Speaker placement and Room Correction Advice

[kharan]

Hello, I'm looking for some general advice as to how to improve my listening situation. Quite happy with it, but improvements are always possible.

Currently, I have a pair of Ascilab C8C installed in my room at the top left and top right of the room, roughly in the corners, they are facing the bottom of the picture. The distance from the back wall to the back of the speakers is about 5 cm, and the distance of the sides of the speakers to the side walls is about 40 cm (1.3") and the speakers are about 2 m (6.6") apart.

The listening position is at the centre of the room, vertically it's in the middle of the two speakers, about 3 m away from them, and the speakers are both pointed towards the listening position.

First, I want to consider all the speaker and listening positions that make sense. I think that considering the configuration of my flat, this is already the optimal one, but I'm open to other possibilities. The room is asymmetric, the top is a TV/HIFI space with the couch facing the top wall. The bottom is a kitchen space, with a dining table in between the couch and the kitchen. The right wall has a large floor to ceiling door opening on a balcony, and the left opens on a corridor. Total space is about 29 m2 (312 sqf) with 2.5 m ceiling (8.2"). I can move some furniture around if it still makes sense afterwards for a living space.

Secondly, I'd like to consider what can be improved either through EQ or minor room treatment. Below are the raw measurements at my listening position and the two corrections with different limiters that Gsonic provided. The Zip file is the MDAT. The three lines at the top are the left channel, and the three at the bottom are the right channel.

The Gsonic correction is very obvious in the bass region but to my ears it's not a night and day with the medium and treble areas. I don't know if that's the expected result, other people have reported much more change with their listening experience.

If that's possible, I'd like to find a passive solution for the massive 50 Hz null with the right channel, it is correctable with EQ, but the additional power and excursion requirements are sizeable. Hence my hope for a passive way to solve the issue.

Thanks.

 

[staticV3]

If at all feasible, I'd try placing the speakers at the two corners marked with blue circles. Just as a test.

Less corner loading might result in a nicer sound.

With just a lounge chair facing that diagonal wall, it looks like there might still be enough space around the kitchen island and balcony entry. Though a couch might be too tight.

 

[kharan]

If at all feasible, I'd try placing the speakers at the two corners marked with blue circles. Just as a test.

Less corner loading might result in a nicer sound.

With just a lounge chair facing that diagonal wall, it looks like there might still be enough space around the kitchen island and balcony entry. Though a couch might be too tight.

To be honest, it looks really off with a chair facing that wall. I also remeasured that wall instead of letting the software fill in the remaining numbers, and it's 20 cm shorter.

 

[raindance]

I don't think the 50Hz null is a huge deal as it is quite narrow. It's due to some asymmetry at the seating position which I think your drawing clarifies. I do think the resulting curve is a bit flat, I'd aim for some downward tilt from bass to treble. Post EQ looks quite nice to be honest but it's possibly a bit bright.

 

[Mr. Widget]

Is frequency response your primary concern or is stereo and a stereo image also important? If your speakers are only 2m apart then the only spot in the room with any sort of stereo image will be 2m from the speakers. I realize this is unimportant for some people, but your speakers are capable of great imaging. It would be a shame to limit them.

I would try to get the speakers further apart. In most cases I find 3m or even a slightly greater distance is going to give you a better overall presentation.

 

[kharan]

Is frequency response your primary concern or is stereo and a stereo image also important? If your speakers are only 2m apart then the only spot in the room with any sort of stereo image will be 2m from the speakers. I realize this is unimportant for some people, but your speakers are capable of great imaging. It would be a shame to limit them.

I would try to get the speakers further apart. In most cases I find 3m or even a slightly greater distance is going to give you a better overall presentation.

The issue is that there is nowhere in that room that allow the speakers to be more than 2 m apart, kind of; the long wall is a possibility, but that would require one of the speakers be placed in front of a south facing floor-to-ceiling window.

I've also tried closer at 1.5 m and 2 m. Stereo imaging is indeed wider, especially at 1.5 m. But either way, it closes off the couch area a bit too much. And surprising, the trade off isn't that bad. From a measurement standpoint, neither seem to be fundamentally better. This is the raw measurement with a sitting position at 2 m.

Though I guess a 80 Hz dip is easier to correct than a 50 Hz one.

 

[Mr. Widget]

Personally I wouldn't focus on the measurement over the listening experience. I am sure you can find a location in the room to place the mic where you will get a great measured response, but this doesn't necessarily equate to a great listening experience.

So, there is no way to place the speakers in locations similar to this?

 

[kharan]

Personally I wouldn't focus on the measurement over the listening experience. I am sure you can find a location in the room to place the mic where you will get a great measured response, but this doesn't necessarily equate to a great listening experience.

So, there is no way to place the speakers in locations similar to this?View attachment 524530

If everyone is willing to leave the blinds closed every day, I could.

