T
The_12NV
Guest
Hi there ppl, Im after a SPL meter that can read up to 180DB. If there is a
schematic available with parts, please post me. cheers
schematic available with parts, please post me. cheers
J
James
Guest
"The_12NV" <The_12NV@swiftdsl.com.au> wrote in message
news:401ca7fa$0$10529$61ce578d@news.syd.swiftdsl.com.au...
What the proverbial are you measuring? a nuclear explosion at 4 meters or
something?
James
news:401ca7fa$0$10529$61ce578d@news.syd.swiftdsl.com.au...
180dB????
What the proverbial are you measuring? a nuclear explosion at 4 meters or
something?
James
R
Ray
Guest
In article <401cb71a$1@usenet.per.paradox.net.au>,
jamkat@SPAMLESScybanet.net.au says...
jamkat@SPAMLESScybanet.net.au says...
"The_12NV" <The_12NV@swiftdsl.com.au> wrote in message
news:401ca7fa$0$10529$61ce578d@news.syd.swiftdsl.com.au...
Hi there ppl, Im after a SPL meter that can read up to 180DB. If there is
a
schematic available with parts, please post me. cheers
180dB????
What the proverbial are you measuring? a nuclear explosion at 4 meters or
something?
Sorry, can't hear you
P
Phil Allison
Guest
"The_12NV" <The_12NV@swiftdsl.com.au>
** You can use a standard SPL meter to measure any sound level possible -
all you do is calibrate the path loss at a distance.
If the SPL is say 120 dB at the point of interest with some test sound
and drops to 70 dB at a point some distance away then you have 50 dB path
loss.
If you read 130 dB SPL at that distant spot then the SPL at the
original one must be 180 dB SPL.
Get the idea ????
............... Phil
** You can use a standard SPL meter to measure any sound level possible -
all you do is calibrate the path loss at a distance.
If the SPL is say 120 dB at the point of interest with some test sound
and drops to 70 dB at a point some distance away then you have 50 dB path
loss.
If you read 130 dB SPL at that distant spot then the SPL at the
original one must be 180 dB SPL.
Get the idea ????
............... Phil
A
Alan Rutlidge
Guest
"The_12NV" <The_12NV@swiftdsl.com.au> wrote in message
news:401ca7fa$0$10529$61ce578d@news.syd.swiftdsl.com.au...
meter?
At 180dB SPL not only will you need a new set of ears, your eyes will
probably pop out and there will be a significant brown stain on your
underwear.
BTW, what do you plan to measure with the meter that has to read that high a
sound pressure level?
Cheers,
Alan
news:401ca7fa$0$10529$61ce578d@news.syd.swiftdsl.com.au...
So I suspect you will need some remote control device to got with the SPL
meter?
At 180dB SPL not only will you need a new set of ears, your eyes will
probably pop out and there will be a significant brown stain on your
underwear.
BTW, what do you plan to measure with the meter that has to read that high a
sound pressure level?
Cheers,
Alan
T
The_12NV
Guest
Well Actually, im in the car audio show and, at present the record is
175.3DB and im currently 173.4DB.
So now u can understand why i need 180DB.
So anyone know where i could find ANY schematic of a SPL meter?
"The_12NV" <The_12NV@swiftdsl.com.au> wrote in message
news:401ca7fa$0$10529$61ce578d@news.syd.swiftdsl.com.au...
175.3DB and im currently 173.4DB.
So now u can understand why i need 180DB.
So anyone know where i could find ANY schematic of a SPL meter?
"The_12NV" <The_12NV@swiftdsl.com.au> wrote in message
news:401ca7fa$0$10529$61ce578d@news.syd.swiftdsl.com.au...
P
Phil Allison
Guest
"The_12NV" <
** How are these levels being measured now ?
** Nope.
** I have posted a simple solution - time for you to reply and prove
you are not a troll.
.............. Phil
** How are these levels being measured now ?
** Nope.
** I have posted a simple solution - time for you to reply and prove
you are not a troll.
.............. Phil
A
Alan Rutlidge
Guest
"The_12NV" <The_12NV@swiftdsl.com.au> wrote in message
news:401d1f94$0$10525$61ce578d@news.syd.swiftdsl.com.au...
Car audio show - geez I should have guessed this one. Isn't this where a
whole bunch of wankers get together and try to out blast each other off the
planet? (a.k.a. a MegaCrank ? ? ? ) The aim being to have the loudest car
stereo, no matter how distorted the sound is?
I've always wanted to know - Who is the idiot who gets to get inside the
car(s) and takes the readings?
AFAIK the one who's stereo blows the windows out of the car (without using
explosive charges) automatically wins ????
BTW, is there anyone who knows of a commercially available microphone that
can handle a SPL of 180dB? Which then brings into question the accuracy and
validity of the measurements. If the contest is all about loudness, your
own measurements would need to be taken with the same brand and model of SPL
meter (using the same settings) and under the exact same conditions for the
measurement to be valid and of useful comparison. It could be reasonably
argued a home built and uncalibrated meter will give a less than accurate
indication of the true SPL developed within the car.
