[Gary Eickmeier]

I can't believe how difficult it is to find some audio frequency response
graph paper. I am doing some measuring and would like to plot it from time
to time, getting a new 31 band equalizer, just want to go to the internet
and download some FR graph paper. No dice. I have been to several sites that
offer free this, free that, Wikipedia, have run out of key words to try.

Anyone know where I can beg, buy, or steal some FR graph paper? The
measurement equipment companies? I was actually hoping to be able to have it
plot the readings for me and then print it out, but I will take anything.

Gary Eickmeier

[Scott Dorsey]

Gary Eickmeier wrote:
I can't believe how difficult it is to find some audio frequency response
graph paper. I am doing some measuring and would like to plot it from time
to time, getting a new 31 band equalizer, just want to go to the internet
and download some FR graph paper. No dice. I have been to several sites that
offer free this, free that, Wikipedia, have run out of key words to try.

log-log paper
semilog paper
three-cycle paper

A quick sweep of the graphic equalizer with all bands set at +5 will show
just how bumpy it is! It's horrifying that people try and use those things
for audio.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[William Sommerwerck]

"Scott Dorsey" wrote in message ...

A quick sweep of the graphic equalizer with all bands set at +5
will show just how bumpy it is! It's horrifying that people try and
use those things for audio.

Whether or not, that's what they're made for!

Five bands don't provide the "subtlety" to make genuinely useful adjustments.
In cars, people commonly push all the controls all the way up, simply to make
the system louder.

[Scott Dorsey]

William Sommerwerck wrote:
"Scott Dorsey" wrote in message ...
A quick sweep of the graphic equalizer with all bands set at +5
will show just how bumpy it is! It's horrifying that people try and
use those things for audio.

Whether or not, that's what they're made for!

Five bands don't provide the "subtlety" to make genuinely useful adjustments.

The problem is that 31 bands make for worse ripple problems than even five.

I understand the argument for PA applications because if a system is starting
to ring you can quickly pull down the slider for the frequency that it's
ringing at. But it's not exactly a precision device.

In cars, people commonly push all the controls all the way up, simply to make
the system louder.

Yes, well, we don't talk about those people.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Gary Eickmeier]

Thanks all for the info - will try those searches and see what pops up. My
earlier search resulted in one of those nightmares of links within links
full of sites that want to download all kinds of crap to you beside what you
are after.

On equalizers, I wonder why they aren't all digital yet, with infinitely
fine number of sliders that are set automatically by the RTA. I know that
some receivers have these "room correction" modes, right? I would love to
see one that measures the output of your system, then allows you to draw the
curve that you want, and have it do it perfectly with no lumpies. Ah well,
we'll see now it goes.

Gary Eickmeier

[John Williamson]

On 08/05/2014 04:46, Gary Eickmeier wrote:
Thanks all for the info - will try those searches and see what pops up. My
earlier search resulted in one of those nightmares of links within links
full of sites that want to download all kinds of crap to you beside what you
are after.

On equalizers, I wonder why they aren't all digital yet, with infinitely
fine number of sliders that are set automatically by the RTA. I know that
some receivers have these "room correction" modes, right? I would love to
see one that measures the output of your system, then allows you to draw the
curve that you want, and have it do it perfectly with no lumpies. Ah well,
we'll see now it goes.

There are systems that go one stage further. You play a sweep with a
microphone at the listening position, and it automatically sets the
frequency response to give you a flat(ish) response there.

They're not cheap...


--
Tciao for Now!

John.

[Trevor]

"Scott Dorsey" wrote in message
...
A quick sweep of the graphic equalizer with all bands set at +5 will show
just how bumpy it is! It's horrifying that people try and use those
things
for audio.

Which is why only a moron would try to use one that way (yes I know there
are plenty of morons)
However graphics and parametrics are still indispensable for reinforced live
sound at least. The days of everyone having one in their HiFi seems have
gone fortunately.

Trevor.

[Adrian Tuddenham[_2_]]

Gary Eickmeier wrote:


Anyone know where I can beg, buy, or steal some FR graph paper? The
measurement equipment companies? I was actually hoping to be able to have it
plot the readings for me and then print it out, but I will take anything.

