Equalizers- Are they necessary anymore?

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On Mon, 27 Sep 2004 04:24:29 GMT, Monte McGuire
<monte.mcguire@verizon.net> wrote:

>I guess I'd favor the summed room response, given an ideal room. it
>seems to me that in a control room, only one person gets the on axis
>response, but everyone else gets the result of the power response. It'd
>be nice if both were nice and accurate, but I think it's better overall
>to have flat power in most situations.

Thanks, makes good sense. I had hesitated to trust my intuition
based on more ordinary speakers in more ordinary rooms, where I
have still only drawn some murky conclusions.


>Of course, I'd love to hear some reasons why this might not be the best
>approach!!! I'm coming at this from working with a speaker that has
>little/no crossover anomalies and no significant beaming, so perhaps
>this viewpoint is not applicable in the real world of multi-way cone
>speakers.

Yeah, rub it in. Arf.

For anybody interested, the argument for flat on-axis response in
multi-way speakers is that the direct sound from the speaker arrives
first, and so is given a significance by our hearing. (It's also the
loudest, which can't hurt.)

The penalty in conventional multi-way speakers is non-flat summed
room ("power") response. FWIW, the D'Appolito geometric removes
this penalty.

Chris Hornbeck

 

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Chris Hornbeck wrote:

> For anybody interested, the argument for flat on-axis response in
> multi-way speakers is that the direct sound from the speaker arrives
> first, and so is given a significance by our hearing. (It's also the
> loudest, which can't hurt.)

Both of which are much more prominent at the sweet region of
a well treated room. This would lead me toward the on axis
criterion for that situation and probably the room average
for a more generic listening environment.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

 

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In article <cj7jo003b8@enews3.newsguy.com>,
Bob Cain <arcane@arcanemethods.com> wrote:
>
>
>Scott Dorsey wrote:
>
>> Bob Cain <arcane@arcanemethods.com> wrote:
>>
>>>Scott Dorsey wrote:
>>>
>>>>See, room problems aren't frequency domain problems, they are time domain
>>>>problems. The frequency response issue is only a symptom, it's not the
>>>>real problem.
>>>
>>>Scott, I often see this stated but take issue with it.
>>>Frequency and time _domain_ are exact duals. One is
>>>entirely determined by the other and both imply a
>>>transformation of both magnitude and group delay as a
>>>function of frequency.
>>
>> Right, this is why you get those frequency domain symptoms.
>
>What do you mean by frequency domain symptoms?

I mean frequency response issues, which are easiest to see in the
frequency domain.

>>>The problem is twofold. First, problems can't be fixed by a
>>>box that only adjusts magnitude response (like a graphic
>>>equalizer) without also fixing the group delay response.
>>
>> This is a minimal issue.
>
>On the contrary, it is essential.

Yes, but if the room is minimum phase, and the equalizer is also, then
if the equalizer actually does fix the frequency response, it will also
fix the group delay. The fact that the room resonances don't have the same
Q as the filters on the graphics equalizer just makes the graphic EQ the
wrong tool for the job. But the graphic EQ does have phase shift to it, and
if the filter on the graphic just happened to match an actual room resonance
(or if a parametric was used), the group delay would be a non-issue since
the filter group delay would cancel out the room group delay error.

>> What I mean, is that the room problems are the result of time delay
>> and summing of delayed reflections. The frequency response issues are
>> only the result of cancellation from the time delay issues.
>
>Yes, the frequency response issues are caused by the time
>delay and summing of delayed reflections, among other things
>like frequency dependant absorption. You seem to be trying
>to distinguish among, room problems, time delay and summing
>and frequency response. They are all the same thing at the
>point where your ear is located.

No, I am saying that because the frequency response issues are caused
by the time delay and summing of delayed reflections, that fixing the
frequency response issues is not solving the problem. Only by dealing
with the original reflections is the problem actually solved.

>When you say "frequency response" do you really mean
>frequency magnitude response? If so then we aren't on the
>same page and that could account for our cross
>communication. When I say "frequency response" I mean
>everything that varies as a function of frequency.

I mean frequency magnitude response. You can include phase response in along
with it, if you can make the good assumption that it's a minimum-phase system.

>I think we would agree that you can't fix a room generally
>by anything that even treats both components of the
>frequency response, other than at a point, much less a thing
>that only treats one of the components.

Right.
--scott

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

 

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Scott Dorsey wrote:


>>>>The problem is twofold. First, problems can't be fixed by a
>>>>box that only adjusts magnitude response (like a graphic
>>>>equalizer) without also fixing the group delay response.
>>>
>>>
>>>This is a minimal issue.
>>
>>On the contrary, it is essential.
>
>
> Yes, but if the room is minimum phase, and the equalizer is also, then
> if the equalizer actually does fix the frequency response, it will also
> fix the group delay.

