis info.
In crossover designer, for specific driver FRD you will import all the FRD files created.
Or much easier in Diffraction Tool click Feed Speaker. In crossover tool Click driver you want to Feed.
Same thing click export, again designate a folder to save to, once done it automatically puts all FRD
files into the driver you highlighted.
I will try to make a screenshot which can vaguely make that confusion clear.
As you can see with everything clicked as said and both windows open. In drivers I created a driver named for the planar and it is highlighted.
Feed speaker is also clicked. Once I click export. I will name that file likely PT6816 so the frd files make sense and save to a file where i know is located.
obliviously click photo to enlarge
when I pressed export, I created a file I wanted to save too, created the name PT6816, I used the tap to save it as FRD. After clicking save.
Bloop like magic all the FRDs appeared into the driver I selected. Now when I wire straight to that in crossover.
You will see all the off axis information. Hopefully clear how feed speaker works. In the driver tap use the ZMA file for PT6816 from dayton
So impedance is also correct.
So obvious now the baffles size must be established, the driver positions must be established.
You will have to use FRD files for the woofers and use the SD size in the datasheet.
Those positions must be established, if you use 2 woofers both need full FRD for those positions.
Yes phase will be different from listening position, and it is a absolute waste of time to not model
correctly.
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Simulating the driver in an actual cabinet with baffle step loss is a decent amount of work. Follow the first link to Google Drive in this post and download the article "Simulation without Measurement in VituixCAD". I am good with VituixCAD and this took me a long time and it was still pretty hard to figure out what was going on, since some things don't look "quite right". [Also, pay attention to the disclaimers - this is all simulation and may not reflect reality.]
The main problem I ran into is that while the woofer is rated 88.4db sensitivity and the GRS Planar is rated 94 db, once I modeled the GRS Planar on the baffle the dip in the 2khz region is lower than the dual woofers. Thus, I couldn't use any resistors or the planar is playing too low relative to the dual woofers. Of course, this may or may not be true in reality, but you won't know without buying the drivers, making a prototype and taking actual measurements, if you go this route.
Here is the simulation of the tweeter on a 12 inch wide baffle.
Simulation of the woofer on baffle in 4-pi space.
And a crossover using roughly LR4 slopes at 550hz. (No idea if the planar can really go that low or not.)
The main problem I ran into is that while the woofer is rated 88.4db sensitivity and the GRS Planar is rated 94 db, once I modeled the GRS Planar on the baffle the dip in the 2khz region is lower than the dual woofers. Thus, I couldn't use any resistors or the planar is playing too low relative to the dual woofers. Of course, this may or may not be true in reality, but you won't know without buying the drivers, making a prototype and taking actual measurements, if you go this route.
Here is the simulation of the tweeter on a 12 inch wide baffle.
Simulation of the woofer on baffle in 4-pi space.
And a crossover using roughly LR4 slopes at 550hz. (No idea if the planar can really go that low or not.)
Note: I incorrectly used the actual physical width of the Planar mid whereas WhiteDragon correctly used the width of the ribbon portion.
EDIT: I revised the Planar dimensions but it did not change anything. I still get a much deeper "valley" around 2khz than WhiteDragon. I would trust WhiteDragon's results over mine.
EDIT: I revised the Planar dimensions but it did not change anything. I still get a much deeper "valley" around 2khz than WhiteDragon. I would trust WhiteDragon's results over mine.
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Vituixcad will not simulate breakup so you want polars, otherwise simulations should be considered inaccurate approaching and beyond 2kHz.
Dayton has some sparse polars if it's not possible to measure yourself..
https://www.parts-express.com/pedocs/tech-docs/295-315--Dayton-Audio-DC250-8_data.zip
Dayton has some sparse polars if it's not possible to measure yourself..
https://www.parts-express.com/pedocs/tech-docs/295-315--Dayton-Audio-DC250-8_data.zip
By the way. The GRS planars are "knock-offs" of the old B&G (Bohlender-Graebener) drivers. While B&G did not have a SLIM version of the 8-inch, here is an application note for the standard 8-inch. There is a sample notch filter on the last page that worked better than the 0.27mh inductor in my xo above. One thing I didn't think about was the stock GRS is open-back. If you build a damped rear enclosure, that may smooth some things out and will also allow it to go a little lower.
In this build, Scott S. states that the full size B&G Neo8 can't go much below 800Hz.
In this build, Scott S. states that the full size B&G Neo8 can't go much below 800Hz.
A large planar in real life will be clean and accurate in its ideal bandwidth.
Going too low it will find distortion, too high also distortion.
Most the limit is off Axis vertical.
It is almost 8" tall and will behave no different than any other 8" surface.
Crossover is going to be down to 1.4 to 1.8K
Ironically it is same point there is a huge rise at these frequencies.
Huge hint where the distortion is in real life.
Same with low frequency. Technically you can see bandwidth down to 500 Hz
In reality I highly recommend a 3rd order no lower than 600 Hz
Realistically more like 700 Hz to stay away from distortion.
10" woofer has no problem doing so.
