Smurfin
Distinguished Member
- Joined
- Aug 13, 2002
- Messages
- 22,503
- Reaction score
- 5,420
- Points
- 4,193
I've always found it odd that the forum is full of posts about kit upgrades, but by comparison there is very little written about room acoustics. In fact, the words "room acoustics" often get interchanged with soundproofing, and of course these are two very different subjects.
It amazes me when I look in the home cinema gallery forum, to see people spending £000s on dedicated rooms, yet in many cases there is no consideration to room acoustics. No matter how "nice" a room looks, the first thing my eyes are drawn to is whether there are acoustic panels fitted and where. I can't help it, and I inwardly groan every time I see nicely painted but completely bare walls.
I posted something similar to this 4 years ago:
Why are there so few threads/discussion around room acoustics?
I've heard many cinema setups, from my own (of which there's been many!), to a number of dedicated rooms of mixed quality, and I've heard treated and untreated rooms, but never have I had the opportunity to hear "before and after" - that is, before treatment, and after treatment, in the space of minutes and with kit I'm very familiar with.
Recently, I bought some GIK acoustic panels from @kbarnes70 ; I bought 7 panels in total, 4 of them measuring 600mm x 1200mm x 100mm thick, and 3 of them the same, but only 50mm thick. These are broadband absorbers, and I planned to position these in my room to cover first and second reflection points.
So what are first and second reflection points?
Firstly, I should say I know practically nothing about room acoustics, and there are plenty of people who can explain these things and offer better advice than me. However, one of the basic principles behind what we actually hear in our rooms is a combination of direct and indirect sound (as I understand it anyway).
Direct sound is the direct output from your speakers.
Indirect sound is a combination of soundwaves which have bounced off various surfaces before they reach your ears.
As an example, take your left front speaker. The soundwaves will emanate from the drivers, and very quickly these will make contact with the nearest wall to the speaker; if there is nothing in the way to absorb this, the sound will bounce off in another direction. If you take a 5.1 system, imagine 3 front speakers, now think of the sound bouncing off the left wall, the right wall, the floor and ceiling, for every single speaker. Put that into a 3D model where a line shows each reflected soundwave, and you will have a very busy drawing with lines all over the place. Then include the surround speakers, go to 7.1, then Atmos....and holy crap, how is that going to sound with everything bouncing around the room?
So what we hear is a combination of direct sound and indirect sound; all of those sound reflections arrive at our ears at different times (but within a split second), and the end result can often be a muddy sound which doesn't image properly; it can be unfocused, dialogue can be difficult to understand, and the whole soundstage becomes less cohesive.
What often happens is that people think "my speakers are poor", or "I need a new AVR as my sound isn't detailed enough". And often people then go and spend a fortune on upgrades, and proclaim a huge improvement because they bought a new receiver. Now, EQ systems aside, I don't believe them. Because what we hear when we watch a movie is as much about the room as it is about the hardware, and so many people seem to forget this!
Kit does come into play of course, although I'd argue speakers can deliver significantly greater improvements than electronics (up to a point), but still...don't deal with the room and you're going to hit that performance ceiling so very quickly. The other factor here is EQ. There are various EQ systems, and in fact I've tried them all over the years (proper high end excepted) - YPAO, MCACC, Audyssey, ARC and finally Dirac, which I'm running in my room currently.
If anyone is wondering the difference the room makes, try this:
Sit in your main listening position, and play a dialogue heavy clip from a movie you know well - set the volume @ a reasonable level (say -10db or -15db).
Now play the clip again, but sit 2' in front of your centre speaker.
In most rooms the centre speaker will sound completely different. It will sound direct; there will likely be an immediacy to the sound, a focus which isn't there when your listening from your normal seating position. What I've always hankered for is that clarity and directness from my sofa, but I've never been able to achieve it. Some of this might come down to the speaker itself, but treating the room can make a HUGE difference in getting you closer to the sound.
So, back to these panels...
With only 7 panels and very little knowledge (those of you who know all about this subject, don't laugh ), I set about positioning them in the room.
I know I should run REW to understand exactly what is going on in my room, but despite having a UMIK-1 I've not got round to dabbling with it yet. Instead, I used the mirror method to find the key reflection points.
Within minutes I identified the reflection points on the left and right walls. On the left hand wall, I moved the mirror until the front left speaker could be seen clearly. 1st panel went here. I carried on moving the mirror until I could see the centre speaker. 2nd panel went here. I then carried on until I could see the reflection of the front right speaker...3rd panel went here.
I repeated this for the right hand wall, and I then had 6 panels positioned.
