Reply
 
Thread Tools Display Modes
  #1   Report Post  
Doug
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.
  #2   Report Post  
CJT
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

Doug wrote:
I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.


PA amps are likely to have features useful for PA applications
(e.g. 70 V outputs), and hifi amps are likely to put more emphasis
on high fidelity, as implied by their names.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .
  #3   Report Post  
Michael R. Kesti
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

Doug wrote:

I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?


There is no reason that you cannot.

I want GOOD sound.


Do yo believe that PA system amplifiers are inherently better sounding
than hi-fi amplifiers?

--
================================================== ======================
Michael Kesti | "And like, one and one don't make
| two, one and one make one."
| - The Who, Bargain
  #4   Report Post  
Richard Crowley
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

"Doug" wrote ...
I am a musician and notice that PA sytems work fine with CD input.


Or with any suitable input, for that matter.

Why can't I just buy a music PA and plug a CD into it for my
home system?


PA amps tend to be optimized for heavy duty higher-power
use. Hi-Fi amps tend to be designed for home use. Some
people have done what you are proposing. Some of the more
common complaints a

PA amps are frequently more noisy physically: mainly the
cooling fans, but sometimes buzzing transformers, etc.

PA amps are frequently more noisy electrically: Optimizing
them for high power sometimes involves trade-offs with low-
level signal to noise ratios. Note that most PA amps are never
heard at the distances and quiet ambience where Hi-Fi amps
are usually found.

PA amps may have lower sensitivity (+4dB professional line
level vs. -10dB consumer line level) This makes them more
difficult to interface to things like consumer preamps, etc.

I want GOOD sound.


And even in the absense of any of those factors, being a "PA"
amplifier does not impart any inherent superiority (of infer-
iority) to any particular "Hi-Fi" amp.


  #5   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

On Mon, 09 Aug 2004 04:32:49 GMT, CJT wrote:

Doug wrote:
I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.


PA amps are likely to have features useful for PA applications
(e.g. 70 V outputs), and hifi amps are likely to put more emphasis
on high fidelity, as implied by their names.


However, a decent PA amplifier is sonically indistiguishable from a
decent 'high fidelity' amplifier, so sound quality isn't really an
issue. The PA amp is however likely to be a lot more powerful, which
is very useful to avoid clipping on things like solo piano.
--

Stewart Pinkerton | Music is Art - Audio is Engineering


  #6   Report Post  
CJT
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

Stewart Pinkerton wrote:

On Mon, 09 Aug 2004 04:32:49 GMT, CJT wrote:


Doug wrote:

I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.


PA amps are likely to have features useful for PA applications
(e.g. 70 V outputs), and hifi amps are likely to put more emphasis
on high fidelity, as implied by their names.



However, a decent PA amplifier is sonically indistiguishable from a
decent 'high fidelity' amplifier, so sound quality isn't really an
issue. The PA amp is however likely to be a lot more powerful, which
is very useful to avoid clipping on things like solo piano.


I don't think PA necessarily implies power. They come in all sizes.

A true PA amp is more likely to be optimized for speech frequencies
rather than a broad audio spectrum.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .
  #8   Report Post  
Mike Gilmour
 
Posts: n/a
Default What is the diff between hifi amps and PA amps


"Doug" wrote in message
m...
I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.



Just tried it out for fun with Marantz CD63 mkII Yamaha P4500 Goodmans
Magnum. Sounds fine, fan noise low enough level not to be intrusive.

Mike



  #9   Report Post  
TonyP
 
Posts: n/a
Default What is the diff between hifi amps and PA amps


"CJT" wrote in message
...
I don't think PA necessarily implies power. They come in all sizes.


Right.

A true PA amp is more likely to be optimized for speech frequencies
rather than a broad audio spectrum.


That would be a pretty narrow definition of PA!
IME the main differences between real PA amps and HiFi amps are :
Mechanical construction is usually more rugged for life on the road.
Fans are more likely to be used for sustained output without a large size
penalty.
Inputs are usually balanced, but of course can be used unbalanced.
Rack mounting designs with less emphasis on looks.

Many amps have been sold in both HiFi shops and Pro-audio shops over the
years.

TonyP.


  #10   Report Post  
Arny Krueger
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

"Stewart Pinkerton" wrote in message

On Mon, 09 Aug 2004 04:32:49 GMT, CJT wrote:

Doug wrote:
I am a musician and notice that PA systems work fine with CD input.
Why can't I just buy a music PA and plug a CD into it for my home
system? I want GOOD sound.


