What does it mean when a speaker sounds like this..... ?

[cbracer]

I'm a mechanical engineer and in recent years have started paying more attention to speakers after years of general listening to music. I'm interested in the science and frequency response along with other aspects of a "good" speaker. But I have a hard time following reviews of people who judge speakers only by their ears and nothing scientific. Okay I get that. But what do all the terms used by these speaker reviewers really mean? What does "spatial" mean? etc.

Well today I tested out a used set of speakers and found something so strong that I wanted to ask what it meant. I put the speakers on my computer desk (not a normal listening position for me).... the vocals sounded like they were coming from an invisible large speaker in between the stereo speakers, which are maybe 3-4 feet apart. Mostly just vocals. Usually I can year all the music coming from each speaker, movement closer, left, right, etc all have an effect, but with these the vocals always came from the center of them. It was amazing. The speakers were a little base heavy so I turned up some EQ in the highs, but the center vocal affect lessened. I tilted them up a bit to be in line with the tweeter and this center vocal affect went away. Put them back flat on the table top and it came back. It has to be tied to the speaker sitting on the table top, so the table top must be vibrating some sound? It's more noticeable at louder volume and lower vocals. I normally put some foam on the bottom of the speakers to isolate, but did not this time. What term do people call this affect where the vocals seem to come from a perfect middle speaker that isn't there? It's kinda nice like this. Is there a definition guide to those words / terms of listening to speakers?

A few years back I tried a set of BW CM1 speakers and the music sounded like it was coming from 1' behind the wall they were in front of, maybe 6" space between them and the wall. That was strange to me. The BW 686 didn't sound like that. So much is room acoustics and placement, but some speakers are less sensitive to this.

The speakers are the Pioneer S-A4SPT-PM which are the ones built from Pure Malt oak barrels about 4" woofer. I saw them 20 years ago in a Pioneer store but couldn't fathom paying $400 a set when I was in my 20's. My curiosity of would these be any good set in and after a while waiting on ebay a set in the US popped up for $320 after some bidding. I know they ship from Japan at a stupid crazy $800 price, and there is a slight updated model without the Kevlar woofer which is suppose to be better. They aren't perfect, and I can't play them too loud tonight with kiddos sleeping but sound good at a low volume.

Thanks in advance

 

[antcollinet]

It is called phantom center. Most well setup stereo systems can do this. In fact you normally hearing only sound directly from the speakers suggest you are not getting the stereo effect working correctly. With most stereo music you should be hearing a sound stage at least as wide as the speakers, with individual voices and instruments placed within it.

I think in your desktop case, you are correct that some of the sound is coming from the desk. This will ether be reflection from the drivers down to the desk and back up to you - or direct mechanical coupling from the base of the speaker. In either case, tilting the speaker can reduce the effect - either by directing the sound away from the desk so there is less to detect, or by reducing the mechanical coupling from the whole bottom surface of the speaker to at most one edge.

 

[antcollinet]

Out of interest, I have a single sub positioned just in front of the left speaker. (what can I say -it is a small room with a lot of stuff in it).

I get reflections off the sub which shifts the balance over to the left (and widens the sound stage). I know this is happening, because if I drape the curtain over the top of the sub, the effect is almost eliminated.

 

[MaxwellsEq]

I'm a mechanical engineer and in recent years have started paying more attention to speakers after years of general listening to music. I'm interested in the science and frequency response along with other aspects of a "good" speaker. But I have a hard time following reviews of people who judge speakers only by their ears and nothing scientific. Okay I get that. But what do all the terms used by these speaker reviewers really mean? What does "spatial" mean? etc.

Well today I tested out a used set of speakers and found something so strong that I wanted to ask what it meant. I put the speakers on my computer desk (not a normal listening position for me).... the vocals sounded like they were coming from an invisible large speaker in between the stereo speakers, which are maybe 3-4 feet apart. Mostly just vocals. Usually I can year all the music coming from each speaker, movement closer, left, right, etc all have an effect, but with these the vocals always came from the center of them. It was amazing. The speakers were a little base heavy so I turned up some EQ in the highs, but the center vocal affect lessened. I tilted them up a bit to be in line with the tweeter and this center vocal affect went away. Put them back flat on the table top and it came back. It has to be tied to the speaker sitting on the table top, so the table top must be vibrating some sound? It's more noticeable at louder volume and lower vocals. I normally put some foam on the bottom of the speakers to isolate, but did not this time. What term do people call this affect where the vocals seem to come from a perfect middle speaker that isn't there? It's kinda nice like this. Is there a definition guide to those words / terms of listening to speakers?

A few years back I tried a set of BW CM1 speakers and the music sounded like it was coming from 1' behind the wall they were in front of, maybe 6" space between them and the wall. That was strange to me. The BW 686 didn't sound like that. So much is room acoustics and placement, but some speakers are less sensitive to this.

