Does a speaker sound brighter or darker in a "large" room?

[skyfly]

How was your experience?

I saw a pro-audio document saying that loudspeakers sound brighter in a large room (large in the sense of pro-audio world, a room that can hold 200 or less people is called a "small room"), because the listeners hear more reflected sound.

This is a part of Gold Line DSP30 manual.

 

[Blumlein 88]

This is an interesting question. I had some ideas, but really the size rooms your referring to in this manual are large enough I decided not to reply. I look forward to those who have some experience with this.

Of course if you had access to a couple places the right size, easy enough to go take some measures, listen, and figure it out.

 

[DonH56]

If you EQ flat then the larger the room the "brighter" the sound. That is mainly because more HF boost is required in a larger room to achieve a flat response. That is clearly shown in the curves in the OP -- note how the speakers' HF rolls off more in a larger room. Most people prefer an in-room response that tilts down a little bit.

 

[skyfly]

I think the curves are target curves, not the measured curve of a loudspeaker.

See the phrase "equalize to this curve."

 

[JohnYang1997]

It also matters your distance to the speakers.

 

[Hipper]

What the article is implying is that microphones and our ear plus brain hear differently. This is true. Microphones will simply sum up the direct and reflected sound (presumably depending how long the measured signal is. If longer I guess it would muddy the whole frequency response) whereas our ear/brain behaves differently by employing the Precedence (Haas) Effect.

https://en.wikipedia.org/wiki/Precedence_effect

This means we can differentiate between direct and their later reflected sounds and depending on the size of the room, can either sum them up or hear them separately. When we sum them up the directional information is taken from the direct sound - the speakers. When they are heard as separate we get multiple direction information which can be either confusing or adds to the sense of spaciousness. The larger the room the more likely reflected sounds will be heard separately.

That's my understanding anyway!

Presumably the article is saying that if for a large room you set the curve which starts to dip at 1.5kHz the resulting sound produced from the speakers will be reduced above 1.5kHz but this will be made up at your ears by reflections so you will hear a flat response. Maybe. I don't know but I would have thought it would depend on how loud the sound is. High frequencies lose energy over shorter distances so the larger the room the more energy is lost. This means then that Equal Loudness Curves come into play too:

https://en.wikipedia.org/wiki/Equal-loudness_contour

Psychoacoustics - a dark but interesting pit!

In my modest listening room with lots of room treatment including efforts to prevent reflections, I do not find a flat frequency response is overly bright. Indeed with EQ all I did was flatten the bass and left the rest of the spectrum to fend for itself. I'm 67 with age related hearing loss in the high frequencies so that of course could be a factor.

 

[JohnYang1997]

Only way outta this is to do the right way, the hard way, the expensive way. EQ can help but it's not the way out.

 

[Senior NEET Engineer]

In my 3000 cu ft room, there is a lot of rolloff in the treble despite minimal treble absorption.

 

[mhardy6647]

Depends on the room.

 

[skyfly]

It seems that it depends on room and speaker's dispersion. So we may need to boost or attenuate high to achieve the rolled off target curve in "large room."

 

[Chromatischism]

It also matters your distance to the speakers.

What the article is implying is that microphones and our ear plus brain hear differently. This is true. Microphones will simply sum up the direct and reflected sound (presumably depending how long the measured signal is. If longer I guess it would muddy the whole frequency response) whereas our ear/brain behaves differently by employing the Precedence (Haas) Effect.

https://en.wikipedia.org/wiki/Precedence_effect

This means we can differentiate between direct and their later reflected sounds and depending on the size of the room, can either sum them up or hear them separately. When we sum them up the directional information is taken from the direct sound - the speakers. When they are heard as separate we get multiple direction information which can be either confusing or adds to the sense of spaciousness. The larger the room the more likely reflected sounds will be heard separately.

That's my understanding anyway!

In my 3000 cu ft room, there is a lot of rolloff in the treble despite minimal treble absorption.

I sit 9 feet from my speakers in my 1400 cu ft room, and there is a lot of rolloff of the measured response at the seat. I presume that is because even though my speakers have flat direct sound:

Their side wall and ceiling reflections are down in level (blue & yellow):

And since my speakers are on the short wall of a carpeted room that is less than 11' wide, that results in those side wall and ceiling reflections making up a large portion of the total sound that reaches my seat, so the curve looks more like those measurements – that is, tilted down:

However, the speakers don't sound rolled off. They have plenty of high-frequency detail. When this is equalized to flat, they sound horridly bright and unnatural. A nearfield tweeter measurement with that kind of EQ would surely show an upward tilting direct sound. This is where I am unable to reconcile the difference between how my ears and brain interpret the sound vs what the microphone measures.

As to the question of speakers sounding brighter in a large room? I would think so, as you would be getting mostly direct sound as the off-axis sound just emanates into empty space.

 

[skyfly]

The target curves are for measuring pink noise with RTA(Real Time Analyzer).

I am wondering how I can measure wall bounce, ceiling bounce, and floor bounce separately. A special mic should be used?

 

[Chromatischism]

No idea, but it's quite a useful bit of a data when both designing a speaker and integrating it with a room. I would guess that some subtraction is done to isolate the desired waves based on arrival times. Or, it's just a fancy Klippel module that does it all for you.

 

[Chromatischism]

Above I posted some graphs showing how the measurement mic will weight the sound when walls are narrow and it picks up more reflections.

I speculated that a larger room without these side-wall reflections, giving mostly direct sound, might sound brighter. I am unsure if this is the case. If only I could expand my walls to hear the difference it makes. It could either be that the speakers sound brighter, or that I just lose spaciousness. Ears and a brain work differently than the mic.