Impact of Reflections: In-Room Speaker Recordings

[maty]

Sealed

BTW, with PKHarmonic v1.3 with H2 -84.5dB and H4 -96.5dB (I am doing tests to find the best values for my second system) -> more bass (less than normal), more "body" or "full sound" and less trebble

 

[Geert]

There appears to be quite distinct transition between the two, at some listening distance to speakers perception of stereo sound seems to shift. Kind of on/off phenomenon, brain seems to lock in quite suddenly and it feels literally stepping inside the sound of recording, or stepping out to local room. I've been writing about this lately a lot on various threads trying to lure people write if they hear it, or what do they think about this. I'm hobbyist and figuring this out by my self so kind of need the community to figure out whats going on.

That effect is real indeed. If you move closer to the speakers you'll reach a point where the direct sound becomes so much stronger than the room reflections that the latter seem to dissappear. In my home setup all it takes is to move forward to the edge of my seat. In recording studio's it's know as near field listening.

 

[tmuikku]

Yep, it is well known in a way that the information floats around everywhere.

It is very powerful thing to actually listen, hear it happen and what difference it makes to sound with my setup in my room.

Actually hearing the transition will help everyone to connect perception of audio to the written text. Hearing the transition basically means you hear the direct sound with envelopment at the close proximity, or direct sound combined with strong early reflections and spaciousness when further away. Or at least you should be hearing them, if there is no envelopment, you gotta do something about it. If you want to get engaged with the sound you know which side you need to be listening at. If you feel like vomiting due to wild panning in the close proximity you know engineers making the recording likely listened it at far distance and you should too, and so on

The transition very clearly points to you when you are on "near field" or "far field". Near field in regards of this critical distance. Near field should not be confused to near field of the speaker, which is different thing, and a reason I'm avoiding using it and just talk about audible critical distance. Critical distance is also a defined term, its distance where direct sound and room sound are equal in SPL, but I think its not the same distance as this audible critical distance.

In my home setup all it takes is to move forward to the edge of my seat.

Have you ever thought about why you have listening spot at that particular distance? Why not have it closer so you always are closer than the audible critical distance? How do you utilize the current listening distance and possibility to adjust the perception, do you lean forward on some records and lean back on some others? Have you been conscious about it and what do you think about it?

 

[Thomas_A]

This also raises the question (again) whether "near-field" speakers should be designed to have wide dispersion to add more reflections (while far-field should have more narrow). Or with other words, should the DR ratio be kept constant with listening distance?

 

[tmuikku]

^ its possible to seek answer to your question: knowing which sound I like and how should I adjust DI of my speakers to my liking in the room I'm given to achieve that

DR ratio slides with frequency, and with speaker DI and room acoustics, and how it relates to perception of sound. I think it's matter of getting the audible transition closer or further from speakers with given room acoustics and positioning If you are at "near field", sound in the room turns into envelopment and is perceived as such. If the envelopment is poor, your room sound is poor for envelopment.

Think about it, at the transition distance where DR of some important bandwidth goes over some threshold to make the shift in perception happen. Now, sound in the room is maximally loud, right, compared to direct sound. If room sound was as good as it could be, then you should be hearing as good envelopment as you like, right? If you don't you have to adjust balance of the room sound. I think it is very likely that "weight" of room sound is front of you, from direction of speakers, and is masked / masking by direct sound and thus you are not having sound all around you that would feel enveloping. What you need to do, is to transfer "weight" of the room sound to be literally more enveloping, coming from all around you instead of just in front. One could use diffusion, absorption, adjust positioning to affect path lengths of the first and strongest early reflections, toe-in to adjust level of sound towards various directions. Now, if you successfully manage it bulk of the early reflections is not in front of you anymore, but should be more equal from all around you, thus envelopment.

