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[Andres Gomez]

Hi everyone. I have been comparing some speaker models in EASE and I am getting some (very) surprising results.

For example I was trying to compare a Geo S12 (80 deg) against a Turbo Flex (biamped, 75 deg). Both manufacturers offer DLL/GLL data, so -so far I can see - the user has less influence on parameter setup on "speaker parameters".

The surprising thing is when I plot direct SPL with 4 element clusters (for example) the results are that the NEXO averages 124 (max 134.7) on my venue while the Turbo averages 110.5 (max 120.5), broadband, no weight (venue 32m long, 20m wide, cluster height 4m).

I find this (very) hard to believe.  Both clusters are located at the same coordinates and have the same number of elements. Could someone try to explain these results (maybe helping me reconsider speaker parameters in ease?)...?  I really doubt both clusters have a max output difference of 13.5dB!!

I can send the packed EASE file to anyone. I hope someone helps me clear this out.

[Peter Morris]

Hi everyone. I have been comparing some speaker models in EASE and I am getting some (very) surprising results.

For example I was trying to compare a Geo S12 (80 deg) against a Turbo Flex (biamped, 75 deg). Both manufacturers offer DLL/GLL data, so -so far I can see - the user has less influence on parameter setup on "speaker parameters".

The surprising thing is when I plot direct SPL with 4 element clusters (for example) the results are that the NEXO averages 124 (max 134.7) on my venue while the Turbo averages 110.5 (max 120.5), broadband, no weight (venue 32m long, 20m wide, cluster height 4m).

I find this (very) hard to believe.  Both clusters are located at the same coordinates and have the same number of elements. Could someone try to explain these results (maybe helping me reconsider speaker parameters in ease?)...?  I really doubt both clusters have a max output difference of 13.5dB!!

I can send the packed EASE file to anyone. I hope someone helps me clear this out.

FWIW here are 4 x flex a side running 3 way recorded on someone’s  iPhone  – no way in the world will 4 x Nexo Geo 12 s do that, not sure how the Flex did - but they did! http://www.youtube.com/watch?v=2amvqeBze7U&feature=related

A Nexo 1230 is only rated @ 131 to 133 max peak SPL at 1 meter  (there are no SPL figurse for the 1210). Thats 3 to 5 dB less than the Flex.   I don’t  see any way 4 a side Geo's  will make 134.7 peak in the audience area!

I  think something is wrong, but  it does  depend on how it’s measured and calculated.

This is a plot of one stack of 4 flex, so add 2 to 3 dB for another stack.

[Andres Gomez]

Peter, thanks for answering.  I too find it very hard to believe the S12 would sound louder than the flex.

Your simulation shows peak values of the flex.  When I spoke of peak values on my last post I meant the highest levels of program material as calculated by EASE, allowing for the crest factor and therefore lower as your values.  Just to make it clear.

What intrigues me does not only have to do with the S12 vs the flex.  As an example 2 graphs comparing a PS15 aganist the NuQ15, although the diference here is nowhere as in the array comparison.  The data for both is on spk format for Ease, the settings for both speakers is "all to max". Around a 6dB diference. Note that Nexo rates max (peak) spl @ 1m to 133-136, the NuQ is rated at 135 dB.

First the PS15R2, the NuQ15  second (graphs show broadband SPL-A).

[Andres Gomez]

Here the line array comparison, plot: broadband, dB-A. clusters at same position.
While I think this is clearly wrong and would not trust my simulation I would like to know where the problem resides.

First geo s12, second TFA-600.

[Andres Gomez]

I could do a measurement with a calibrated mic at work to compare for example a PS10R2 against Turbo point source, but perhaps someone can tell me before that what could be leading to these differences in the simulation.

[Peter Morris]

I could do a measurement with a calibrated mic at work to compare for example a PS10R2 against Turbo point source, but perhaps someone can tell me before that what could be leading to these differences in the simulation.

