Subwoofer audio/acoustics test, any opinions?

[boggy]

Hi all,


some time ago we make some special wav files
with shaped sine wave bursts. Because this is
being very useful for us, we decide to make
public version of it. It's based on Siegfried
Linkwitz idea to listen shaped tone bursts...
After some learning, talented people can hear
very precisely where are "some strange things"
in loudspeakers and acoustics. But, even without
any learning we can hear that some loudspeaker
driver has damaged or sounds strange...
In this test we don't favorite any "special"
frequency, we tried to make "sweep alike" test.
Note that test is fairly slow, about 17 minutes
for 91 discrete frequencies.

We make it like movie, and then you can see which
frequency is played, even on some new "all-players"
for home theater. Listen loudspeakers one
by one, you have two same channels in video.

Note that we don't have strong background in
loudspeakers and acoustics; we are engineers
with experience in some other areas

Please download it and test it... any opinion
will be highly appreciated.

http://www.bozoel.com/products/bozotest/index.html

Thanks

-boggy

[wildfire99]

Interesting concept. My "comments":

- Compress the file as a ZIP. I have a RAR decompressor, but I doubt most people do.

- Explain that the tone will be played every time the counter ticks off... I didn't get that right away, and a lot of people may not get it for a while longer.

- Go from higher frequencies to lower. It's annoying to wait through all the 10hz notes that my system won't play, before I get to the quiet, then regular notes.

- Play the note more often than 3 times. How about 5?

- It may be nice to have a slow version and a fast version. The fast version could play the frequency just three times, but with a much faster interval (1 sec) and only play every other frequency (100hz, 98hz, 96hz, 94hz, etc.). Or perhaps interleave them (100, 98, 99, 96, 97, 95)... or have a set of 5hz steps, each step plays 1 frequency then the other, such as 100hz-95hz, you play 5 notes each 1hz lower than the last, with an interval of 1 sec.

- Have the counter tick down in real seconds. Given the number is in the same place and looks the same as the second timer, I expect it to be in seconds, yet it counts down 1 every 3-4 seconds.

- I would love to hear a small musical passage instead of the beats. A mono-frequency tone, with no change in volume, would be nice, and would let people evaluate the 'speed' of their system.

- Try multi-frequency tunes, such as a simple song with notes only in the spectrum from 30hz - 40hz. It would be an interesting tool to spot the effects of room gains or nulls, if each note was supposed to be identical in volume.

- Since you have video, how about the more common frequency sweeps, with a visual display of the current frequency being played? I've always wanted something like that.

- Lastly but not leastly, I would really love to see this in the mid and high freq versions mentioned on the site!

[boggy]

Hello wildfire99,

Thank you for your opinions and your time...

Let's see:

Interesting concept. My "comments":

- Compress the file as a ZIP. I have a RAR decompressor, but I doubt most people do.

Right.
With winzip we have 50% larger archives...
We use rar to save some bandwidth.

- Explain that the tone will be played every time the counter ticks off... I didn't get that right away, and a lot of people may not get it for a while longer.

Ok, we don't have real User Manual yet, and sorry because that. We prepare it.

- Go from higher frequencies to lower. It's annoying to wait through all the 10hz notes that my system won't play, before I get to the quiet, then regular notes.

We start with lower frequencies because they needs user attention...
And 10Hz tones is useful because it is inaudible, and when you hear
something, that isn't good.... woofer/port noise check.

- Play the note more often than 3 times. How about 5?

I can double check our test, but I think that we are in middle...
We play it four times, when tick go 3,2,1,0
Tick say how many tones are left for written frequency when play current
(sorry, I see, we must have at least readme.txt, if we don't have nice and colored user manual :x )

- It may be nice to have a slow version and a fast version. The fast version could play the frequency just three times, but with a much faster interval (1 sec) and only play every other frequency (100hz, 98hz, 96hz, 94hz, etc.). Or perhaps interleave them (100, 98, 99, 96, 97, 95)... or have a set of 5hz steps, each step plays 1 frequency then the other, such as 100hz-95hz, you play 5 notes each 1hz lower than the last, with an interval of 1 sec.

THIS is nice idea for low frequency! 8)
Our midrange test take some time (about one hour!), but if we play only one tone with
smaller pause, and faster repetition, they will be shorter.
Please check for Mid and High frequency parts at download page

- Have the counter tick down in real seconds. Given the number is in the same place and looks the same as the second timer, I expect it to be in seconds, yet it counts down 1 every 3-4 seconds.

Some players has some sort of this feature included, and we try to keep video part of test
smaller as possible... now is only a couple of megabytes... more than 95% of test file is
uncompressed PCM audio.

- I would love to hear a small musical passage instead of the beats. A mono-frequency tone, with no change in volume, would be nice, and would let people evaluate the 'speed' of their system.

Ah, this is also my idea, but for now, we may check usability of shaped tone burst testing...
Shaped tone bursts are well known, but (possible) much more in world of professionals. Our intent is to bring up this nice test principle to some ordinary people.

- Try multi-frequency tunes, such as a simple song with notes only in the spectrum from 30hz - 40hz. It would be an interesting tool to spot the effects of room gains or nulls, if each note was supposed to be identical in volume.

For this, we need advice, we aren't acousticians... :cry:

- Since you have video, how about the more common frequency sweeps, with a visual display of the current frequency being played? I've always wanted something like that.

This proposal is good, we will see what we can do... to make new test or to include it
in existing tests... this will take some time.

But, what other people think about all this?

- Lastly but not leastly, I would really love to see this in the mid and high freq versions mentioned on the site!

Sorry, I read this today, version 0.8 is released yesterday.
You can expect some modifications in version 0.9 of all tests

Thank you for your time,

Best regards,

-boggy