In article ,
Pooh Bear wrote:


As a long time audio professional, I can assure you that it's unlikely that
any of Adcom, Rotel, and Parasound amplifiers would be used in a true
professional
situation. Alesis make toy amplifiers btw, suitable ( questionably ) perhaps
for home hobby studios not professional ones.

Graham

In the case of Parasound, the late Denny Purcell of Georgetown Masters
in Nashville had one in his surround room, and I know of several in use
at Universal in Los Angeles as well. The Halo series has balanced I/O
and John Curl is an experienced designer. Though not exceedingly common
in pro sound, I'd say they fit the bill. Other "hi-fi" amps like Pass
Labs and Classe certainly also find their way into high-level
professional use, though these aren't exactly budget solutions.

--
Jay Frigoletto
Mastersuite
www.promastering.com

Jay-atldigi wrote:

In article ,
Pooh Bear wrote:


As a long time audio professional, I can assure you that it's unlikely that
any of Adcom, Rotel, and Parasound amplifiers would be used in a true
professional
situation. Alesis make toy amplifiers btw, suitable ( questionably ) perhaps
for home hobby studios not professional ones.

Graham

In the case of Parasound, the late Denny Purcell of Georgetown Masters
in Nashville had one in his surround room, and I know of several in use
at Universal in Los Angeles as well. The Halo series has balanced I/O
and John Curl is an experienced designer. Though not exceedingly common
in pro sound, I'd say they fit the bill. Other "hi-fi" amps like Pass
Labs and Classe certainly also find their way into high-level
professional use, though these aren't exactly budget solutions.

As you say, these aren't common at all. You'll note that I never said serious high
end audio was inferior to pro-audio. They certainly aren't typical of what's more
routinely used though.

Graham

On Sun, 28 May 2006 16:31:16 -0700, David Nebenzahl
wrote:

Please clarify; do you mean *all* amplifiers, or only (presumably)
lower-quality home hi-fi ones? Mikey is saying that "they" (meaning guys
like you, I guess) design home hi-fi equipment using resistive loads,
while "pro" equipment (studio amps) get the royal treatment with
reactive loads. What say you to this?

I think the point was that published power ratings referred to
resistive loads, not that either weren't designed to cope with
reactive loads. It wasn't much of a point.

On Mon, 29 May 2006 02:57:58 +0100, Pooh Bear
wrote:

It
would in fact be somewhat smarter to spec amplifers in terms of *voltage* output

Into what load? :-)

On Sun, 28 May 2006 19:10:28 -0700, David Nebenzahl
wrote:


You mean to tell us that there's no way to design a dummy load that
1) has the same effective reactance as a real load (like a speaker) and
2) can dissipate the amp's power?

I find this hard to believe. I couldn't do it, but I'm sure some smart
guy somewhere has figured this out.

Well, you could use a speaker, I suppose :-) I expect amps ARE tested
into such loads. What's your point?

Laurence Payne wrote:

On Mon, 29 May 2006 02:57:58 +0100, Pooh Bear
wrote:

It
would in fact be somewhat smarter to spec amplifers in terms of *voltage* output

Into what load? :-)

The same loads as currently.

Graham

On Mon, 29 May 2006 10:38:22 +0100, Pooh Bear
wrote:

would in fact be somewhat smarter to spec amplifers in terms of *voltage* output

Into what load? :-)

The same loads as currently.

So how different to wattage?

Laurence Payne wrote:

On Mon, 29 May 2006 10:38:22 +0100, Pooh Bear
wrote:

would in fact be somewhat smarter to spec amplifers in terms of *voltage* output

Into what load? :-)

The same loads as currently.

So how different to wattage?

No difference but you'd specify volts not watts. Same for speakers too.

Graham

Pooh Bear wrote:
"Dr. Dolittle" wrote:


Pooh Bear wrote:


Tascam is *semi-pro*. It's also ****e.

You mean like this one?

http://fr.audiofanzine.com/img/produ.../1/5/15911.jpg


Never seen one in the real world. Proper pros don't use Tascam. Tascam is the
'poor relation' in the pro world.

Well then, since YOU have never seen one, the only proper conclusion is
that it is a piece of ****. As I said...




