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Spinorama for the brand new JBL PRX900 serie

JBL PRX900 are PA speakers which are optimised for high output. They are active, relatively cheap, easy to get and have an internal DSP. JBL is nice enough to provide a lot of datas for these speakers. I used the data to generate the spinorama and derive some information.


Here is the marketing blurb from JBL:

JBL PRX900 Series powered loudspeakers and subwoofers take professional portable PA performance to a new level with advanced acoustics, comprehensive DSP,
unrivaled power performance and durability and complete BLE control via the JBL Pro Connect ecosystem. The line, which includes three powered two-way loudspeakers and two powered subwoofers, has been entirely built from the ground up to leverage JBL’s most advanced acoustic innovations. Next-generation driver systems—powered by ultra-efficient 2,000-watt (peak) Class D amplifiers—deliver clarity and definition at maximum volume, with improved dispersion and smooth low-frequency extension. The PRX900 Series is a versatile solution for DJs and bands, music venues, rental houses, corporate A/V providers, or anyone who needs durable professional systems that deliver powerful, room-filling sound in any portable or installed scenario.



picture of series




All 3 speakers have common properties:
  • 1.5'' compression driver with a wave guide
  • active speaker
  • optimised for high SPL
  • DSP included (similar to a dbx DriveRack)
The name of the speaker give you the size of the woofer PRX915 is a 15'' woofer.


Some data from JBL website:
ModelPrice (each)-3dB pointSPL MaxPattern
PRX908900$65Hz126dB105x60
PRX9121000$65Hz132dB90x50
PRX9151100$60Hz135dB90x50

JBL PRX908

Out of the box


Let's start with the standard graphs:

spinorama




The directivity is not great (the green curve should be as linear as possible) but on axis and listening window are reasonably flat.
We have -3dB point at 62Hz. Frequency deviation is +/3.2dB. Tonality score is 3.9 and would be 6.4 with a perfect subwoofer.


onaxis


You can see that the speaker has been optimised to have a nice PIR (Predicted in room response):

pir


We have a good horizontal pattern:

horizontal contour

And we see the classical pinch of dipoles:
vertical contour


More graphs are available.

With an EQ​

Here is a potential EQ. Filter 4-9 are sharp and can be removed. They may marginally help.

Code:
EQ for JBL PRX908 computed from Vendors-JBL data
Preference Score 3.5 with EQ 4.5
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.16
Dated: 2022-11-03-09:15:17

Preamp: -4.4 dB

Filter  1: ON PK Fc    87 Hz Gain -4.92 dB Q 4.40
Filter  2: ON PK Fc  1958 Hz Gain +4.08 dB Q 3.63
Filter  3: ON PK Fc   927 Hz Gain -2.80 dB Q 1.92
Filter  4: ON PK Fc  4923 Hz Gain +2.57 dB Q 5.88
Filter  5: ON PK Fc    80 Hz Gain -1.40 dB Q 5.70
Filter  6: ON PK Fc  1629 Hz Gain +1.77 dB Q 5.49
Filter  7: ON PK Fc 13172 Hz Gain +4.29 dB Q 5.70
Filter  8: ON PK Fc 11761 Hz Gain -4.34 dB Q 5.87
Filter  9: ON PK Fc  7760 Hz Gain -2.57 dB Q 5.93



spinorama

And you see that's the PIR is significantly flatter:

pir


A more visual comparison:
comparison

JBL PRX912​

Out of the box​

Let's start with the standard graphs: spinorama

The directivity is still not great but a bit better (the green curve should be as linear as possible) but on axis and listening window are reasonably flat.
We have -3dB point at 62Hz. Frequency deviation is +/3.2dB. Tonality score is 3.9 and would be 6.4 with a perfect subwoofer. If you add an EQ, the the score goes up to 4.7 and 7.2 with both EQ and subwoofer.
onaxis
You can see that the speaker has been optimised to have a nice PIR (Predicted in room response): pir
We have a good horizontal pattern: horizontal contour
And we see the classical pinch of dipoles with a narrowing of vertical response: stay at tweeter height. vertical contour
More graphs are available.

