Well, all I can say is that if my approach ultimately doesn't sound good then there must be another issue in your system causing bad sound reproduction. A bass problem can have many and multiple causes. Introducing more subs may (somehow) relieve the audible problem but not cure the cause.
Yes, that's the problem. When you neglect to ask your software (REW?) to smooth, you get fiercely bumpy plots. Those micro-bumps means zilch.
Go with 1/12, like the rest of us. That will average-out the unimportant micro-grain but still leaves a good picture of the FR. Once you do that, you won't be quite so agitated by what looks to me like a pretty darn good FR, once you smooth it a bit.
AllenB: as a man with 14 grandchildren, I do have a more than passing acquaintance with children's birthday parties.
B.
Last edited:
I think you could learn a lot from dr Geddes (and Toole) about lf reproduction in HiFi rooms
Do you have any measurements to backup your claims about "different phase behavior"? What do you even mean by that?
And jitter causing lf reproduction issues? That's one of the most remarkable claim if heard for some time!
Back to "hearing with your eyes" - looking at plots instead of listening with your ears and the frantic search for flat FR.
Let's say a cello or double-bass (AKA bass) is playing. Just how would your ear know or care if there's a dip at 50 Hz or a little peak at 55 Hz?
Not saying it doesn't matter, just adding context.
B.
Let's say a cello or double-bass (AKA bass) is playing. Just how would your ear know or care if there's a dip at 50 Hz or a little peak at 55 Hz?
Not saying it doesn't matter, just adding context.
B.
I subscribe to the Geddes approach of multiple subs. I have (4) asymmetrically distributed subs in a room that is 16 feet wide, 10 feet tall and 26 feet deep. Small 50Hz notch is a ceiling mode and not audible as it is not wide range. Getting close to 200Hz or so is probably Schroeder frequency transition. Only area of boost EQ is around 15-30Hz area, which makes absolute sense acoustically. 3 days and 6 hours of measurements each day. Only manipulated sub positions, various XO points, slopes and phase. No delay used at all. Mains run full range without a HP crossover.
LF response, 50 dB vertical range, 5 dB vertical scaling, no smoothing:
LF response, 70 dB vertical range, 10 dB vertical scaling, no smoothing:
LF response, 50 dB vertical range, 5 dB vertical scaling, 1/12th octave smoothing:
LF response, 70 dB vertical range, 10 dB vertical scaling, 1/12th octave smoothing:
LF response, 70 dB vertical range, 10 dB vertical scaling, 1/12th octave smoothing, with Target Curve overlay:
Subjectively I am deeply satisfied. Target Overlay shows an overall gentle rise from 150Hz to 20Hz of about 5 dB which I find subjectively more 'pleasing' and dynamic. That's still experimental but the only area of experimentation at this point.
Best,
Anand.
LF response, 50 dB vertical range, 5 dB vertical scaling, no smoothing:
LF response, 70 dB vertical range, 10 dB vertical scaling, no smoothing:
LF response, 50 dB vertical range, 5 dB vertical scaling, 1/12th octave smoothing:
LF response, 70 dB vertical range, 10 dB vertical scaling, 1/12th octave smoothing:
LF response, 70 dB vertical range, 10 dB vertical scaling, 1/12th octave smoothing, with Target Curve overlay:
Subjectively I am deeply satisfied. Target Overlay shows an overall gentle rise from 150Hz to 20Hz of about 5 dB which I find subjectively more 'pleasing' and dynamic. That's still experimental but the only area of experimentation at this point.
Best,
Anand.
Well it just determines the amplitude at that frequency that reaches your ears.
Not saying that any peak or dip is equally audible though......
There are those of us who believe that hearing is the final judge and those of us who understand that subjective assessments are all over the map. (Just look at the "Is it Possible to Cover the WHole Spectrum ..." thread to see how the wide variety of subjective opinions tends to lead nowhere.) The experts understand that subjective assessments are virtually always biased and have been shown to be totally unreliable (unless done blind, which no one ever really does.)