Why I liked the idea. Wanted a 10" woofer so the large planer can be crossed
over not to low.
12" could work too, with 15" your getting into trouble.
Problem with planers is impedance is dead flat and very very small bumps in the lowend
to hint the real bandwidth.
Can look at the impedance there is likely 2 itty bitty little bumps down low.
Dont lie to yourself, crossover or less distortion will be towards the higher little bump.
Going too low it will find distortion, too high also distortion.
Most the limit is off Axis vertical.
It is almost 8" tall and will behave no different than any other 8" surface.
Crossover is going to be down to 1.4 to 1.8K
Ironically it is same point there is a huge rise at these frequencies.
Huge hint where the distortion is in real life.
Same with low frequency. Technically you can see bandwidth down to 500 Hz
In reality I highly recommend a 3rd order no lower than 600 Hz
Realistically more like 700 Hz to stay away from distortion.
10" woofer has no problem doing so.
Why I liked the idea. Wanted a 10" woofer so the large planer can be crossed
over not to low.
12" could work too, with 15" your getting into trouble.
Problem with planers is impedance is dead flat and very very small bumps in the lowend
to hint the real bandwidth.
Can look at the impedance there is likely 2 itty bitty little bumps down low.
Dont lie to yourself, crossover or less distortion will be towards the higher little bump.
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As mentioned zoom way in there at the impedance curve.
The dominate lower bump around 400 Hz might make people think
" oh ok , as long as im above 400 Hz , everything is fine.
The little guy at around 680 Hz is the actual hint.
I have found this with large or small planars.
Dont kid yourself, the hidden little upper bumps in impedance are the clue where the drivers real bandwidth is.
Otherwise like most of them, the dead flat 7 ohms across is beautiful
I don't like the idea of two large woofer placed above each other, on the bottom of a cabinet, run in parallel and reproducing 1 kHz or more. An important part of the frequency range will come basicaly from the floor, while the planar will be at ear position, reflecting fom the ceiling. The resulting response at listening position will be some kind of strange, to say it polite.
Usually in such a construction, the lower woofer would be limited to be a sub, lifting the source of midrange higher. What makes it a 3-way.
Another option may be one woofer on top, framing the planar. This may work even better, with a quite low crossover point like 800-1000Hz. Going for 10" or even better 8" drivers would make it more of a HIFi speaker. The idea of an integrated, active sub on the side would be a smart move. IMO low bass should always see some active correction today. Not worth building something nice and making the low end some random product of the room.
Usually in such a construction, the lower woofer would be limited to be a sub, lifting the source of midrange higher. What makes it a 3-way.
Another option may be one woofer on top, framing the planar. This may work even better, with a quite low crossover point like 800-1000Hz. Going for 10" or even better 8" drivers would make it more of a HIFi speaker. The idea of an integrated, active sub on the side would be a smart move. IMO low bass should always see some active correction today. Not worth building something nice and making the low end some random product of the room.
Correct , this has been the suggestions all along.
Ranging from 600 Hz to 800 Hz
The 8" planar and likely another planar for highs
Would cover listening level.
As noted in post 78
Dont expect much usable range from 500Hz to 2000 Hz with a planar this size.
And noted by others to stay away from lowend distortion.
That creeps up to around 600 to 800 Hz
Also noted vertical being taller area, limited to whatever off axis masterpiece he is willing to create.
That will be limited to 1400 to 1800 Hz.
Trying not to confuse the poor guy to much.
He just got a little quiet with new software....
Im sure he is yelling at the screen and getting over that frustrating learning curve. LOL
been there
2 woofers moves more towards .5 anyways.
But that is way out of league at the moment.
All in good time.
Yes vertical in all simplicity 2x 10" gonna behave like a 20"
So lets see if the insanity is caught by the awakening of Sim.
Before real life rips your hair out.
Since many seem to ignore that " Vertical" button
.5 to the rescue
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Thank you so much, I will try to implement this and learn more. Appreciate all the help!
Very best,
Thank you so much for all of that, I appreciate you taking the time, I will try this out and read the article! Appreciate it!
Very best,
This is a good point, thanks, I have been going back and forth thinking of using smaller woofers and tighter grouping for a 2 way and then going active with integrated subwoofer in the lower chamber in the tower. Every time I started placing the 10's, it got weird.
Very best,
Not at all, I'm happy to receive corrections and guidance. Crossover work is my weakest point easily, I'm spoiled with active DSP on everything. So exploring this is good exercise to help change my way of thinking. So I appreciate all commentary! It's not a problem, every step is progress and I like it!
Very best,
So based on some comments above, I'm looking at moving to a simple 2 way sealed portion of the tower to hold the planar wideband and a smaller mid-woofer, like this:
GRS 6PT-8
92db sensitivity
8ohm
https://www.parts-express.com/GRS-6PT-8-6-1-2-Paper-Cone-Prosound-Woofer-8-Ohm-292-800?quantity=1
To see if I can cross around 1khz or so. And let it drop to whatever it can get to in a sealed volume, 100~120hz would be fine.
Then active subs with dedicated low pass filter and amp for the rest of the volume of the tower below these.