With an EQ​

Here is a potential EQ.
Code:
EQ for JBL PRX912 computed from Vendors-JBL data
Preference Score 3.9 with EQ 4.7
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.16
Dated: 2022-11-03-09:21:27

Preamp: -1.6 dB

Filter  1: ON PK Fc    95 Hz Gain -4.21 dB Q 4.91
Filter  2: ON PK Fc    82 Hz Gain -1.57 dB Q 6.00
Filter  3: ON PK Fc   189 Hz Gain +1.24 dB Q 3.07
Filter  4: ON PK Fc  1737 Hz Gain +2.21 dB Q 2.74
Filter  5: ON PK Fc   383 Hz Gain -1.38 dB Q 1.40
Filter  6: ON PK Fc   231 Hz Gain +1.37 dB Q 4.95
Filter  7: ON PK Fc  9603 Hz Gain -2.83 dB Q 4.96
Filter  8: ON PK Fc  1713 Hz Gain -1.56 dB Q 5.98
Filter  9: ON PK Fc  3441 Hz Gain +1.38 dB Q 2.79



spinorama
And you see that's the PIR is significantly flatter: pir
A visual comparison: comparison

JBL PRX915​

Out of the box​

Let's start with the standard graphs: spinorama

The directivity is not improving and on axis and listening window are less flat.
We have -3dB point at 62Hz. Frequency deviation is +/3.8dB. Tonality score is 2.9 and would be 5.2 with a perfect subwoofer.
If you add an EQ, the the score goes up to 3.6 and 6.0 with both EQ and subwoofer.

This one is significantly less good than the other two.
onaxis
You can see that the speaker has been optimised to have a nice PIR (Predicted in room response). pir
We have a good horizontal pattern: horizontal contour
And we see the classical pinch of dipoles but also the speaker is significantly more directional. vertical contour
More graphs are available.

With an EQ​

Here is a potential EQ.
Code:
EQ for JBL PRX915 computed from Vendors-JBL data
Preference Score 2.9 with EQ 3.6
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.16
Dated: 2022-11-03-09:22:25

Preamp: -3.3 dB

Filter  1: ON PK Fc    84 Hz Gain -4.55 dB Q 4.29
Filter  2: ON PK Fc   363 Hz Gain -1.89 dB Q 3.83
Filter  3: ON PK Fc  1539 Hz Gain +3.20 dB Q 1.62
Filter  4: ON PK Fc    78 Hz Gain -1.16 dB Q 5.63
Filter  5: ON PK Fc   279 Hz Gain -0.81 dB Q 5.60
Filter  6: ON PK Fc   803 Hz Gain -1.24 dB Q 5.43
Filter  7: ON PK Fc   193 Hz Gain +1.35 dB Q 3.61
Filter  8: ON PK Fc   110 Hz Gain -0.66 dB Q 5.86
Filter  9: ON PK Fc 10935 Hz Gain -4.11 dB Q 5.92



spinorama
And you see that's the PIR is significantly flater: pir
A visual comparison: comparison

Comparison​

JBL PRX908 v.s. JBL 708P​

The 708P is also an active 8'' but optimised for studio use. It's maximum output is 108dB continuous and 114dB peak which is way lower that the PRX908.
The 708P has been reviewed by @amirm (review) and Erin (review).

Looking at the 2 spinoramas: comparison The DI curves are very similar but the studio version is smoother especially above 8kHz.
If you add some EQ to both, the difference decrease significantly: comparison

Conclusion​

For PA speakers, the data shows very well executed speakers. I have not listen to this serie (brand new) but the previous one was already not bad.
Nice review, a good opportunity you took to use their data - why not!

It's interesting that the bass is not particularly extended on the PA speakers, I suppose that's so that they can hit high SPL's, and as a side benefit these probably won't receive much room EQ when being used for their intended purpose, so the early rolled off bass will get some room reinforcement which might prevent them from being boomy when used without roomEQ. I don't know much about PA speakers and their use, but it does seem that the 908 and the 912 would work well, indeed as you highlight they measure better than the 915 in most ways.
 
The 708P's -10dB point is a about two-thirds octave lower than PRX908's. If you sacrifice SPL for bass extension in EQ, how much is left if we try to make the PRX908 match the 708P's roll off? The vertical difference at about 40 Hz is about 20 dB, is that a rough guide?

(Btw, I see my previous question about 50 min ago cannot make sense.)
 
Nice review, a good opportunity you took to use their data - why not!

It's interesting that the bass is not particularly extended on the PA speakers, I suppose that's so that they can hit high SPL's, and as a side benefit these probably won't receive much room EQ when being used for their intended purpose, so the early rolled off bass will get some room reinforcement which might prevent them from being boomy when used without roomEQ. I don't know much about PA speakers and their use, but it does seem that the 908 and the 912 would work well, indeed as you highlight they measure better than the 915 in most ways.
This kind of line up with 8", 12" and 15" models is common in this market. And the overall specs in terms of bass extension and SPL are typical.

