Measure your C50 in REW and tell us how your bass sounds!

[TheZebraKilledDarwin]

100%. Room modes at 105, 120 and 140. Creates a gigantic mess with the fundamentals and the harmonics. Mid bass was a mess. Takes many, many very thick traps to get it under control and even then, still not even close to where I'd like it.

Keep in mind, that we do not hear with the ears, but with the brain.
Glady our brain eliminates most of the physical anomalies, reflections, cancellations, modes, comb filtering, otherwise, if we would hear with the ears like a mic, we would become insane.
Contrary to our hearing, measurements show all the anomalies, even if we do not hear them and therefore can be extremely misleading, if they are not interpreted correctly. It is imperative to choose a graphical representation, that reflects what we hear (for example 1/3 octave resolution/smoothing to judge spectral balances).

 

[TheZebraKilledDarwin]

Yes.

I don't know how to make that happen, the system sounds good to me though : )

I'll work on some new measurements with the Yamaha NS-333s. So far I hear more detail with those than the Spektor 2s (more detail and spacial location on cymbals without being bright). Here's a couple more graphs from the old Spektor 2 measurements. I get the cleanest crossover with the subs at about 116Hz. I do like having control of both the high and low points with the Rolls units:

View attachment 237720View attachment 237721View attachment 237722

116 Hz XO? Do you use a sub at each main channel?

Could you post a burst decay in linear % scaling, please?

 

[Fredygump]

Hi,
I've been interested about stereo listening triangle size, and how to extend it, how to get good sound further in room (DIY speakers). This is apartment living room with no acoustic treatment other than furniture. Room is open plan to kitchen, asymmetric positioning on the long side, about 8mx6m or so, 2.5m ceiling.

Something happens in between, around 2.2meters there is quite clear transition from good imaging to slightly blurred one, like stepping in / out to good sound, some threshold gets crossed so that brain changes the impression of it. Difference isn't very big in these clarity graphs so its interesting and thought to post it even if its not bass motivated

Measurements are at 2m and 2.6m distance from left speaker.
View attachment 287795View attachment 287796
Same for the right
View attachment 287799View attachment 287800

I thought ~1-2kHz dip on left was flutter echo as its relatively constant between the two, but not sure what it is. Perhaps problem in speaker as its DIY after all right speaker data looks more plausible.

On one hand the answer is simple: acoustic treatment! The C50 measures the ratio of sound energy arriving before 50ms and after 50ms, so the more direct the sound, the better the rating. So the ways to improve clarity are to sit closer to the speaker, have acoustic treatment that absorbs reflections (so less sound arrives after 50ms), or use speakers that have narrower directivity. But of course, if you pursue all these things, you eventually turn your house into a recording studio! And some people prefer less clarity, preferring omnidirectional speakers on largely untreated rooms, so this number isn't the "ultimate" measure of sound quality/ audio enjoyment.

 

[chych7]

Hi,
I've been interested about stereo listening triangle size, and how to extend it, how to get good sound further in room (DIY speakers). This is apartment living room with no acoustic treatment other than furniture. Room is open plan to kitchen, asymmetric positioning on the long side, about 8mx6m or so, 2.5m ceiling.

Something happens in between, around 2.2meters there is quite clear transition from good imaging to slightly blurred one, like stepping in / out to good sound, some threshold gets crossed so that brain changes the impression of it. Difference isn't very big in these clarity graphs so its interesting and thought to post it even if its not bass motivated

Measurements are at 2m and 2.6m distance from left speaker.
View attachment 287795View attachment 287796
Same for the right
View attachment 287799View attachment 287800

I thought ~1-2kHz dip on left was flutter echo as its relatively constant between the two, but not sure what it is. Perhaps problem in speaker as its DIY after all right speaker data looks more plausible.

I don't think Clarity alone is the right indicator of imaging quality, but it does show you have asymmetries in the response, which isn't good for imaging. Plotting them as overlays and just C50 may be an easier way to look at asymmetries.

For imaging, generally I find it to be a combination of:

1. How well speakers are SPL matched over their freq range
2. How well speakers are phase matched over their freq range
3. How much direct sound you have vs. reflected sound (Clarity C50/C80 plots), and related, how many early peaks you have in the ETC.
4. How well the impulse responses are aligned (time alignment)

So I think there is more to investigate here, if you're looking for a measurement based explanation of what you hear.

 

[tmuikku]

Yeah its a peculiar thing. I have good match as its DSP system and phantom center feels rock solid, its the in/out of good sound kind of thing. Perhaps multiple things align so that brain sees it more clearly.