 

[Keith_W]

Would you consider this?

When I used to live in a small apartment, I would have my dining table pushed against the wall. It was fine, I lived alone. But when friends came over, I pushed the listening sofa closer to the speakers and pulled the dining table out. You might have to do the same.

 

[olieb]

As the C8C are more or less omni in the subbass it might be interesting to simulate the room and move speaker and listener around a bit with https://www.vesalaasanen.com/tools/room-mode-calculator
There is a thread here, too.

Room simulator for non-shoebox rooms

Couldn't find a room mode simulator that handled anything other than shoebox rooms, so I made one. Been using it for my own projects, but decided to throw it online. https://www.vesalaasanen.com/tools/room-mode-calculator Rectangular rooms do the usual analytical mode calculation. The more...

www.audiosciencereview.com

 

[Mr. Widget]

If everyone is willing to leave the blinds closed every day, I could.

Placing a loudspeaker in front of a window is a compromise to be sure, but one that lots of people accept.

 

[Newman]

I'd like to find a passive solution for the massive 50 Hz null with the right channel, it is correctable with EQ, but the additional power and excursion requirements are sizeable.

It looks more to me like it was corrected via attenuation, with very little boost. The 'corner gain' is so large that the EQ has actually reduced the power and excursion requirements in the bass. Which is good news! IMHO the bass correction looks like a success.

I actually think that your choice of position is pretty good. Put the chair where you get a 60 degree 'listening angle' between speakers. Point the speakers towards you...partly get the best of the speaker's output, partly to reduce the side wall reflections at high frequencies.

I do think the resulting curve is a bit flat, I'd aim for some downward tilt from bass to treble. Post EQ looks quite nice to be honest but it's possibly a bit bright.

Initially I thought the same, but a closer look and looking at it by decade, below 100 Hz is highest, 100-1000 Hz is a bit lower, and 1000-10000 Hz is lower again. Pretty good! If @kharan smoothed his response curves to half octave or even full octave, it might look quite sweet.

Also, looking at the EQ above the bass, there is already a couple of dB of lift through the midrange, and the treble is left relatively untouched. I wouldn't want to increase that for fear of changing the direct / anechoic sound quality, which I believe is excellent for those speakers. Remembering that direct sound FR is the primary component of perceived sound quality. For speakers that are naturally excellent in that regard, it is highly desirable to minimise its EQ above the bass.

@kharan if you are finding it a bit bright consistently, with excellent recordings, then (with such excellent speakers) I would suggest that you 'soften the room' a bit with absorption, such as fatter couches, heavier curtains (even where there is no window!), and dense carpeting/rugs.

cheers

 

[janbth]

I'd like to find a passive solution for the massive 50 Hz null with the right channel, it is correctable with EQ, but the additional power and excursion requirements are sizeable. Hence my hope for a passive way to solve the issue.

In general it's not a good idea to boost dips in the frequency response. It might conceivably be done in a very few cases, like when a speaker is located near the null of a room mode. But your speakers are located in corners, so they will excite the modes maximally. The dip is likely due to the listening position being located in a null.

How does the L+R measurement look like? Use Var smoothing to see full resolution and how narrow the dip at 50 Hz really is? Is it audible? It could possibly the null of the lowest lying mode in the width direction. If so, try to move the MLP a little to the side, and see if it makes a difference. It may sacrifice exact stereo symmetry, but if you gain a smoother bass it might be an acceptable tradeoff.

 

[Redacted]

I'm no expert, but in a small space with so many angles, I wonder if speakers with passive side radiators / cardioid output are really working at their best?
I may have gone for something conventional, at the 'top' of the room, but avoiding speakers with rear ports if they must be near that top wall.

 

[Purité Audio]

Cardioid really helps in ameliorating the effect of the room.
Keith

 

[Redacted]

Perhaps. But yet the OP seems to want to find "improvements"....

 

[Purité Audio]

Speakers like ‘these’, C8C/ D&D8C are designed to work with the room as much as possible, constant directivity, cardioid, completely adjustable etc etc , any improvements might be secured by looking at alternative placement / acoustic measurement and the implementation of and required EQ which is built in.
Keith

 

[melomane13]

Have you tried moving the speakers closer to the listening position?
Without changing the listener’s position, I would move the speakers away from the wall to establish an ideal listening triangle and reduce SBIR. That said, these are cardioid speakers, but nothing is perfect…

 

[Purité Audio]

Generally the advice from measurement led loudspeaker manufacturers is to place the speakers close to ( within 60 cm ) of the front wall.
Keith

 

[Redacted]

constant directivity

Probably OK in the middle of a room, but how much energy do you get from multiple reflections from the various wall positions in this room? I have no idea, I just like to keep it simple. And inexpensive! And I expect placement from a wall will vary with the speakers and the room. I don't really care though - I just listen to music!