The speakers are the Pioneer S-A4SPT-PM which are the ones built from Pure Malt oak barrels about 4" woofer. I saw them 20 years ago in a Pioneer store but couldn't fathom paying $400 a set when I was in my 20's. My curiosity of would these be any good set in and after a while waiting on ebay a set in the US popped up for $320 after some bidding. I know they ship from Japan at a stupid crazy $800 price, and there is a slight updated model without the Kevlar woofer which is suppose to be better. They aren't perfect, and I can't play them too loud tonight with kiddos sleeping but sound good at a low volume.

Thanks in advance

The "stereo" in stereophonic comes from the Greek for "solid". A correctly setup stereo speaker system always creates a soundstage (at least) between and behind the speakers. An orchestra should normally have the violins more to the left of the image (but not sounding as if the sound is coming from the speaker) and the double bass towards the right of the image. BUT, the percussion, brass and woodwind should sound as if they are further away, behind the strings and more central (the timpani are often in the middle). I have some recordings where the sounds appear to come from tens of feet behind the speakers. Also, the sounds should not appear to come directly from the speakers.

Some people can't experience this, like some people see 3D movies as two overlaid blurry images.

Stereo imaging is NOT a mechanical property of the speakers (although some designs may negatively damage the effect), but is a consequence of level and phase differences stored in the stereo recording.

Personally, I believe that a stereo system that can't create a good image is fundamentally broken.

 

[antcollinet]

Stereo imaging is NOT a mechanical property of the speakers (although some designs may negatively damage the effect),

I think it is the case that speaker/room interaction can have a significant impact on the soundstage. Optimisation of speaker positioning in the room is important.

 

[MaxwellsEq]

I think it is the case that speaker/room interaction can have a significant impact on the soundstage. Optimisation of speaker positioning in the room is important.

Absolutely true.

I've always managed to get any reasonable playback system to create a stereo image in any room. But sometimes the correct layout (both speakers away from boundaries, equilateral triangle, same height) is simply not livable with, and the real-world compromise makes the image deformed.

 

[DSJR]

Out of interest, I have a single sub positioned just in front of the left speaker. (what can I say -it is a small room with a lot of stuff in it).

I get reflections off the sub which shifts the balance over to the left (and widens the sound stage). I know this is happening, because if I drape the curtain over the top of the sub, the effect is almost eliminated.

View attachment 321896

Can you roll the sub out at a lower frequency and (donning my well knackered old dealer hat) pull the left (and right) speaker forwards a bit and toe it in towards you (assuming that TV screen is directly in front of you)? Having 'stuff' in between the speakers (as I also have to) can mess with perceived imaging between them.

 

[antcollinet]

Can you roll the sub out at a lower frequency and (donning my well knackered old dealer hat) pull the left (and right) speaker forwards a bit and toe it in towards you (assuming that TV screen is directly in front of you)? Having 'stuff' in between the speakers (as I also have to) can mess with perceived imaging between them.

Not really - and not necessary. I can cure the issue with damping material on top of the sub, and I am otherwise happy with the soundstage I get. Actually I find it incredible it works at all, let alone as well as it does, given the room limitations.

Speakers are already toed in slightly - though manufacturer states this is not necessary (Dali Oberon 5). I could toe them in more, where they currently are. I'll perhaps experiment with that, but motivation (due to current performance) is low.

 

[ZolaIII]

It means phase shift (hanging between chenels) at distance is reached so it meats in the way it form's good separation and back to front refractions are satisfactory.
You really need/want to get a decent measurements mic and play a lot with it.
Regarding surface buzz (table top and such) it's a material property fundamental (peek) loscillation frequency. Energy doesn't disappear so you can try to ground and partially disperse it (spikes and such) or simply use (thick enough) material with very low fundamental to ground, disperse and keep it out of sensible audible range. I found silicone much better than rubber or foam. Some people actually like a buzz and lots of it (physical vibrations they actually can feel). I prefer tight controled bass and not being shaked by it. Room mods are in the way similar but there you only correct that peek room frequency (PEQ it down). Try to think about it sort of inside the box (speaker enclosure - refractions and room moods), as every box has them.
I am in the relatively small room on a 2.2 chenel setup (100 Hz Linkwitz Riley fort order SPL matched L-R and as true stereo) and opening the window wide gets me to third post's situation (L gets higher SPL as window is more to the right). It's a minimal phase (close to the wall) placement (realistically for most folks) in half treated room with plugged port's of main speaker and siled sub's but even so back to front refractions play significant difference to let's say good clearance behind them to improve ratio. Again almost impossible to do to the very bottom (that's why the best next thing (minimal phase is used for setup in the first place in my case at least).

 

[DSJR]

Not really - and not necessary. I can cure the issue with damping material on top of the sub, and I am otherwise happy with the soundstage I get. Actually I find it incredible it works at all, let alone as well as it does, given the room limitations.