Other mid woofers to consider maybe (singles, with 92~94db sensitivity):
https://www.parts-express.com/GRS-8PT-8-8-Paper-Cone-Prosound-Woofer-8-Ohm-292-802?quantity=1
https://www.parts-express.com/Dayto...Power-Midbass-Driver-8-Ohm-295-636?quantity=1
https://www.parts-express.com/Dayto...Power-Midbass-Driver-8-Ohm-295-635?quantity=1
The new baffle width going this direction would likely be 10" total.
Very best,
GRS 6PT-8
92db sensitivity
8ohm
https://www.parts-express.com/GRS-6PT-8-6-1-2-Paper-Cone-Prosound-Woofer-8-Ohm-292-800?quantity=1
To see if I can cross around 1khz or so. And let it drop to whatever it can get to in a sealed volume, 100~120hz would be fine.
Then active subs with dedicated low pass filter and amp for the rest of the volume of the tower below these.
Other mid woofers to consider maybe (singles, with 92~94db sensitivity):
https://www.parts-express.com/GRS-8PT-8-8-Paper-Cone-Prosound-Woofer-8-Ohm-292-802?quantity=1
https://www.parts-express.com/Dayto...Power-Midbass-Driver-8-Ohm-295-636?quantity=1
https://www.parts-express.com/Dayto...Power-Midbass-Driver-8-Ohm-295-635?quantity=1
The new baffle width going this direction would likely be 10" total.
Very best,
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I still like your previous idea, you just need a different woofer. Consider a pair of RS225-8s. This is a great driver and can reach to 1.4khz with an LR4 crossover and an F3 of 34 hz. I'll simulate something tonight using actual RS225 measurements on a 10.5" wide baffle, since I have them from a previous build.
Even if you go with your idea above with separate subs, the RS225 sealed is agood great choice.
Even if you go with your idea above with separate subs, the RS225 sealed is a
Thanks, both are still options, I'm just trying to organize thoughts, and it helps to talk about it out loud with others as the criticism and idea sharing helps iron out issues and get closer to a good solution to move forward on.
Thanks for any help! Appreciated!
Very best,
Revisiting the idea of doing a single planar and a single mid-woofer to be a basic 2 way. And the rest of the tower being an active integrated subwoofer with its own power, etc.
Here's the 2 way planar & mid woofer draft:
This is:
1 x GRS PT6816-8 Planar wideband
1 x GRS PT6-8 Mid Woofer
The rest of the tower would be:
2 x GRS 8SW4HE (subwoofer drivers) in series
Sealed
2.5 ft^3 volume
300w plate amp with low pass filter, auto on, 30hz +6db boost, etc powering all the subs.
I'll run it up to about 120hz to the mid-woofer above.
Here's a sim of the +6db boost at 30hz:
Gives me the flat to 30 goal without bass reflex and without passive radiator. Just good old sealed.
Very best,
Here's the 2 way planar & mid woofer draft:
This is:
1 x GRS PT6816-8 Planar wideband
1 x GRS PT6-8 Mid Woofer
The rest of the tower would be:
2 x GRS 8SW4HE (subwoofer drivers) in series
Sealed
2.5 ft^3 volume
300w plate amp with low pass filter, auto on, 30hz +6db boost, etc powering all the subs.
I'll run it up to about 120hz to the mid-woofer above.
Here's a sim of the +6db boost at 30hz:
Gives me the flat to 30 goal without bass reflex and without passive radiator. Just good old sealed.
Very best,
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And, going back to passive, here's a stab at using two RS225 woofers.
1 x GRS PT6816-8 Planar Wideband
2 x Dayton RS225-8 Woofers
Here's the two RS225 woofers in bass reflex, 2 drivers in parallel.
3 ft^3 net
30hz tune
70w on this one
Very best,
1 x GRS PT6816-8 Planar Wideband
2 x Dayton RS225-8 Woofers
Here's the two RS225 woofers in bass reflex, 2 drivers in parallel.
3 ft^3 net
30hz tune
70w on this one
Very best,
I simmed the GRS Planar Slim 8 with dual RS225-8's and it looked fine. I won't post it, unless you specifically want to see it, as I think the sims at this point will reveal if there is something drastically inconsistent with the driver-pairing but otherwise aren't that close to reality to know too much.
The sim and idea you posted above looks perfectly fine.
Not sure how often you monitor Parts Express, but they started another big "Warehouse Bargain Blowout" today with some pretty good deals. Nothing against the PT6-8 (I think I may even have some on my basement shelf) but take a look at the Reference Series in 6, 7 or 8 inches, aluminum or paper.
EDIT: you posted your sim of the RS225 while I was typing, so hadn't seen it.
The sim and idea you posted above looks perfectly fine.
Not sure how often you monitor Parts Express, but they started another big "Warehouse Bargain Blowout" today with some pretty good deals. Nothing against the PT6-8 (I think I may even have some on my basement shelf) but take a look at the Reference Series in 6, 7 or 8 inches, aluminum or paper.
EDIT: you posted your sim of the RS225 while I was typing, so hadn't seen it.