advertisement


Room measurements - what do they mean?

I think I can do that with the XTZ software Keith, I'll give it a go tomorrow. Thanks for the input chaps.
 
I didn't get the same quality of bass at a show compared to home, but obviously the room was a different shape/size. I get good bass down to about 25hz/30hz in my bedroom, so quite a bit more extension than Harbeth P3ESR I'd imagine:

NSbYzDrl.jpg
As I said bumpy +-10dB each direction or +20dB depending on the reference point. That is quite the opposite from "good".:(
It looks relatively flat, but that is only be the case because the scale is to corse and zoomed out. It will look as many other rooms if you go for 5 dB steps and zoom in. If you have not, use 1/6 octave band smoothing then you can better see what is really going on.

I guess you will see too much reverberation time under 100Hz.

Again, I'm not offending you. I write this because you guessed that your bed will help in the low frequencies but it doesn't. BTW I'm dealing with similar problems too right now.;)


To show you the difference Harbeth C7ES3 XD in 14sqm:

That looks very good, doesn't it?



This is exactly the same measurement only with 5dB steps scale and 1/6 octave band smoothing instead of 1/1 octave band smoothing and 10dB steps scale.


BTW: The Harbeth P3ESR was an example and I used it because the tiny driver and cabinet can't overload a small room as much as a bigger speaker can. A P3ESR will also play deeper in a smaller room than the specs are telling because of room gain.
 
As I said bumpy +-10dB each direction or +20dB depending on the reference point. That is quite the opposite from "good".:(
It looks relatively flat, but that is only be the case because the scale is to corse and zoomed out. It will look as many other rooms if you go for 5 dB steps and zoom in. If you have not, use 1/6 octave band smoothing then you can better see what is really going on.

I guess you will see too much reverberation time under 100Hz.

Again, I'm not offending you. I write this because you guessed that your bed will help in the low frequencies but it doesn't. BTW I'm dealing with similar problems too right now.;)


To show you the difference Harbeth C7ES3 XD in 14sqm:

That looks very good, doesn't it?



This is exactly the same measurement only with 5dB steps scale and 1/6 octave band smoothing instead of 1/1 octave band smoothing and 10dB steps scale.


BTW: The Harbeth P3ESR was an example and I used it because the tiny driver and cabinet can't overload a small room as much as a bigger speaker can. A P3ESR will also play deeper in a smaller room than the specs are telling because of room gain.

Different softwares must use different smoothing algorithms, - the 1/6 example above looks more like 1/24 in RoomEQWizard.

PS - I expect a bed will make quite a noticeable improvement in reducing RT60. My ex-music room sounded much better after a king-size bed with plush fabric/foam headboard was introduced, far better than it ever did when I used the room for listening to music, all I had then was a 2-seater sofa and thin rug, all the other furniture was made from wood and highly reflective, including the sofa which was leather! I wish I understood as much about room acoustics then as I do now...
 
As I said bumpy +-10dB each direction or +20dB depending on the reference point. That is quite the opposite from "good".:(
It looks relatively flat, but that is only be the case because the scale is to corse and zoomed out. It will look as many other rooms if you go for 5 dB steps and zoom in. If you have not, use 1/6 octave band smoothing then you can better see what is really going on.

I guess you will see too much reverberation time under 100Hz.

Again, I'm not offending you. I write this because you guessed that your bed will help in the low frequencies but it doesn't. BTW I'm dealing with similar problems too right now.;)


To show you the difference Harbeth C7ES3 XD in 14sqm:

That looks very good, doesn't it?



This is exactly the same measurement only with 5dB steps scale and 1/6 octave band smoothing instead of 1/1 octave band smoothing and 10dB steps scale.


BTW: The Harbeth P3ESR was an example and I used it because the tiny driver and cabinet can't overload a small room as much as a bigger speaker can. A P3ESR will also play deeper in a smaller room than the specs are telling because of room gain.


It's very difficult to produce accurate measurements of a room, and I would personally take any you see with a pinch of salt (including mine). As the sound is bouncing around all over the place in all different directions, it's adding and subtracting (in and out of phase). So as you move the microphone around, you'll get different measured results.
The moving microphone technique is supposed to be one of the most accurate ways to measure, because you're not just measuring in one spot. I haven't bothered because playing test tones shows an even frequency response in my room. I've been able to find bass problems in a friends room by just listening to test tones. It's really not too difficult.