Will experiment with it, I bet both acoustics and how the speaker works in with itself and with the room are all at play, like always. Next tests are: new bass boxes above which the top sits, midrange should clear out as the old boxes are kind of a messy old prototype boxes. They also allow to lower the tops to furniture level to hopefully increase the direct/reflected sound ratio. Then few acoustic panels to address the flutter echo. A new top, possibly with narrower pattern, or even wider, if it was the flutter for example also new measurements both for DSP and for acoustics. Well, many hours of work before all tested

 

[Tim Link]

Hi,
I've been interested about stereo listening triangle size, and how to extend it, how to get good sound further in room (DIY speakers). This is apartment living room with no acoustic treatment other than furniture. Room is open plan to kitchen, asymmetric positioning on the long side, about 8mx6m or so, 2.5m ceiling.

Something happens in between, around 2.2meters there is quite clear transition from good imaging to slightly blurred one, like stepping in / out to good sound, some threshold gets crossed so that brain changes the impression of it. Difference isn't very big in these clarity graphs so its interesting and thought to post it even if its not bass motivated

Measurements are at 2m and 2.6m distance from left speaker.
View attachment 287795View attachment 287796
Same for the right
View attachment 287799View attachment 287800

I thought ~1-2kHz dip on left was flutter echo as its relatively constant between the two, but not sure what it is. Perhaps problem in speaker as its DIY after all right speaker data looks more plausible.

I'm thinking that clarity may not reliably tell you what you'll get from imaging. As you move away from the speakers, the time delay is reduced, and the level difference is reduced from those reflections. I've got a graph on the wall in front of me that shows time delay vs maximum level of reflections that will alter the imaging. From somewhere around 8 ms and earlier the relative level of the reflection has to go down as the time delay goes down, which is the opposite of what's typically happening in a small room as you move away from the speakers. This may not have much negative effect on the clarity rating, which is dealing with much longer time intervals.

 

[NIN]

My room is 704x567x232 cm (23,1x18,6x7,61 feet) big and have some some acoustic treatment but it is a "normal" livingroom. I use no EQ, delay or anything else than the crossover between the "topspeakers" and my passive subwoofers (78hz)


At listening position around 460 cm/15,1 feet away from the left speaker I got this.

I also had an older measurement from my right speaker at 200 cm/6,56 feet away.

I wonder if there is anything more one can do to get even better "clarity" or if the clarity measurement is not really that important for the perceived sound quality?

 

[TheZebraKilledDarwin]

High values of C50, nice. It's not possible to make conclusions from one dataset. But the rising clarity seems to indicate, that the room is absorbing too much of the treble energy?

 

[NIN]

High values of C50, nice. It's not possible to make conclusions from one dataset. But the rising clarity seems to indicate, that the room is absorbing too much of the treble energy?

May be. But is it really possible to have as high C50 at the listening position 460cm/15,1 feet as a close measurement at 200cm/6,56 feet from the speaker?

 

[Gary_G]

Room is 15'x15'x9'
Listening position is toward the rear and offest from center 1.5'
Speakers are Focal 926

 

[STC]

I never understood the Clarity values. So any help is appreciated. The measurement is for the at the left ear using in-ear mic with both speakers output.

 

[ZööZ]

I would also like to know what is concidered a good looking curve in the clarity window.

 

[SDC]

My room. 3 sides and ceiling acoustical treated

main salon2. 2 diy 18"subs 2 arendal 1961 1v.

decay graph. Rising frequency starting from 200hz to 20hz

very short decay time. rise at higher frequency by using many diffuser. diffuabosorber types.

topt dropping as low as 50ms. V shape curve.

results in reverse V shape C curve. I have no idea how to get the upper frequency higher. Maybe one of small room problems...


So, how does this sounds?

First, I've been using quad subwoofers for sometime but never tried reversing polarity till very recently.
(reversing polarity, faster decay and better bass distribution around the room is achieved.)

comparing to it, current system sounds bass dry. even with all the rise in FR the bass vanish so fast it just don't feel abundant.

But I can't just say high C numbers results in lacking bass. It is extremely punchy with right music. Very analytic system it is.

I'll keep the setting but not sure about the superiority of high C number and lower rt60.

 

[Fredygump]

I never understood the Clarity values. So any help is appreciated. The measurement is for the at the left ear using in-ear mic with both speakers output.

I would also like to know what is concidered a good looking curve in the clarity window.

Clarity C50 is the ratio between the sound arriving before 50ms and after 50ms. So high clarity is lack of echos, or delayed reflections, that would make speach difficult to understand.

C80 is the ratio at 80ms, and is considered to be better at determining the clarity for music.

I've heard pro audio people commenting that a room/ auditorium was designed for speach or for music, and I'm pretty sure the difference is described by the clarity measurement.

I believe clarity is therefore mostly a measurement of the room, not the speakers. However, I suspect that if comparing 2 speakers in the same room, the speaker with narrower directivity would measure higher clarity than an omnidirectional speaker. That's my theory, not a fact....but I expect there isn't a "best" measurement, and more clarity is not necessarily better. A very high number may indicate the room is too dead. If the low frequencies are low clarity, and then there is an abrupt jump to high clarity at high frequencies, then maybe the high frequencies are over-damped in the room? I think this is the type of info you're going to get out of a clarity measurement.