PA amps are likely to have features useful for PA applications
(e.g. 70 V outputs), and hifi amps are likely to put more emphasis
on high fidelity, as implied by their names.


70 volt outputs are remarkably rare in modern SR systems. They still show up
in distributed music and true public address (lage building, multiple room)
applications.

However, a decent PA amplifier is sonically indistinguishable from a
decent 'high fidelity' amplifier, so sound quality isn't really an
issue.


Agreed.

The PA amp is however likely to be a lot more powerful, which
is very useful to avoid clipping on things like solo piano.


I've used so-called PA amps like the QSC USA 400 in my main audio system for
years.

Here's the things to consider:

(1) PA amps, even those with moderate power, are likely to have cooling fans
that can be noisy. I'm thinking specifically of a Fidek and a Mackie amp
that literally scream at you.

(2) PA amps, as is befitting their professional context, will probably have
balanced inputs, and may have only XLR and/or TRS or 1/4" input jacks. There
not be any RCA jack inputs at all. Adaptors or adaptor cables are indicated.
There's a RCA to 1/4 adaptor that Radio Shack and others sell for like $5 a
pair. They work just fine!

(3) If it seems like it is too good to be true, it's probably is too good to
be true. There are some very low-end, low-cost PA amps that don't even
belong in SR systems, let alone good high fidelity systems. Since they
arguably don't come under the FTC regs, some manufacturers play games with
power ratings. Beware of "Pyramid watts" and other scams.

On balance, there are some so-called "PA" amps from manufacturers like Crown
and Hafler, not to mention QSC and Crest that can sound really good in a
home system.




  #11   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

On Mon, 09 Aug 2004 06:09:40 GMT, CJT wrote:

Stewart Pinkerton wrote:

On Mon, 09 Aug 2004 04:32:49 GMT, CJT wrote:


Doug wrote:

I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.

PA amps are likely to have features useful for PA applications
(e.g. 70 V outputs), and hifi amps are likely to put more emphasis
on high fidelity, as implied by their names.



However, a decent PA amplifier is sonically indistiguishable from a
decent 'high fidelity' amplifier, so sound quality isn't really an
issue. The PA amp is however likely to be a lot more powerful, which
is very useful to avoid clipping on things like solo piano.


I don't think PA necessarily implies power. They come in all sizes.


Indeed, but they are *likely* to be more powerful than the average
'hi-fi' amp.

A true PA amp is more likely to be optimized for speech frequencies
rather than a broad audio spectrum.


Not true. They often have *additional* features such as specialised EQ
for horn use and for lifting some bands, but under all that, they are
generally good full-range amps. Take a typical reasonably priced unit
such as the 'bottom of the range' Mackie M800:

Cost about $480

Output 2x150 watts into 8 ohms
2x225 watts into 4 ohms
2x280 watts into 2 ohms
All the above are 40-20,000Hz at less than 0.1% THD.

FR 10Hz to 70kHz -3dB, 20Hz to 40kHz -1dB

THD, SMPTE IMD and TIM all below 0.025% up to 150 watts into 8 ohms

Slew rate 40V/usec

I/P sensitivity 1.23 volts for full output into 4 ohms

S/N ratio 104dB below full output into 4 ohms

Transient recovery 1usec for 20dB overdrive at 1kHz (a very important
spec that you never see for 'hi-fi' amps)


The Mackie also has several EQ devices which are targeted at PA, a
very useful 'soft limiter' circuit, and of course it has front panel
level controls, so it can be used with say a CD or Universal player to
make a 'purist' 2-channel system. Basically, it's an excellent
amplifier by any reasonable standard, and it costs less than any
roughly equivalent 'hi-fi' amplifier, such as the Bryston 3B.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #12   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

On Mon, 09 Aug 2004 10:06:09 +0100, Laurence Payne
wrote:

On 8 Aug 2004 21:21:10 -0700, (Doug)
wrote:

I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.


As far as the power amp goes, you could be right. Note, however,
that a PA amp will be designed for far greater output than a Hi-Fi
amp. It may have a cooling fan which would be audible in a home
situation,

A PA amp will normally be fed from a mixing board. A home system
probably needs a front end with switching for various inputs.

PA SPEAKERS are generally quite unsuitable for home listening.
They're designed to be LOUD, not to be smooth and detailed.


