First of all: Thanks to
@amirm for testing such systems.
I would LOVE more such measurements.
In Pro-Audio dispersion is arguably even more important than at home due to listeners being spread all over the place.
Many manufacturers advertise with precise dispersion but many speakers sadly don't shine here.
Against some other posters here I think PA speakers should totally be flat with good dispersion.
I do a lot of sound reinforcement and with often limited time for setup you just want a neutral speaker.
You then can quickly compensate for the usecase or the enviroment, but only if the speaker isn't up for some funny business.
Air attenuation is normally a non issue with such small systems. Listeners are typically close to the Speaker (<20m or even <10m at
the farest point of interrest).
I am a little bit disappointed of this speaker.
Many flaws here are designed by choice.
They even used FIR filters, wich would make it more than easy to correct the frequency response.
Some other things may not be the speakers fault.
The chewed up response of the tweeter may very well be (in part) caused by the grill. Of course the large compression driver also does it's part.
I am currently designing simmilar speakers and while I am not finished, I still quickly compared the response with and without grill some time ago.
I use a custom made hex-grill very similar to the one JBL uses.
Here is how that looks. Without smoothing it is even worse. Please note that this is indoor and heavily gated.
You can even see the reflection in the impuls response (green with, yellow without grill). I am not shure about this, but I use FIR-filters for flat phase response, which might make this more visible than usual. The JBL speaker also has linearised phase. Maybe this shows in your measurements too
@amirm
I also have problems with abnormal bass response due to the large enclosure.
It takes some real effort to to something here and I am still not there by far.
This is also visible in other large speakers measured here. For example the large JBL Monitor with the 12" woofer I think.
For reference, this is the speaker measured. Just imagine a grill similar to the JBL
Lastly:
In short, the lab testing was not reflecting the real life for that speaker, then why should it? As a near field testing system, NFS is not suitable for large field sound analysis.
@amirm says he tests pro gear because ASR community is interested in their use at home. It is his site, his decision. Though, I wish he wouldn't spend his efforts on them. His words sums up the dilemma of testing big pro speakers.
Please don't say that. Read up on how the NFS actually works.
The NFS is more than suitable, as it generates real far field responses, wich are otherwise really hard to obtain for large speakers.
On the Klippel website you can even see Photos of the NFS with some D&B V Linearray cabinets on it, wich should have an immensly complex soundfield
While I am interrested in PA speakers for PA use, there are reasons to look at them from a Hifi standpoint.
There is a lot to learn und I would (and probably will
) totally listen with my big speakers at home if I had the space.
Edit: One question that is bugging me: Why is this thing so damn large?
As a designer I would not want that much space for a modern 15" even if I had no restrictions there.
Even 15" PA Subs are often smaller, including my own designes.
Bass extension is quit good for a fullrange PA speaker, but 40Hz are totally possible with a smaller footprint while still getting enough output.