Speaker "clarity"/ "transparency" - Most representative measurement?

[dweeeeb2]

Hi, I'm just trying to wrap my head around speaker measurements and performance. I understand that a speakers performance is a dynamic multi-factorial issue and that no one measurement summarizes completely how a speaker will perform. But if I am after clarity (EDIT: in a single seated position in a fully treated room and we just focus on the speaker, ignoring any possible problems with room acoustics), what measurement should I be looking to and what "value" us considered good enough to most people.
For example:
- if I am listening to electric guitar how come some speakers allow me to hear all the tones in the strum, yet others "muddy" the note?
- In a busy piece of music what helps to separate all the instruments?
- What determines that I can hear the kick drum being hit and resonating as opposed to a single tone thud.

For these examples I am talking about using the same music track. Is it just frequency response? or that I am hitting a resonance at this spot?
Thank you

 

[Chrispy]

Without defining how you particularly experience such, hard to know....it varies....YMMV.....what you like may sound horrible to me.

 

[Mikey Antonakakis]

Hi, I'm just trying to wrap my head around speaker measurements and performance. I understand that a speakers performance is a dynamic multi-factorial issue and that no one measurement summarizes completely how a speaker will perform. But if I am after clarity in a single seated position in a fully treated room what measurement should I be looking to and what "value" us considered good enough to most people.
For example:
- if I am listening to electric guitar how come some speakers allow me to hear all the tones in the strum, yet others "muddy" the note?
- In a busy piece of music what helps to separate all the instruments?
- What determines that I can hear the kick drum being hit and resonating as opposed to a single tone thud.

For these examples I am talking about using the same music track. Is it just frequency response? or that I am hitting a resonance at this spot?
Thank you

Here’s a long, but good, answer:

 

[Keith_W]

Here are a few answers off the top of my head.

- Excessive reverberation and flutter echoes will blur the sound and reduce clarity. This corresponds to the RT60 measurement, which is the time taken for an impulse to decay by 60dB.
- Frequency response. Excessive bass will cause you to turn down the volume and reduce the higher order harmonics, so a drum will sound like a thud without resonating. Too much mids and high ends will give you the resonating quality but without the body.
- Related to the above, a smooth power output is as important as the on-axis frequency response for the same reason. Reflections have to be spectrally correct , otherwise some frequency bands will overwhelm others, and you turn down the volume and lose information.
- Step response. Some people say it affects clarity.

I used to think that timing anomalies, e.g. the wavefront of the tweeter and midrange driver arriving at the same time at your ear was important. These days I am not so sure because my own experimentation has shown it to be either miniscule or inaudible for certain frequency bands. But if there was a very large difference between drivers, it would certainly affect clarity.

 

[eddantes]

Head in a vice? Then aim for a smooth on axis FR (and the slope that you prefer) and extremely narrow directivity... Or better still, put on some headphones.

 

[Blumlein 88]

The Martin-Logan CLS is pretty transparent. So much so you can simply look at it and see how transparent it is.

 

[kemmler3D]

if I am after clarity in a single seated position in a fully treated room

My answer:
-Flat on-axis frequency response
-Few / no resonances
-Low distortion
-Minimal excess group delay
-Narrow dispersion (since you've allowed a single seat for the LP)


This basically describes a good studio monitor, and "single seated position in a fully treated room" basically describes a recording studio, so there are a lot of options if you're actually shopping for new speakers.

 

[ernestcarl]

Once you already have what appears now as a smooth and flattish response, I would, at the very least, look at the decay and spectrogram views. These have a bunch of adjustable parameters that need to be adjusted along the way so the course of the “analysis” is not going to be done and over after a single glance — you will need to change parameters and have another point(s) of comparison — easiest and most immediate one would be by simply letting REW create a “minimum phase version” of your current flattish, smoothish in-room measurement; generally, the less differences you see in the superimposed frequency-time domain plots the better. By the time you’re done, I don’t see any reason why you should skip the other plot views — someone mentioned group delay and excess GD, step response etc.

Personally, I’d like to get a hold of some actual REW measurements from well designed, acoustically treated listening spaces… I want all their measurements! and not just at the single on-axis, main listening position data. Then again, the primary seat takes priority, and for some folks out there that may be more than enough.