Try:
http://www.poppyrecords.co.uk/other/...hPaper0-80.gif
http://www.poppyrecords.co.uk/other/...Paper20-20.gif

They took about 5 minutes to knock up with ClarisWorks4 spreadsheet; and
it would also have plotted the graphs for me if I had put in some data.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Adrian Tuddenham[_2_]]

Scott Dorsey wrote:

Gary Eickmeier wrote:
I can't believe how difficult it is to find some audio frequency response
graph paper. I am doing some measuring and would like to plot it from time
to time, getting a new 31 band equalizer, just want to go to the internet
and download some FR graph paper. No dice. I have been to several sites that
offer free this, free that, Wikipedia, have run out of key words to try.

log-log paper
semilog paper
three-cycle paper

A quick sweep of the graphic equalizer with all bands set at +5 will show
just how bumpy it is! It's horrifying that people try and use those things
for audio.

Why do people persist in calling it an "equaliser"? It is an effects
unit and does not equalise anything


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Dave Plowman (News)]

In article id.invalid,
Adrian Tuddenham wrote:
A quick sweep of the graphic equalizer with all bands set at +5 will
show just how bumpy it is! It's horrifying that people try and use
those things for audio.

Why do people persist in calling it an "equaliser"? It is an effects
unit and does not equalise anything

I'd say it dates from when landlines had their frequency response adjusted
to match another - so equalised. I've seen that term used dating from the
1930s. The term stuck for any frequency response adjustment.

--
*The best cure for sea sickness, is to sit under a tree.

Dave Plowman London SW
To e-mail, change noise into sound.

[Gary Eickmeier]

"John Williamson" wrote in message
...
On 08/05/2014 04:46, Gary Eickmeier wrote:
Thanks all for the info - will try those searches and see what pops up.
My
earlier search resulted in one of those nightmares of links within links
full of sites that want to download all kinds of crap to you beside what
you
are after.

On equalizers, I wonder why they aren't all digital yet, with infinitely
fine number of sliders that are set automatically by the RTA. I know that
some receivers have these "room correction" modes, right? I would love to
see one that measures the output of your system, then allows you to draw
the
curve that you want, and have it do it perfectly with no lumpies. Ah
well,
we'll see now it goes.

There are systems that go one stage further. You play a sweep with a
microphone at the listening position, and it automatically sets the
frequency response to give you a flat(ish) response there.

They're not cheap...

Well, what I mean is you don't necessarily want flat, but a "room curve" at
the listening position. McIntosh used to publish such a curve that their
technicians used in the field to set up their speaker systems when
requested. It has a slight hump below 1k and a gradually falling hi freq
beyond that.

Gary Eickmeier

[Gary Eickmeier]

"Adrian Tuddenham" wrote in message
valid.invalid...
Gary Eickmeier wrote:


Anyone know where I can beg, buy, or steal some FR graph paper? The
measurement equipment companies? I was actually hoping to be able to have
it
plot the readings for me and then print it out, but I will take anything.

Try:
http://www.poppyrecords.co.uk/other/...hPaper0-80.gif
http://www.poppyrecords.co.uk/other/...Paper20-20.gif

They took about 5 minutes to knock up with ClarisWorks4 spreadsheet; and
it would also have plotted the graphs for me if I had put in some data.

Beautiful - thanks Adrian.

Gary

[William Sommerwerck]

"Adrian Tuddenham" wrote in message
nvalid.invalid...

Why do people persist in calling it an "equaliser"? It is an effects
unit and does not equalise anything.

Its original purpose was to remove known errors in frequency response. But, of
course, as with many inventions, its use has been perverted.

Current consumer systems can automatically flatten the response at the
listening position. These have been around for several years.

[Mike Rivers[_2_]]

On 5/7/2014 3:25 PM, Gary Eickmeier wrote:
I can't believe how difficult it is to find some audio frequency response
graph paper.

