tallbeardedone
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- Sep 3, 2022
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Hey everyone,
Last night I hooked up my Macbook Pro to my Hegel h390 integrated amp and ran frequency sweeps in REW to determine the best placement of my Monitor Audio gx300's in my listening room.
It's super easy to do and really helped me nail the perfect placement in my room resulting in the flattest frequency response. It affirmed what my ears had already determined, mainly that some rear wall reinforcement brings up the mid-bass and tames the highs in my room, and that listening slightly near-field is audio nirvana with my Monitor Audio gx300’s!
If you want to hear how I did it so you can try it for yourself, read on.
Equipment:
Umik-1 microphone ($78) (kindly loaned to me by a buddy)
Macbook Pro 13”
usb-c to usb-b cable ($20)
usb-a to usb-c adapter ($5)
tripod
furniture sliders
Software:
REW (free download)
Amplifier:
Hegel h390
Speakers:
Monitor Audio gx300
Connection:
I connected my Macbook Pro to my amplifier with a usb-c to usb-b cable. The Hegel h390 is plug-n-play so all I had to do was set it as the audio output device on my macbook and I was ready to go. I downloaded REW and opened up the application. When I connected the Umik-1 microphone to my Macbook via usb, REW found it immediately and connected.
Room:
My listening room is 5.6 m wide by 4.0 m deep with a 3.0 m opening at the back leading to my open-plan kitchen and living area. The left and front walls are covered in floor-to-ceiling bookshelves. The right wall contains a window seat and bay window covered with a velvet curtain. The floor is carpeted and the fireplace is covered with a fur rug during listening sessions.
Speaker Positioning:
Speaker distance apart: 8’7” (2.66m)
Speaker distance from side walls: 4’10” (1.47m)
The distance between speakers was selected as the widest I could get them while still maintaining a sharp and focused center image. Toe-in is around 15 degrees.
Speaker distance from the front wall was adjusted using REW sweeps to find ideal placement. Results below.
1.01m from wall (FINAL mic position):
This is an absolutely excellent response. The peak at 65hz is a room anti-node that cannot be attenuated without EQ, but to be honest I rather like the slam and meat it adds to the bass. The key to getting this flat response was both determining the correct distance of the speakers from the front wall AND the correct listening position relative to the speakers, which ended up being more near-field than is often suggested. The final listening position was around 30cm inside the tip of the equilateral triangle formed by the tweeters and my ears. All distortion is well below the 50dB threshold of audibility.
This exactly matches the experience I was having of leaning forward in my chair to “enter the room” of the recording as shown in the following photo.
Note how a difference of only ~30cm steps me “through the wall” and “into the room” of the recording. It really is an incredible experience.
Here’s how I got there.
1.31m from wall (START POSITION):
I started with my speakers 1.3m from the front wall and got the above measurement.
Note that the high frequency sound pressure from 2900-10,000Hz is all above the line. At this position the speakers sound bright due to this. There is also a reasonably strong bass node (destructive interference) at 90Hz which I wanted to attenuate. The bass anti-node at 68Hz is from the room and cannot be attenuated unless I use EQ, but to be honest I quite like it as it adds meat to the vocals and some slam which helps soothe the highs.
1.21m from wall:
Bringing the speakers in 10cm slightly attenuated the bass suck-out, but with it came other problems. Mainly a drop in the bass and mid-bass as well as another dipped region in the mid-range. Again, this resulted in the speakers sounding a bit bright. Moving on . . .
1.11m from wall:
Not much better here. Bass cancellation node is slightly attenuated but a little wider. Bass and mids still below highs.
After this I decided to go as far into the wall as possible and see how that changed things.
0.41cm from wall (as close as I could get due to bookshelves)
Yikes. Here there was a major base node suck-out at 140Hz. This note is at -25dB from the rest of the frequencies and would result in that note being markedly less audible. Can’t have that. Due to the rear-wall reinforcement however, the upper bass and mids were slightly higher and more evened out with the highs. Speakers sound less bright here, but I’m completely missing a 140Hz bass note.
So where is the happy medium?
0.91m from wall
That’s better. The bass node at 130Hz isn’t as severe and the bass and mids are rising! We’re getting closer to the right spot.
1.01m from wall
Again at this distance the bass node (at 110Hz this time) is attenuated. I am still tossing up whether here or the previous measurement is the best. I have to decide which note I want the suck-out to be centered at (110Hz or 130Hz) and where the upper bass and mids sound better. 0.91m may still be better but for now I have my speakers set here.
BUT WE’RE NOT QUITE DONE!!!
Up until now I’d been measuring from a listening position centered at the exact tip of the equilateral triangle created between the tweeters and the mic. But in my listening experience, the imagine, soundstage, and realism are always best when I lean forward in my chair and put my ears more near-field to the speakers. So I moved the mic here and did a sweep.
The results, as seen at the start, speak for themselves.
1.01m from wall (sitting 30cm nearfield from tip of equilateral triangle):
At the moment this is where I have my speakers positioned. It sounds absolutely incredible from the near-field listening position. I can listen at any volume without fatigue and the soundstage is incredible. I can “see” in three-dimentional space every single instrument in well-recorded material and am surrounded on all sides by ambience and spatial cues. It’s so immersive it really has to be heard to be believed so if you’re in the area, come over for a demo!
What next?
This is a continual tinker, so next I’m going to adjust by the centimeter from 1.01m to 0.91m, measuring both from tip of equilateral triangle and nearfield, to find the absolute best spot. I’m very close but there are still minute improvements to be made. There always are. That’s the joy of this hobby.
If you have any questions or comments I’d love to hear from you. Thanks for reading!