Speakers are already toed in slightly - though manufacturer states this is not necessary (Dali Oberon 5). I could toe them in more, where they currently are. I'll perhaps experiment with that, but motivation (due to current performance) is low.

I just saw the speaker basically in a corner and alarm bells rang, but if it works for you, then that's brilliant as rooms are seriously odd and variable things.

 

[DVDdoug]

But I have a hard time following reviews of people who judge speakers only by their ears and nothing scientific.

All of the speakers reviewed by here by Amir are measured and listened-to. And with with same setup and measurement standards, the measurements are comparable.

Okay I get that. But what do all the terms used by these speaker reviewers really mean? What does "spatial" mean? etc.

Reviewers and "audiophiles" use lots of meaningless terminology...


The perception of the "soundstage" is obviously an illusion since the sound is coming from two speakers. It depends on many things... The recording, speaker placement, room acoustics, the speaker's dispersion characteristics, the recording, and your brain.

Personally, I only perceive an exact location when the sounds are hard-panned left & right. The center and everything else is rather vague. I assume this is normal, otherwise surround setups wouldn't need a center channel. (Although, I've read that the center is so that people in different seating positions can get a better perception of the center.)

...so the table top must be vibrating some sound? It's more noticeable at louder volume and lower vocals. I normally put some foam on the bottom of the speakers to isolate, but did not this time.

Probably not the desk vibrating which would normally be some kind of annoying and obvious buzz or rattle. But the sound will reflect off of the desktop, or any surface.

 

[Gringoaudio1]

Really early stereo recordings had instruments hard panned to one channel or the other. They sound kind of laughable today when you hear one. Old Beatles for instance.
The stereo image is the drug that got me interested in audio again after decades of having other priorities and expenses. It is magical to hear and a happy accident of speaker and room interaction and better recording techniques.

 

[MattHooper]

Out of interest, I have a single sub positioned just in front of the left speaker. (what can I say -it is a small room with a lot of stuff in it).

I get reflections off the sub which shifts the balance over to the left (and widens the sound stage). I know this is happening, because if I drape the curtain over the top of the sub, the effect is almost eliminated.

Acoustics are complicated. But sometimes it seems people who nerd out on this stuff make it seem like you have to use precisely the right properly designed acoustic materials or products in order to "do it right." Yet as your post indicates, very simple solutions are often at hand in our homes for some issues. It's amazing how effective just some cloth or a curtain can be in mitigating a reflection problem. One of my speakers is next to a very reflective tile surface (fireplace) and it shifts the tonal balance to that side. All it took was putting a velvet drape on that surface (I have it on hooks) and the problem was solved (to subjective satisfaction).

It reminds me of all the technical talk on the AVSforum in regards to renovating for home theater. I have a wide entrance way to my listening/home theater room, which is on the main floor of the house, and was concerned about sound leaking in to the room and leaking out for movie watching. People chimed in with technical information about the lengths one would have to go in order to soundproof that barrier. In the end? I just used a thick velvet curtain I draw across that room entrance. It solved the problem easily.

 

[antcollinet]

Acoustics are complicated. But sometimes it seems people who nerd out on this stuff make it seem like you have to use precisely the right properly designed acoustic materials or products in order to "do it right." Yet as your post indicates, very simple solutions are often at hand in our homes for some issues. It's amazing how effective just some cloth or a curtain can be in mitigating a reflection problem. One of my speakers is next to a very reflective tile surface (fireplace) and it shifts the tonal balance to that side. All it took was putting a velvet drape on that surface (I have it on hooks) and the problem was solved (to subjective satisfaction).

It reminds me of all the technical talk on the AVSforum in regards to renovating for home theater. I have a wide entrance way to my listening/home theater room, which is on the main floor of the house, and was concerned about sound leaking in to the room and leaking out for movie watching. People chimed in with technical information about the lengths one would have to go in order to soundproof that barrier. In the end? I just used a thick velvet curtain I draw across that room entrance. It solved the problem easily.

Here's a picture of my high-tech solution. Without this, the image is shifted left and downwards on the left-hand side, probably because the virtual image from the reflection goes down behind the sub.

 

[Anton D]

Cbracer! Welcome to "imaging!"

You are going to be very happy, I think this is the foundation of stereo sound. The reason for the hobby!

Gear can be flawed, have uneven frequency response, etc...but imaging can be joyful almost any place you hear it!

I know it is anathema in these parts, but this is a fun 'subjective' part of the hobby: you get to decide where you want things, what speakers do it best for you, etc...it's where listening takes the baton from 'audibly perfect' electronics.

Keep us posted on all the cool new experiences you have, it's like you gained a whole new music collection, no matter the format!

It's going to take you over, it is just the greatest Hi Fi phenomenon of all. (Purely a subjective listening based opinion, some may prefer measuring a good song, so I admit in advance that I have no measuring sheet I use to measure the imaging I hear. Again, purely worthless subjective enjoyment, nothing more.)