Let's build a room. How big? What dimensions?

[Al.M]

19 minutes ago, Crabsticks said:

And also because that's not their job.

It is if you specify it, otherwise it becomes no one’s job.

 

If not done the wall plasterer will only float it with 10-15mm of mortar and plaster and noise transmission path exists. If the bricky doesn’t do it while there, no one will return to individually fill in the 90mm deep numerous gaps.

 

Building Code higher internal transmission standards require this between shared common walls such as in apartment construction. This is also one of the causes of internal building noise complaints and has been identified as a construction fault, where people in modern built apartments can hear neighbours toilets flushing, down pipe and other internal service noises. Very hard to fix other than laying extra sheets over the incorrectly built wall.

Edited January 9, 2021 by Al.M

[Al.M]

19 minutes ago, MrC said:

I completely disagree ... 1 metre from the side walls is plenty of room (similarly from the front wall).  I have had my room analyzed and measured and it got the big thumbs up!!

That may be so in your room and your speaker setup but many others are recommending the speaker to be 1/3 out into the room from the wall. Many have subjectively tried this and found it to be the best sounding arrangement if it is practical to do so. We’re also talking about ideal larger scenarios if practical to do so not saying that what you have is wrong. My own setup is similar to what you have from experimenting with room position and that’s the compromise for me and works well enough.

Edited January 9, 2021 by Al.M

[frednork]

What is/are the objective measure/s of a (very) good sounding room?  There are some easy ones associated with noise coming in and going out but after that?

[MrC]

1 hour ago, Al.M said:

That may be so in your room and your speaker setup but many others are recommending the speaker to be 1/3 out into the room from the wall. Many have subjectively tried this and found it to be the best sounding arrangement if it is practical to do so.

Jeez .... 1/3 out into a room would mean that the separation between your left and right speakers is only 1/3 of the room width ... in my view this is way too narrow and does not allow a wide enough sound stage or provide enough stereo separation.  Of course if you have a 10m wide room (which is ridiculous for home theatre) then a 3.33 m separation between left and right would be fine.  But for home theatre setups your 1/3  idea does not make sense.  IF you are talking about subwoofer placement then yes fine, but not for left and right speakers.

[Al.M]

3 hours ago, frednork said:

What is/are the objective measure/s of a (very) good sounding room?  There are some easy ones associated with noise coming in and going out but after that?

Audiophysic website https://www.audiophysic.com/en/rules-about-positioning/ and others have a good explanation of speaker setup such as avoiding equal distance between, behind and side walls, but whatever works and sounds good for individual room sizes, shapes, furnishing and dampening etc makes the final result.

 

They also urge not too overdamp walls as it reduces higher frequency and dynamics with room sounding dead and the use of furnishing in places for bass trapping as opposed to what we often see people starting with an empty room with very little furnishing and then amounts of trapping to address problems.

 

And mentions different size listening triangles for standmount speakers, floorstanders and relevance of room effects for more/less than 2m triangles.

Edited January 9, 2021 by Al.M

[aussievintage]

1 hour ago, MrC said:

Jeez .... 1/3 out into a room would mean that the separation between your left and right speakers is only 1/3 of the room width ... in my view this is way too narrow and does not allow a wide enough sound stage or provide enough stereo separation.  Of course if you have a 10m wide room (which is ridiculous for home theatre) then a 3.33 m separation between left and right would be fine.  But for home theatre setups your 1/3  idea does not make sense.  IF you are talking about subwoofer placement then yes fine, but not for left and right speakers.

 

You may not like the idea, but it is true.  I have found it to be the best positioning on many occasions.   The old idea of sticking the speakers as far apart as possible is just wrong.

[Ittaku]

1 hour ago, aussievintage said:

 

You may not like the idea, but it is true.  I have found it to be the best positioning on many occasions.   The old idea of sticking the speakers as far apart as possible is just wrong.

 I have to agree, and if you have almost no constraints on the size of the room you build, designing it with this 1/3 ratio in mind gives you an immense amount of freedom. Yes it means you need much bigger and more powerful speakers to fill the space, but I have placed no limits on that in my query about what makes an ideal room. Let's assume for argument's sake I'm starting with Magico M9 speakers (I'm not and will never spend that much on speakers but want the ability to scale to that size.)

[andyr]

1 hour ago, aussievintage said:

 

The old idea of sticking the speakers as far apart as possible is just wrong.

 

 

^  ^  ^  what da man said!  

