In , on 07/27/03
at 12:31 PM, "Frank C. Dauenhauer" said:

[ ... ]

The problem is that when we are (apparently) using the system
correctly (i.e., good sound overall for all the instruments and voices
-- the instruments are acoustic and are played into microphones, and
the instruments and voices are adjusted well for high, mid, and low
tones -- any brief increase in dynamics, or volume, from an instrument
(e.g., guitar) or voice, causes a "blackout" of sound from the
speakers. That is, the stream of music from the speakers (Yamaha
S115IV) stops and is replaced by brief silence that is preceded and
followed by a "crack." It's almost like a circuit breaker has
intercepted an overload and has kept it from getting through to the
speakers. I am guessing that this is called "clipping." My impression
(I'm not the person who owns or is allowed to adjust the Yamaha
equipment) is that there is no room (i.e., headroom?) in the system to
allow for momentary pulses of loud sound. For years we previously used
what I would describe as Yamaha's 300-watt version of this board and
we never had this kind of problem.

[ ... ]

Strictly speaking, your problem is related to, but different from
"clipping". Basically, you are pushing the amplifier beyond it's power
limit and it's "protection" circuit is shutting the unit down.

Each design team has its own ideas about "protection". Some protection
circuits operate discretely in the background, others are in your face.
I'm not sure what the best answer is. Some of the discrete protection
circuits lull the user into thinking everything is OK while the
amplifier secretly suffers, then fails early because of the chronic
abuse. Other more aggressive protection schemes, such as this one, let
you know when you step over the limit. While there is value in this
approach (the user will back off and respect the limits), it can be
annoying in professional applications.

The "crack" you describe is a side effect of the protection. In some
designs this "crack" is caused by the amplifier's reaction to the
speakers. Different speakers may not cause the same level of "crack".

Basically, you must turn things down, play in smaller rooms, or find
some more power.

You didn't say how many speakers you are using. If you hook-up too many
speakers, the amplifier has a right to complain.

-----------------------------------------------------------
SPAM:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, SPAMers are ruining my mailbox]
-----------------------------------------------------------

"Barry Mann" wrote in message =
om...
| In , on 07/27/03=20
| at 12:31 PM, "Frank C. Dauenhauer" said:
|=20
| [ ... ]
|=20
| The problem is that when we are (apparently) using the system
| correctly (i.e., good sound overall for all the instruments and =
voices
| -- the instruments are acoustic and are played into microphones, and
| the instruments and voices are adjusted well for high, mid, and low
| tones -- any brief increase in dynamics, or volume, from an =
instrument
| (e.g., guitar) or voice, causes a "blackout" of sound from the
| speakers. That is, the stream of music from the speakers (Yamaha
| S115IV) stops and is replaced by brief silence that is preceded and
| followed by a "crack." It's almost like a circuit breaker has
| intercepted an overload and has kept it from getting through to the
| speakers. I am guessing that this is called "clipping." My impression
| (I'm not the person who owns or is allowed to adjust the Yamaha
| equipment) is that there is no room (i.e., headroom?) in the system =
to
| allow for momentary pulses of loud sound. For years we previously =
used
| what I would describe as Yamaha's 300-watt version of this board and
| we never had this kind of problem.
|=20
| [ ... ]
|=20
| Strictly speaking, your problem is related to, but different from
| "clipping". Basically, you are pushing the amplifier beyond it's power
| limit and it's "protection" circuit is shutting the unit down.
|=20
| Each design team has its own ideas about "protection". Some protection
| circuits operate discretely in the background, others are in your =
face.
| I'm not sure what the best answer is. Some of the discrete protection
| circuits lull the user into thinking everything is OK while the
| amplifier secretly suffers, then fails early because of the chronic
| abuse. Other more aggressive protection schemes, such as this one, let
| you know when you step over the limit. While there is value in this
| approach (the user will back off and respect the limits), it can be
| annoying in professional applications.
|=20
| The "crack" you describe is a side effect of the protection. In some
| designs this "crack" is caused by the amplifier's reaction to the
| speakers. Different speakers may not cause the same level of "crack".
|=20
| Basically, you must turn things down, play in smaller rooms, or find
| some more power.
|=20
| You didn't say how many speakers you are using. If you hook-up too =
many
| speakers, the amplifier has a right to complain.
|=20
| -----------------------------------------------------------
| SPAM:
| wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
| 13 (Barry Mann)
| [sorry about the puzzle, SPAMers are ruining my mailbox]
| -----------------------------------------------------------

Barry,=20

We're using only two Yamaha speakers.

Thank you for your reply and info. I will pass them on to the board =
owner.

Frank

"Gareth Magennis" wrote in message =
. ..
|=20
| "
| Strictly speaking, your problem is related to, but different from
| "clipping". Basically, you are pushing the amplifier beyond it's =
power
| limit and it's "protection" circuit is shutting the unit down.
|
| Each design team has its own ideas about "protection". Some =
protection
| circuits operate discretely in the background, others are in your =
face.
| I'm not sure what the best answer is. Some of the discrete =
protection
| circuits lull the user into thinking everything is OK while the
| amplifier secretly suffers, then fails early because of the chronic
| abuse. Other more aggressive protection schemes, such as this one, =
let
| you know when you step over the limit. While there is value in this
| approach (the user will back off and respect the limits), it can be
| annoying in professional applications.
|
|=20
| I agree with your diagnosis, but am a bit sceptical that Yamaha would
| incorporate such a nasty device ( I don't know this particular unit). =
I
| would get the unit checked out by whoever installed the system, =
especially
| if it is still covered under warranty, as the protection may not be =
working
| properly.
|=20
| gareth.
|=20

Gareth,=20

Both you and Barry make a lot of sense. Since the unit is less than a =
year old, I'll suggest that we have it looked at under warranty. Thank =
you.=20

Frank