Optimum position of big ATC in small room

[Old Sea]

Hi there,

 

I have ATC scm150asl pro pair which sound great at low volume but always feel a bit noisy when try louder. The room is 4×5m and hard to make fundamental changes but I added some wall foamings . Would uptilting the speakers i.e. drivers then slightly pointing upwards  give any better？Or a certain spacing which is optimum？I have added support frames which improved the low end much. They are so heavy so not fun to move and try all possibilities. 

 

Thanks and  Cheers

Old Sea

[frankn]

Hello OS,

ATC   Good info there, you probably know of it?

Section4 : Listening specifically comments on perceived distortion and says if you experience distortion either the system or your ears are being overloaded and volume should be reduced. 
These are Pro Monitor speakers and you might find their clarity a bit “shouty”.   They have wide dispersion and narrower vertical dispersion so how high is the “acoustic axis (as ATC refer to it in Section3 : Positioning) which is the mid-range driver in the 150 relative to your ears when listening?  

Are the speakers about 1m from the side walls and 1-2m from the front wall (wall behind speakers)?  Distance from walls is measured from driver centre for side walls and driver face for distance front and rear, not cabinet edges. 

How far away from the speakers is your listening position?  You should be listening from the same distance away from your speakers as they are apart, or a bit more say 1.5 times the distance. 
Assuming your speakers are across the narrow dimension of your room the speakers will be somewhere between 2m to 2.5m apart (driver centre -to - driver centre), so your listening position will be 2m, 2.5m away (perpendicular to the plane of speakers)? 
Be careful how close your listening position is to the wall behind you. 1m away from it is the least you want to be if you can. 

Unfortunately, getting a good sound does take a bit of moving speakers around and when they weigh as much as those it is work!  
You could put the speakers and their stands on to dolly platforms (from Bunnings) to assist in moving them around. I did that with some large speakers until I was satisfied. 
Once you have them in the best position (which will be a compromise of minimising issues) , then work on further reduction of remaining issues. 
Take your time, enlist a friend (or two) and report back. 

Edited February 1 by frankn
Clarity

[Old Sea]

Thank you Frankn for the great info and advices. Now I actually managed to DIY two trailers (chipboard on four wheels) as new stands which give great convenience! Playing with different positions/angles gives quite different imaging and also low end profile. A small further improvement is not to put speaker directly on the trailer, a soft rubber bar is inserted under it which creates a small uptilt angle. Low end has more clarity/natural.  Position/angle can improve imaging and also low end however a more immersive low end may bring standing waves as bonus,  some music become a bit tardy/boomy then.  In general I feel the ATC150 is versatile with top-class midrange(has been amazed by vocals for months), great low end control while tweeter may be a bit dry/shouty. I try to listen at the right height (as you mentioned) which does improve my experience. The speaker has great balance/clarify at low volume which makes me wonder if the high is tuned a bit too much since the equal loundness contour tells the opposite. I guess it might not be practical to make the speaker shining for all types of music, but I really wonder if the a bit dry high is music native or something went wrong.  I connected to ATC CA2 which I also feel a bit dry(but really detailed), if I skip it, music become a bit more musical. Probably human ears do not like honesty. Have not compared many HiFi systems so only speculations.

 

[TerryO]

I have a pair of 150 actives in my main room at present, which is very similar in size to your room, mine is 4..2 x 6m. There are so many factors that can make or break a hifi system and just about the most important is the room itself and what treatment you have or don’t have, especially with speakers of this large size in a room of our similar size.. 
 

Then take into consideration the rest of the system feeding the speakers but especially the front end, as the old saying goes, rubbish in rubbish out, which means the front end does make a huge difference in sq delivered. I have found that ATC’s will faithfully deliver in spades what they are feed. I sell many different excellent brands of speakers including ATC and I am happy to admit I personally listen to either active ATC100’s or 150’s more than any other speaker. Bang for dollar, especially for the active models, they are extremely hard to better and the better the front end the more they rise to the occasion.
 

While you have not said how old your speakers are and if they are the current model with the in-house tweeter, which is far superior than previous versions, even then, ATC speakers don’t tend to be dry sounding. It would be interesting to know what the rest of your system is made up off.

 

A couple of pics of your room, your system and your seating position would be good.

 

cheers,

Terry

 

 

Edited February 8 by TerryO

[frankn]

I did notice that the recommended setup is to have the offset tweeters on the inside and you have some leeway in the vertical position. Centre of the Midrange driver is the reference for listening.  If you find that tilting the speakers up at the front improves performance you could also try lifting them up instead?  
The speakers are active and I also note there are fine tuning options for the tonal characteristics of the speaker using the bass boost - see manual.  Once you have the speakers position to the best location , then perhaps some diffusion at 1st reflection on the walls (large pot plants , bookcases (and the books obviously) or properly designed diffusion panels)) will probably help. 
What happens in your room when you clap your hands - does the clap reverberate, sound ringy?  
Keep going, they are good speakers and it takes a bit of work for it all to “click”.  
I haven’t yet suggested getting a measurement (usb) and analysis software like REW (free) but if you really want to get the room under control this is where you should go to evaluate and understand the issues.  Then you could make a plan as to how far to reduce them. 

[frankn]

28 minutes ago, TerryO said:

I have a pair of 150 actives in my main room at present, which is very similar in size to your room, mine is 4..2 x 6m. There are so many factors that can make or break a hifi system and just about the most important is the room itself and what treatment you have or don’t have, especially with speakers of this large size in a room of our similar size.. 
 

