Distortions of Underdriven PA Subwoofers

[STill]

Hello everyone

I am struggling to decide on a subwoofer driver of what will most likely be a vented box with dual opposed drivers with horizontal mounting.
My goal is ~100 dB/1 m (excluding room gain) at 20 Hz with good distortion levels. It will be driven by a high voltage output Class-D amp with DSP equalization.

The Scan Speak Revelator 32w4878 measures very well due to its BL and suspension linearity over its excursion range and low resonance frequency.
However, its suspension is rather soft for a horizontal mounting and it is very expensive.

PA subwoofer drivers are much less expensive even at sizes of 18 inches, providing much higher displacement and effective BL, but at higher resonance frequencies and with "rougher" suspensions.
My problem is that I fail to obtain distortion measurements which allow a comparison to HiFi subwoofer drivers like the Revelator.

For example, Audio Express measured the before mentioned Scan Speak sub in a sealed enclosure, while measuring PA subs in open air and usually at higher SPL's.

Considering a well designed 15/18 inch PA sub driver with a quite linear BL and suspension curve, does anyone have distortion measurements at <50% excursion near and belwo the resonance frequency or can someone make an educated guess?

 

[ppataki]

I have been using PA drivers only in all my DIY sub projects
You have to simulate the drivers first, you will see the SPL and the xmax if you drive them with a given output power
If you are within the xmax range then there will be no distortion for sure

 

[nc535]

Half Xmax is my rule of thumb also; sorry I don't have any data to back it up. Most times I listen well below my target MaxSPL so it doesn't really matter anyway.

 

[Flaesh]

My goal is ~100 dB/1 m (excluding room gain) at 20 Hz

With room transfer function, UMIK-1 in LP, ~4 m from speakers\subs, 2 old-fashioned country cheap PA 18" (Fs 29. Qts .29 Vas ~400 l) in a bad 200 liter sealed box each, without any eq.
9 V:

and 2.8 V:

p. s.: calcuated @9V:

p. p. s.:
Same drivers in another room, in IB (wooden partition between rooms), uncrossed, about 3 m distance, presumably ~2.8V:

 

[nc535]

Nice to see real data! What is Xmax on that driver? 200L is huge box for sealed....

 

[Flaesh]

200L is huge box for sealed....

Moderate for 400 l Vas IMO))
IIRC 10 mm claimed Xmax at the time of purchase (btw 100 euros\pcs new).
Photo of the same from https://www.ebay.com/itm/325559353197 :

LOL, US $449,99 used (made in Europe, RF, Saint-Petersburg)
Actual data sheet:

 

[Flaesh]

Nice to see real data!

Real natural compession\limitation (no software or hardware compressor or limiter was harmed)

It can be assumed(?) that the suspension flexibility is the limiting factor at the lowest frequencies, despite the 9 mm voice coil overhang.

 

[Flaesh]

Addition: the measurements above were made in DBA setup. The rear subwoofers "compensate" reflections from the rear wall, but rear subwoofers distortion does exist. That is, the measurements show the actual sum of distortion of all four subs.