So what is one to do? Only by understanding how objective data ("hearing with your eyes") relates to what we (as a group) actually perceive can one narrow down on what matters and what doesn't and what needs fixing and how. Subjective only judgements invariably lead in circles - round and round we go - "I like this" (this week) - "Johnny says this works best" - ... all based on cursory subjective evals and presented without any objective validity.
I have spent nearly 60 years hearing these arguments and my conclusion is that only objective approaches to sound reproduction ever lead to real improvements. Everything else is just someone's personal taste or preference for what they already have (not willing to accept that this might not actually be true.) I prefer the light to the dark, thank you.
Ben, play a bass signal at 50 Hz and then at 55 Hz in your example and there will be a strong tembre shift from the change in the harmonic structure - not a good thing!
PossiblyI think you could learn a lot from dr Geddes (and Toole) about lf reproduction in HiFi rooms
But I don't see how multiple subs can improve anything like room modes in a 'small room'.No measurements, though I might make some if this is a controversial issue here. Different drivers will play the same frequencies in a different phase, thus partially cancelling each other out. IME 'overlapping' main speakers and subs are problematic. Multiple subs might work if they have the exact same phase/frequency behavior.
I've done (blind) tests with a number of different coax to optical/Toslink converters, the only variable being jitter. The difference between converters was especially audible in the bass reproduction.
Last edited:
Hm, not sure if I understand you. Sorry, I'm not a native speaker so let me confirm if we're on the same pege here:
You think my FR is pretty darn good? Unfortunately, it isn't. It may look good with some smoothing but it sure does not sound good.
Here's another plot with 3 subs with proposed smoothing. This was the best result I could get but it still didn't satisfy my ears. I could feel some vibrations behind my seat so clearly something wasn't right.
Attachments
Yes, I can't see why people are disagreeing with this part. Maybe the connotation of the word 'interfere', which ought be taken relatively.
beige,
Can you repost your FR plot? It’s very hard to interpret as is because it lacks resolution. Please change your vertical range to 50-100dB and change your horizontal range to 20-200Hz. Remove all smoothing at first to examine the “warts” in the frequency response curve.
How many subs do you have? What are your main speakers? Do you have any low frequency damping/room treatments in your room? What is your wall construction? Concrete or wood? A picture would be useful.
Best,
Anand.
Can you repost your FR plot? It’s very hard to interpret as is because it lacks resolution. Please change your vertical range to 50-100dB and change your horizontal range to 20-200Hz. Remove all smoothing at first to examine the “warts” in the frequency response curve.
How many subs do you have? What are your main speakers? Do you have any low frequency damping/room treatments in your room? What is your wall construction? Concrete or wood? A picture would be useful.
Best,
Anand.
Last edited:
You could have awful sound despite a great FR - with distortions, troublesome reflections, dunno what.
But as far as your FR goes, I'd send it to the Guiness Book of World Records. It is as perfect as they come.
B.
This is a real problem in LF perception. I have a lot of experience with structure born sound and your butt is a structure. Any vibrations that you can feel are adding to the perception (this can be both + and -.) Make sure that you are not sitting in a piece of furniture that itself has resonances. That can be a huge problem. I once rebuilt a sofa in a sound room just to get rid of its awful resonances.
To me there is nothing wrong with "interfer". It may sound like it has a bad connotation, but to me it's just an engineering word describing events. They can be + or -. The trick then is to get all these "interferences" to play together as best they can in the given room. The more "degrees of freedom" that you have the better your chances are.
Last edited:
Yes, it seems to me that a single crossed sub is best for bass reproduction and the audible preservation of a sense of the room for the brain to work with.
You might want to go back to the acoustics forum and check out the thread about Toole's critique.
There is no way to make the room go away. The recording of Diana Krall is always being played back in your room. But you can make the room better. 90% of the room photos at DIYaudio look like they must sound atrocious due to many hard surfaces and little absorption.
You can move your chair.
EQ adjusts the speakers not the room.
B.
Last edited: