We have got some data from Danny and waiting for the final batch to arrive to make sure all the data is the same but should be.
The first thing you notice with XBL^2 driver is they sound over all clear and clean.
Meaning the same driver using the same soft parts on them, the motor change only .People pick out the XBL driver as sounding clean and clear as well as some find the bass is tighter with a fuller upper mid range as well.This has a lot to do with the BL having more control with the XBL driver.
This test can be done for anyone who wants to listen here or I belive Danny can as well.
That is just put the pair of drivers in a box same volume with a on off switch on each driver to switch from one driver to the next.
Adire has this for a 10" driver and anyone who has ever done the A,B test when I was around Adire all picked the XBL driver as a sound quality pick over the other .
No one made a direct comment to more bass ,which most people really think is the main advantage of XBL.
When XBL gets implimented into a driver it takes a lot of work working with Adire and the manufacture as Dan made
here
XBL^2 designs are also harder to get built right (most build houses don't understand how critical the VC length and placement is to the performance).
In reality, VC length is crucial to a good linear XBL² motor. And in reality it is EXTREMELY easy to get right; the issue has been getting manufacturers to actually ACCEPT that when you say 4 layers with 162 turns of 0.3mm single-coat wire, you MEAN exactly that. With most drivers, anywhere from 152 to 180 turns would be fine.
Winding voice coils, though, is quite simple to get to the exact number of turns. You just have to convince the manufacturer to pay attention to it. Often you'll call out a 6.2mm long voice coil, and they have 6mm and 6.5mm in stock, so will use one of those. No, it needs a specific length. It's not hard - in fact, getting accurate, repeatable VC winding lengths is trivially simple! It just takes time to convince the factories that it needs to happen.
Once it does, though, watch out!
When Adire makes notes for a manufacture to follow they must follow the design layout.Not just use parts they have in stock most times.
This is the main issue what has taken so long to get the drivers made for the M-130X.
Back to your questions about tuning.
The low end of the M-130X will stay the same meaning same ports tuning will be a little lower but not a lot.But the XBL driver sounds like it has a lot lower tuning .All due to the XBL.
Here is a test with the m-130 Danny did
Here is a M-130 mounted in a box with damping material. The measurement was taken at 7" (near field just like John's) with a 4ms gated time window. This is an un-smoothed response.
Here below is the RAV1X finished speaker with the crossover.There is no upper scale of the M-130 driver to the fact there is no tweeter present.
