Prototype baffle and FRD Measurements

I am ready to make measurements of my drivers for a new system (3way). I dont have the actual cabinet yet, only a design. How accurate o representation does the temp baffle have to be? My design is for a 40x14 inch front.
Also since it is a 3 way do I take measurements of (tweet and mid) or( woofer and Mid) etc I dont connect all 3 together do I (as in a 2 way system??)
 
You would probably want to:

(all drivers mounted in cabinet)

  • measure each driver individually one-by-one without XO (protect the tweeter by starting sweep at say 500 - not to loud!)
  • measure each driver individually one-by-one with its intended XO
  • measure the whole system with XO.

No reason to measure any pairs of drivers... and you dont seem to be ready as measuring without a box will be very different from only having a baffle...

//
 
It depends on your measuring setup and software.

If you are using a USB mic then I think the reason you have measuring tweeter and mid together is to determine acoustic offset. If that is the case then you are correct to do that and would want to also measure tweeter and woofer together, assuming your software is going to look at everything relative to the tweeter. If you have a dual channel measurement setup then you don't need to do this.

If you plan on using VituixCAD then the measurement instructions recommend measuring each driver on its axis, i.e., you WOULD move the mic (but NOT change the volume or anything else). I believe most other programs (PCD for sure) you measure everything on the tweeter axis.
 
You would probably want to:

(all drivers mounted in cabinet)

  • measure each driver individually one-by-one without XO (protect the tweeter by starting sweep at say 500 - not to loud!)
  • measure each driver individually one-by-one with its intended XO
  • measure the whole system with XO.

No reason to measure any pairs of drivers... and you dont seem to be ready as measuring without a box will be very different from only having a baffle...

//
Granted this is a bit older- I was told to measure drivers as a pair NO xo for offset...Is this not true? Also thanks for that information...I almost made just a baffle to start RnD on a build I made a post about.
 
Some progress updates on my project
 

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Progress Photos. Im getting the feeling I should start a new thread lol
 

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The reason to measure all 3 drivers in parallel at a low drive level (0.5v - no more to protect a dome tweeter) is to get exact acoustic Z offset for individual driver measurements where you are not using measured phase response in your crossover simulation.

You basically take your individual driver measurements... and change Z offset until the overall frequency response of the combined individual measurements matches the combined measurement.