Rooms are anything but minimum phase. A better example of
mixed phase could hardly be found. The reflections and
interference effects yield highly reactive fields with
considerable variance from point to point. I don't think,
either, that a multi-band equalizeer is minimum phase (less
sure about that.)


>>When you say "frequency response" do you really mean
>>frequency magnitude response? If so then we aren't on the
>>same page and that could account for our cross
>>communication. When I say "frequency response" I mean
>>everything that varies as a function of frequency.
>
>
> I mean frequency magnitude response. You can include phase response in along
> with it, if you can make the good assumption that it's a minimum-phase system.

On the contrary, if you can assume it's minimum phase then
there is no need. There is only one minimum phase response
for any given magnitude response and it is easy to calculate.

It's when the response is mixed phase that a full
characterization requires both the phase and magnitude
components.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

 

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> See, room problems aren't frequency domain problems, they are time domain
> problems. The frequency response issue is only a symptom, it's not the
> real problem.

Yes!




Skler

 

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I'd like to put my 2cents worth in on this topic...
I'm no expert (and believe me, I know just enough to be
dangerous) - BUT, my ears work fairly well.
Going by old school technology, vinyl records, reel-to-reel and
cassette tapes and FM radio, I can hear 'big' differences
between one song's production and another.
Chicago, for example, horns, piano, guitar, etc... The bass
guitar is weak, hardly anything below about 500 on some songs...
Gino Vannelli or Deep Purple may have a lot of bass and need to
be toned down... A Jeff Beck song just doesn't 'sound' right,
but the rest of the album sounds great or maybe 'you' want to
hear what the drummer is doing...

To me, those are reasons to 'use' an equalizer.

The final mix, production, recording, may have been 'off' a bit
that day, for what-ever reason... With these old forms of media,
non-digital, un-re-mastered, music, they sometimes need to be
'tailored' just a little to get that 'fat' sound or to bring out
the high-hat and cymbals... Just a little 'tweak' to make it
sound the way you want it to with your speakers and your room.
A decent 1/3 octave - 31 band eq does wonders for a piece of
music... (even a cheap 10 band can make a big difference) Unless
of course, you'd prefer to just use the bass and treble knobs on
your receiver.
OR
If you put one speaker on a carpeted floor, flat against the
wall, and the other in the corner. One speaker is going to be
'boomy' and the other a little hollow, right? Another reason to
use an eq.

And then there is the consideration of the 'type' of speakers
you are using. (not to be confused with brandname) Are they
2-way? 3-way? 4-way? Are they efficent? Work well with 100 watts
and still good at 10 watts?

And then you can still argue about using a DBX expander /
compressor... A whole other ball of wax...


Right, wrong or otherwise, that's my opinion.


ds

--

"Bob Cain" <arcane@arcanemethods.com> wrote in message
news:cj8e6g0kvv@enews4.newsguy.com...
>
>
> Chris Hornbeck wrote:
>
> > For anybody interested, the argument for flat on-axis
> > response in multi-way speakers is that the direct sound
> > from the speaker arrives first, and so is given a
> > significance by our hearing. (It's also the loudest,
> > which can't hurt.)
>
> Both of which are much more prominent at the sweet region of >
a well treated room. This would lead me toward the on axis
> criterion for that situation and probably the room average
> for a more generic listening environment.
>
>
> Bob
> --
>
> "Things should be described as simply as possible, but no
> simpler."
>
> A. Einstein

 

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"Scott Dorsey" <kludge@panix.com> wrote in message
news:cjjsn0$e6n$1@panix2.panix.com...
> But these are deliberate decisions made by the artists and/or the record
> companies. They wanted them to sound this way. Now, if you don't like
> that and you want to override that with EQ, that's okay, but you should be
> aware that you're not hearing what the folks in the mastering room were.

You never will unless you have an identical room and identical speakers
anyway.

TonyP.

 

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TonyP <TonyP@optus.net.com.au> wrote:
>"Scott Dorsey" <kludge@panix.com> wrote in message
>news:cjjsn0$e6n$1@panix2.panix.com...
>> But these are deliberate decisions made by the artists and/or the record
>> companies. They wanted them to sound this way. Now, if you don't like
>> that and you want to override that with EQ, that's okay, but you should be
>> aware that you're not hearing what the folks in the mastering room were.
>
>You never will unless you have an identical room and identical speakers
>anyway.

True, but you can get close. And I do agree that we need a standard for LF
monitoring systems so that it's easier to get close.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."