There are a few products with a 15" and significantly lower roll-off point, like the Mackie Thump, and I guess the idea is to sacrificing quality to get a more visceral perception of bass for a DJ rig, or someone throwing a party who wants that effect.

This kind of gear is used in all sorts of spaces including outdoors, tents, big halls and modest rooms so I don't think the designers can make many assumptions of what will or will not sound boomy.

As you see, the difference between the 8", 12" and 15" models performance specs isn't huge. And when you consider that a most program material has little important to say that's strictly below 50 Hz, i.e. that information isn't easily inferred from the rest of the spectrum, it's no wonder people choose which model to buy based on what they can lift, fit in their vehicle, and afford.
 
This kind of line up with 8", 12" and 15" models is common in this market. And the overall specs in terms of bass extension and SPL are typical.

There are a few products with a 15" and significantly lower roll-off point, like the Mackie Thump, and I guess the idea is to sacrificing quality to get a more visceral perception of bass for a DJ rig, or someone throwing a party who wants that effect.

This kind of gear is used in all sorts of spaces including outdoors, tents, big halls and modest rooms so I don't think the designers can make many assumptions of what will or will not sound boomy.

As you see, the difference between the 8", 12" and 15" models performance specs isn't huge. And when you consider that a most program material has little important to say that's strictly below 50 Hz, i.e. that information isn't easily inferred from the rest of the spectrum, it's no wonder people choose which model to buy based on what they can lift, fit in their vehicle, and afford.
Don't worry any serious DJ's will not mix on PRX912 alone, they will have the matching subwoofers.
 
For $2000/pair list price (actual negotiated price probably quite a bit lower) the 912s seem an incredible bargain. The bottom end around 60-70 Hz is the source for the visceral bass slam and at normal listening levels that 12" will be loafing. Consider also these have Bluetooth so chain a reasonable powered subwoofer and you have a complete kick-ass system with full DSP.
 
For $2000/pair list price (actual negotiated price probably quite a bit lower) the 912s seem an incredible bargain. The bottom end around 60-70 Hz is the source for the visceral bass slam and at normal listening levels that 12" will be loafing. Consider also these have Bluetooth so chain a reasonable powered subwoofer and you have a complete kick-ass system with full DSP.
I am not sure why would someoneone use Bluetooth to pair a sub. I Think it's just thought out to be an input for some music. They do however have throughputs, crossover functionalities and both a 15 inch and a 18 sub in the line (PRX915XLF, PRX918XLF), I would assume most will do that.
 
I am not sure why would someoneone use Bluetooth to pair a sub. I Think it's just thought out to be an input for some music. They do however have throughputs, crossover functionalities and both a 15 inch and a 18 sub in the line (PRX915XLF, PRX918XLF), I would assume most will do that.
No cables, pick the best placement. Plus no audible distortion or noise from BT since subs have fairly high distortion and high audible threshold. A sub is the best candidate for Bluetooth.
 
135 db max, yikes!
 
No cables, pick the best placement. Plus no audible distortion or noise from BT since subs have fairly high distortion and high audible threshold. A sub is the best candidate for Bluetooth.
I am assuming you are thinking home use, but this is huge, uglyish and way overkill in term of generated SPL for any home. In the typical use case. the best placement will be in phase with the tops like we see on the picture, why would we want to create cancellations. Bluetooth has a latency, but in the en this is all moot since these are speakers, they don't generate audio content. you can use BT subs if you want but this is a receiver not a transmitter.
1667747359878.png
 
Nope, that’s not my point, what I meant maybe due to English, is that it’s not that impressively flat as in their studio/home line with the basically perfect directivity. And then from say, the horizontal directivity I was guessing it’s less demanding in its intended application compared to say, max SPL or the requirement for a bug proof grille which is more likely needed in its pro use range. So that’s it, not blaming jbl as a whole

There are several priorities PA speaker designers and customers value beyond perfect looking spinoramas. Some of this have been summarized by @Matthias McCready here:


When criticizing products, it's important to as least understand what the working and design constraints are, and the market these speakers are aimed at filling. As pointed out by @Neale, JBL already have "better" pro audio speakers. If one is going to damn a new speaker model(s), one might as well present one's case with better alternatives belonging in the same category. Of course, there are definitely PA speakers that are good enough to be used as home "studio monitors" out there -- that much should be obvious -- but they are generally way more expensive.
 
This kind of line up with 8", 12" and 15" models is common in this market. And the overall specs in terms of bass extension and SPL are typical.