 

2 hours ago, MrC said:

Jeez .... 1/3 out into a room would mean that the separation between your left and right speakers is only 1/3 of the room width ... in my view this is way too narrow and does not allow a wide enough sound stage or provide enough stereo separation.  Of course if you have a 10m wide room (which is ridiculous for home theatre) then a 3.33 m separation between left and right would be fine.  But for home theatre setups your 1/3  idea does not make sense.  IF you are talking about subwoofer placement then yes fine, but not for left and right speakers.

 

2/5ths in (instead of 1/3rds) is also good.

 

And, as Al.M wrote, make sure the distance behind each spkr (ie. to the front wall) is different to the distance from the centre line of the woofer to the side wall. IMO the ratio of these distances should ideally be 0.618 or 1.618.

 

Andy

 

Edited January 9, 2021 by andyr

[MrC]

6 hours ago, aussievintage said:

 

You may not like the idea, but it is true.  I have found it to be the best positioning on many occasions.   The old idea of sticking the speakers as far apart as possible is just wrong.

I clearly did not state that put the speakers as far apart as is possible ... I said 1 metre in from the side walls and at least 1 metre in from the front wall is more than adequate.  My main point is that if you go with the theory and take into account the practical dimensions most people face (where room widths are less than 5-6 metres) then they will be too close together.  IF you want to talk about massive width rooms then that is different.

[aussievintage]

10 hours ago, MrC said:

My main point is that if you go with the theory and take into account the practical dimensions most people face (where room widths are less than 5-6 metres) then they will be too close together. 

 

How do you determine "too close"?   It's all about the proportions, not absolute distances.  In a small room, you sit closer to the speakers, so they SHOULD be closer together.  That's what I meant by it sounding like you want to get them further apart, you shouldn't do that, they will sound best at the proper ratio of the distances involved.

[MrC]

2 hours ago, aussievintage said:

 

How do you determine "too close"?   It's all about the proportions, not absolute distances.  In a small room, you sit closer to the speakers, so they SHOULD be closer together.  That's what I meant by it sounding like you want to get them further apart, you shouldn't do that, they will sound best at the proper ratio of the distances involved.

How does one determine too close for a room that is 4.5 metres wide and 6 metres long?  Being a mathematician I am very aware of numbers and ratios but clearly if you subscribe to the 1/3 theory having speakers 1.5 metres apart is too close given that you could be sitting 4-5 metres back !!!!  Pretty obvious really.  I believe the 1/3 theory is for relevant for large rooms that most people do not have.  Remember many room are also not just for 2 channel stereo but are home theatre rooms (mine is a dual purpose room).

[aussievintage]

1 minute ago, MrC said:

clearly if you subscribe to the 1/3 theory having speakers 1.5 metres apart is too close given that you could be sitting 4-5 metres back !!

 

Ah but you don't.   In a long narrow room, you can't sit at the other end of the room for serious listening.  You have to put a couch up closer to the end of the room where the speakers are.

[MrC]

48 minutes ago, aussievintage said:

 

Ah but you don't.   In a long narrow room, you can't sit at the other end of the room for serious listening.  You have to put a couch up closer to the end of the room where the speakers are.

You keep making assumptions .... did you know that I have open doors at the end of this "narrow" room?  The sound in my prime listening position (5 metres back) is just superb ... remember I have accoustic treatments and I have the Trinnov doing its magic.

[Guest DrSK]

On 10/01/2021 at 1:03 PM, MrC said:

How does one determine too close for a room that is 4.5 metres wide and 6 metres long?  Being a mathematician I am very aware of numbers and ratios but clearly if you subscribe to the 1/3 theory having speakers 1.5 metres apart is too close given that you could be sitting 4-5 metres back !!!!  Pretty obvious really.  I believe the 1/3 theory is for relevant for large rooms that most people do not have.  Remember many room are also not just for 2 channel stereo but are home theatre rooms (mine is a dual purpose room).

 

The 1/3 theory can create problems too. Doesn't work in my room (7m wide) . This would be too close between the speakers. 

 

'Too close' between your speakers for the room relates to the time delays for the reflected signal off the side walls, unless you have the unlikely situation of 100% absorption across the audio range. Eg if they are too close the delays are audible. Eg my room is 7m wide and I have my speakers around 3m width to reduce the delays from lateral reflections. 

 

This then puts me 'too close' to the speakers from my chair. 

 

'Too close' to the speakers from the seat can to some extent be corrected with toe in as too close usually means you are in the off axis region.

 

Reality is any speaker positioning is room dependent and about best combination of controlling 1st order reflections to maintain the acoustic image and not creating a strong response to periodic summed reflections (otherwise known as modes, where it can be helpful if your speaker positions do not result in enhancing the strength of the summed periodic reflections, but work against them instead and preserve the direct signal). 