Cheers,
Alan
news:401d1f94$0$10525$61ce578d@news.syd.swiftdsl.com.au...
Car audio show - geez I should have guessed this one. Isn't this where a
whole bunch of wankers get together and try to out blast each other off the
planet? (a.k.a. a MegaCrank ? ? ? ) The aim being to have the loudest car
stereo, no matter how distorted the sound is?
I've always wanted to know - Who is the idiot who gets to get inside the
car(s) and takes the readings?
AFAIK the one who's stereo blows the windows out of the car (without using
explosive charges) automatically wins ????
BTW, is there anyone who knows of a commercially available microphone that
can handle a SPL of 180dB? Which then brings into question the accuracy and
validity of the measurements. If the contest is all about loudness, your
own measurements would need to be taken with the same brand and model of SPL
meter (using the same settings) and under the exact same conditions for the
measurement to be valid and of useful comparison. It could be reasonably
argued a home built and uncalibrated meter will give a less than accurate
indication of the true SPL developed within the car.
Cheers,
Alan
M
Michael
Guest
"Phil Allison" <philallison@optusnet.com.au> wrote in message news:<401d779c$0$28869$afc38c87@news.optusnet.com.au>...
whats the limit of air? what happens when rarefactions get close to a total vacuum?
whats the limit of air? what happens when rarefactions get close to a total vacuum?
P
Phil Allison
Guest
"Michael"
** The distortion free limit is about 160 dB SPL.
............ Phil
** The distortion free limit is about 160 dB SPL.
** Massive non linearity.
............ Phil
P
Phil Allison
Guest
"Alan Rutlidge"
** Many SPL meters have the facility to remote the mic head - ie an
extension cable connecting the capsule and preamp to the meter/switch unit.
** No.
Which then brings into question the accuracy and
** The method I suggested would give valid answers with a normal SPL
meter. The car needs to go inside a concrete bunker while the meter and
its operator remain outside. You only need to measure the attenuation
factor in dB of the bunker first.
.......... Phil
** Many SPL meters have the facility to remote the mic head - ie an
extension cable connecting the capsule and preamp to the meter/switch unit.
** No.
Which then brings into question the accuracy and
** The method I suggested would give valid answers with a normal SPL
meter. The car needs to go inside a concrete bunker while the meter and
its operator remain outside. You only need to measure the attenuation
factor in dB of the bunker first.
.......... Phil
N
Newsy
Guest
"Alan Rutlidge" <rutlidge*nO-sPaM*@mail.iinet.net.au> wrote in message
news:401db3d9$0$1724$5a62ac22@freenews.iinet.net.au...
to 168dB below 4 KHz.
Rod
news:401db3d9$0$1724$5a62ac22@freenews.iinet.net.au...
The best I know of is the DPA 4004, with a 130v power supply. It is rated
to 168dB below 4 KHz.
Rod
N
Newsy
Guest
"Alan Rutlidge" <rutlidge*nO-sPaM*@mail.iinet.net.au> wrote in message
news:401db3d9$0$1724$5a62ac22@freenews.iinet.net.au...
http://www.realcaraudio.com/forums/showthread/t-996.html
The X-Meter by Terrasonde www.terrasonde.com, but I can't find the unit on
their site.
Rod
news:401db3d9$0$1724$5a62ac22@freenews.iinet.net.au...
Just found this:
http://www.realcaraudio.com/forums/showthread/t-996.html
The X-Meter by Terrasonde www.terrasonde.com, but I can't find the unit on
their site.
Rod
N
Newsy
Guest
"Newsy" <rllg000@hotmail.com> wrote in message
news:401de393@duster.adelaide.on.net...
www.measureeverything.com on the site.
news:401de393@duster.adelaide.on.net...
I obviously didn't look too closely - follow the link to
www.measureeverything.com on the site.
S
Steve Robertson
Guest
Why not get a normal SPL meter & put it further away??
2x the distance = 1/4 the sound level ???
Not sure how log factors in: Im sure someone here knows the math
Dont the guys in the car shows have to sit on the windscreen to stop them poping
out?? I know they make sub drivers just for volume level alone:not designed for
sound quality, huge XMax and big peak in freq response (giving a nice boom for the SPL meters)
It really no crazier than putting supercharged V8's in mini's I guess, no real world use, just
another expensive hobby.
2x the distance = 1/4 the sound level ???
Not sure how log factors in: Im sure someone here knows the math
Dont the guys in the car shows have to sit on the windscreen to stop them poping
out?? I know they make sub drivers just for volume level alone:not designed for
sound quality, huge XMax and big peak in freq response (giving a nice boom for the SPL meters)
It really no crazier than putting supercharged V8's in mini's I guess, no real world use, just
another expensive hobby.