People who post their actual REW mdat files often still have unresolved “issues” — mine included — so there’s really no near “perfect” examples to draw direct comparisons from.

And while we do have some “picture-perfect” examples all over the forums, these are nearly always static images that may not always be so easy to compare between one another as the viewing settings and room context details are not all the same. We’re still only looking at a particular snapshot… usually from a single microphone position. But, that’s just out of convenience. In the end, there’s no replacement for experience.


Morlet CWT (Continuous Wavelet Transform)



Discontinuity appears to be caused by the speakers and floor-bounce and/or room height mode as measured at the MLP. Pre-ringing/echo/early bass start due to FIR filtering is low enough in level here to not be an audible issue.

 

[Mikey Antonakakis]

A few people already mentioned flat on-axis frequency response. That’s a great place to start, but one of the main points Dr. Toole makes in the talk I linked above is that for a speaker that is *in a room* you need good off-axis response too. If it has poor off-axis performance it will lose its good on-axis response once it’s in a room with walls. The talk in the video was eye-opening for me.

 

[dweeeeb2]

Head in a vice? Then aim for a smooth on axis FR (and the slope that you prefer) and extremely narrow directivity... Or better still, put on some headphones.

So I think you're suggesting that after FR the rooms response is the main factor in clarity?

My answer:
-Flat on-axis frequency response
-Few / no resonances
-Low distortion
-Minimal excess group delay
-Narrow dispersion (since you've allowed a single seat for the LP)


This basically describes a good studio monitor, and "single seated position in a fully treated room" basically describes a recording studio, so there are a lot of options if you're actually shopping for new speakers.

Thanks

A few people already mentioned flat on-axis frequency response. That’s a great place to start, but one of the main points Dr. Toole makes in the talk I linked above is that for a speaker that is *in a room* you need good off-axis response too. If it has poor off-axis performance it will lose its good on-axis response once it’s in a room with walls. The talk in the video was eye-opening for me.

Thanks, I am watching the video now.

 

[dweeeeb2]

Great video

 

[dweeeeb2]

Here are a few answers off the top of my head.

- Excessive reverberation and flutter echoes will blur the sound and reduce clarity. This corresponds to the RT60 measurement, which is the time taken for an impulse to decay by 60dB.
- Frequency response. Excessive bass will cause you to turn down the volume and reduce the higher order harmonics, so a drum will sound like a thud without resonating. Too much mids and high ends will give you the resonating quality but without the body.
- Related to the above, a smooth power output is as important as the on-axis frequency response for the same reason. Reflections have to be spectrally correct , otherwise some frequency bands will overwhelm others, and you turn down the volume and lose information.
- Step response. Some people say it affects clarity.

I used to think that timing anomalies, e.g. the wavefront of the tweeter and midrange driver arriving at the same time at your ear was important. These days I am not so sure because my own experimentation has shown it to be either miniscule or inaudible for certain frequency bands. But if there was a very large difference between drivers, it would certainly affect clarity.

Thanks, I found this out playing around with cheap "acoustic foam". I turned the volume up to my desired listening volume and then when the bass came in it felt 50% louder! Caught me off guard, learnt something that day.

 

[Gorgonzola]

I listen to Classical music primarily and I find that large scale music, orchestral but even more so choral, demands and reveals the maximum clarity/transparency. Mind you, the quality of the recording has got to be there: if the recording as mushy sounding the loudspeaker is not going to compensate.

I would never dispute the importance of frequency response but FR is easy adjust with DSP. Nor would I dispute that even dispersion across the frequency spectrum is important as Toole and Olive argue; however I do wonder if the direct, (nor echo, not resonant), sound isn't the most critical for clarity specifically. And maybe equally important are loudspeaker distortion and drive time-alignment, but I'm no scientist or engineer.

In my subjective estimation, my current speaker are the have the most accurate detail and, (accordingly?), clear and "transparent" the I've owned. They happen to be the Zaph Audio ZRT two-way vented "box" design. Mine are DIY and cost perhaps US$1800 to build -- no super expensive at all, though an equal commercially-finish speak would probably cost 2x as much or more.