So is a Krell 700.............................

There's absolutely no reason why a powerful PA amp can't sound
perfectly smooth and detailed - and many of them do. The only downside
is that they usually have quite noisy cooling fans. Consider that
they'll often be used with highly sensitive horn speakers, so that if
say a ballad is being sung in an indoor theatre, they may only be
putting out a few dozen *milliwatts* - and they still have to sound
good, and convey all the breathy details you expect of a good live
performance.

But, yes. A smaller, quality PA amp can be a useful substitute for a
Hi-Fi power amp. And won't be subject to the same silly pricing.


Quite so - compare for example Mackie and Krell pricing for similar
power outputs - and then see if you can tell the difference in sound
quality in a level-controled blind test.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #13   Report Post  
CJT
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

Stewart Pinkerton wrote:

On Mon, 09 Aug 2004 06:09:40 GMT, CJT wrote:


Stewart Pinkerton wrote:


On Mon, 09 Aug 2004 04:32:49 GMT, CJT wrote:



Doug wrote:


I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.

PA amps are likely to have features useful for PA applications
(e.g. 70 V outputs), and hifi amps are likely to put more emphasis
on high fidelity, as implied by their names.


However, a decent PA amplifier is sonically indistiguishable from a
decent 'high fidelity' amplifier, so sound quality isn't really an
issue. The PA amp is however likely to be a lot more powerful, which
is very useful to avoid clipping on things like solo piano.


I don't think PA necessarily implies power. They come in all sizes.



Indeed, but they are *likely* to be more powerful than the average
'hi-fi' amp.

A true PA amp is more likely to be optimized for speech frequencies
rather than a broad audio spectrum.



Not true. They often have *additional* features such as specialised EQ
for horn use and for lifting some bands, but under all that, they are
generally good full-range amps. Take a typical reasonably priced unit
such as the 'bottom of the range' Mackie M800:

Cost about $480

Output 2x150 watts into 8 ohms
2x225 watts into 4 ohms
2x280 watts into 2 ohms
All the above are 40-20,000Hz at less than 0.1% THD.

FR 10Hz to 70kHz -3dB, 20Hz to 40kHz -1dB

THD, SMPTE IMD and TIM all below 0.025% up to 150 watts into 8 ohms

Slew rate 40V/usec

I/P sensitivity 1.23 volts for full output into 4 ohms

S/N ratio 104dB below full output into 4 ohms

Transient recovery 1usec for 20dB overdrive at 1kHz (a very important
spec that you never see for 'hi-fi' amps)


The Mackie also has several EQ devices which are targeted at PA, a
very useful 'soft limiter' circuit, and of course it has front panel
level controls, so it can be used with say a CD or Universal player to
make a 'purist' 2-channel system. Basically, it's an excellent
amplifier by any reasonable standard, and it costs less than any
roughly equivalent 'hi-fi' amplifier, such as the Bryston 3B.


I would distinguish sound reinforcement amps from public address amps.

But the lines do blur.


--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .
  #14   Report Post  
Arny Krueger
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

"CJT" wrote in message


I don't think PA necessarily implies power. They come in all sizes.


Of course they do, but if you compare the number of SR amps with more than
1000 wpc to the number of hi fi amps with 1000 wpc, you'll see what was
being talked about.

A true PA amp is more likely to be optimized for speech frequencies
rather than a broad audio spectrum.


Nope.There's just too much rock PA for SR amp manufactuerers to be able to
skimp on bass or treble performance. IOW, PA amps are frequently used to
drive subwoofers and amplify musical instruments, not just voice.


  #15   Report Post  
Laurence Payne
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

On Mon, 9 Aug 2004 15:47:29 +0000 (UTC), Stewart Pinkerton
wrote:


PA SPEAKERS are generally quite unsuitable for home listening.
They're designed to be LOUD, not to be smooth and detailed.


So is a Krell 700.............................


A Krell 700 is a SPEAKER, all of a sudden? :-)


  #16   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

On Mon, 09 Aug 2004 18:32:21 +0100, Laurence Payne
wrote:

On Mon, 9 Aug 2004 15:47:29 +0000 (UTC), Stewart Pinkerton
wrote:


PA SPEAKERS are generally quite unsuitable for home listening.
They're designed to be LOUD, not to be smooth and detailed.


So is a Krell 700.............................


