Let me ask you just two questions.
1. Have ever heard the term "optical illusion"?
2. Do you always "believe" your own eyes?
Ben
Subject: Auditory illusion
Warning: this will mess with your perception of reality.
Here's a experiment you can do (you'll need an EQ) . Listen to about 15min of music with 250Hz notched out -15db. Then after 15min move the eq back to normal position and listen to the same music again.
ever been in a room with just red light then gone outside? fun stuff but the brain is doing the same thing in both cases.
Warning: this will mess with your perception of reality.
Here's a experiment you can do (you'll need an EQ) . Listen to about 15min of music with 250Hz notched out -15db. Then after 15min move the eq back to normal position and listen to the same music again.
ever been in a room with just red light then gone outside? fun stuff but the brain is doing the same thing in both cases.
Let me ask you just two questions.
1. Have ever heard the term "optical illusion"? Optical illusion are short lived, just walk up to the illusion and it disappears.
2. Do you always "believe" your own eyes? Eyes, ears, and the brain can play tricks on anyone.
I thought I was going to receive suggestions like: dope the cones, I should have angled the box walls, I should have added glue and sand to the enclosure walls (which I may do).
However, I am relieved that I don’t have to change my log-in name.
1. Have ever heard the term "optical illusion"? Optical illusion are short lived, just walk up to the illusion and it disappears.
2. Do you always "believe" your own eyes? Eyes, ears, and the brain can play tricks on anyone.
I thought I was going to receive suggestions like: dope the cones, I should have angled the box walls, I should have added glue and sand to the enclosure walls (which I may do).
However, I am relieved that I don’t have to change my log-in name.
Sorry... meant REW. I am sure any number of proprietary or free programs can be helpful. But there are many "threats to validity" in acoustic testing so there's little you can learn from just a mic and an audio oscillator.
And keeping with the "optical illusion" analogy, Toole has shown in his large test-group study that people can't distinguish his lowered shelf in the upper bass from raised shelf in the lower treble. Under either condition, people say "ummm, seems a bit bright." And that's that.
If you have invincible faith in your hearing and invincible faith that you can "always walk up to" the illusion and make it go away by force of your invincible brain power.... then you have no problems and no need for any help from anybody. (But learning something about how perception works would immediately change your views.)
Ben
Footnote: psychologists don't find it helpful to think of these departures from correct perception simply as "illusions." In the tradition of Helmholtz, they are viewed as "best guesses" given the inputs available to the person and the ordinary way the eyes and brain work with these inputs.
And keeping with the "optical illusion" analogy, Toole has shown in his large test-group study that people can't distinguish his lowered shelf in the upper bass from raised shelf in the lower treble. Under either condition, people say "ummm, seems a bit bright." And that's that.
If you have invincible faith in your hearing and invincible faith that you can "always walk up to" the illusion and make it go away by force of your invincible brain power.... then you have no problems and no need for any help from anybody. (But learning something about how perception works would immediately change your views.)
Ben
Footnote: psychologists don't find it helpful to think of these departures from correct perception simply as "illusions." In the tradition of Helmholtz, they are viewed as "best guesses" given the inputs available to the person and the ordinary way the eyes and brain work with these inputs.
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Goldenears… invincible brain power?
Ben,
Folks have been very generous with ideas in this forum, but getting a different reaction here; I am getting to the point where I wish I hadn’t said anything on this thread.
The sub has some quirky upper resonance, it’s not subtle, it’s very noticeable. The concept of the design was inline with the parameters.
This is only a $20 project, 1 ½ days of work with stuff lying around.
Btw, Noshuchpro is only an hour dive, he may want some work done someday.
Ben,
Folks have been very generous with ideas in this forum, but getting a different reaction here; I am getting to the point where I wish I hadn’t said anything on this thread.
The sub has some quirky upper resonance, it’s not subtle, it’s very noticeable. The concept of the design was inline with the parameters.