You want semi-log graph paper, four cycles if you want the full audio
range (10 Hz to 100 kHz). Here's a "make your own" web site that's
pretty flexible:
http://customgraph.com/piart.php?art=579

What I'm surprised that I can't find, given how common computers with
sound cards are, is a modern computerized version of the clunky General
Radio chain-driven synchronized oscillator and plotter that we had in
our college lab in 1960. Connect the device you want to test between the
audio output and input of a computer, use a program to generate a slow
sine wave sweep, and generate a plot of what comes back into the
computer's audio input. There are a number of FFT programs but it's just
not the same thing.

I've tried Room EQ Wizard and RightMark but haven't had much success
with either one. This seems so simple. Why hasn't anyone done it?


--
For a good time, visit http://mikeriversaudio.wordpress.com

[Mike Rivers[_2_]]

On 5/8/2014 4:36 AM, Adrian Tuddenham wrote:
They took about 5 minutes to knock up with ClarisWorks4 spreadsheet; and
it would also have plotted the graphs for me if I had put in some data.

I've spent years fighting with Excel's plotting routines and still
haven't been able to figure out how to make a normal looking frequency
response graph. Is ClarisWorks a Mac-only program? It's an old name but
I haven't heard much about it in at least 10 years.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[Scott Dorsey]

Gary Eickmeier wrote:

On equalizers, I wonder why they aren't all digital yet, with infinitely
fine number of sliders that are set automatically by the RTA. I know that
some receivers have these "room correction" modes, right? I would love to
see one that measures the output of your system, then allows you to draw the
curve that you want, and have it do it perfectly with no lumpies. Ah well,
we'll see now it goes.

These days, a lot of them _are_ digital. But in the studio world, people
use parametrics instead of graphics so they don't have any of those problems
to begin with.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

John Williamson wrote:

There are systems that go one stage further. You play a sweep with a
microphone at the listening position, and it automatically sets the
frequency response to give you a flat(ish) response there.

They're not cheap...

But the end result sure sounds that way....
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Adrian Tuddenham[_2_]]

Mike Rivers wrote:

On 5/8/2014 4:36 AM, Adrian Tuddenham wrote: They took about 5 minutes
to knock up with ClarisWorks4 spreadsheet; and it would also have
plotted the graphs for me if I had put in some data.

I've spent years fighting with Excel's plotting routines and still
haven't been able to figure out how to make a normal looking frequency
response graph. Is ClarisWorks a Mac-only program? It's an old name but
I haven't heard much about it in at least 10 years.

It was developed in the early 1990s; the spreadsheet was based on
Lotus123 (Excel also came from the same origins), the drawing section
started as MacDraw and it also integrated a database, a word processor,
painting and communications packages (it could emulate a Teletype and
program a modem). Version 4, which I still use, was from 1995 and was
the last one that worked as an industrial heavyweight before they added
all the eye-candy. In conjunction with "Pub & Sub" (now also
discontinued in OSX) it could provide all the software to run a
medium-sized business.

Although the full version is only meant for Macs (because the comms
module doesn't work on P.C. hardware) there is a version for Windows
(CW5) and documents are interchangeable between the two platforms as
long as Mac users remember to put the ".cwk" file extension on the file
name.

It exports drawing files in PICT format, which any photographic program
can convert to GIF or JPEG.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Scott Dorsey]

Adrian Tuddenham wrote:

Why do people persist in calling it an "equaliser"? It is an effects
unit and does not equalise anything

It is a historical holdover from the days of telephone practice when filter
banks _were_ used to equalize line response.

Now we are stuck with it, just as we are stuck with "condenser microphones"
that do not condense any fluid and "passive preamplifiers" that are actually
attenuators.

Please notify the Oxford University Press.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Gary Eickmeier wrote:
"John Williamson" wrote in message
They're not cheap...

Well, what I mean is you don't necessarily want flat, but a "room curve" at
the listening position. McIntosh used to publish such a curve that their
technicians used in the field to set up their speaker systems when
requested. It has a slight hump below 1k and a gradually falling hi freq
beyond that.

Yes, and the end result was terrible sound... because making everything
so that all third-octave sections have the same level is NOT the same as
making the system "flat," even ignoring the non-minimum-phase effects.