A Krell 700 is a SPEAKER, all of a sudden? :-)


Ah, missed your sudden change in direction, since the thread was about
amplifiers. OTOH, the best PA SPEAKERS have significantly lower
distortion than so-called 'high-end' speakers.......................
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #17   Report Post  
Doug
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

Yes, it seems I can get a muscicians Crown PA amp for a lot less than
hifi amps like Anthem etc. If I buy PA style speakers and put in my
living room will it sound as good as an equivalent wattage Athem? And
as a bonus, if the band needs some more PA, I can take it. Also, I can
plug my acoustic/electric into my home PA, and sing through my mic. So
what will I give up?

Not true. They often have *additional* features such as specialised EQ
for horn use and for lifting some bands, but under all that, they are
generally good full-range amps. Take a typical reasonably priced unit
such as the 'bottom of the range' Mackie M800:

Cost about $480

Output 2x150 watts into 8 ohms
2x225 watts into 4 ohms
2x280 watts into 2 ohms
All the above are 40-20,000Hz at less than 0.1% THD.

FR 10Hz to 70kHz -3dB, 20Hz to 40kHz -1dB

THD, SMPTE IMD and TIM all below 0.025% up to 150 watts into 8 ohms

Slew rate 40V/usec

I/P sensitivity 1.23 volts for full output into 4 ohms

S/N ratio 104dB below full output into 4 ohms

Transient recovery 1usec for 20dB overdrive at 1kHz (a very important
spec that you never see for 'hi-fi' amps)


The Mackie also has several EQ devices which are targeted at PA, a
very useful 'soft limiter' circuit, and of course it has front panel
level controls, so it can be used with say a CD or Universal player to
make a 'purist' 2-channel system. Basically, it's an excellent
amplifier by any reasonable standard, and it costs less than any
roughly equivalent 'hi-fi' amplifier, such as the Bryston 3B.

  #18   Report Post  
Doug
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

Can I use a Crown to drive high quality speakers like Klipsh
(spelling?), or should I get PA speakers? Klisph are $1000 each!! or
so. Gosh I could buy a LOT of PA speakers for that. What are the most
expensive Yamaha PA speakers. What I am wondering if there isn't some
inherent diffference in Crown PA amp and an Anthem home hifi amp. It
seems not, but.....

As for hookups, just get a mixing board with gobs of inputs and plug
the CD player in there.

I dunno.

Must be a downside somewhere.
  #19   Report Post  
Michael R. Kesti
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

Doug wrote:

Can I use a Crown to drive high quality speakers like Klipsh
(spelling?),


Yes, or it may be better to say probably, as it may be possible that there
is some Crown amp that is inappropriate to use with some Klipsch (note
spelling) speakers. Except in cases of extreme over- or under-power, though,
I suspect that the answer is "Yes."

or should I get PA speakers? Klisph are $1000 each!! or
so. Gosh I could buy a LOT of PA speakers for that. What are the most
expensive Yamaha PA speakers. What I am wondering if there isn't some
inherent diffference in Crown PA amp and an Anthem home hifi amp. It
seems not, but.....


Have you not been reading the previous responses in this thread? The
primary differences between amplifers intended for PA and hi-fi use is
their ancillary features. The function of their power output sections
differ little if at all.

As for hookups, just get a mixing board with gobs of inputs and plug
the CD player in there.


That would be one way. Another would be to simply connect a CD player's
output to an amplifier's input if the signal level, I/O impedances, and
format are compatible.

I dunno.

Must be a downside somewhere.


Again, the ancillary features of PA amplifers may make them unsuitable
for hi-fi use. These may include things such as signal I/O issues,
cooling techniques, enclosure format, and more.

--
================================================== ======================
Michael Kesti | "And like, one and one don't make
| two, one and one make one."
| - The Who, Bargain
  #20   Report Post  
Dave Platt
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

In article ,
Doug wrote:

Yes, it seems I can get a muscicians Crown PA amp for a lot less than
hifi amps like Anthem etc. If I buy PA style speakers and put in my
living room will it sound as good as an equivalent wattage Athem?


I think you're making a fundamental error here.

You seem to be thinking "Ah, if a PA amp is essentially equivalent to
a hi-fi amp, then PA speakers are essentially equivalent to hi-fi
speakers."

That's not a good assumption. PA speakers are usually designed for a
rather different set of goals - "sound reinforcement" in a large open
space. I believe they tend to be optimized for efficiency, and
ruggedness... with flat frequency response being somewhat of a
secondary concern.