Edited January 15, 2021 by DrSK

[Get off My lawn]

This thread inspired me to actually do some measurements in my room ( distances only, nothing more complicated than than that!)

 

The speakers are approximately 1.5 m out from the wall, 3m apart , and 2.5 m from the side walls. They're about 2.5 from the sofa where  listen. I guess its almost a nearfield arrangement in a large room, so hopefully minimises the influence of the walls.

 

Over the years I've tried many different positions of equipment/speakers etc, including having them firing down the long axis of the room, and currently,  I'm enjoying the best sound I've had so far from my system.

 

[Guest DrSK]

16 hours ago, pine weasel said:

This thread inspired me to actually do some measurements in my room ( distances only, nothing more complicated than than that!)

 

The speakers are approximately 1.5 m out from the wall, 3m apart , and 2.5 m from the side walls. They're about 2.5 from the sofa where  listen. I guess its almost a nearfield arrangement in a large room, so hopefully minimises the influence of the walls.

 

Over the years I've tried many different positions of equipment/speakers etc, including having them firing down the long axis of the room, and currently,  I'm enjoying the best sound I've had so far from my system.

 

More people should try something like this.

 

Getting close enough that direct field (noting that what is commonly called near field isn't actually an acoustic near field as occurs very close to speaker diagrams where velocity and pressure phase relationships have not settled down) from the speakers completely dominates room effects is an effective low cost solution in bigger rooms. I have suggested this before for people having issues in large open plan living areas but it never gains much traction. 

 

It is also a good way to test the imaging of equipment to understand the best you can get out of gear before deciding whether you should spend on the room and returning to other speaker locations.

 

I have temporarily set up gear in impractical locations to run tests to get rid of room effects. Just need to know it can impact base response if well away from boundaries, but not that important when testing imaging. Speaker response curves generally assume boundary reflection for base. 

 

For a few reasons my room is also not set up firing along the long axis. Your distances are fairly similar to mine. I needed subtle bass EQ, but that isn't unsual in any room. 

Edited January 17, 2021 by DrSK

[Al.M]

41 minutes ago, DrSK said:

More people should try something like this.

 

Getting close enough that direct field (noting that what is commonly called near field isn't actually an acoustic near field as occurs very close to speaker diagrams where velocity and pressure phase relationships have not settled down) from the speakers completely dominates room effects is an effective low cost solution in bigger rooms. I have suggested this before for people having issues in large open plan living areas but it never gains much traction. 

 

It is also a good way to test the imaging of equipment to understand the best you can get out of gear before deciding whether you should spend on the room and returning to other speaker locations.

 

I have temporarily set up gear in impractical locations to run tests to get rid of room effects. Just need to know it can impact base response if well away from boundaries, but not that important when testing imaging. Speaker response curves generally assume boundary reflection for base. 

 

For a few reasons my room is also not set up firing along the long axis. Your distances are fairly similar to mine. I needed subtle bass EQ, but that isn't unsual in any room. 

I agree and have had more success with this type of approach than firing speakers down the long end of the room. Sit closer within the listening triangle at least 2m between speakers, sit 2m from speakers, speakers at least 1-1.5m from side walls and 1m behind. If the speaker is large and tall this won’t work as well and the triangle needs to get bigger to get into the sweet spot. If the room is bigger keep those ratios and widening the distance between speakers. It even works well enough in small rooms with a wall behind the seat though insulation behind helps reflections although this is theoretically not recommended.

Edited January 17, 2021 by Al.M

[aussievintage]

16 hours ago, pine weasel said:

The speakers are approximately 1.5 m out from the wall, 3m apart , and 2.5 m from the side walls. They're about 2.5 from the sofa where  listen. I guess its almost a nearfield arrangement in a large room, so hopefully minimises the influence of the walls.

 

39 minutes ago, DrSK said:

I have suggested this before for people having issues in large open plan living areas but it never gains much traction. 

 

2 minutes ago, Al.M said:

Sit closer within the list  listening triangle at least 2m between speakers, sit 2.7-3m from speakers, speakers at least 1-1.5m from side walls and 1m behind. If the room is bigger keep those ratios and widening the distance between speakers.

 

Yes.  Setting up a nice tight listening triangle in the middle of a troublesome room is often the best thing you can do.  I currently use it in a long narrow room with an open "L" shaped area at the far end and various large openings along the long sides with lots of odd reflections.

[Pim]

On 02/01/2021 at 6:44 PM, andyr said:

 

Aah, any SNA members who came to my last house, Con, will confirm that my then 'listening room' was special!  