I've seen plenty of Ampex, Studer, Otari and Sony though.

Well la de ****ing da.

How about the Stevens? The Scully? The MCI?

They have their issues to be sure. But since YOU have never seen one,
I'm sure no proper pro would ever use one.


You're an idiot.


You don't have a clue about real pro audio. You also don't work in pro-audio. I
do.


How the hell do YOU know what I do?

Pooh Bear wrote:

Who do you think would be likely to specify one ?

Specify one?

Hint. If it's not rack mountable
it's already less likely to be selected.

Were not talking about likelyhood. Your claim is that no pro studio
would use one.


If it doesn't have reliable XLR inputs even
less so. Do you seriously think any slf respecting pro would rely on an unbalanced RCA
phono connector for his critical monitoring signal ?


Uhh, yeah. I suppose now you are going to tell me that and XLR makes an
amp sound better?

Dr. Dolittle wrote:



Pooh Bear wrote:

Who do you think would be likely to specify one ?


Specify one?

Hint. If it's not rack mountable
it's already less likely to be selected.


Were not talking about likelyhood. Your claim is that no pro studio
would use one.


If it doesn't have reliable XLR inputs even
less so. Do you seriously think any slf respecting pro would rely on
an unbalanced RCA
phono connector for his critical monitoring signal ?



Uhh, yeah. I suppose now you are going to tell me that and XLR makes an
amp sound better?


An XLR isn't gonna vibrate out of socket and dump a bunch of
*GROOOOOONK* hum on the customers.

And given that XLR connections are, more or less, gas-tight,
RCA's are much more likely to oxidize badly. That has every
potential to change the sound.

RCA connectors are a consumer adaptation, no doubt to cut cost.
They're not Bad, but they cannot be trusted.

--
Les Cargill

Les Cargill wrote:


An XLR isn't gonna vibrate out of socket and dump a bunch of
*GROOOOOONK* hum on the customers.

And given that XLR connections are, more or less, gas-tight,
RCA's are much more likely to oxidize badly. That has every
potential to change the sound.

RCA connectors are a consumer adaptation, no doubt to cut cost.
They're not Bad, but they cannot be trusted.



Sure an XLR is *better*, but that isn't the point. And I have been using
amps and receivers connected with RCA's for over 40 years and have NEVER
had one "vibrate" out (your amp is vibrating?) or oxidize. NEVER!

Dr. Dolittle spake thus:

Les Cargill wrote:

An XLR isn't gonna vibrate out of socket and dump a bunch of
*GROOOOOONK* hum on the customers.

And given that XLR connections are, more or less, gas-tight,
RCA's are much more likely to oxidize badly. That has every
potential to change the sound.

RCA connectors are a consumer adaptation, no doubt to cut cost.
They're not Bad, but they cannot be trusted.

Sure an XLR is *better*, but that isn't the point. And I have been using
amps and receivers connected with RCA's for over 40 years and have NEVER
had one "vibrate" out (your amp is vibrating?) or oxidize. NEVER!

Same here. Never had *any* problems with phono connectors. I suspect
this is a case of "Ohhhh, RCA plugs, ick!" audiophool-itis. Sure,
they're cheap and ugly, but the suckers work.

And I agree about the oxidation. Unless the equipment is inside a
sailing ship, or in a corrosive industrial environment, corrosion isn't
going to be a problem.


--
I hope that in a few years it [Wikipedia] will be so bloated that it
will simply disintegrate, because I can't stand the thought that this
thing might someday actually be used as a serious reference source.
Because in its current form, it's not to be taken seriously at all.

- Horst Prillinger (see
http://homepage.univie.ac.at/horst.p...06/000623.html)

"Dr. Dolittle" wrote:

If it doesn't have reliable XLR inputs even
less so. Do you seriously think any slf respecting pro would rely on an unbalanced RCA
phono connector for his critical monitoring signal ?

Uhh, yeah. I suppose now you are going to tell me that and XLR makes an
amp sound better?

If you don't understand how balanced can help, never mind a decent connector, you shouldn't
be posting in a pro newsgroup.

Graham

David Nebenzahl wrote

And I agree about the oxidation. Unless the equipment is inside a
sailing ship, or in a corrosive industrial environment, corrosion isn't
going to be a problem.