•  I have always found Turbo’s SPL ratings to VERY conservative.
•  I heard a demo the other day where Nexo Geo 12S were compared with EAW730 and db Technologies T12s – my gut feeling in terms of SPL was that the 730’s and Geo 12S were about the same. The T12s were the loudest.
•  I have owned both 730’s and Flex - as a guess in use the Flex are about 6 dB up on the 730s.
•  Ease-Focus 1 shows the peak SPL of a Flex to be about 20dB higher than the maximum SPL I can get out of Ease-Focus 2.
•  Unfortunately I don’t have Ease to check your results.
•  I also own PS15’s and have AB them with the Turbo NuQ. I thought they were about the same, which is what you would expect give the components in them are very similar.  I have not heard the new PS15’s which I believe goes louder and sounds a little better than mine.
•  If you use Flex I would suggest you go 3 way and use the Lake / LM26 FIR settings, they sound fantastic, without them they just another nice box. 

[Ivan Beaver]

I don't know anything specifically about the products in question, but will add a few comments about EASE and output (and other "stuff").

1: It depends on what data is entered by the manufacturer into the EASE file.  Some use the "peak" output, others use the point of power compression (quite a bit lower) and others are somewhere in the middle.  This can result in often more than a 10dB difference for the same box.

2: You also have to look at the eq response of the box (as entered into EASE).  If there is a peak in the response-and you go "all to max" then the output level may be quite a bit higher than the rest of the "usable" response.  I know of one case in which there is a large peak in a cabinet-and this is stated as the "peak output", but it is 12dB higher than what the rest of the cabinet can produce.   You HAVE to look at the bandwidth of the plot-is it a single freq (1/3rd oct) or a wide range?  and what is "included" in that wide range average?  A single loud peak will make the whole range "appear" louder than it actually is.

So yes, the cabinet will get VERY loud at than very limited freq range-but it is not usable-as the average response is well below that.  That peak HAS to be eqed down in order for the box to sound acceptable-so now the peak output is much lower-across the freq band

3: I NEVER look at the max outputs in EASE.  Because of the above reasons.  I use EASE to predict coverages.  Then I use my experience with the particular product and a little ol inverse square math-and having an idea of how loud the customer needs it, to determine if a particular product will be loud enough.

Of course you also have to know where some of the numbers come from in the spec sheet to actually figure max output-actual sensitivity-power handling etc to be able to figure this out.  If you don't have accurate data to begin with, then your numbers are going to be off.

Belive it or not-there is a lot more to sound than just loudness.  Yes it has to be loud enough to do the job, HOWEVER what does it sound like at that loudness?  That is something you will not find on anybodies spec sheet.  ie" How loud will this product get before it starts to sound like crap."  I've not seent hat one yet and probably never will.

Mainly because the point of "crap" varies from person to person.  Some people actually prefer the "crap" sound as the loudspeaker starts to break up.  THey won't admit it, but when listening they will choose the "crap" one-because they think it is "right".  I have seen that happen VERY often-even by people who would consider themselves "audio pros".

Basically all I am saying is-don't put to much faith in the models-especially on the loudness side of things.  I would NEVER buy one product over another based on that.

And without going into all sorts of other issues that can get real ugly, there is a lot of EASE data that is "cooked" by the manufacturer to make it model better than it actually performs (arraybility interference issues-polar plots etc).

So that goes back to the whole "know your product and how it actually performs" and then use the model to give some guidance.  But you have to know what parameters in terms of outcome predictions YOU are entering into the program to see how the results will actually be.

Just like in the measurement world.  How many times do you do an alignment (with whatever form of measurement system) and then "tweek" it by ear to get it right for the HUMAN listener? 

The various computer programs are simply TOOLS.  It is up to the USER of those tools to determine the REAL outcome.

Just be careful when looking at the various modeling programs.  The model is only as accurate as the data that was entered into it-by both the manufacturer (data base) and the user (prediction outcomes).