This is only a $20 project, 1 ½ days of work with stuff lying around.
Btw, Noshuchpro is only an hour dive, he may want some work done someday.
Ben you need to tone it down immediately..
sorry ODougbo, I didn't realize there was a quesion being asked.
anyway, i'll sim it and see if anything stands out.
do you have the ts parameters? is this the same driver: Peerless 831857 Cc 12" Woofer 297-618
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I think my box is on the large size (or right on) since I’m using two drivers Isobaric.
Red Box ID: 37cm x 34cm x 42cm = 52.84liters [there is a good amount of bracing and of course the inside woofer]
Although with the testing with one woofer then adding the second leads me believe I’m on the small size.
Btw, This is my first sealed sub woofer box; I have bass reflex boxes stacked to the ceiling.
This premium quality polypropylene driver has a FS/QT ratio of 55. This indicates
that this driver has relatively low damping and therefor most suitable for use in
CLOSED BOX systems. A sealed enclosure of about 80L (about 2 to 3ft will
give a smooth and controlled roll-off in the lower bass and infrasonic region. This
predictable response generally reflects the gain of most rooms (if correctly
positioned) and therefor gives a close to flat frequency characteristics at the
listening position. The sealed box also adds to produce a dry firm bass sound that's
free from typical boomy responses of some ported designs and thus this woofer has
received an admirable reputation from audiophile connoisseurs. The accurate low
mids produced by this driver makes it suitable for both SUB or MAIN…….
Red Box ID: 37cm x 34cm x 42cm = 52.84liters [there is a good amount of bracing and of course the inside woofer]
Although with the testing with one woofer then adding the second leads me believe I’m on the small size.
Btw, This is my first sealed sub woofer box; I have bass reflex boxes stacked to the ceiling.
This premium quality polypropylene driver has a FS/QT ratio of 55. This indicates
that this driver has relatively low damping and therefor most suitable for use in
CLOSED BOX systems. A sealed enclosure of about 80L (about 2 to 3ft will
give a smooth and controlled roll-off in the lower bass and infrasonic region. This
predictable response generally reflects the gain of most rooms (if correctly
positioned) and therefor gives a close to flat frequency characteristics at the
listening position. The sealed box also adds to produce a dry firm bass sound that's
free from typical boomy responses of some ported designs and thus this woofer has
received an admirable reputation from audiophile connoisseurs. The accurate low
mids produced by this driver makes it suitable for both SUB or MAIN…….
At home theater shack, if you sign up you can download REW v5.0 (free) it's quite good at measuring many things. REW - Room EQ Wizard Home Page
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Options:
I had a couple of ideas:
1) Supersize a box similar to the red one, 100 liters; then swap drivers over.
2) Add a third (3rd) woofer over the clamshell, I do have stack of 15” x 15” scraps ready for laminating a tunnel. It would be a 5” snorkel added on.
Any project in the shop is way more fun than cutting grass or painting the back door.
“nothing else to do I guess” - Miranda Lambert
I had a couple of ideas:
1) Supersize a box similar to the red one, 100 liters; then swap drivers over.
2) Add a third (3rd) woofer over the clamshell, I do have stack of 15” x 15” scraps ready for laminating a tunnel. It would be a 5” snorkel added on.
Any project in the shop is way more fun than cutting grass or painting the back door.
“nothing else to do I guess” - Miranda Lambert
To tell you the truth, I’d rather be building speakers in the shop than a lot of other things. I just received a Zaph SR71 kit that I’m building for a buddy; the 7” reed pulp cone is impressive looking.
I should have them together by the end of the weekend; I did get a jump start on them mid week. [I’ve been on a roll this month….]
Small box for such a heavy woofer 9”x 15.3”x10.5D.
I should have them together by the end of the weekend; I did get a jump start on them mid week. [I’ve been on a roll this month….]
Small box for such a heavy woofer 9”x 15.3”x10.5D.
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