You should see what a studio control room atmosphere can do to stuff !

Graham

Pooh Bear spake thus:

David Nebenzahl wrote

And I agree about the oxidation. Unless the equipment is inside a
sailing ship, or in a corrosive industrial environment, corrosion isn't
going to be a problem.

You should see what a studio control room atmosphere can do to stuff !

So I take it you guys over there on the other side of the pond still
smoke in your control rooms?


--
I hope that in a few years it [Wikipedia] will be so bloated that it
will simply disintegrate, because I can't stand the thought that this
thing might someday actually be used as a serious reference source.
Because in its current form, it's not to be taken seriously at all.

- Horst Prillinger (see
http://homepage.univie.ac.at/horst.p...06/000623.html)

Pooh Bear spake thus:

"Dr. Dolittle" wrote:

If it doesn't have reliable XLR inputs even
less so. Do you seriously think any slf respecting pro would rely on an unbalanced RCA
phono connector for his critical monitoring signal ?

Uhh, yeah. I suppose now you are going to tell me that and XLR makes an
amp sound better?

If you don't understand how balanced can help, never mind a decent connector, you shouldn't
be posting in a pro newsgroup.

Really, how much difference could this make? We're talking about a
line-level signal, after all, which is pretty robust, and (presumably) a
short cable run.

Yeah, yeah, I know all about common-mode rejection and all that. My
guess is it wouldn't make any discernable difference in this situation.
(In other words, no noise or hum pickup.)

Low-level inputs, like microphones, yes: balanced is essential there.


--
I hope that in a few years it [Wikipedia] will be so bloated that it
will simply disintegrate, because I can't stand the thought that this
thing might someday actually be used as a serious reference source.
Because in its current form, it's not to be taken seriously at all.

- Horst Prillinger (see
http://homepage.univie.ac.at/horst.p...06/000623.html)

David Nebenzahl wrote:

Pooh Bear spake thus:

David Nebenzahl wrote

And I agree about the oxidation. Unless the equipment is inside a
sailing ship, or in a corrosive industrial environment, corrosion isn't
going to be a problem.

You should see what a studio control room atmosphere can do to stuff !

So I take it you guys over there on the other side of the pond still
smoke in your control rooms?

I certainly don't but yes you've got the picture.

Graham

David Nebenzahl wrote:

Pooh Bear spake thus:

"Dr. Dolittle" wrote:

If it doesn't have reliable XLR inputs even
less so. Do you seriously think any slf respecting pro would rely on an unbalanced RCA
phono connector for his critical monitoring signal ?

Uhh, yeah. I suppose now you are going to tell me that and XLR makes an
amp sound better?

If you don't understand how balanced can help, never mind a decent connector, you shouldn't
be posting in a pro newsgroup.

Really, how much difference could this make? We're talking about a
line-level signal, after all, which is pretty robust, and (presumably) a
short cable run.

Yeah, yeah, I know all about common-mode rejection and all that. My
guess is it wouldn't make any discernable difference in this situation.
(In other words, no noise or hum pickup.)

Low-level inputs, like microphones, yes: balanced is essential there.

Stop to think for a sec and consider if it's essential for mics why isn't it essential for your
monitor amp ?

Graham

Pooh Bear spake thus:

David Nebenzahl wrote:

Pooh Bear spake thus:

"Dr. Dolittle" wrote:

If it doesn't have reliable XLR inputs even
less so. Do you seriously think any slf respecting pro would rely on an unbalanced RCA
phono connector for his critical monitoring signal ?

Uhh, yeah. I suppose now you are going to tell me that and XLR makes an
amp sound better?

If you don't understand how balanced can help, never mind a decent connector, you shouldn't
be posting in a pro newsgroup.

Really, how much difference could this make? We're talking about a
line-level signal, after all, which is pretty robust, and (presumably) a
short cable run.

Yeah, yeah, I know all about common-mode rejection and all that. My
guess is it wouldn't make any discernable difference in this situation.
(In other words, no noise or hum pickup.)

Low-level inputs, like microphones, yes: balanced is essential there.