I then put the mirror on the floor in front of the MLP, to find where the centre speaker reflection point on the floor is (sadly, divorce would be on the cards if I tried anything on the ceiling ).
Having put the panels in position, I re-ran Dirac, sat back and watched some movies.
And wow. Just wow.
It felt like I'd upgraded all of my kit. The difference in the soundstage was immediate and striking, especially when playing movies at a loud volume. I watch everything at -10db now, and when the kids are out I'll regularly push it to -5db, and the difference is enormous.
I must admit, previous to this Dirac had the same effect (in that it became easier to watch movies at a louder level), but after treatment it's like someone's grabbed the whole soundstage and clenched a giant fist: everything is tighter, cleaner, and somehow more dynamic.
My dad is 71 and he's about as far from being an audiophile as possible. I put on the first millenium falcon/tie fighter chase scene from A Force Awakens, cranked it to -5db and watched it with the panels; then I took the panels away, switched the Dirac profile back to the previous one, and re-played it.
Within seconds my dad said "It sounds harsh - it's not as nice to listen to".
If you're thinking "well my system doesn't sound harsh" - well, it might not, but until you've heard the effect your room is having on your system, how exactly do you know how much of what you're hearing is the room?
Movie after movie, the effect of room treatment shines through. Dialogue heavy movies are a joy; that directness I mentioned earlier is now there, and there is a precise, clean quality to speech that I was missing before.
The whole soundstage images better. There is no overhang and it's made even the surrounds sound more precise and obvious. I'm running out of audio cliches (this stuff is difficult to describe really), but it's been fantastic to experience such a difference, and the experiment has confirmed what I've always thought.
Of course, there's a huge caveat in this. How many of us have dedicated rooms? Not many, and my dilemna is that I can't go back to having no panels. At the moment I put them away after movie night, and they take up too much space. The wife hates them which also doesn't help, so the compromise for me is to keep the 3 thinner panels (and just treat the first reflection points), and get rid of the 4 thicker ones.
Even if - like me - your room isn't dedicated, it's still worth getting a mirror and finding out where your reflection points are. Heavy curtains, cushions, soft furnishings and rugs can make a huge difference in the right place, and I'll bet that even if you know nothing about acoustics like me, you can make some improvements with a little thought and research.
Room acoustics is science and art and I'm interested to learn more; we would all be served well to consider this before thinking of changing to that new shiny AVR.
Now, where's that dedicated room I've been talking about building (for the last 10 years!)
It amazes me when I look in the home cinema gallery forum, to see people spending £000s on dedicated rooms, yet in many cases there is no consideration to room acoustics. No matter how "nice" a room looks, the first thing my eyes are drawn to is whether there are acoustic panels fitted and where. I can't help it, and I inwardly groan every time I see nicely painted but completely bare walls.
I posted something similar to this 4 years ago:
Why are there so few threads/discussion around room acoustics?
I've heard many cinema setups, from my own (of which there's been many!), to a number of dedicated rooms of mixed quality, and I've heard treated and untreated rooms, but never have I had the opportunity to hear "before and after" - that is, before treatment, and after treatment, in the space of minutes and with kit I'm very familiar with.
Recently, I bought some GIK acoustic panels from @kbarnes70 ; I bought 7 panels in total, 4 of them measuring 600mm x 1200mm x 100mm thick, and 3 of them the same, but only 50mm thick. These are broadband absorbers, and I planned to position these in my room to cover first and second reflection points.
So what are first and second reflection points?
Firstly, I should say I know practically nothing about room acoustics, and there are plenty of people who can explain these things and offer better advice than me. However, one of the basic principles behind what we actually hear in our rooms is a combination of direct and indirect sound (as I understand it anyway).
Direct sound is the direct output from your speakers.
Indirect sound is a combination of soundwaves which have bounced off various surfaces before they reach your ears.
As an example, take your left front speaker. The soundwaves will emanate from the drivers, and very quickly these will make contact with the nearest wall to the speaker; if there is nothing in the way to absorb this, the sound will bounce off in another direction. If you take a 5.1 system, imagine 3 front speakers, now think of the sound bouncing off the left wall, the right wall, the floor and ceiling, for every single speaker. Put that into a 3D model where a line shows each reflected soundwave, and you will have a very busy drawing with lines all over the place. Then include the surround speakers, go to 7.1, then Atmos....and holy crap, how is that going to sound with everything bouncing around the room?
So what we hear is a combination of direct sound and indirect sound; all of those sound reflections arrive at our ears at different times (but within a split second), and the end result can often be a muddy sound which doesn't image properly; it can be unfocused, dialogue can be difficult to understand, and the whole soundstage becomes less cohesive.