Then take into consideration the rest of the system feeding the speakers but especially the front end, as the old saying goes, rubbish in rubbish out, which means the front end does make a huge difference in sq delivered. I have found that ATC’s will faithfully deliver in spades what they are feed. I sell many different excellent brands of speakers including ATC and I am happy to admit I personally listen to either active ATC100’s or 150’s more than any other speaker. Bang for dollar, especially for the active models, they are extremely hard to better and the better the front end the more they rise to the occasion.
 

While you have not said how old your speakers are and if they are the current model with the in-house tweeter, which is far superior than previous versions, even then, ATC speakers don’t tend to be dry sounding. It would be interesting to know what the rest of your system is made up off.

 

A couple of pics of your room, your system and your seating position would be good.

 

cheers,

Terry

 

 

all very good points. I wonder what the differences are in room construction/framing/insulation and therefore the room “performance”are in Sweden.  Generally much better than our homes that is for certain. 

Personally I’d go the / REW (or similar software) route. That the author is here asking questions perhaps indicates his willingness to expend more effort to get the best out of his system. 
 

[TerryO]

42 minutes ago, frankn said:

all very good points. I wonder what the differences are in room construction/framing/insulation and therefore the room “performance”are in Sweden.  Generally much better than our homes that is for certain. 

Personally I’d go the / REW (or similar software) route. That the author is here asking questions perhaps indicates his willingness to expend more effort to get the best out of his system. 
 

I didn’t build this house but the people who did had it designed and built well.
 

The main listening room was built as a dedicated HT room, with heavily insulated walls and ceiling and solid 50mm MDF rear centred double doors with seals, the room is that airtight that it has its own return on the Airconditioning otherwise with the doors closed you go to sleep after about 30 minutes. This all worked extremely well for HT, but sounded like total rubbish for 2-channel. 
It wasn’t until I had it measured and treated that it started to sound good, I have gone much further since then and it now sounds very good. When using Antipodes music servers I also use HQ Player and have had Mark (Frednork) come up several times to measure the room and put together convolutions for HQ, this refined the SQ to a extremely high level, but on its own I doubt it would have been enough to make up for the issues with the room before having it treated. 
 

REW is very good but it can only go so far if the room is a big problem, I combination of both works best in my opinion.
 

cheers,

Terry

Edited February 9 by TerryO

[jeromelang]

Show some photos already 

[frankn]

It all depends on how far the author wants to follow the rabbit hole. 

[Old Sea]

Thank you everyone for the inputs. The best position I can have is to place the big guys like this. 1 meter away from a concrete wall to the left, and a open space to the right (kitchen). The building however, IMO, is not audio friendly(glass doors, some walls are concrete while internal walls are cheap boards). After comparing different positions, I feel that low end impact is huge while not the highs.

 

I used Shanling dac-50 as decoder which feels bass-shy(maybe ATC150 itself is also bass shy), and tried to tune the ATC 150 (bass can +6dB via a tiny hole in the back) but the bass was not so natural IMHO.  A FiiO BTA30 RCA output however impressed me with LDAC connect that I have been using most. Right now the thing I am struggling most is treble. Maybe need to get an expensive decoder that can be a reliable reference. One possibility is that B&W tweeter has internal cosmetic that I have been used to? Or my MSR-7 headphone is a bit too sweet? 

BTW the ATC tweeter is old version(four screws). The new one seems to be 3 screws. I have a slight illusion that a warmer amplifier gives better treble, not sure if anyone experiences the same. Even though I feel "dry" sometimes, every time I listen to it, I want to stay a bit longer and "re-check" very old songs.

 

[TerryO]

7 hours ago, Old Sea said:

Thank you everyone for the inputs. The best position I can have is to place the big guys like this. 1 meter away from a concrete wall to the left, and a open space to the right (kitchen). The building however, IMO, is not audio friendly(glass doors, some walls are concrete while internal walls are cheap boards). After comparing different positions, I feel that low end impact is huge while not the highs.

 

I used Shanling dac-50 as decoder which feels bass-shy(maybe ATC150 itself is also bass shy), and tried to tune the ATC 150 (bass can +6dB via a tiny hole in the back) but the bass was not so natural IMHO.  A FiiO BTA30 RCA output however impressed me with LDAC connect that I have been using most. Right now the thing I am struggling most is treble. Maybe need to get an expensive decoder that can be a reliable reference. One possibility is that B&W tweeter has internal cosmetic that I have been used to? Or my MSR-7 headphone is a bit too sweet? 

BTW the ATC tweeter is old version(four screws). The new one seems to be 3 screws. I have a slight illusion that a warmer amplifier gives better treble, not sure if anyone experiences the same. Even though I feel "dry" sometimes, every time I listen to it, I want to stay a bit longer and "re-check" very old songs.

 

 

Personally I’d start off with getting a pair of proper stands for them and get them off those trolleys and up at the normal height. Also add Spikes with pucks under the stands which will make a good SQ difference as well. I have used Graphite Audio pucks under spikes on ATC’s with very good results over the standard steel ones. Which XLR’s you use to the speakers also makes a big difference, but that’s something to keep in mind for the future.
 

Once you have that done then it’s time to try refining positioning.
 

Most of the front end you have there I have no experience with, so can’t comment, but I will say that either rubbish or greatness flows down hill from the source, so the better the front end the more the big ATC’s will open up and sound natural. 
 

cheers

Edited February 10 by TerryO

[alex87]

How old are your ATCs? The tweeters have ferrofluid in them, and if the fluid dries the tweeter response can change.