Thank God that the Seventies are over and people have pretty much abandoned
all that stuff.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Sylvain Robitaille]

On Thu, 08 May 2014 09:43:50 -0400, Mike Rivers wrote:

What I'm surprised that I can't find, given how common computers
with sound cards are, is a modern computerized version of the
clunky General Radio chain-driven synchronized oscillator and
plotter that we had in our college lab in 1960. Connect the device
you want to test between the audio output and input of a computer,
use a program to generate a slow sine wave sweep, and generate a
plot of what comes back into the computer's audio input. ... This
seems so simple. Why hasn't anyone done it?

Possibly something like this?

http://kokkinizita.linuxaudio.org/li...jaaa-pict.html

Admittedly I'm not sure whether it'll do a frequency sweep. I don't use
this software very frequently, and I've not tried to make it do that,
but it seems to be pretty good at giving the user a sense of frequency
response of connected equipment (photos in the link above are of noise
floor not frequency response, I know ...)

--
----------------------------------------------------------------------
Sylvain Robitaille

Systems analyst / AITS Concordia University
Faculty of Engineering and Computer Science Montreal, Quebec, Canada
----------------------------------------------------------------------

[Peter Larsen[_3_]]

Gary Eickmeier wrote:

I can't believe how difficult it is to find some audio frequency
response graph paper. I am doing some measuring and would like to
plot it from time to time, getting a new 31 band equalizer, just want
to go to the internet and download some FR graph paper. No dice. I
have been to several sites that offer free this, free that,
Wikipedia, have run out of key words to try.

Solving what problem? - measure at iso frequencies and plot on standard
"squares" and be happy.

Gary Eickmeier

Kind regards

Peter Larsen

[Peter Larsen[_3_]]

Gary Eickmeier wrote:

"John Williamson" wrote in message
...

There are systems that go one stage further. You play a sweep with a
microphone at the listening position, and it automatically sets the
frequency response to give you a flat(ish) response there.

They're not cheap...

Some actually are, considering that they are built into AV amplifiers.

Well, what I mean is you don't necessarily want flat, but a "room
curve" at the listening position. McIntosh used to publish such a
curve that their technicians used in the field to set up their
speaker systems when requested. It has a slight hump below 1k and a
gradually falling hi freq beyond that.

20 Hz - 6 dB, 200 Hz 0 dB and 20 kHz -6 dB is a good starting point for a 20
to 40 square meter room, larger room make it 20 kHz -10 dB, beyond
"larger" - whatever that is - the theather curve 40 to 1000 linear and -3 dB
/ octave above gets to be the target curve. With a sanely designed
loudspeaker system those curves will be what the system tries to provide.

Note that it is often claimed that it malpractice to move sliders on a
graphic eq that are next to each other to opposites, ie. boost one and
attenuate the next. That is misunderstood because just that is how to move
the adjustment center sideways as is "easily seen" in 10 minutes when
equalizing with an analyzer running.

Two important points: the treble may not appear to be detached and a
subwoofer, if available, may not be detectable on male vox.

Gary Eickmeier

Kind regards

Peter Larsen

[Peter Larsen[_3_]]

Mike Rivers wrote:

On 5/7/2014 3:25 PM, Gary Eickmeier wrote:
I can't believe how difficult it is to find some audio frequency
response graph paper.

You want semi-log graph paper, four cycles if you want the full audio
range (10 Hz to 100 kHz). Here's a "make your own" web site that's
pretty flexible:
http://customgraph.com/piart.php?art=579

What I'm surprised that I can't find, given how common computers with
sound cards are, is a modern computerized version of the clunky
General Radio chain-driven synchronized oscillator and plotter that
we had in our college lab in 1960. Connect the device you want to
test between the audio output and input of a computer, use a program
to generate a slow sine wave sweep, and generate a plot of what comes
back into the computer's audio input. There are a number of FFT
programs but it's just not the same thing.

You want Speaker Workshop by Audua.

I've tried Room EQ Wizard and RightMark but haven't had much success
with either one. This seems so simple. Why hasn't anyone done it?