There are a few products with a 15" and significantly lower roll-off point, like the Mackie Thump, and I guess the idea is to sacrificing quality to get a more visceral perception of bass for a DJ rig, or someone throwing a party who wants that effect.

This kind of gear is used in all sorts of spaces including outdoors, tents, big halls and modest rooms so I don't think the designers can make many assumptions of what will or will not sound boomy.

As you see, the difference between the 8", 12" and 15" models performance specs isn't huge. And when you consider that a most program material has little important to say that's strictly below 50 Hz, i.e. that information isn't easily inferred from the rest of the spectrum, it's no wonder people choose which model to buy based on what they can lift, fit in their vehicle, and afford.
Yeah, good point, I suppose I can't assume these speakers will get room reinforcement. They'd certainly lack subbass then when used on their own outside in a tent. I suppose people who use these in outside venues would likely bring some subs to marry with them if they wanted the bass to be right.
 
Yeah, good point, I suppose I can't assume these speakers will get room reinforcement. They'd certainly lack subbass then when used on their own outside in a tent. I suppose people who use these in outside venues would likely bring some subs to marry with them if they wanted the bass to be right.
Yes, but this question of bass being right is still interesting. Even dub reggae band with bass guitar eq set as low as it goes (think of some Bill Laswell where he isn't using the envelope following filter, for example this kind of bass guitar), there's still nothing musical below 40 Hz and if the speakers rolls off at 40 or 50 Hz hardly anyone will notice let alone care about frequency response being "right".

The decision about what equipment you need for the job is much more about: What kind of experience does the audience expcect? What experience you want them to have and remember having? And what are you willing to expend on it? And expenditure isn't just measured in $$s.
 
Yes, but this question of bass being right is still interesting. Even dub reggae band with bass guitar eq set as low as it goes (think of some Bill Laswell where he isn't using the envelope following filter, for example this kind of bass guitar), there's still nothing musical below 40 Hz and if the speakers rolls off at 40 or 50 Hz hardly anyone will notice let alone care about frequency response being "right".

The decision about what equipment you need for the job is much more about: What kind of experience does the audience expcect? What experience you want them to have and remember having? And what are you willing to expend on it? And expenditure isn't just measured in $$s.
It might depend on which music you're trying to reproduce, most of the music I listen to has significant content below 40Hz according to me viewing spectrum analysers as the music plays - but also you can hear the content down there, which is reinforced by watching the spectrum analyser respond to what you're hearing. To be honest I listen to a quite wide variety of content, some types of music, think music that contains some electronically generated content can have loads of response down there, but most of what I listen to has significant or at least some content down there. People wouldn't have subwoofers if the content down there was unimportant. Of course it's down to the professionals who buy this kind of PA gear to decide if they're gonna be bothering to reproduce for the audience the content below 40Hz.
 
Normal use case for this without Subs:

-A small conference with some motivational speaker or someone up there with a mic trying to sell you something, or teach you something
-A ceremony in some Hotel Ballroom where the big boss is going to do a speach at some point, some prizes will be awarded and a video might be shown to tell you how your company is rockin', while you eat some lukewarm food and drink cheap wine.
-An outside sporting event where a presenter is doing some crowd cheering and commenting
-Any variations of the above, with the common ground of being low budget, small crowd and not focused on a musical performance. There are tons and tons of those everywhere in the world at any given time, and they will sell tons and tons of these speakers.

If you have a band, or a DJ, there will be subs.
 
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It might depend on which music you're trying to reproduce, most of the music I listen to has significant content below 40Hz according to me viewing spectrum analysers as the music plays - but also you can hear the content down there, which is reinforced by watching the spectrum analyser respond to what you're hearing.
Be very careful with those displays. The bandwidth theorem (iirc) is a bit like Heisenberg uncertainty. If you want to measure frequency accurately you need a lot of time. So the windows and sampling used in the FFTs for real-time displays that update several times a second smear the lower octaves enormously, hiding the truth in a big hump that's really just an artifact of the math involved.

This is where FFT windowing, size, and sample rate becomes a rather touchy art. On the one hand we want the overall FFT time slice to be short enough so that we can see how it corresponds to what we can hear (e.g. bass guitar, drums, etc) but if it is too short then we simply cannot see the peaks. And a really low peak, say at 41 Hz looks, the lowest a 4-string bass in standard tuning can make, looks like a

When I was using FFTs to look at the resonances in my acoustic guitars together the bass modes of my music room, I generally used maximum samples and reduced the sample rate in whatever app it was, and I wasn't looking below 75 Hz.

I made a video for you to show how dramatic this in the lower audible octaves.
 
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