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Spinorama for the brand new JBL PRX900 serie

Robbo99999

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I have only recently used:
  • Reaper which comes with a spectrum analyzer as I demonstrated in the video, but this doesn't seem suitable to producing a single hi-res characteristic spectrum for long segment (e.g. 10 seconds of music)
  • Visual Analyser https://www.sillanumsoft.org/ idk if it can do it. it is certainly very flexible
  • REW has a decent analyzer but again idk what options it has for combining a sequence of hi-res FFTs
Tbh, idk if it makes much sense to attempt this. I mentioned the idea only to illustrate that frequency analysis can be a tricky business and finding a good position among the inherent trade-offs of the various choices involves subjectivity.
Many options to analyze tracks, here is some. They will show exactly what is there.

Audacity:

Spectrogram using SOX:

Good realtime analyzer for foobar2000 users:
Well, I suppose there are different ways to collect and look at data.

For me, the point was to see how playback through speakers related to the source.

I figured if the peaks match up, then what goes on at lower levels likely matches too.

I came close enough for my purposes, I think.

Below, Left and Right of the CD source (no EQ), and the combined result coming from the speakers measured at the listening position, at 10 feet (with EQ)...

Top trace is the "in-room", with considerable DSP to make the in-room frequency response follow the source. The "room curve" applied via DSP is flat - no curve or slope.

The speakers are playing the stereo source, so what is picked up by the microphone is the sum of the two channels.

The most inaccurate area is the bass, below maybe 80Hz, background noise intrudes on the silence of the source below 25Hz, and the rest of the bass response is a bit ragged.

Such is life.

index.php
Earlier in the thread some of us were talking about how these PA speakers lack subbass and whether or not a subwoofer would be needed for various applications with these PA speakers. I think they certainly would for a proper bass response. We then got on to talking about how to actually analyse bass content accurately in tracks as some real time spectrum analysers seem to sometimes give a false impression that a lot of subbass is being used when it might not be there. One of the solutions that seemed to be arrived at was to run your music tracks through an analyser to get a characteristic frequency response curve that characterises the whole track. I decided to therefore run what I consider some of my most bass heavy music through this analyser (lots of Massive Attack tracks) - I used Audacity and exported the results to REW, following is a plot of all those tracks together:
Massive Attack, Spectrum Analysis.jpg

To me from that graph, I think you'd want your speaker to be able to reproduce down to 30Hz properly for most of those tracks, and there's two tracks that to me look like they have significant content down to 20Hz. I don't know what you guys would interpret from that graph, maybe the same? I'd say that for certain for those traces you'd be wanting to have a sub paired with these PA speakers for example, what do you reckon?

EDIT: these are based on FFT 8192 and Hann Window in Audacity.

EDIT #2: also did a version of the graph above but with an average line that represents all tracks, which is the highlighted purple line in the following graph - to get a handle on some more general trends (curiosity), see following thumbnail:
Massive Attack, Spectrum Analysis - Average Line.jpg
 
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hege

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I'd say that for certain for those traces you'd be wanting to have a sub paired with these PA speakers for example, what do you reckon?
I'd say your graphs illustrate pretty good average. It's common for PA systems to only play well down to 30-35hz with subs, since that's where music commonly ends (it's no secret). Any other requirements would be more special cases requiring many more larger subwoofers, lots of extra cost for seemingly little benefit. Of course you can always find some cases of hiphop, electronic or organ stuff etc with even lower hz, as seen in Bass! thread, but at home it's much easier to achieve full range setup and enjoy them fully.

For these kinds of portable tiny 12" or 15" tops it would make no difference if they play down to 30hz instead of 60hz, as they simply don't have the physical capability to play so loud down there (Hofmann's Iron Law), that's why they are always on top of subs when required. Simple and modular, use the subs when needed.
 

nick-v

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Could you get away with EQ'ing the 15" version to play down to ~30Hz at moderate levels? All of my systems are roon ready (I'd run them through a Bluesound node or similar Roon Ready device). With roon I can easily measure with REW and create convolution filters to correct for room anomalies and boost the low end.

I'm thinking these might be decent for my garage system. It's just a 2 car garage, 24' x 22' with 12' ceilings. Decent sized space, but I won't be throwing any raves in there or anything. I recently cleaned and organized it, I'm throwing up a nice slat wall system and getting a Polyaspartic coating on the concrete floor. I figured it would be nice to have a decent system in there.
 

MediumRare

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Could you get away with EQ'ing the 15" version to play down to ~30Hz at moderate levels? All of my systems are roon ready (I'd run them through a Bluesound node or similar Roon Ready device). With roon I can easily measure with REW and create convolution filters to correct for room anomalies and boost the low end.

I'm thinking these might be decent for my garage system. It's just a 2 car garage, 24' x 22' with 12' ceilings. Decent sized space, but I won't be throwing any raves in there or anything. I recently cleaned and organized it, I'm throwing up a nice slat wall system and getting a Polyaspartic coating on the concrete floor. I figured it would be nice to have a decent system in there.
Nope, even with EQ you’ll get down only to 55 Hz, according to the spinoramas on page 1. There are better choices if you can’t include a sub.
 