This is something I've just reasoned from perception I'm having and relating it to Griesinger paper(s) so I'm not sure how coarse simplification it is and take it as is. It seems to correlate nicely with written concepts though so I'm trying to get everyone to listen and figure this stuff themselves with their setups. Correlates or not, I should be able to listen about envelopment, listen if envelopment changes if I do these adjustments and whether the hypothesis is accurate enough to be useful, practical.

Again, important thing is I know what to listen for and how and what I should be hearing.

 

[Geert]

Have you ever thought about why you have listening spot at that particular distance? Why not have it closer so you always are closer than the audible critical distance? How do you utilize the current listening distance and possibility to adjust the perception, do you lean forward on some records and lean back on some others? Have you been conscious about it and what do you think about it?

I would love to move my couch forward but then it would become a big obstacle in the living room, carpet would no longer fit and so on. But when I want to hear something specifically into more detail, I'll move forward. Even more detail wanted, move to my studio monitors and/or headphones.

 

[Geert]

This also raises the question (again) whether "near-field" speakers should be designed to have wide dispersion to add more reflections (while far-field should have more narrow).

The whole idea of near field listening is to get rid of reflections. At least, in a studio control room it is. Maybe your question is if more reflections would be beneficial for home use (consuming music instead of producing it)? That has been discussed in the recent GoldenSound acoustic treatment thread. Science suggests people in general prefer some reflections because it increases spaciousness. Again one of the reasons it's so remarkable that half of the people in this thread go for the narrower image.

 

[tmuikku]

I would love to move my couch forward but then it would become a big obstacle in the living room, carpet would no longer fit and so on. But when I want to hear something specifically into more detail, I'll move forward. Even more detail wanted, move to my studio monitors and/or headphones.

Aha! same problem as I have, and quite likely most of living room listeners, a practical issue!

Now it's matter of knowing what one wants regarding this subject. There could be possibility to have such speakers that reach the audible critical distance beyond the practical listening spot if one likes to have the sound of recording. Or, you could be content to what you have right now if the adjustability is nice, listening spot around the critical distance so you can just zoom in if you wish.

Nice, thanks for commenting about it! Nice because it correlates what I've found out which kind of indicates it should be a common thing indeed. And hints that most people listen beyond the critical distance, perhaps ever knowing "better sound" is in front of their nose. Better sound in quotes, they might not know which one they like if not hearing the transition and paying attention.

 

[Geert]

Correlates or not, I should be able to listen about it, listen if envelopment changes if I do these adjustments. Important thing is I now know what to listen for and how and what I should be hearing.

You indeed need to do a lot of experimenting to learn to recognise the effects of speaker directivity and room acoustics. Listening is something you can develop. Just sitting in your cosy chair enjoying music for hours a day doesn't do.

 

[Thomas_A]

The whole idea of near field listening is to get rid of reflections. At least, in a studio control room it is. Maybe your question is if more reflections would be beneficial for home use (consuming music instead of producing it)? That has been discussed in the recent GoldenSound acoustic treatment thread. Science suggests people in general prefer some reflections because it increases spaciousness. Again one of the reasons it's so remarkable that half of the people in this thread go for the narrower image.

I am not referring to professional music production, but only end user. Since we all listen from short distance desktop to large living room setups, should we aim for the same DR ratio? As far as I know, speakers today are not designed according to those principles.

 

[tmuikku]

You indeed need to do a lot of experimenting to learn to recognise the effects of speaker directivity and room acoustics. Listening is something you can develop. Just sitting in your cosy chair enjoying music for hours a day doesn't do.

Yeah, knowing the audible critical distance is very good tool for this, one can knowingly change the perception and learn it, quite fast and reliable in a way if it is what Griesinger writes about. I could speculate it's the most important tool any listener has to evaluate sound of room and sound of speaker, and sound of recording for that matter.

 

[Geert]

Now you its matter of knowing what you want regarding this subject. There could be possibility to have such speakers that reach the audible critical distance beyond you if you want to listen like that. Or, you could be content to what you have right now if the adjustability is nice, listening spot around the critical distance so you can just zoom in if you wish.