Stop to think for a sec and consider if it's essential for mics why isn't it essential for your
monitor amp ?

Because the monitor amp uses a signal at least two orders of magnitude
higher in voltage, therefore much less susceptible to hum and noise.


--
I hope that in a few years it [Wikipedia] will be so bloated that it
will simply disintegrate, because I can't stand the thought that this
thing might someday actually be used as a serious reference source.
Because in its current form, it's not to be taken seriously at all.

- Horst Prillinger (see
http://homepage.univie.ac.at/horst.p...06/000623.html)

David Nebenzahl wrote:

Pooh Bear spake thus:

David Nebenzahl wrote:

Pooh Bear spake thus:

"Dr. Dolittle" wrote:

If it doesn't have reliable XLR inputs even
less so. Do you seriously think any slf respecting pro would rely on an unbalanced RCA
phono connector for his critical monitoring signal ?

Uhh, yeah. I suppose now you are going to tell me that and XLR makes an
amp sound better?

If you don't understand how balanced can help, never mind a decent connector, you shouldn't
be posting in a pro newsgroup.

Really, how much difference could this make? We're talking about a
line-level signal, after all, which is pretty robust, and (presumably) a
short cable run.

Yeah, yeah, I know all about common-mode rejection and all that. My
guess is it wouldn't make any discernable difference in this situation.
(In other words, no noise or hum pickup.)

Low-level inputs, like microphones, yes: balanced is essential there.

Stop to think for a sec and consider if it's essential for mics why isn't it essential for your
monitor amp ?

Because the monitor amp uses a signal at least two orders of magnitude
higher in voltage, therefore much less susceptible to hum and noise.

As you say, it's *less* susceptible but not immune.

Graham

Pooh Bear wrote:

If you don't understand how balanced can help, never mind a decent connector, you shouldn't
be posting in a pro newsgroup.

For short distances there is often NO advantage to a balanced
connection. And in fact balancing involves a more involved signal path,
FURTHER from a straight wire circuit. Yeah, aren't you the "pro" expert.
(..)

Dr. Dolittle wrote:



Les Cargill wrote:


An XLR isn't gonna vibrate out of socket and dump a bunch of
*GROOOOOONK* hum on the customers.

And given that XLR connections are, more or less, gas-tight,
RCA's are much more likely to oxidize badly. That has every
potential to change the sound.

RCA connectors are a consumer adaptation, no doubt to cut cost.
They're not Bad, but they cannot be trusted.



Sure an XLR is *better*,

Really, RCA connectors are awful. Just awful.

but that isn't the point. And I have been using
amps and receivers connected with RCA's for over 40 years and have NEVER
had one "vibrate" out (your amp is vibrating?)

Sure. Everything in the room is vibrating, unless you just
buy the stuff and admire it visually. You mean to tell me
you've never had problems with equipment vibrating? Much
less moving stuff around. Seems like I can never just set a
computer up and leave it. And my primary recorder is a portable
harddisk unit.


or oxidize. NEVER!


I've had multiple problems with RCA connectors, and I'm not
even doing heavy duty stuff. I even bought some RCA patch cables
that didn't fit/weren't standard size - you hadda crimp them to
get good contact. There for a while, all the RCA molded cable
assemblies I bought went bad in a short amount of time.

I really did have a set that oxidized, and changed the sound.
I think they were actually zinc plated. But to be sure, that's
taking a bad connector way too far. And yes, you'll have
oxidation on any metal you don't touch for a couple years,
even in an air conditioned space. Although DeOxit sure seems
to have made that better.

These days, I mostly use XLR and 1/4". 1/4" is bad enough,
although I managed to buy about a dozen good little 6' 1/4"
unbalanced patch cables before MARS went under. Great little
cables.

--
Les Cargill

On Mon, 29 May 2006 18:14:19 GMT, Les Cargill
wrote:


An XLR isn't gonna vibrate out of socket and dump a bunch of
*GROOOOOONK* hum on the customers.

Have you experienced this much with phonos?


And given that XLR connections are, more or less, gas-tight,
RCA's are much more likely to oxidize badly. That has every
potential to change the sound.

Yes, remaking the connection every few yeas is good practice. But
it's not a big practical issue.


