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Speaker/Room Measurement Witchcraftery

You would have to measure them in your room, if you then have any large peaks you can EQ them with the built in filters.
Keith
 
Strictly Stereo said:
I have many such measurements, from many different rooms. They say more about the rooms than the speakers. What are you hoping to learn?
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I was just interested to see if the 8c’s dsp gives a nice clean waterfall plot like they do with the smooth frequency response graphs we’ve seen.
Thanks
 
S-Man said:
I have tried the speakers closer to the wall. The result is less clarity in the midrange. The CAOW1s have full BSC and I think this messes up the balance if they are too close to the wall.
I can sit further back, but prefer the subjective balance at the usual listening position.

I don't want to use DSP on the bass because I don't want to introduce any delays. The speakers are effectively a 3-way with correct time alignment from mid to bass.

Time accuracy matters more than amplitude accuracy at these low frequencies, in my experience.

Even at the room mode frequency the system doesn't sound boomy, it just sounds a bit louder than it ought to at the very bottom end.
As a point of reference, a pair of Kii3s sounded significantly less extended, tight and tuneful in the bass than my speakers (in the same room/position).
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Then look at something like Dirac or Acourate software. I use Acourate to perform linear phase crossover, time alignment and EQ duties for my own design 3 way active dsp speakers. Sounds like you need to go the whole hog :)

Ref the kiis sound in your room, I suspect you have become very accustomed to the long ringing bass. When you get rid of this it can sound a little anaemic by comparison at first, but then you realise you can hear all the bass instruments instead of being a blur :)
 
March Audio said:
Ref the kiis sound in your room, I suspect you have become very accustomed to the long ringing bass. When you get rid of this it can sound a little anaemic by comparison at first, but then you realise you can hear all the bass instruments instead of being a blur :)
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No this is not the case at all.
My speakers are tighter, deeper and more tuneful than the Kiis. It's easy to hear and it's not just me that's heard the comparison.
 
Thanks S-Man for letting us see your vital statistics ;). Regarding the peak at 30 Hz the real question is how much music signal goes down that low and thus how much effect it has on the overall presentation. More worrying is the decay around 60 Hz although some of that may be down to noise as indicated by it going down and up with time. As for placing the speaker close to the wall, unless it is designed for that position it is unlikely to give an overall benefit to the presentation of the sound. At least none of the many box speakers I have owned have sounded best against the wall behind.

In the end, whilst measurements are a very useful tool, it comes down to how the speakers fill the room to give the most realistic sound. We listen with our ears to the sound, not with our eyes to the charts. Measurements should surely be at the service of our ears, not an end in itself.
 
camverton said:
Thanks S-Man for letting us see your vital statistics ;). Regarding the peak at 30 Hz the real question is how much music signal goes down that low and thus how much effect it has on the overall presentation. More worrying is the decay around 60 Hz although some of that may be down to noise as indicated by it going down and up with time. As for placing the speaker close to the wall, unless it is designed for that position it is unlikely to give an overall benefit to the presentation of the sound. At least none of the many box speakers I have owned have sounded best against the wall behind.

In the end, whilst measurements are a very useful tool, it comes down to how the speakers fill the room to give the most realistic sound. We listen with our ears to the sound, not with our eyes to the charts. Measurements should surely be at the service of our ears, not an end in itself.
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Agreed that the 60hz mode is the one of most concern, but it isn't noise, it corresponds with the room dimensions plus the way rew measures makes it to a degree insensitive to thd noise.

Re measurements I have never come across a situation where these room issues have been judiciously ameliorated by treatments or EQ that the sound wasn't improved.
 
S-Man said:
No this is not the case at all.
My speakers are tighter, deeper and more tuneful than the Kiis. It's easy to hear and it's not just me that's heard the comparison.
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That's fair enough, I haven't heard the Kiis, my comment was based on experience of many other rooms, speakers and people's reactions to treatments/EQ. People really do get used to the problems and equally take a bit of adjusting when removed.
 
March Audio said:
Agreed that the 60hz mode is the one of most concern, but it isn't noise, it corresponds with the room dimensions plus the way rew measures makes it to a degree insensitive to thd noise.

Re measurements I have never come across a situation where these room issues have been judiciously ameliorated by treatments or EQ that the sound wasn't improved.
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I did say some of the decay may down to noise, certainly not all, it is still a concern. Some EQ treatment should improve things. I have found that whilst measurements may give a good starting point, final position is often what sounds best. Not measurements or listening, but both!
 
Yer tis

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Some possible mitigating circumstances on the audibility/unpleasantness of the 30 Hz problem:
- The ear is not very sensitive as such low frequencies
- Most program material is rolled off at the bottom end or if there is content it's at a low level
- The ear/brain "expects" to hear something of the room (which is why only DSPing a proportion of the deviations sounds best)

That said, there is one track which I find a nuisance to listen to at high levels : Boz Scaggs/Vanishing Point (1st occurance at 1:53). I can hear the note texture/timbre and certainly wouldn't describe it as boomy but the sustained deep note is just too loud and stands out too much.
Another example is Christine and the Queens/Tilted. This is nowhere near as bad as BS but the subjective effect is a bit too much emphasis on the lowest notes, the timing, texture and pitch are still readily apparent.

I know what the 1st track should sound like, having heard it (using all the relevant parts of my system) in a heavily treated professional speaker evaluation room as well as in my friend's much larger room.

At some point I need to borrow the microphone again and see what I can do about the 60Hz issue.

BTW, the LS50s or the CAOW1s run as ported 2-ways (how they were designed to work) could be described as boomy when used in the same room/position. And there are far more offensively tuned ported speakers available!!
 
I notice that when I play the Boz Scaggs track the ceiling lights rattle (as does the door if it's not shut).
I wonder if the ceiling is acting like a giant passive radiator at 30Hz? I think I can feel it vibrating.

It would be a royal PITA to brace and damp the ceiling, but this is a stupidly obsessive hobby ;)
 
S-Man said:
I notice that when I play the Boz Scaggs track the ceiling lights rattle (as does the door if it's not shut).
I wonder if the ceiling is acting like a giant passive radiator at 30Hz? I think I can feel it vibrating.

It would be a royal PITA to brace and damp the ceiling, but this is a stupidly obsessive hobby ;)
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Actually the last thing you want with low frequencies is rigid surfaces that very effectively reflect. This is purely a function of the room dimensions.
 
Good point!

I guess I have anumber of options:
- Don't play the BS track
- Un'FLAC it, eq a notch out at 30Hz, reFLAC it
- Use the parametric Eq function in Moode or Volumio (didn't find this useful in the past. The software processing seems to hinder the sound)
- Turn the bass amp off (a bit drastic to have nowt under 100Hz)
- Adjust the LF cuttoff of my system to a higher frequency (can't be bothered, just for one track, and makes everything else sound worse)

The first one seems the best option!
 
Looks good.
However, as I have already said, I can get better measurements my moving the lf units. But this loses the time alignment and results in inferior sound.
 
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