B
Bob M
Guest
"Phil Allison" <philallison@optusnet.com.au> wrote in message news:<401cc6c8$0$29131$afc38c87@news.optusnet.com.au>...
Phil, although your idea would work from a theoretical point, it
wouldn't help these guys make the measurements they need.
I first viewed this new sport/activity???? while channel surfing. Boys
and their mega toys!
Anyways the object of the exercise is to create the loudest reading on
the SPL possible. Fidelity is not part of the equation. To do that all
kinds of strange techniques are employed, including "focusing" the
sound with reflectors inside the car. Therefore, you can create a
"suite spot" where the sound pressure maxes out. Some of the tricks
used include lining the door panels with concrete to "stiffen the
reflector" There are many others possible if you let your imagination
go.
The car becomes a "sealed chamber" to contain and maximize the SPL.
And yes, they sit on the 3 inch thick lexan wind screens to hold them
in place during the "run" which only lasts a few seconds and is a
burst of a single fairly low frequency "tone".
If you were using a mechanical "attenuator", it would be close to
impossible to reasonably accurately calibrate it due to all the
non-linearity that exists at these levels. I would even question the
ability of the event sponsors to accurately measure anything.
FYI, the show stated that a Space Shuttle launch measured in the 155
DB range.
Cheers from Canada!
Bob Morgoch
Hi there,
Phil, although your idea would work from a theoretical point, it
wouldn't help these guys make the measurements they need.
I first viewed this new sport/activity???? while channel surfing. Boys
and their mega toys!
Anyways the object of the exercise is to create the loudest reading on
the SPL possible. Fidelity is not part of the equation. To do that all
kinds of strange techniques are employed, including "focusing" the
sound with reflectors inside the car. Therefore, you can create a
"suite spot" where the sound pressure maxes out. Some of the tricks
used include lining the door panels with concrete to "stiffen the
reflector" There are many others possible if you let your imagination
go.
The car becomes a "sealed chamber" to contain and maximize the SPL.
And yes, they sit on the 3 inch thick lexan wind screens to hold them
in place during the "run" which only lasts a few seconds and is a
burst of a single fairly low frequency "tone".
If you were using a mechanical "attenuator", it would be close to
impossible to reasonably accurately calibrate it due to all the
non-linearity that exists at these levels. I would even question the
ability of the event sponsors to accurately measure anything.
FYI, the show stated that a Space Shuttle launch measured in the 155
DB range.
Cheers from Canada!
Bob Morgoch
M
Mark van der Eynden
Guest
"The_12NV" <The_12NV@swiftdsl.com.au> wrote in message news:<401ca7fa$0$10529$61ce578d@news.syd.swiftdsl.com.au>...
burglar alarms). With a suitable size you should be able to go up to
1,000DB or so (level of the 'big bang'?).
Of course it probably would be useless below 100DB and I have no idea
how you would calibrate it.
Cheers,
Mark
You probably should use a piezo vibration sensor (often used in car
burglar alarms). With a suitable size you should be able to go up to
1,000DB or so (level of the 'big bang'?).
Of course it probably would be useless below 100DB and I have no idea
how you would calibrate it.
Cheers,
Mark
P
Phil Allison
Guest
"Bob M" <bmorgoch@sympatico.ca
** The fact they use a low frequency tone makes the measurement of the
path loss in dB very easy. The tone is measured first at the "sweet spot"
at a reduced power and level within the SPL meter's range - then at a
remote spot where the level is 30 or 40 dB lower.
Whatever non-linearities ocurr on a full power run they will only
detract from the actual SPL at either position and in the same way.
............. Phil
** The fact they use a low frequency tone makes the measurement of the
path loss in dB very easy. The tone is measured first at the "sweet spot"
at a reduced power and level within the SPL meter's range - then at a
remote spot where the level is 30 or 40 dB lower.
Whatever non-linearities ocurr on a full power run they will only
detract from the actual SPL at either position and in the same way.
............. Phil
C
Clifford Heath
Guest
Phil Allison wrote:
Do you happen to know what SPL causes liquefaction?
J
John Tserkezis
Guest
The_12NV wrote:
and modifies the audio in a predictable and repeatable manner. You modify the
readings of the meter as per the attenuator spec.
You'd be hard pressed to find a reasonable specced mic to read that that
level, and there's a minor issue of design problems with levels that high too.
This would definitely NOT be a DIY job.
--
Linux Registered User # 302622 <http://counter.li.org>
Your best bet would be to use an acoustic attenuator. This fits over the mic
and modifies the audio in a predictable and repeatable manner. You modify the
readings of the meter as per the attenuator spec.
You'd be hard pressed to find a reasonable specced mic to read that that
level, and there's a minor issue of design problems with levels that high too.
This would definitely NOT be a DIY job.
--
Linux Registered User # 302622 <http://counter.li.org>