RCA connectors are a consumer adaptation, no doubt to cut cost.
They're not Bad, but they cannot be trusted.

I've probably had to mend more XLR cables than RCA cables. But RCA
connections tend to be round the back of static equipment. XLRs are
often mic cables that get yanked and trodden on.

On Mon, 29 May 2006 22:37:30 +0100, Pooh Bear
wrote:

You should see what a studio control room atmosphere can do to stuff !

Why? No-one smokes over the board these days, do they?

On Tue, 30 May 2006 00:15:04 +0100, Pooh Bear
wrote:

Low-level inputs, like microphones, yes: balanced is essential there.

Stop to think for a sec and consider if it's essential for mics why isn't it essential for your
monitor amp ?

Do your monitors need a mic-level feed?

Laurence Payne wrote:

On Mon, 29 May 2006 22:37:30 +0100, Pooh Bear
wrote:

You should see what a studio control room atmosphere can do to stuff !

Why? No-one smokes over the board these days, do they?

You reckon ?

Graham

Laurence Payne wrote:

On Tue, 30 May 2006 00:15:04 +0100, Pooh Bear
wrote:

Low-level inputs, like microphones, yes: balanced is essential there.

Stop to think for a sec and consider if it's essential for mics why isn't it essential for your
monitor amp ?

Do your monitors need a mic-level feed?

You're incorrectly assuming that a higher level means there's absolutely no problem at all. A touch
unwise for the *monitor* path. In even quite a modest studio a monitor amp may be on a different ac
circuit from the console too which makes unbalanced very unwise.

Graham

On Tue, 30 May 2006 15:32:13 +0100, Pooh Bear
wrote:

Do your monitors need a mic-level feed?

You're incorrectly assuming that a higher level means there's absolutely no problem at all.

No, you are :-)

Noise pick-up will always be measurable. But it may well be at a
level that makes it no problem.

David Nebenzahl wrote:

You mean to tell us that there's no way to design a dummy load that
1) has the same effective reactance as a real load (like a speaker) and
2) can dissipate the amp's power?

No, he's saying that the reactive part doesn't dissipate the power. Real
speakers are a combination of resistances and reactances.

And, in fact, REAL speakers often have additional nonlinearities which
prevent them from being possible to accurately model as lumped-sum devices.
But not all of them do.

I find this hard to believe. I couldn't do it, but I'm sure some smart
guy somewhere has figured this out.

There are thousands of different lumped-sum speaker models out there.
It's because there are thousands of different speaker designs, each
which present different loads.

As for me, I'm still using the Magnapans, which are just frighteningly
close to a 6 ohm resistive load.
--scott

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

Scott Dorsey spake thus:

David Nebenzahl wrote:

You mean to tell us that there's no way to design a dummy load that
1) has the same effective reactance as a real load (like a speaker) and
2) can dissipate the amp's power?

No, he's saying that the reactive part doesn't dissipate the power. Real
speakers are a combination of resistances and reactances.

Fine; then design a load that is a combination of resistances and
reactances. Is that so hard to do?

And, in fact, REAL speakers often have additional nonlinearities which
prevent them from being possible to accurately model as lumped-sum devices.
But not all of them do.

Of course. But couldn't you take an average of real speakers' values,
and use this for the dummy load? It wouldn't *exactly* match any
particular speaker design, but it should be a hell of a lot better than
using a purely resistive load, no?


--
I hope that in a few years it [Wikipedia] will be so bloated that it
will simply disintegrate, because I can't stand the thought that this
thing might someday actually be used as a serious reference source.
Because in its current form, it's not to be taken seriously at all.

- Horst Prillinger (see
http://homepage.univie.ac.at/horst.p...06/000623.html)

Laurence Payne spake thus:

On Tue, 30 May 2006 15:32:13 +0100, Pooh Bear
wrote:

Do your monitors need a mic-level feed?

You're incorrectly assuming that a higher level means there's absolutely no problem at all.

No, you are :-)

Noise pick-up will always be measurable. But it may well be at a
level that makes it no problem.

Yes. I'm thinking specifically of monitor *speakers* (not headhpones) in
a studio. The monitors are some distance from the engineer's head;
they're not slap up against his or her ears.