What often happens is that people think "my speakers are poor", or "I need a new AVR as my sound isn't detailed enough". And often people then go and spend a fortune on upgrades, and proclaim a huge improvement because they bought a new receiver. Now, EQ systems aside, I don't believe them. Because what we hear when we watch a movie is as much about the room as it is about the hardware, and so many people seem to forget this!
Kit does come into play of course, although I'd argue speakers can deliver significantly greater improvements than electronics (up to a point), but still...don't deal with the room and you're going to hit that performance ceiling so very quickly. The other factor here is EQ. There are various EQ systems, and in fact I've tried them all over the years (proper high end excepted) - YPAO, MCACC, Audyssey, ARC and finally Dirac, which I'm running in my room currently.
If anyone is wondering the difference the room makes, try this:
Sit in your main listening position, and play a dialogue heavy clip from a movie you know well - set the volume @ a reasonable level (say -10db or -15db).
Now play the clip again, but sit 2' in front of your centre speaker.
In most rooms the centre speaker will sound completely different. It will sound direct; there will likely be an immediacy to the sound, a focus which isn't there when your listening from your normal seating position. What I've always hankered for is that clarity and directness from my sofa, but I've never been able to achieve it. Some of this might come down to the speaker itself, but treating the room can make a HUGE difference in getting you closer to the sound.
So, back to these panels...
With only 7 panels and very little knowledge (those of you who know all about this subject, don't laugh ), I set about positioning them in the room.
I know I should run REW to understand exactly what is going on in my room, but despite having a UMIK-1 I've not got round to dabbling with it yet. Instead, I used the mirror method to find the key reflection points.
Within minutes I identified the reflection points on the left and right walls. On the left hand wall, I moved the mirror until the front left speaker could be seen clearly. 1st panel went here. I carried on moving the mirror until I could see the centre speaker. 2nd panel went here. I then carried on until I could see the reflection of the front right speaker...3rd panel went here.
I repeated this for the right hand wall, and I then had 6 panels positioned.
I then put the mirror on the floor in front of the MLP, to find where the centre speaker reflection point on the floor is (sadly, divorce would be on the cards if I tried anything on the ceiling ).
Having put the panels in position, I re-ran Dirac, sat back and watched some movies.
And wow. Just wow.
It felt like I'd upgraded all of my kit. The difference in the soundstage was immediate and striking, especially when playing movies at a loud volume. I watch everything at -10db now, and when the kids are out I'll regularly push it to -5db, and the difference is enormous.
I must admit, previous to this Dirac had the same effect (in that it became easier to watch movies at a louder level), but after treatment it's like someone's grabbed the whole soundstage and clenched a giant fist: everything is tighter, cleaner, and somehow more dynamic.
My dad is 71 and he's about as far from being an audiophile as possible. I put on the first millenium falcon/tie fighter chase scene from A Force Awakens, cranked it to -5db and watched it with the panels; then I took the panels away, switched the Dirac profile back to the previous one, and re-played it.
Within seconds my dad said "It sounds harsh - it's not as nice to listen to".
If you're thinking "well my system doesn't sound harsh" - well, it might not, but until you've heard the effect your room is having on your system, how exactly do you know how much of what you're hearing is the room?
Movie after movie, the effect of room treatment shines through. Dialogue heavy movies are a joy; that directness I mentioned earlier is now there, and there is a precise, clean quality to speech that I was missing before.
The whole soundstage images better. There is no overhang and it's made even the surrounds sound more precise and obvious. I'm running out of audio cliches (this stuff is difficult to describe really), but it's been fantastic to experience such a difference, and the experiment has confirmed what I've always thought.
Of course, there's a huge caveat in this. How many of us have dedicated rooms? Not many, and my dilemna is that I can't go back to having no panels. At the moment I put them away after movie night, and they take up too much space. The wife hates them which also doesn't help, so the compromise for me is to keep the 3 thinner panels (and just treat the first reflection points), and get rid of the 4 thicker ones.
Even if - like me - your room isn't dedicated, it's still worth getting a mirror and finding out where your reflection points are. Heavy curtains, cushions, soft furnishings and rugs can make a huge difference in the right place, and I'll bet that even if you know nothing about acoustics like me, you can make some improvements with a little thought and research.
Room acoustics is science and art and I'm interested to learn more; we would all be served well to consider this before thinking of changing to that new shiny AVR.
Now, where's that dedicated room I've been talking about building (for the last 10 years!)
Last edited: