Speaker/Room calibration
- Thread starter Bruce B
- Start date
As far as I can understand the room is divided by a giant bass trap far away from the back wall - this will change the effective length in the low bass.
Bruce, can you confirm (or denyit?
The back wall has fabric covered 2" 703. The front wall has the bass trap in front of it, shaped like a "V". The deepest part about 6', going down to about 1'.
Bruce that is very interesting what those controls do. I never knew that there is such flexibility to change the sound. What did you notice when making these adjustments? Could you post a response going out 5,000hz?
thanks
Jack
thanks
Jack
Sorry I can not figure how such a room has Over a third of the cubic volume is bass trapping.
It the room is 22' long at the edge of the V and the V bass trap is 6' deep may be your drawing is completely out of scale, but even in this case the volume of the bass would be around one sixth of the volume. Most probably I am missing something. Sorry for being so insistent, by my room has similar width and I am particularly interested in the details of your room and the conclusions of this thread. As FrankM wisely said, it is not always that we can find all the details exposed for debate with such openness.
Sorry I can not figure how such a room has Over a third of the cubic volume is bass trapping.
.
The back corners are triangulated with bass trapping as well as the front wall. As you'll see in several photos I've posted, there is a soffit above that is over 2' tall and wraps the perimeter of the room. On the sides it's over 2' and in the front and back of the room it's over 6'. The soffit alone is over 500 cu/ft of bass trapping
I never really "listened" to what the controls did. I was wearing ear protection. I can post a couple of graphs going out to 5k this evening.
Thanks. I can now figure better. Can I ask you what is the thickness and material of panel of the front bass trap? I need it to model its absorption.
Bruce said "I never really listened. I was wearing hearing protection"
Why would you wear hearing protection? Don't you want to hear what is changing?
Why would you wear hearing protection? Don't you want to hear what is changing?
You do not use also a resonator plate, such as 1/4 or 1/8¨ plywood? Just the 703?
When you're doing freq. sweeps and pink noise, you should ALWAYS wear ear protection! This is what I was doing when making the graphs.
The bass traps have 2-4" 703 with fabric covering in the front and on the inside they are lined with 2-4" 703 and Roxul
I bet he meant when taking measurements, from mono signals; test tones.
* Then he listens to real music afterwards (after each set of measurements) to compare;
right Bruce?
Hi Beuce, if you are performing the test at 75 db why do you need hearing protection? Would you not want to correlate the changes with what you are hearing with what you are measuring? I say lose the muffs.
Jack
Jack
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Thanks Jack.... guess I'm pretty anal about my hearing. A mastering engineer lives or dies by their hearing. Certainly I'll toss the protection when I'm trying to correlate what the adjustments sound like with music, but I don't think much can be garnered with test tones.
Hi Bruce, Ok on the hearing caution. But is 75 db sine waves or pink noise worse than 75 db of music?
Thanks
Jack
Thanks
Jack
Hi Bruce, well now I m beginning to realize why I adjust everything by ear and leave all of the controls flat. Straight wire with gain is looking pretty good right now. The othe thing is this room treatment business. Looking hit or miss also. Why bother? Even you said that your system sounded great before. Why bother with all of this ear muff and ear damaging noise. From what I have heard it can even destroy your speakers.
All of this talk about 75db and 50 this and 40 that is beginning to make my head spin.
I still say your system was fine before all of this nonsense. So what's the point? Ten pages of posts and this is where you are.
Where are the acoustic experts on this forum? My guess is they can't help you with this either, because it does not work!
Wendell
POE143
All of this talk about 75db and 50 this and 40 that is beginning to make my head spin.
I still say your system was fine before all of this nonsense. So what's the point? Ten pages of posts and this is where you are.
Where are the acoustic experts on this forum? My guess is they can't help you with this either, because it does not work!
Wendell
POE143
Jack, there have been a number of constructive suggestions made which advise moving/adding LF transducers and/or EQ. Bruce can do much better than the measurements, so far.
Yes. Sine waves are pure tones so the maximum energy is concentrated on a small locus on the basilar membrane resulting in maximum displacement. Pink noise and music have the same 75dB distributed more widely.
Jack, with all due respect, it is a discussion, not a scientific report.
Plus Bruce just said to you; as a sound recording engineer he has developed practices over the years on safety, or the respect for his hearing (I don't blame him as test tones are just too irritating after just few minutes), so he can still continue to enjoy his passion until his last breath of air, and still healthy hearing.
Also, it is not an analysis of test tones, but at the end of all the maths and careful measurements by positioning and repositioning, it's all about the music sweet and balanced sounding in your ears. Right? :b
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