So let's say there is some measurable hum and noise. Even if there is,
my guess is that if the monitors are set to anything but an earsplitting
volume, at that distance, any measurable hum and noise are going to be
inaudible to the engineer anyhow, and won't interfere with this vaunted
"accuracy" in the sound we've been hearing so much about in this thread.


--
I hope that in a few years it [Wikipedia] will be so bloated that it
will simply disintegrate, because I can't stand the thought that this
thing might someday actually be used as a serious reference source.
Because in its current form, it's not to be taken seriously at all.

- Horst Prillinger (see
http://homepage.univie.ac.at/horst.p...06/000623.html)

David Nebenzahl wrote:
Scott Dorsey spake thus:

David Nebenzahl wrote:

You mean to tell us that there's no way to design a dummy load that
1) has the same effective reactance as a real load (like a speaker) and
2) can dissipate the amp's power?

No, he's saying that the reactive part doesn't dissipate the power. Real
speakers are a combination of resistances and reactances.

Fine; then design a load that is a combination of resistances and
reactances. Is that so hard to do?

It's easy to do. But which speaker does it represent? There are a couple
ISO standards that are out there for testing purposes, but neither one of
them represent any particular speaker.

Look at the impedance curves of an Apogee Scintilla, a Bose 901, and a
Quad ESL57. They all look totally different from one another. They all
present totally different loads to the amp and move the poles and zeros
around to different places. Which one do you use?

And, in fact, REAL speakers often have additional nonlinearities which
prevent them from being possible to accurately model as lumped-sum devices.
But not all of them do.

Of course. But couldn't you take an average of real speakers' values,
and use this for the dummy load? It wouldn't *exactly* match any
particular speaker design, but it should be a hell of a lot better than
using a purely resistive load, no?

Real speakers are all over the place.
That's the problem.
A purely resistive load tells you something useful. It doesn't tell you
everything, but it tells you something useful. A reactive load that doesn't
represent the one you're using very well tells you nothing.
--scott

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

Pooh Bear wrote:

Laurence Payne wrote:


On Tue, 30 May 2006 00:15:04 +0100, Pooh Bear
wrote:


Low-level inputs, like microphones, yes: balanced is essential there.

Stop to think for a sec and consider if it's essential for mics why isn't it essential for your
monitor amp ?

Do your monitors need a mic-level feed?


You're incorrectly assuming that a higher level means there's absolutely no problem at all. A touch
unwise for the *monitor* path. In even quite a modest studio a monitor amp may be on a different ac
circuit from the console too which makes unbalanced very unwise.

Graham




For crying out loud Graham, why don't you just be a man and admit you
are wrong?

Laurence Payne wrote:

On Mon, 29 May 2006 18:14:19 GMT, Les Cargill
wrote:


An XLR isn't gonna vibrate out of socket and dump a bunch of
*GROOOOOONK* hum on the customers.


Have you experienced this much with phonos?



I had a home stereo that lost a channel because
of it once. Somebody stepped on a cable...
snip

--
Les Cargill

"Scott Dorsey" wrote in message
...
David Nebenzahl wrote:

You mean to tell us that there's no way to design a dummy load that
1) has the same effective reactance as a real load (like a speaker) and
2) can dissipate the amp's power?

No, he's saying that the reactive part doesn't dissipate the power. Real
speakers are a combination of resistances and reactances.

And, in fact, REAL speakers often have additional nonlinearities which
prevent them from being possible to accurately model as lumped-sum
devices.
But not all of them do.

I find this hard to believe. I couldn't do it, but I'm sure some smart
guy somewhere has figured this out.

There are thousands of different lumped-sum speaker models out there.
It's because there are thousands of different speaker designs, each
which present different loads.

As for me, I'm still using the Magnapans, which are just frighteningly
close to a 6 ohm resistive load.

Magnepans can deliver great sonic realism in the right room with the right
source material, but they just aren't very good studio monitor speakers. :-)

"David Nebenzahl" wrote in message
.com...
Scott Dorsey spake thus:

David Nebenzahl wrote:

You mean to tell us that there's no way to design a dummy load that
1) has the same effective reactance as a real load (like a speaker) and
2) can dissipate the amp's power?