His marketing flunked, but it is should be out there somewhere, I may still
have the download archive if an old computer powers up as expected.

Kind regards

Peter Larsen

[Don Pearce[_3_]]

On Thu, 08 May 2014 09:43:50 -0400, Mike Rivers
wrote:

On 5/7/2014 3:25 PM, Gary Eickmeier wrote:
I can't believe how difficult it is to find some audio frequency response
graph paper.

You want semi-log graph paper, four cycles if you want the full audio
range (10 Hz to 100 kHz). Here's a "make your own" web site that's
pretty flexible:
http://customgraph.com/piart.php?art=579

What I'm surprised that I can't find, given how common computers with
sound cards are, is a modern computerized version of the clunky General
Radio chain-driven synchronized oscillator and plotter that we had in
our college lab in 1960. Connect the device you want to test between the
audio output and input of a computer, use a program to generate a slow
sine wave sweep, and generate a plot of what comes back into the
computer's audio input. There are a number of FFT programs but it's just
not the same thing.

I've tried Room EQ Wizard and RightMark but haven't had much success
with either one. This seems so simple. Why hasn't anyone done it?

Not surprising. You can't equalise a room. You can equalise the path
from one speaker to one ear provided you don't move, and that is it.
You know as well as I do that if you move more than a few inches the
modal patterns surrounding you have changed utterly. "Equalizing" at
one position makes things ten times as bad at another. The best you
can ever do is make the source as good as possible.

d

[Gary Eickmeier]

"Peter Larsen" wrote in message
k...
Gary Eickmeier wrote:

I can't believe how difficult it is to find some audio frequency
response graph paper. I am doing some measuring and would like to
plot it from time to time, getting a new 31 band equalizer, just want
to go to the internet and download some FR graph paper. No dice. I
have been to several sites that offer free this, free that,
Wikipedia, have run out of key words to try.

Solving what problem? - measure at iso frequencies and plot on standard
"squares" and be happy.

Hi Peter -

I sort of ended up doing that, before I got all the responses above. In the
Bruel & Kjaer test CD the booklet has a teensy tiny FR graph that goes along
perfectly with the recorded pink noise narrow band signals. So I scanned it
into my photo edit program, enlarged it to sheet of paper size, and then I
can plot the FR directly above the test band freqs listed along the
horizontal axis. It is also great because it has the vertical axis in dB
from 50 to 100 dB, so I can plot the readings directly without having to
interpolate or translate.

Hey Peter - you are the one with the "orange" freq response plot theory for
recordings, right? That thing has fascinated me ever since. This is the fact
that there is a rising response up to 100 Hz, then a gradually falling
response the rest of the way. For the readers who haven't seen it, it is
based on the frequency analysis graph that probably most audio edit programs
have. You can highlight any section of your track, and that curve will
almoat always hold true. If you have an unwelcome resonance or deviation,
this window will tell you what to cut and how broadly.

Why does this work so well????

Gary Eickmeier

[Mike Rivers[_2_]]

On 5/8/2014 1:03 PM, Don Pearce wrote:
I've tried Room EQ Wizard and RightMark but haven't had much success
with either one. This seems so simple. Why hasn't anyone done it?

Not surprising. You can't equalise a room.

I know that, and I was never trying to equalize a room. I was using it
like I described it, pretending that the device I was testing was the
room. Room EQ Wizard wasn't simple enough to remember how to work, and
RightMark was never happy with the input level. Either it clipped or it
said that it was too low.


--
For a good time, visit http://mikeriversaudio.wordpress.com

[Mike Rivers[_2_]]

On 5/8/2014 12:51 PM, Peter Larsen wrote:
Speaker Workshop by Audua.

That looks like it's an FFT sort of program. I want a simple sine sweep
that measures the amplitude at one frequency, them moves on to the next
frequency. I can do this with my NTI Minirator and Minilizer, but it
generates only at 1/3 octave steps. That's not good enough resolution to
see what the response of an equalizer really looks like.

I'm not looking to measure rooms or speakers here, I want to measure
hardware with analog inputs and outputs. I can do it by hand of course,
it's just that this seems like the sort of thing that a computer can do
well, if only someone bothered to write the program.