 

[eddantes]

So I think you're suggesting that after FR the rooms response is the main factor in clarity?

After the speaker, the room has the greatest impact on sound quality. I wish, more people would have the experience of listening to large (12") full range drivers with a whizzer (parasitic) cone. Not because they have good FR or low distortion, they don't, but it really paints a strong picture of what the room contributes to the sound. Even a tilt of the head changes the sound... the beam is that narrow. So yeah - if you want to get lost in the midrange - that would be a way to do it. Not exactly "clarity" - but it feels that way.

 

[Zapper]

I agree with the importance of frequency response and directivity control, but I suspect distortion is a limiting factor in many speakers. Speakers introduce massive amounts of distortion (THD & IMD) compared to any other element in the signal chain. IMD in particular generates frequencies not present in the source material and this has to muddy the sound.

I suspect distortion has been a primary source of dissatisfaction with all my previous speakers. None have sounded clear and effortless playing even moderately loud. My next pair of speakers must have an excellent spinorama AND very low distortion.

 

[eddantes]

I would generally agree on distortion, but as we see in Amir's tests most speakers pass with reasonable distortion at 86db. As someone that almost never listens at 86 or above (usually high 70s low 80s) - for me distortion may not be a factor. If anyone likes to listen louder (much louder -to get to 96db) then I suggest keeping an eye on distortion measurements. Also - I'm not clear how discernable (by average human ears) distortion is in the bass and sub-bass. Does anyone know?

 

[ozzy9832001]

For my small room reverberation and flutter echo were the 2 biggest killers. When standing waves start combining with each other it really wrecks havoc on the sound, and as has been pointed out, forces you to turn the volume down to compensate. Even EQ can only do some much to combat the problem. Once I started treating things in the low end, you'd be surprised how much of a difference it can make. With reasonable decay times, you can start to focus on FR.

Lower decay times gives you a sense you can pick instruments out of the mix easily but also they blend well together.

Unless you have some massive room already, treating the bass is the single biggest "upgrade" one could do. However, it is also probably the most expensive part and may not be aesthetically pleasing. Depending on the music you listening to, you may only need to treat to 60hz or so. Classical you'd probably need to go lower and those traps are thick, expensive and fairly intrusive (though there are ways around it)

However, the final piece I would say is this: everyone hears differently and listens to music from a different perspective, so what sounds good to me, might sound horrible to you.

 

[dweeeeb2]

Thank you for the feedback guys. This thread lead me on a bit of a journey. I watched the following which I believe are incredibly awesome videos. So focused on perceived sound quality (which I guess its all about ).

This video talks about how your ears / brain mask certain "distortions / resonances" based on their relation to the primary signal and volume. Masking increases with volume and vicinity of resonance to primary. It also talks about how perceived "distortion" varies dependent on whether its linear (group delay) or nonlinear (THD) and sound volume. As volume increases group delay becomes more noticeable, THD is not considered a real issue. My last take away was that compression (effects of system heating up - how I understand it) is probably a bigger issue than thought and that smaller speakers are probably effected by it more.

This video talks about many topics, primarily elements of the spinorama and their relation to perceived sound. It covers many topics of the video earlier in this thread. Interestingly Dr. Toole does not consider floor reflections (and ceiling to a lesser extent) to really be an issue, yet Dr. Geddes has his floor and ceiling treated, but not his side walls. Dr. Toole also make comment about resonances causing the sound to localize from a speaker and how the flatter the response the more likely your speakers will disappear. He also strongly suggests the use of subs and HPF for mains.

I have to hand it to Erin here, they are a great watch.

So after these comments and these videos I think I need to go and look into group delay and decay times a bit more. It sounds like my focus on clarity really is just about a flat FR, and a flat room response. My speakers are the Wharfedale Lintons and looking at their graphs they seem pretty good.

Thanks for your help

 

[ozzy9832001]

It would be interesting to see some measurements in your space, so we could get a better idea of what your dealing with.

 

[dweeeeb2]

It would be interesting to see some measurements in your space, so we could get a better idea of what your dealing with.

I’m actually pretty happy with mine. My speakers are mobile and when I listen to them Im basically near field with reflections along way away. My question is purely to understand and help with future decisions.