That's what I have been able to figure out, but I'd be happy if someone with more expertise could bring more "clarity" to the subject!

 

[chych7]

I would also like to know what is concidered a good looking curve in the clarity window.

I would put as a general rule of thumb: C50 greater than 10 dB over the entire frequency range; perhaps >15 dB for a center channel that carries dialogue. If clarity is too low, add absorption panels to early reflection points (and corner bass traps for bass freqs). This is more to do with room acoustics than speakers, although wide dispersion speakers can trigger more room acoustic issues.

I never understood the Clarity values. So any help is appreciated. The measurement is for the at the left ear using in-ear mic with both speakers output.

View attachment 312327

That is a really odd looking clarity graph with extremely high values. Not sure if your mic is giving you valid results... being in ear, it may be blocking a lot of reflections. A measurement mic pointing upwards (diffuse sound field) is the standard way to collect this measurement, I believe.

 

[Tim Link]

I never understood the Clarity values. So any help is appreciated. The measurement is for the at the left ear using in-ear mic with both speakers output.

View attachment 312327

This is a very interesting result. This suggests you have a tremendous amount of absorption above 1000Hz, dropping off to normal levels around 200Hz. By 50Hz there's not enough damping. Or perhaps there's just not much bass output. Without hearing your room I'd predict it might be overdamped sounding to some listeners.

 

[Tim Link]

Clarity C50 is the ratio between the sound arriving before 50ms and after 50ms. So high clarity is lack of echos, or delayed reflections, that would make speach difficult to understand.

C80 is the ratio at 80ms, and is considered to be better at determining the clarity for music.

I've heard pro audio people commenting that a room/ auditorium was designed for speach or for music, and I'm pretty sure the difference is described by the clarity measurement.

I believe clarity is therefore mostly a measurement of the room, not the speakers. However, I suspect that if comparing 2 speakers in the same room, the speaker with narrower directivity would measure higher clarity than an omnidirectional speaker. That's my theory, not a fact....but I expect there isn't a "best" measurement, and more clarity is not necessarily better. A very high number may indicate the room is too dead. If the low frequencies are low clarity, and then there is an abrupt jump to high clarity at high frequencies, then maybe the high frequencies are over-damped in the room? I think this is the type of info you're going to get out of a clarity measurement.

That's what I have been able to figure out, but I'd be happy if someone with more expertise could bring more "clarity" to the subject!

Yes, unless your speakers are having very strange problems (like mine do around 85Hz) these clarity measurements shouldn't have much to do with the speakers, but almost entirely to do with the room and the location you are measuring from compared to the location of the speakers. However there is some interaction between the speaker type and the room, so different types of speakers in the same location in the room can result in signifcantly different clarity measurements. Generallly speaking, speakers always have excellent clarity, but their interaction with the room can result in varying levels of clarity.

 

[ozzy9832001]

Yes, unless your speakers are having very strange problems (like mine do around 85Hz) these clarity measurements shouldn't have much to do with the speakers, but almost entirely to do with the room and the location you are measuring from compared to the location of the speakers. However there is some interaction between the speaker type and the room, so different types of speakers in the same location in the room can result in signifcantly different clarity measurements. Generallly speaking, speakers always have excellent clarity, but their interaction with the room can result in varying levels of clarity.

I would agree as well. It's more an room acoustics issue.

116 Hz XO? Do you use a sub at each main channel?

Could you post a burst decay in linear % scaling, please?

My XO is 120hz and I do so to combat room modes. With 2 subs and the mains all working properly it completely smooths out the low end for me.

 

[NIN]

I believe clarity is therefore mostly a measurement of the room, not the speakers. However, I suspect that if comparing 2 speakers in the same room, the speaker with narrower directivity would measure higher clarity than an omnidirectional speaker. That's my theory, not a fact....but I expect there isn't a "best" measurement, and more clarity is not necessarily better. A very high number may indicate the room is too dead. If the low frequencies are low clarity, and then there is an abrupt jump to high clarity at high frequencies, then maybe the high frequencies are over-damped in the room? I think this is the type of info you're going to get out of a clarity measurement.

That's what I have been able to figure out, but I'd be happy if someone with more expertise could bring more "clarity" to the subject!

Clarity also depends on how close one measure from the speakers. My sweetspot is about 15,4 feet from each front speaker and if I try to measure it at 8 feet, same room and same speaker, I will get better clarity.

 

[STC]

This is a very interesting result. This suggests you have a tremendous amount of absorption above 1000Hz, dropping off to normal levels around 200Hz. By 50Hz there's not enough damping. Or perhaps there's just not much bass output. Without hearing your room I'd predict it might be overdamped sounding to some listeners.

You are amazing! I think you are right about the bass. I probably did the sweep above 100 Hz. The room is very much damped as I use variable reverberation via 26 additional speakers. The RT60 can go higher than 4s.

So the measurements can vary depending on the reverbs like here