Actually, Chris Juried of Tube Equipment Corporation has just what I'm
looking for, and he's offered to send me a copy a few times now, but
hasn't, so I guess it may not be ready to get out of the shop yet. He
uses it to characterize transformers and tubes.


--
For a good time, visit http://mikeriversaudio.wordpress.com

[Frank Stearns]

(Scott Dorsey) writes:

John Williamson wrote:

There are systems that go one stage further. You play a sweep with a
microphone at the listening position, and it automatically sets the
frequency response to give you a flat(ish) response there.

They're not cheap...

But the end result sure sounds that way....

Chuckle, no kidding. Freq response is only one thing - uneven or inappropriate
reverb times and phase (time) irregularities being the others, often more
significant. All you can do with graphic EQ is typically make it worse, even though
it "measures" flat. Woo hoo. Parametric is "better" but is still only a partial
solution for many underlying problems.

But hey, whatever floats your boat or bumps your already peaky/dippy bass. (For
that, traps are highly recommended.)

Maybe I missed it. Tell me again, Gary, why you're looking for category of solution,
particularly this one? I thought you were happy with your room.

Frank
Mobile Audio
--

[William Sommerwerck]

"Scott Dorsey" wrote in message ...

...the end result was terrible sound... because making everything
so that all third-octave sections have the same level is NOT the
same as making the system "flat," even ignoring the non-minimum-
phase effects.

I did a fair number of consumer equalizations, all intended to produced "flat"
response at the listening position. If the room wasn't overly reverberant, the
result was invariably an improvement -- lower coloration, better imaging, etc.


Thank God that the Seventies are over and people have pretty
much abandoned all that stuff.

Current EQ systems don't necessarily aim for flat steady-state response. But I
haven't studied them, and I'm not sure how they work.

[William Sommerwerck]

"Scott Dorsey" wrote in message ...

It is a historical holdover from the days of telephone practice when
filter banks _were_ used to equalize line response.

Now we are stuck with it, just as we are stuck with "condenser
microphones" that do not condense any fluid...

You are mistaken, sir... They condense the electrical fluid!

[Gary Eickmeier]

"Frank Stearns" wrote in message
...

Chuckle, no kidding. Freq response is only one thing - uneven or
inappropriate
reverb times and phase (time) irregularities being the others, often more
significant. All you can do with graphic EQ is typically make it worse,
even though
it "measures" flat. Woo hoo. Parametric is "better" but is still only a
partial
solution for many underlying problems.

But hey, whatever floats your boat or bumps your already peaky/dippy bass.
(For
that, traps are highly recommended.)

Maybe I missed it. Tell me again, Gary, why you're looking for category of
solution,
particularly this one? I thought you were happy with your room.

Frank
Mobile Audio

Hi Frank -

Whew - I am getting some odd reactions about the whole subject of EQing a
room or a speaker system. Basically, my system has no tone controls on the
receiver. I have no big complaints, but some of my audio buddies are always
wanting me to measure the FR in my system, so I did. Just a Radio Shack SLM,
digital, and a B&K test CD with 30 bands of narrow pink noise, but it works
and reveals some anomolies that I cannot correct with my system as is. I am
using a Velodyne subwoofer and just setting it by ear. So in measuring at
the listening position, I am getting a hump at 63 Hz that is about 5 dB
higher than I would like, then fairly smooth thru the midrange from 100 Hz
to 5k, then another hump at 8k of 5 or 6 dB too high, then falling off
smoothly to 20k with the zero crossing at 12.5 and 8 dB down at 16k.

When we did the Linkwitz Challenge with my cheap hacked together prototype
emulating my radiation pattern ideas, the test designer Dave Clark was able
to EQ both challenger speakers, mine and a pair of Behringer box speakers,
to sound just like the Linkwitz Orions in freq response. This was necessary
to eliminate that one variable from the one under test, the radiation
pattern and its effect on imaging. It was impressive to me that he was able
to do this with mine and make it sound so good that it won the challenge.