I know for myself I prefer the direct sound of a recording. But I also recognise some people don't. Other speakers might provide a more direct sound, but they'll come with other tradeoffs and won't fix the problem 100% anyway.

 

[tmuikku]

I know for myself I prefer the direct sound of a recording. But I also recognise some people don't. Other speakers might provide a more direct sound, but they'll come with other tradeoffs and won't fix the problem 100% anyway.

Can you elaborate, what do you think speakers couldn't do here? I have DIY speakers and plan is to try and extend the critical distance further so I'm interested in any insight, thanks!

 

[Geert]

Can you elaborate, what do you think speakers couldn't do here? I have DIY speakers and plan is to try and extend the critical distance further so I'm interested in any insight, thanks!

Solve the issue that I'm to close to the back wall. First thing on my agenda is to fix the acoustic properties of that wall.

 

[tmuikku]

^ Ah yeah, another practical issue

I am not referring to professional music production, but only end user. Since we all listen from short distance desktop to large living room setups, should we aim for the same DR ratio? As far as I know, speakers today are not designed according to those principles.

It's practical matter, and preference, some people like the other and others seem to like the other. Only thing we can do about is to listen and learn about it, which one do you like and on which records? If you read a loudspeaker review, do you know which side of critical distance the subjective impression is from and on which recordings and how it relates to what you like? See, very important stuff that needs to be communicated about and have personal knowledge of. Otherwise any attempts to improve our setups regarding this matter is just shooting in the dark, confusing.

I think good speaker sounds good on both sides of audible critical distance. Also, it could be possible speaker or room is so bad there is no critical distance but you are always on the far side. Or have so big speakers in combination with some issues that the audible critical distance is near field of the speaker and you'll never get good sound if you prefer the close sound.

After learning to listen for it at home you'd be able to spot this in live venues as well, movie theatre, anywhere. Spot the sound of the room, or if you are close or far and hear proximity or not. Auditoriums, what ever. Griesinger presentations in youtube are great start to have stab at it, but eventually one has to experiment with their selves and learn how it sounds.

Regarding loudspeakers designed for some particular duty, for studio work and home listening, I don't think there is any other difference than what the audible critical distance makes. One can have good sound for both I think, that's what I'd like to have, but on my setup the transition is not at practical listening distance at sofa but bit in front which is a bummer. Anyway, the audio engineers that made all your recordings are humans as well, it is highly likely what they listened at while making a recording sounded very good to them.

edit.
For loudspeaker DIYers, think this: by Griesinger, being beyond audible critical distance means that brain is not able to lock in to the sound because harmonics are messed up by sound in the room. Now, tweaking edge diffraction or time alignment or anything related to loudspeaker phase like worrying about excess group delay is likely more audible as shift of the critical distance, or some spatial effect if you are always closer than the critical distance. If you are beyond critical distance all you'd hear is effects in frequency response, by definition phase is messed up (on some important bandwidth) and you'd not be able to hear it. Extreme claim would be to say that listening beyond critical distance, where most people likely listen at in their homes, it is not possible to hear any of it because room has it all messed up already. And not so extreme, the audible critical distance seems to be midrange bandwidth phenomenon, while lows (in room) are always beyond and highs always closer. And, I'm just exploring this, reasoning with the perception and Griesinger papers and experimenting with my own system.

Well, back to topic. Have fun listening your stereo, and effect of room, everyone!

 

[goat76]

As I thought, the original has an even wider stereo image than the first recording. You can perfectly locate the instrument groups. How I knew? Every recording of classical music I own has a wide stereo image that the second recording.

There was never any doubt that both recordings would lack in width compared to the original sound file as crosstalk is obviously at play with such recordings.