[Brad Weber]

Adding to Ivan's comments, how are you modeling the arrays in EASE?  Are you using the manufacturer's software (or EASE Focus) to create the array and then bringing that into EASE via dll?  Are you creating an array in EASE using the gll files for the boxes?  Or are you inserting four boxes using the individual gll files?

[Andres Gomez]

Adding to Ivan's comments, how are you modeling the arrays in EASE?  Are you using the manufacturer's software (or EASE Focus) to create the array and then bringing that into EASE via dll?  Are you creating an array in EASE using the gll files for the boxes?  Or are you inserting four boxes using the individual gll files?

I am modeling using the dll/gll drivers form the manufacturers., and set them up (choose inter-box angle, dispersion, gain) For aiming and curvature I use manufacturers software.

1: It depends on what data is entered by the manufacturer into the EASE file.  Some use the "peak" output, others use the point of power compression (quite a bit lower) and others are somewhere in the middle.  This can result in often more than a 10dB difference for the same box.

Ivan, I think too that data from different manufacturers doesn't have the same meaning. I would add this is the case even with dll files, in which the user can manipulate less parameters (no flat max, all to max, etc. to choose from, only headroom). The difference I find should be much more than 10 dB (as Peter Morris's experience has confirmed), and that is was discomforts me the most.

I find this really sad, because I think the software should tell you how the system would really work (within approximation). It seems then one has to evaluate speakers to know how to scale the results.

Coverage  and many other parameters from EASE are very helpful, but I would say the lack of trustable attainable SPL's is a minus. I think many useful calculations that are a function of the difference between noise and max levels would be then incomparable between different speaker set ups (for example, the STI measure for an evacuation and alarm audio system).

Peter:

you have made another comparison that interested me a lot (PS15 - NuQ15), and your comments on the Flex with the 3 ways I find very interesting. Could you please say a little on the differences between the 3-way + FIR and the 2-way Flex? I would also like to ask if you have had experience with the active (DP) version of the Flex.

The PS15R2 is 2 dB over the older version.  I am getting around 7dB difference  between the turbo and the nexo, which I found too much given the similarity in components. 3-4 dB would already be a lot between the highest range of that kind of boxes from both manufacturers.

[Ivan Beaver]

Ivan, I think too that data from different manufacturers doesn't have the same meaning. I would add this is the case even with dll files, in which the user can manipulate less parameters (no flat max, all to max, etc. to choose from, only headroom). The difference I find should be much more than 10 dB (as Peter Morris's experience has confirmed), and that is was discomforts me the most.

I find this really sad, because I think the software should tell you how the system would really work (within approximation). It seems then one has to evaluate speakers to know how to scale the results.

Coverage  and many other parameters from EASE are very helpful, but I would say the lack of trustable attainable SPL's is a minus. I think many useful calculations that are a function of the difference between noise and max levels would be then incomparable between different speaker set ups (for example, the STI measure for an evacuation and alarm audio system).

.

I agree.  I REALLY wish there was a single standard of measurement-spec that our industry would use.  So that models could be compared accurately. 

Heck we can't even get the drive voltage to be in agreement (1 watt or 2.83V).

So untill that day happens (not in my lifetime I suspect) we have to take all data with a grain of salt. I can-but won't- show all kinds of examples of data that is just plain wrong-by a huge factor (well over 10dB).

Right now it really is up to the end user to take what data he is given-and try to "adjust it" to other data and combine that with actual experience with the products to come up with a determination on the actual performance.

You can't take the simple 1 line numbers and compare.

There is a lot of confusion in the industry, and a good bit of it starts with the manufacturers.  There are all kinds of numbers games that are played.

I wish there was a SINGLE entity that fall loudspeakers would have to send their products to, to be measured and that data used.   There are a coupld independant labs, but I know of one htat will measure, but then let the manufacturer put wfhatever sensitivity numbers in they want.  So some of the data is good, but other parts aren't.

rant off

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