I am now building, or having built by someone that knows how to build
speakers, a final prototype that my engineer is doing with computer models
and by ear on the voicing and a variable radiation pattrn etc etc for which
I predict it will be very useful to have the ability to shape the response
of the things with a 31 band. I will be using the Velodyne with those new
speakers too, and this Behringer FBQ6200 equalizer has a subwoofer output
and adjustable crossover freq that is almost designed for my situation. I
will be able to shape the sub bass curve as well as the upper range so that
the FR is not a factor in the audibility of my design for rad pat and room
positioning of speakers for soundstaging. The engineer has already listened
in mono to the first one, and he remarks that it has the ability to "shape"
the soundstage anywhere from too far forward and too small, to too far
rearward and too flat a presentation (imaging wise, not FR wise). This is
exactly what I wanted, and should prove educational as well as spectacular
in stereo. To screw this up by not being able to voice it to my room would
be a true tragedy!

Gary

[Gary Eickmeier]

"Scott Dorsey" wrote in message
...
Gary Eickmeier wrote:

On equalizers, I wonder why they aren't all digital yet, with infinitely
fine number of sliders that are set automatically by the RTA. I know that
some receivers have these "room correction" modes, right? I would love to
see one that measures the output of your system, then allows you to draw
the
curve that you want, and have it do it perfectly with no lumpies. Ah well,
we'll see now it goes.

These days, a lot of them _are_ digital. But in the studio world, people
use parametrics instead of graphics so they don't have any of those
problems
to begin with.
--scott

Is that because a parametric has a broader Q than a 31 band graphic?

Gary

[John Williamson]

On 09/05/2014 03:52, Gary Eickmeier wrote:
"Scott Dorsey" wrote in message
These days, a lot of them _are_ digital. But in the studio world, people
use parametrics instead of graphics so they don't have any of those
problems
to begin with.
--scott

Is that because a parametric has a broader Q than a 31 band graphic?

A parametric can be set up to have almost any Q that you wish at any
centre frequency that you wish. You could, if that's what's wanted, set
it to almost completely take out a band a tenth of an octave wide,
leaving the rest of the spectrum undisturbed. Or pass only that tenth of
an octave band while almost removing the rest of the spectrum. Or you
can set it to give a 0.5 dB or less lift or cut spread over a five
octave bandwidth.

--
Tciao for Now!

John.

[Adrian Tuddenham[_2_]]

Gary Eickmeier wrote:

"Scott Dorsey" wrote in message
...
Gary Eickmeier wrote:

On equalizers, I wonder why they aren't all digital yet, with infinitely
fine number of sliders that are set automatically by the RTA. I know that
some receivers have these "room correction" modes, right? I would love to
see one that measures the output of your system, then allows you to draw
the
curve that you want, and have it do it perfectly with no lumpies. Ah well,
we'll see now it goes.

These days, a lot of them _are_ digital. But in the studio world, people
use parametrics instead of graphics so they don't have any of those
problems
to begin with.
--scott

Is that because a parametric has a broader Q than a 31 band graphic?

Many of the frequency/phase distortions that need equalising are caused
by resonant systems and their effect on the response can be represented
by three parameters: Q, centre frequency and amplitude. The parametric
equaliser allows all three to be adjusted so as to accurately counteract
the distortion.

The graphic effects unit has fixed frequencies and fixed Q factors,
which means that only the amplitude can be adjusted, therefore it
incapable of being used as an equaliser (unless the distortions happen
to lie exactly at the correct frequencies with the correct Q factors).

A similar relationship exists between proper equaliser networks and
"tone controls".


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Scott Dorsey]

Peter Larsen wrote:

Note that it is often claimed that it malpractice to move sliders on a
graphic eq that are next to each other to opposites, ie. boost one and
attenuate the next. That is misunderstood because just that is how to move
the adjustment center sideways as is "easily seen" in 10 minutes when
equalizing with an analyzer running.

Well, it's almost always a bad thing to do that becauyse invariably if you
see two adjacent bands that are considerably different in level, you're apt
to be seeing narrowband problems that you can't fix with a graphic equalizer
and attempting to fix them that way is apt to cause more harm than good.