The reason I prefer the second recording doesn't have anything to do with the lack of stereo width compared to the first recording, it's more about faults caused by the recordings themselves and maybe also the positioning of the loudspeakers, and these faults are exaggerated and way more obvious in the first recording. If you compare the original sound file to the first recording you can easily hear that the first recording is much skewed to the right channel, this or a too large distance between the loudspeakers in the upright position causes the phantom-centered sounds to sound very "bland" and "washed-out". The fault with the lacking phantom center is way less obvious with the second recording even though it obviously lacks in width compared to the first recording, if that got to do with the loudspeakers laying down or if they are acoustically wise closer to each other, I don't know?

I'm also surprised no one else noticed the comb filtering I heard, and the muddy low mid in the second recording. I looked at the spectrum of both recordings and the response of the second one is clearly more jagged than the first, including an ugly low mid bump.

I notice a lot of faults with both of the recordings including the fault you are talking about, but because of the faults I mentioned above which are way more obvious in the first recording, I still prefer to go with the lesser width but with the better phantom-center of the second recording.

So half of the audience prefers a speaker setup that detoriates the sound of recordings? They even call it 'more real', while no other recording sound like this. I would say I'm shocked, if it wasn't the first time this happened in a test like this.

Again, both recordings have faults that deteriorate the sound and it's more about "picking your poison", don't you hear that the first recording is lacking a lot in the phantom center compared to the original sound file?

I think the lack of a phantom center is caused by both the skewed stereo image and also that the speakers being positioned too far apart from each other. So just for fun, I did a few adjustments to the first recording. Some adjustments to get a better balance to the stereo field and an EQ adjustment just to the phantom-centered sound to give it a bit more presence as the original file.
With the adjustments I prefer the first recording, without it I prefer the second recording.

https://www.dropbox.com/scl/fi/1zdp...ted.flac?rlkey=as6fqb5jy1h9zvkvwrcxoo3f9&dl=0

I hope that @BenB has no problems with my little manipulation of his recording.

 

[goat76]

Funny, I was just thinking if the people who prefered the more focused sound indeed have their speakers closer together or have taken other measures (like using horns speakers).

Personaly I use coaxial speakers at home, delivering a great phantom image without reducing spaciousness.

My speakers are set up in an equilateral triangle, it's a fairly small triangle of just 2,04 meters for a higher ratio of direct sound. This setup is giving me both a very good and distinct-sounding phantom image and a wide stereo image when the recordings contain such information.

The only reduced spaciousness that may occur with some recordings is the lack of artificial widening caused by side reflections, but instead of that I hear the width of what's on the actual recording and this can with some recordings appear wider than the position of the loudspeakers. That comes with what we call the stereo illusion and envelopment.

 

[goat76]

Revel 126Be, oversimpliying first stereo, second mono. What really surprised me is that some prefer the second, we are animals of different taste, aren't we.

By listening to the recordings with your speakers, you reduce the width of the recordings even further as it will be "two layers" of crosstalk that way. Both recordings are already reduced in width and to avoid it being further reduced you must listen using headphones.

 

[Geert]

Again, both recordings have faults that deteriorate the sound and it's more about "picking your poison", don't you hear that the first recording is lacking a lot in the phantom center compared to the original sound file?

It's a big orchestra, so the concept of phantom image is a bit vague in this context. You can expect to have different instruments groups being spread from left to right. I clearly hear the flutes somewhere in the middle. In comparison, what's happening at the outer edges is indeed to strong in this recording, but that's also the case also in the original track. For me it was clear this was an issue with the original recording, and the recording with the speakers in vertical position was least detrimental, certainly when you take the frequency spectrum issues into account. Like I said at the start, not I track I would use to judge sound quality.

So unfortunately this test missed its objective a bit because it became a discussion about recording quality instead of an assessment of what speaker placement does to sound.

 

[Geert]

So just for fun, I did a few adjustments to the first recording. Some adjustments to get a better balance to the stereo field and an EQ adjustment just to the phantom-centered sound to give it a bit more presence as the original file.

Your EQ-ing is certainly an improvement, but I still hear so much information is lost in this recording compared to the first.