 

It was 8m long x 5.1m wide - ceiling was pitched, with a centre-line going down the length ... height 2.7m at the side walls and about 4.5m at the ridge.  I decided on the width after plotting room modes for an 8m long room.  The pitch was arrived at by having a 100 deg angle between the 2 ceiling slopes - which gradually dispersed floor to ceiling reflections (a 90 deg angle would've had them repeating, endlessly).

 

So I would say that >8m long is probably not required - but a high, pitched ceiling is!  

 

Andy

 

 

Our kitchen/living/dining room has a pitched ceiling and high walls like yours. It is 11.8m long and 6.9m wide. I haven't compared with a similar sized room with a flat ceiling but my feeling is that a lot of the reflection issues I have are ceiling related. The way I see it, a pitched ceiling is larger than a flat ceiling so there's more surface that needs treating. It looks great though.

 

When the room was empty it had a reverberation time of 2.15 seconds measured with my ears (make a noise and wait until I can't hear the echo anymore and measure time).

 

I've managed to get nice sound by setting my speakers up semi-near field but I can't wait to have a dedicated room where I can go nuts with room treatment. I always thought this larger room was going to be the bees knees but I found it bitterly disappointing. So I'd say go big and go rectangle.

[Tony Martello]

The classic Golden Ratio is 1 x 1.6 x 2.56 (Height, Width, Length).

I built my room to these specs and my music sounds amazing 

[Ittaku]

2 minutes ago, Tony Martello said:

The classic Golden Ratio is 1 x 1.6 x 2.56 (Height, Width, Length).

I built my room to these specs and my music sounds amazing 

This is a known good starting point, but that's only useful for a perfectly sealed box which is 100% reflective for all frequencies. A real room is infinitely more complex than this.

[andyr]

1 hour ago, Tony Martello said:

The classic Golden Ratio is 1 x 1.6 x 2.56 (Height, Width, Length).

I built my room to these specs and my music sounds amazing 

 

Actually it's:

• 0.618 x 1 x 1.618
• or 1 x 1.618 x 2.618.

I wholeheartedly agree that a room built the the GR is an excellent starting point for a good-sounding room.  But as Con inferred ... you can still stuff up the SQ by, say, making all 4 walls glass!  

 

Andy

 

[davewantsmoore]

Some good advice in this post....

 

On 09/01/2021 at 10:33 AM, DrSK said:

The bigger the room, the bigger the delays off reflecting surfaces due to path length differences. So unless you run around 100% frequency range treatment the reflections will go from imaging broadening to audible delays as a seperate source. 

 

Yes... the bigger=better theme in this thread seems somewhat misguided.

 

On 09/01/2021 at 10:33 AM, DrSK said:

A smaller room has image broadening from lateral reflection and will also shift the image up due to ceiling reflection. Rear wall reflection will also add to this and depth issues. Some of this can be beneficial. 

 

Yep... it's a balance between this and SBIR and early reflections.

 

 

On 09/01/2021 at 10:33 AM, DrSK said:

To answer the question of how big, I'd start with seating position and speaker placement. Essentially, how big is your desired triangle. 

 

Then add at least twice that seating to speaker distance for the seating to the rear wall. 

Yes.... al least.

 

Too many setups have the listener without enough space behind them.

 

On 09/01/2021 at 10:33 AM, DrSK said:

Similarly I'd then look at rear and front wall diffusion. Expand the size to create the space including allowances for getting out of the near field. 

 

Ideally the rear should be far enough way that it's not big issue.

 

On 09/01/2021 at 10:33 AM, DrSK said:

The achievable result will be strong 3d imaging with room ambience from the diffusion without the liveliness impacting imaging. This is big budget stuff. 

Is it?

Which bits cost a lot?

[givita_burl]

On 02/01/2021 at 8:05 PM, Ittaku said:

A room can be treated. Walls can't be moved. I plan to make the back "half" of the room facing the other way a home theatre too so there'll be other furnishings and stuff.

That makes for another interesting challenge. If I had to/could allocate a footprint to suit an ideal music room, then I would feel compelled to use it for HT as well, probably along the lines you suggest.

How do you think you will be able to balance the compromises?

[Ittaku]

36 minutes ago, givita_burl said:

That makes for another interesting challenge. If I had to/could allocate a footprint to suit an ideal music room, then I would feel compelled to use it for HT as well, probably along the lines you suggest.

How do you think you will be able to balance the compromises?

Make it extra long, use heavy treatment and absorbent furnishings, and effectively listen nearfield anyway.