If you're trying to equalize something with an analyzer whose filters are
no more narrow than the equalizer you're using, you're going to be doing
more harm than good. The good news is that we now live with inexpensive
FFT systems that can show you what the narrowband response really is, so you
know what you can fix annd what you can't.

Two important points: the treble may not appear to be detached and a
subwoofer, if available, may not be detectable on male vox.

Detached?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Gary Eickmeier wrote:
Whew - I am getting some odd reactions about the whole subject of EQing a
room or a speaker system. Basically, my system has no tone controls on the
receiver. I have no big complaints, but some of my audio buddies are always
wanting me to measure the FR in my system, so I did. Just a Radio Shack SLM,
digital, and a B&K test CD with 30 bands of narrow pink noise, but it works
and reveals some anomolies that I cannot correct with my system as is. I am
using a Velodyne subwoofer and just setting it by ear. So in measuring at
the listening position, I am getting a hump at 63 Hz that is about 5 dB
higher than I would like, then fairly smooth thru the midrange from 100 Hz
to 5k, then another hump at 8k of 5 or 6 dB too high, then falling off
smoothly to 20k with the zero crossing at 12.5 and 8 dB down at 16k.

And that 63 Hz hump moves around, depending on where you do the measurement.

It sounds like you have some serious room problems. Equalization does not
fix room problems, because the frequency response aberration is only the
_symptom_ of a time-domain problem. Fix the room.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Gary Eickmeier wrote:
"Scott Dorsey" wrote in message
Gary Eickmeier wrote:

On equalizers, I wonder why they aren't all digital yet, with infinitely
fine number of sliders that are set automatically by the RTA. I know that
some receivers have these "room correction" modes, right? I would love to
see one that measures the output of your system, then allows you to draw
the
curve that you want, and have it do it perfectly with no lumpies. Ah well,
we'll see now it goes.

These days, a lot of them _are_ digital. But in the studio world, people
use parametrics instead of graphics so they don't have any of those
problems
to begin with.

Is that because a parametric has a broader Q than a 31 band graphic?

It's because a parametric has whatever Q you want it to have, so you can
match whatever it is that you're trying to deal with whether it is a narrowband
problem or a wideband one.

I can notch out PA feedback in a recording without touching the notes a
semitone above or below the feedback tone, with the Q very narrow. I can
make a very minor reduction in the top end with the Q very wide. I just
set the knob for where it needs to go.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Peter Larsen[_3_]]

Scott Dorsey wrote:

Peter Larsen wrote:

Two important points: the treble may not appear to be detached and a
subwoofer, if available, may not be detectable on male vox.

Detached?

Yes, apparently elevated after a dip, something like:

[perception]

xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx
xxxxxx x
xxxxx

--scott

Kind regards

Peter Larsen

[Gary Eickmeier]

"Scott Dorsey" wrote in message
...


It's because a parametric has whatever Q you want it to have, so you can
match whatever it is that you're trying to deal with whether it is a
narrowband
problem or a wideband one.

I can notch out PA feedback in a recording without touching the notes a
semitone above or below the feedback tone, with the Q very narrow. I can
make a very minor reduction in the top end with the Q very wide. I just
set the knob for where it needs to go.
--scott

I suppose I should look up a few of the parametric kind and see just what
they can do, and for how much. It does seem quite ideal to be able to adjust
those factors, if you know just what they are with a really good RTA. But
how many center freqs do most of them have? In my case I have three, maybe
four freqs at which I would like to make a counter-adjustment.

On your room comment, one thing that happened is that when I moved the
Velodyne from two or three ft out from the corner along one side wall to
right into the corner, the bass response jumped up so much that I had to
completely reset the level control. I do believe in corner placement, but I
didn't realize it would make that kind of difference. Anyway, my response is
quite smooth and flat other than those two anomolies, one at 63 and one at
8k. I think the 8k one is the main reason I wanted to do something about my
system, my big band recordings sounding a little to bright, horns not as
"creamy smooth" as in real life but everything else wonderful.

Gary Eickmeier