No, he's saying that the reactive part doesn't dissipate the power. Real
speakers are a combination of resistances and reactances.

Fine; then design a load that is a combination of resistances and
reactances. Is that so hard to do?

And, in fact, REAL speakers often have additional nonlinearities which
prevent them from being possible to accurately model as lumped-sum
devices.
But not all of them do.

Of course. But couldn't you take an average of real speakers' values, and
use this for the dummy load? It wouldn't *exactly* match any particular
speaker design, but it should be a hell of a lot better than using a
purely resistive load, no?

Go back and study electronics, speaker design, and acoustics, then you'll
realize that your isn't really valid. The answer is, No, it would not be any
better than a purely resistive load. Why? Because:
1. speaker reactance varies so much from speaker to speaker that there is no
"average" value that would give data that would be meaningful from speaker
to speaker.
2. since reactance goes both ways frequency-wise, a resistive load is
somewhere in the middle of the range, amking it something of an average
value for testing speakers..
3. speaker reactance actually changes according to its sonic environment, so
how is one to know the reactance of his speakers in his room?.

David Nebenzahl wrote:

Scott Dorsey spake thus:

David Nebenzahl wrote:

You mean to tell us that there's no way to design a dummy load that
1) has the same effective reactance as a real load (like a speaker) and
2) can dissipate the amp's power?

No, he's saying that the reactive part doesn't dissipate the power. Real
speakers are a combination of resistances and reactances.

Fine; then design a load that is a combination of resistances and
reactances. Is that so hard to do?

The thing is that *a* load like you suggest will only at best be representative of
one or two speaker models !

And, in fact, REAL speakers often have additional nonlinearities which
prevent them from being possible to accurately model as lumped-sum devices.
But not all of them do.

Of course. But couldn't you take an average of real speakers' values,
and use this for the dummy load? It wouldn't *exactly* match any
particular speaker design, but it should be a hell of a lot better than
using a purely resistive load, no?

The variation is truly so huge as to make any compromise load meaningless. It would
be a harsh test compared to some speakers that are near resistive ( and it's
possible to design speakers to be near resistive knowing that they may well sound
better by providing a 'nicer load to the amp ) whilst not modelling the truly awful
ones.

Graham

David Nebenzahl wrote:

Laurence Payne spake thus:

On Tue, 30 May 2006 15:32:13 +0100, Pooh Bear
wrote:

Do your monitors need a mic-level feed?

You're incorrectly assuming that a higher level means there's absolutely no problem at all.

No, you are :-)

Noise pick-up will always be measurable. But it may well be at a
level that makes it no problem.

Yes. I'm thinking specifically of monitor *speakers* (not headhpones) in
a studio. The monitors are some distance from the engineer's head;
they're not slap up against his or her ears.

You can hear a noisy ( 80dB s/n ) signal from 2 metres easily.

The 'mini speakers' wil be closer anyway -typically about ametre.

So let's say there is some measurable hum and noise. Even if there is,
my guess is that if the monitors are set to anything but an earsplitting
volume, at that distance, any measurable hum and noise are going to be
inaudible to the engineer anyhow, and won't interfere with this vaunted
"accuracy" in the sound we've been hearing so much about in this thread.

The *whole point* of a monitor system is to make it as accurate as possible not some TV quality
thing.

Graham

"Dr. Dolittle" wrote:

Pooh Bear wrote:

Laurence Payne wrote:


On Tue, 30 May 2006 00:15:04 +0100, Pooh Bear
wrote:


Low-level inputs, like microphones, yes: balanced is essential there.

Stop to think for a sec and consider if it's essential for mics why isn't it essential for your
monitor amp ?

Do your monitors need a mic-level feed?

You're incorrectly assuming that a higher level means there's absolutely no problem at all. A touch
unwise for the *monitor* path. In even quite a modest studio a monitor amp may be on a different ac
circuit from the console too which makes unbalanced very unwise.

Graham

For crying out loud Graham, why don't you just be a man and admit you
are wrong?

Decent studios don't use monitor amps with unbalanced inputs. In fact they don't take chances anywhere
with the signal chain. Period.

Graham