Is there clarity display possible with higher resolution as the T60M ?

[user44455555]

Hello

I mean the clarity have 1/3 resolution if the clarity can also get such a high resolution as the T60M ?
with treated room i get much more clarity above 135 hz in compare to old untreated measures. I have upto 12 cm basotect foam and Basstraps.. maybe the clarity at least in the bass range can be more precise to see the result precise when place basstraps and foam diffrent ?. i hear that clarity in bass is most problem . the treated room results look in larger parts more worse than untreated in bass because there are only 1/3 resolution

 

[Keith_W]

Please think a bit about what the Clarity measurement is. It has nothing to do with subjective clarity. I think it is the most useless measurement, and I can't think of any application for it.

How REW calculates clarity C50: the first 50ms of the impulse is expressed as a % of total energy measured.

This is the problem: a 20Hz sound wave has a period of 50ms. This means that C50 only captures one sine wave at 20Hz. This would be "very very very early". At 10kHz, the period is 0.1ms. So C50 captures 500 cycles of 10kHz. 500 cycles should be enough to be considered "late". Go look at your impulse response or ETC and see how many reflections you can spot below 50ms. IOW: 50ms is "early" for low frequencies, and "late" for high frequencies. This is probably why REW has a custom clarity time.

On top of this - we know that with most speakers and most systems, the sound power is tilted downwards (i.e. there is more sound power at low frequencies, and less at high frequencies). So the Clarity measurement is severely underestimating low frequency sound power because only the first 50ms is captured.

And here is yet another point: in most typical listening rooms, the noise floor rises at low frequencies because rooms act as a low-pass filter. This is precisely at the same frequency range where output from the loudspeaker drops. As a result, the signal-to-noise ratio is typically very poor in the bass region. Now think about how this would affect your "clarity" measurement if the sound energy of the bass is barely above the noise floor.

As a result, ALL Clarity measurements should be upward tilting - less "clarity" in the bass, more "clarity" in the treble.

I don't think anybody knows what ideal "clarity" should be. If you add more room treatment, your "clarity" measurement will improve since reflections are suppressed and there will be less "late" sound power. If you measure "clarity" in an anechoic chamber, your measurement would look excellent. But we also know that adding more room treatment will REDUCE speech clarity after a certain point. I have looked for papers to see if there is a clarity target, and I haven't been successful. Maybe John knows of a study.

So: ideal "clarity" would only be interpretable above a certain frequency (we don't know what that is) and should have upper and lower thresholds (I don't think we know what that is either). Either the thresholds should be frequency dependent, or the "Clarity" calculation should be applied on a logarithmic scale (longer window for low frequencies, less for high frequencies). And finally: proper interpretation of the "Clarity" measurement depends on capturing a proper measurement with an adequate SNR at all frequencies of interest.

Because I don't find this measurement helpful, I don't look at it at all.

 

[user44455555]

Please think a bit about what the Clarity measurement is. It has nothing to do with subjective clarity. I think it is the most useless measurement, and I can't think of any application for it.

How REW calculates clarity C50: the first 50ms of the impulse is expressed as a % of total energy measured.

This is the problem: a 20Hz sound wave has a period of 50ms. This means that C50 only captures one sine wave at 20Hz. This would be "very very very early". At 10kHz, the period is 0.1ms. So C50 captures 500 cycles of 10kHz. 500 cycles should be enough to be con

A 50 hz wave has 20 ms. so over 2 cycles can see. but it is enough if can see 80 hz upo 135 hz more precise. maybe there are also in higher frequecies sharp clarity gaps. this can only see with higher resolution

ETC have the problem can not see which frequency do the problems the lower the frequency get. the foam does not damp frequencies below 60 hz, but in the ETC can see that level at 60 ms is also lower. so not possible to translate the ms to frequency value

the clarity display i notice show the sound enhancement that can hear better, but i think it need on bass better resulution as 1/3 octave. here is a compare. the blue is the newest measure. here

 

[Keith_W]

That ETC looks excellent, I don't think you have much to complain about.

If you want a better idea what your bass is doing, use the spectro and waterfall. The spectro needs to be "normalized to peak at each frequency" to give you an idea of bass decay. The waterfall should be extended to 1000ms and zoomed out so that you can see the noise floor. Alternatively you could look at RT60 Decay and place your pointer at individual frequencies to examine the decay slope.

I don't think going higher than 1/3 octave will give you any worthwhile information in the Clarity graph. Like I said, it's almost useless at low frequencies.

 

[user44455555]

That ETC looks excellent, I don't think you have much to complain about.

Im always compare with calibrate headphones and mono music. when i reduce in headphone frequencies lower 150 hz, i hear no enhancement in clarity. but when i reduce in speakers lower than 150 hz i still get a enhancement in clarity. larger speakers sound more mud as small speakers. currently i do tests with my biggest and expensievest speakers. the focal alpha 65 evo .without foam it was even more worse, but i see it can be better. expensive speakers did not help . in the ETC i see peaks at ~12.2 ms and 14.4 ms. and 38 ms which are same as untreated. I have not all treat, here can see how room look https://www.avnirvana.com/threads/what-would-you-treat.16270/#post-121292 . but i change foam positions for this new measures

the rt60 decay also not good in bass. it show a problem with that speakers at 200 hz too.
The JBL 104 in compare is excellent, but it is of course weak in bass. It have the smallest case and it is very rounded.
maybe all large speakers are bad or rt60 decay line you see is influenced on the FR huge ? . rt60 decay is very diffrent. speakers and positions are same with same room foam level

in clarity is not so much diffrence see between this speakers. so i do not trust rt60 and more the clarity

here is the rt60 and also the kali lp 6 1. version add. the lp6 have not the longer decay at 200 hz and is in bass decay simular to alpha 65. both have 6,5 inch speaker. i also add the mdat files of that compare

 

[user44455555]

I get in mind the focal have bass knobs to reduce the bass. So i do new measure normal and with 6 db bass reduction. it get only slightly better in RT60 . mdat i upload too. microphone and speaker are in this focal measure exact same place. in clarity is bass stay very same rt60 more diffrence. maybe it is really that large speakers have much more resonances in Bass. so it seem really usefull to have clarity in higher resolution ?

 

[Keith_W]

One glance at your RT60 chart and it is easy to see that you have WAY OVERTREATED your room, look at that - the RT60 at high frequencies is 150ms or less. At times it's less than 20ms. It would sound close to an anechoic chamber. And if you are not used to those numbers, it should be about 200ms or more, to an upper limit of about 500ms. It depends on your room volume and your application. Maybe the target can go as low as 150ms if it's a small room and you are a recording studio.REW has a RT60 target calculator which will display upper/lower tolerances.

It is easy to think that your bass is inadequately treated from this graph since it sticks out like a sore thumb. But remember what the "R" in RT60 stands for - "reverberant". A "reverberant field" means that the SPL at that frequency is the same no matter where it is measured in the room. You may get a 40-50Hz reverberant field in a concert hall, or a large church, or a basketball stadium - but you certainly won't get one in your listening room. You get room modes and early reflections.

And you also get measurement artefacts that will mislead you into thinking the RT60 is higher than it actually is:

I suggested that you extend your waterfall out to 1000ms and normalize to peak at every frequency. You didn't do that, so I did it for you. Now, take a really good look at this waterfall. You can clearly see the noise floor. See what the noise floor is doing? See how it rises in the bass region?

Now look at your frequency response graphs. Take note that the bass is falling below 40Hz.

Conclusion: your bass RT60 isn't high. It's poor signal to noise ratio.