I don't know why your in room measurement doesn't show a sloping down frequency response (the top one). A flat anechoic measuring speaker (as mine is) should have a downward slope in room. Yours looks flat from 60hz to 2khz which doesn't look right to me. It does look like there's a ton of smoothing or something, but even so, it shouldn't look like that unless the speaker isn't flat to begin with.

I don't believe for one minute my bed does nothing, it's more of a question of how much and at what frequencies.
 
Coherence-wise:
- Keep speakers away from side walls (>=1m) and if you can't do that then treat side wall first reflection points (I do this).
- Try to keep speakers away from from, or at least in front of, large objects (>=1m) such as racks, TVs, fireplace etc.
- Equilateral triangle between speakers and listener is a decent aim, with some flex.

Bass-wise:
- Keep speakers either close to the wall behind them (<=0.6m) or far away (>=2m). This is to stop boundary response causing FR dips. ('Wall Reflections and Cancellations' at https://www.genelec.com/monitor-placement).
- Don't have your listening seat(s) up against a wall. Bass modes, and everything else for that matter, should be better when the listening position is in space (>=1m from all boundaries for a start). Nearer to boundaries is warmer in general. Neither bass traps nor DSP can fix bass everywhere in the room, I see these helping to find a listening position with maybe a better compromise, not as cure-alls. Personally I use custom tuned bass traps.
 
Last edited:
I expect a bed will make quite a noticeable improvement in reducing RT60. My ex-music room sounded much better after a king-size bed with plush fabric/foam headboard was introduced, far better than it ever did when I used the room for listening to music, all I had then was a 2-seater sofa and thin rug, all the other furniture was made from wood and highly reflective, including the sofa which was leather!
I didn't say that a bed won't have influence on the reverberation time, the question is where. I'm still very sure that a bed won't reduce deeper or mid bass, maybe upper bass. The other thing is that it can do worse if it has influence at a frequency range where is a drop already.
 
It's very difficult to produce accurate measurements of a room, and I would personally take any you see with a pinch of salt (including mine). As the sound is bouncing around all over the place in all different directions, it's adding and subtracting (in and out of phase). So as you move the microphone around, you'll get different measured results.
The moving microphone technique is supposed to be one of the most accurate ways to measure, because you're not just measuring in one spot. I haven't bothered because playing test tones shows an even frequency response in my room. I've been able to find bass problems in a friends room by just listening to test tones. It's really not too difficult.

I don't know why your in room measurement doesn't show a sloping down frequency response (the top one). A flat anechoic measuring speaker (as mine is) should have a downward slope in room. Yours looks flat from 60hz to 2khz which doesn't look right to me. It does look like there's a ton of smoothing or something, but even so, it shouldn't look like that unless the speaker isn't flat to begin with.

I don't believe for one minute my bed does nothing, it's more of a question of how much and at what frequencies.

Sure you will have different results at different positions, how else could it be? I only use the measurements as a coarse basis for speaker positioning, I find it helpful to get a quick response after moving the speakers or the listening position.

You can only optimize for one spot in your room.

Maybe the Behringer microphon needs a calibration data but I can't imagine that is will change the whole curve in a sloping curve. If you look at the 2. plot you can see a more or less sloping curve, because the bass bumps aren't smoothed.

I really don't want to offend you but your room response can't be "even", the room and the music waves are following physical rules and as long as you don't have measured and optimized the room especially in the low frequencies (see my first post) you won't get a even response, that is absolutely impossible.

I believe you that you aren't distracted by the bumps and dips but they are there like in every ones room.

I didn't say your bed won't have any influence but it won't necessarily in the low frequency as you said and also the low frequencies aren't even like your measurement already showed. That the bass isn't flat in reality. A peak of 10dB and dip of -10dB is the double amount or half of the loudness from reference signal loudness. Maybe if you don't listen very loud the liftet bass will give you a linear impression because of the un-linear listening sensitivity at different volume.

Anyhow, the most important thing is, that you are happy. So enjoy your system and have a nice weekend.
 
Well there you have it. My ears are playing tricks on me, and Old Shattinhand above knows what my speakers sound like in my room.
 
I didn't say that I know what it sounds like. I was objective and told the facts which are backed up by the laws of physic and proofed by your measurements. I also sayed that this will be in every room and told you more than once is nothing personal.:)
 


advertisement


Back
Top