I think you'd probably find them to be a good deal more "colored"
(non-flat frequency response, other artifacts) than a good set of
hi-fi speakers, when used in a home environment.

Now, what you almost certainly can do, is buy a good set of hi-fi
speakers, and a good sound-reinforcement ("PA") amplifier, and have
very satisfactory results.

If you then want to run some extra sound for a band, you could take
the sound-reinforcement amp, and plug it into a set of PA speakers,
and use this combination on stage.

There is one thing about sound-reinforcement / PA amps which you ought
to be aware of. Many (most?) of them use fans to blow air over their
heatsinks. If you buy a PA amp with a fan that runs all of the time,
you may find that the fan noise is annoying when the amp is used in a
home environment. Some amps have fans which are switchable (either
manually, or via an automatic thermostat). Such amps may run cool
enough, when used at low average power levels, that the fans don't
need to be switched on, and wouldn't suffer from fan noise.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!


  #21   Report Post  
Laurence Payne
 
Posts: n/a
Default What is the diff between hifi amps and PA amps

On 9 Aug 2004 16:08:14 -0700, (Doug)
wrote:

Can I use a Crown to drive high quality speakers like Klipsh
(spelling?), or should I get PA speakers? Klisph are $1000 each!! or
so. Gosh I could buy a LOT of PA speakers for that. What are the most
expensive Yamaha PA speakers. What I am wondering if there isn't some
inherent diffference in Crown PA amp and an Anthem home hifi amp. It
seems not, but.....

As for hookups, just get a mixing board with gobs of inputs and plug
the CD player in there.


Yup. Recorded music you listen to was almost certainly recorded
through something like that. It won't hurt the music to pass through
another one.

Speakers? As always, try before you buy. A lot of PA speakers can
sound rather rough in a living room. You might find it interesting to
look at speakers sold as studio monitors rather than ones sold as
hi-end hi-fi. Even a medium-priced pair of nearfield monitors placed
the right distance from your ears (a few feet) may give you a VERY
pleasant surprise.

My nearfields, for non-musical reasons, had been crammed in under a
shelf, near a wall, with a large crt monitor between them. I knew
this wasn't optimum. But, having got rid of some clutter, moving
them to an unimpeded position, with no wall near and more than half
the room behind them as free space made even more difference than I
expected. It's not only Quad ELS that blossom with such treatment
:-)

  #23   Report Post  
Richard Kuschel
 
Posts: n/a
Default


I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.




There is very little difference between good "PA" power amplifiers and "hifi"
amplifiers.

However most PA amps are designed for a professional level on the input of
+4dBm or higher las opposed to the consumer level of -10dBV which is a
difference of almost 12 dB in sensitivity.

If you are using a mixing board as opposed to a hifi preamp for the front end,
there is no problem at all.

Many hifi amps have been used for PA use and vice-versa. Crown, Phase Linear,
Hafler have all shared these uses.


Richard H. Kuschel
"I canna change the law of physics."-----Scotty
  #24   Report Post  
Doug Schultz
 
Posts: n/a
Default

People have been using hi end Pro Audio amps in home stereos and recording
studio environments for years
Bryston 4B are still sought after.
H&H800's are amazing sounding mosfet amps.
I think the difference is in the build quality.
a good SR amp is built in a strong chassis that is meant to be rack mounted,
home stereo equipment is usually far too flimsy for life on the road.
the other difference is Balanced inputs on SR amps and the unbalanced inputs
on the home stereo amps.

Doug

"Doug" wrote in message
m...
I am a musician and notice that PA sytems work fine with CD input. Why
can't I just buy a music PA and plug a CD into it for my home system?
I want GOOD sound.



Reply
Thread Tools
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
ALL amps are equal?? Pug Fugley Car Audio 60 August 17th 04 03:33 AM
Audio Myths was "System I'm designing - two questions" Les Car Audio 3 May 28th 04 08:19 AM
Audio Myths was "System I'm designing - two questions" Les Car Audio 0 May 27th 04 07:33 AM
amps, amps, amps Justin Burns Car Audio 4 August 10th 03 08:28 AM
Tons of stuff to sell - amps, head unit, processors, etc. Ge0 Car Audio 3 August 5th 03 04:24 AM


All times are GMT +1. The time now is 02:00 PM.

Powered by: vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AudioBanter.com.
The comments are property of their posters.
 

About Us

"It's about Audio and hi-fi"