Iluzun

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Was n Rhino records outside LA couple weekends ago. Big, open, authoritative, sound. Kicked butt. Tracked it down to the house rig. HK 2000 watt 12’’ dsp topped by stackable narrow line array columns with 6 x 3” drivers each. Similar pricing, $1200 each. I was impressed by the sound and it wasn’t driving anybody out of the record store, quite the contrary…

 

nick-v

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Was n Rhino records outside LA couple weekends ago. Big, open, authoritative, sound. Kicked butt. Tracked it down to the house rig. HK 2000 watt 12’’ dsp topped by stackable narrow line array columns with 6 x 3” drivers each. Similar pricing, $1200 each. I was impressed by the sound and it wasn’t driving anybody out of the record store, quite the contrary…

Interesting...
 

AnalogSteph

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Could you get away with EQ'ing the 15" version to play down to ~30Hz at moderate levels?
I could see them flattened out to about 50 Hz but that's about it. Pushing -10 dB to much under 40 Hz seems like a stretch. Still, for music and for a garage that seems plenty good enough. Garages are notoriously reflective places, too, so unless you plan on throwing a party right outside the 12" versions may do just fine already.
 

nick-v

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I'm thinking something like JBL Control 30/31 might be better for my application. They don't play as loud (which is fine for my application) and they play down into the 30's (-10dB) with a 10" woofer.
 

Philbo King

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Earlier in the thread some of us were talking about how these PA speakers lack subbass and whether or not a subwoofer would be needed for various applications with these PA speakers. I think they certainly would for a proper bass response. We then got on to talking about how to actually analyse bass content accurately in tracks as some real time spectrum analysers seem to sometimes give a false impression that a lot of subbass is being used when it might not be there. One of the solutions that seemed to be arrived at was to run your music tracks through an analyser to get a characteristic frequency response curve that characterises the whole track. I decided to therefore run what I consider some of my most bass heavy music through this analyser (lots of Massive Attack tracks) - I used Audacity and exported the results to REW, following is a plot of all those tracks together:
View attachment 242239
To me from that graph, I think you'd want your speaker to be able to reproduce down to 30Hz properly for most of those tracks, and there's two tracks that to me look like they have significant content down to 20Hz. I don't know what you guys would interpret from that graph, maybe the same? I'd say that for certain for those traces you'd be wanting to have a sub paired with these PA speakers for example, what do you reckon?

EDIT: these are based on FFT 8192 and Hann Window in Audacity.

EDIT #2: also did a version of the graph above but with an average line that represents all tracks, which is the highlighted purple line in the following graph - to get a handle on some more general trends (curiosity), see following thumbnail:
View attachment 242242
Down to about 30 Hz - coincidentally the fundamental frequency of the lowest string of a 5 string electric bass... Hmmm.
 

ocinn

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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.
Even the best bluetooth protocol has far too much latency for any inter-box use. The average consumer of a $2k/pr of powered speakers will not have the knowledge or tools (SMAART/REQ/etc....) to be able to determine the correct amount of delay to apply to the mid/hi to bring it into time with the bluetooth sub.

And even if they did, now your whole system has a massive amount of latency which makes it absolutely useless for any live-performed material (yes, incl djing, since most actual live performance DJs use a combination of their headphone signal in one ear and the booth mon/PA in the other to beatmatch). So now you have a system which can only play a music playlist, and your speakers have to sit on ugly tripod stands vs the slick subwoofer pole arrangement.

All a moot point since the bluetooth functionality in these is receive only, not transmit.

It is worth noting that when looking at PA speakers there are tiers of quality and performance. For example, with some simplification, there are three tiers of mid-sized self-powered PA speakers:

≈$US5000 each ... Meyer, L'Acoustics, D&B, Adamson, Nexo, Fulcrum Acoustic, JBL VP/VRX series and a handful of others
≈$US2000 each ... Yamaha-DZR, RCF, FBT, JBL SRX series and numerous others
<$US1000 each ... JBL PRX Series, plus too many others to count

The top tier are stunning; the extra $$ results in real sound quality and performance gains.

If ASR is to start reviewing PA speakers the above above tiers need to be understood. There's no going back once the top tier have been heard!
D&B, L'A and Meyer (and Danley in some applications) are absolutely a step above all others you listed in that top tier. Both in performance and price. I'd argue 5 tiers, with that mentioned uber-high tier and also the super budget stuff (Alto, Mackie, etc...)

Yamaha DZR & Martin CDDLive are the best actually consumer-accessible powered compact PA speakers IMO. But not rider acceptable by most, so you never really see them apart from the custom install market or grassroots music.

Was n Rhino records outside LA couple weekends ago. Big, open, authoritative, sound. Kicked butt. Tracked it down to the house rig. HK 2000 watt 12’’ dsp topped by stackable narrow line array columns with 6 x 3” drivers each. Similar pricing, $1200 each. I was impressed by the sound and it wasn’t driving anybody out of the record store, quite the contrary…

All of these column arrays suck. They are incredibly SPL limited nearing the lower limits of the 3" drivers and are not nearly tall enough to start to beat point source inverse square. So you basically just get a comb filtering distortion source lol. The only reason to EVER buy these is if space/sight lines are a priority. But even the cheapest $300 box speakers (alto ts312/etc...) smoke these in every objective and subjective metric, apart from maybe not having DSP built in.
 
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