Nick
Last night I hooked up my Macbook Pro to my Hegel h390 integrated amp and ran frequency sweeps in REW to determine the best placement of my Monitor Audio gx300's in my listening room.
It's super easy to do and really helped me nail the perfect placement in my room resulting in the flattest frequency response. It affirmed what my ears had already determined, mainly that some rear wall reinforcement brings up the mid-bass and tames the highs in my room, and that listening slightly near-field is audio nirvana with my Monitor Audio gx300’s!
If you want to hear how I did it so you can try it for yourself, read on.
Equipment:
Umik-1 microphone ($78) (kindly loaned to me by a buddy)
Macbook Pro 13”
usb-c to usb-b cable ($20)
usb-a to usb-c adapter ($5)
tripod
furniture sliders
Software:
REW (free download)
Amplifier:
Hegel h390
Speakers:
Monitor Audio gx300
Connection:
I connected my Macbook Pro to my amplifier with a usb-c to usb-b cable. The Hegel h390 is plug-n-play so all I had to do was set it as the audio output device on my macbook and I was ready to go. I downloaded REW and opened up the application. When I connected the Umik-1 microphone to my Macbook via usb, REW found it immediately and connected.
Room:
My listening room is 5.6 m wide by 4.0 m deep with a 3.0 m opening at the back leading to my open-plan kitchen and living area. The left and front walls are covered in floor-to-ceiling bookshelves. The right wall contains a window seat and bay window covered with a velvet curtain. The floor is carpeted and the fireplace is covered with a fur rug during listening sessions.
Speaker Positioning:
Speaker distance apart: 8’7” (2.66m)
Speaker distance from side walls: 4’10” (1.47m)
The distance between speakers was selected as the widest I could get them while still maintaining a sharp and focused center image. Toe-in is around 15 degrees.
Speaker distance from the front wall was adjusted using REW sweeps to find ideal placement. Results below.
1.01m from wall (FINAL mic position):
This is an absolutely excellent response. The peak at 65hz is a room anti-node that cannot be attenuated without EQ, but to be honest I rather like the slam and meat it adds to the bass. The key to getting this flat response was both determining the correct distance of the speakers from the front wall AND the correct listening position relative to the speakers, which ended up being more near-field than is often suggested. The final listening position was around 30cm inside the tip of the equilateral triangle formed by the tweeters and my ears. All distortion is well below the 50dB threshold of audibility.
This exactly matches the experience I was having of leaning forward in my chair to “enter the room” of the recording as shown in the following photo.
Note how a difference of only ~30cm steps me “through the wall” and “into the room” of the recording. It really is an incredible experience.
Here’s how I got there.
1.31m from wall (START POSITION):
I started with my speakers 1.3m from the front wall and got the above measurement.
Note that the high frequency sound pressure from 2900-10,000Hz is all above the line. At this position the speakers sound bright due to this. There is also a reasonably strong bass node (destructive interference) at 90Hz which I wanted to attenuate. The bass anti-node at 68Hz is from the room and cannot be attenuated unless I use EQ, but to be honest I quite like it as it adds meat to the vocals and some slam which helps soothe the highs.
1.21m from wall:
Bringing the speakers in 10cm slightly attenuated the bass suck-out, but with it came other problems. Mainly a drop in the bass and mid-bass as well as another dipped region in the mid-range. Again, this resulted in the speakers sounding a bit bright. Moving on . . .
1.11m from wall:
Not much better here. Bass cancellation node is slightly attenuated but a little wider. Bass and mids still below highs.
After this I decided to go as far into the wall as possible and see how that changed things.
0.41cm from wall (as close as I could get due to bookshelves)
Yikes. Here there was a major base node suck-out at 140Hz. This note is at -25dB from the rest of the frequencies and would result in that note being markedly less audible. Can’t have that. Due to the rear-wall reinforcement however, the upper bass and mids were slightly higher and more evened out with the highs. Speakers sound less bright here, but I’m completely missing a 140Hz bass note.
So where is the happy medium?
0.91m from wall
That’s better. The bass node at 130Hz isn’t as severe and the bass and mids are rising! We’re getting closer to the right spot.
1.01m from wall
Again at this distance the bass node (at 110Hz this time) is attenuated. I am still tossing up whether here or the previous measurement is the best. I have to decide which note I want the suck-out to be centered at (110Hz or 130Hz) and where the upper bass and mids sound better. 0.91m may still be better but for now I have my speakers set here.
BUT WE’RE NOT QUITE DONE!!!
Up until now I’d been measuring from a listening position centered at the exact tip of the equilateral triangle created between the tweeters and the mic. But in my listening experience, the imagine, soundstage, and realism are always best when I lean forward in my chair and put my ears more near-field to the speakers. So I moved the mic here and did a sweep.
The results, as seen at the start, speak for themselves.
1.01m from wall (sitting 30cm nearfield from tip of equilateral triangle):
At the moment this is where I have my speakers positioned. It sounds absolutely incredible from the near-field listening position. I can listen at any volume without fatigue and the soundstage is incredible. I can “see” in three-dimentional space every single instrument in well-recorded material and am surrounded on all sides by ambience and spatial cues. It’s so immersive it really has to be heard to be believed so if you’re in the area, come over for a demo!
What next?
This is a continual tinker, so next I’m going to adjust by the centimeter from 1.01m to 0.91m, measuring both from tip of equilateral triangle and nearfield, to find the absolute best spot. I’m very close but there are still minute improvements to be made. There always are. That’s the joy of this hobby.
If you have any questions or comments I’d love to hear from you. Thanks for reading!
Nick
Last edited: