I’m not sure I follow what you want to do about sliding the 10F back? It needs to mount flush on baffle or else there is diffraction.
The 4mH is a low pass at 900Hz so sort of matches where the baffle step starts.
Felt will take care of diffraction.
Just trying to get the 10f 2.5" to 3" back for time alignment.
I believe florianderton is right.
Upside down, the 10f is 1.6" behind, and you even said it needs to be closer to 2.5 to 3" behind.
I think the classic right triangle step response can be improved (yea I'm talking to you stereophile, take note).
In the classic "correct" step response for alignment, we see the tweet hit first then the woof, but not at the same time.
So, yea, I'll go out on a limb and say the classic sharp step is not as good as it can be.
Please, someone find a step response 2-way picture of a time phase aligned speaker that also shows to woof and tweet firing like the picture below.
And yes, you hear a change.
Dunlavy commented on alignment down to microseconds.
The woof should fire first but tweet fire just after but both hitting max at the same time.
In post 1973, i believe your picture, you showed this.
I am sure i am not the only one who has this question ?
If this is a sore spot i will stop posting on this thread.
Here is your picture.
Just trying to get the 10f 2.5" to 3" back for time alignment.
I believe florianderton is right.
Upside down, the 10f is 1.6" behind, and you even said it needs to be closer to 2.5 to 3" behind.
I think the classic right triangle step response can be improved (yea I'm talking to you stereophile, take note).
In the classic "correct" step response for alignment, we see the tweet hit first then the woof, but not at the same time.
So, yea, I'll go out on a limb and say the classic sharp step is not as good as it can be.
Please, someone find a step response 2-way picture of a time phase aligned speaker that also shows to woof and tweet firing like the picture below.
And yes, you hear a change.
Dunlavy commented on alignment down to microseconds.
The woof should fire first but tweet fire just after but both hitting max at the same time.
In post 1973, i believe your picture, you showed this.
I am sure i am not the only one who has this question ?
If this is a sore spot i will stop posting on this thread.
Here is your picture.
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I did similarly:
Reference Build - Google Photos
My first baffles had the setback built in. I've also made baffles for just the 225's, and some boxes for the full range driver so I can dial in the set back, measure, move, etc. until it's right.
I haven't done this yet, as we're in the middle of a large master suite re-model.
I measured and dialed in a bit with the small open baffle on top of the test lf box I built, but I can't find them.
Just a hobby project, but we are trying to do it right. We are new to speaker building but have a ton of other DIY experience. I would like to compete in the Dayton Audio speaker building competition. We'll see if these are the ones that could win it. I'm not sure who the ribbon would go to; so many people helping us build these. XRK is our technical lead and should probably get the credit. I'll use my DIY experience to make him a blue ribbon....LOL
Foam Dampening
I ran out of the black foam, but I had some red foam. It's thinner and not as dense, but I think it will work just as well, if not better. The red ones are for XRK. I used four small dabs of hot glue in each corner. The foam can easily be replaced if you like a different kind but it's so much easier to do before they are closed up. I'm also planning on adding polyfill and wiring for you. It's easy enough for me to do in the assembly line. You should only need to add: Stain, Drivers & Crossovers. This consistency should help us collaborate on testing results.
I ran out of the black foam, but I had some red foam. It's thinner and not as dense, but I think it will work just as well, if not better. The red ones are for XRK. I used four small dabs of hot glue in each corner. The foam can easily be replaced if you like a different kind but it's so much easier to do before they are closed up. I'm also planning on adding polyfill and wiring for you. It's easy enough for me to do in the assembly line. You should only need to add: Stain, Drivers & Crossovers. This consistency should help us collaborate on testing results.
I feel like using thinner and denser foam might be good on transition line speakers, like these. I want to leave a more open channel for sound waves to travel and this 2" open sell egg crate takes up a lot of space in the cabinet. I feel like a thinner egg crate like the 1" red one might be a better use of cabinet space. This is very nit picky, but I thought it was worth mentioning.
Studiomic,
There might be some differences in the damping between the 2in and the 1in red. The 2in one has pointy pyramids and looks like it was for sound treatment in studios. The red looks more like a mattress liner, but that's ok - I would have done the same thing if I ran out. It can be adjusted with stuffing.
If you look at the internal photos of PMC's transmission lines, you will see that the actual cross sectional areas are quite small and constricted with foam - and this is by design, to reduce the boomy bass reflex bass and keep it well damped (but lower output SPL). It is adjusted by measurements and by ear. If you like how it sounds, that is all that matters. If you want to compare them side by side, I can send you my drivers and XO to install.
Thanks to the both of you for making the speakers for me!
There might be some differences in the damping between the 2in and the 1in red. The 2in one has pointy pyramids and looks like it was for sound treatment in studios. The red looks more like a mattress liner, but that's ok - I would have done the same thing if I ran out. It can be adjusted with stuffing.
If you look at the internal photos of PMC's transmission lines, you will see that the actual cross sectional areas are quite small and constricted with foam - and this is by design, to reduce the boomy bass reflex bass and keep it well damped (but lower output SPL). It is adjusted by measurements and by ear. If you like how it sounds, that is all that matters. If you want to compare them side by side, I can send you my drivers and XO to install.
Thanks to the both of you for making the speakers for me!
XRK- Thanks for that info. The red ones are yours. You can easily tear out the red and put in whatever you like. I tried to use the smallest amount of hot glue I could get away with, just in case you needed to replace them. They make a nice pattern for cutting good foam and inserting it. This can be done on this design but it's a much harder job once it's all together.
Great news: the TL’s have been arrived at my house. Sadly, they need to sit in quarantine for a few days before I can okay with them. They look great though. Much larger in real life than I imagined - with nice presence. Yet at the same time, a very compact footprint on the ground. Studiomic and his neighbor cabinetmaker really did a nice job. 
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Or simply drink some bleach as it knocks it out in 1 minute. 
Actually, all stuff brought into the house, whether it be mail, packages, groceries have to sit for a few days in the garage, or get wiped down with bleach first or washed with detergent or vinegar (as is the case with good stuff and perishables). Since this is bare wood, the wiping with bleach is not an option.
Actually, all stuff brought into the house, whether it be mail, packages, groceries have to sit for a few days in the garage, or get wiped down with bleach first or washed with detergent or vinegar (as is the case with good stuff and perishables). Since this is bare wood, the wiping with bleach is not an option.