Does someone have a .wav of such a tone so I can fine tune my amp gain
setting for my subwoofer (via oscilloscope or voltage meter)?

Thanks.

--
Please remove SPAM notice from my e-mail if replying directly.

Does someone have a .wav of such a tone so I can fine tune my amp gain
setting for my subwoofer (via oscilloscope or voltage meter)?

Thanks.

Why on earth would you need a 50Hz tone to set gains, and why are you going
to try to do it with an o-scope??

"MZ" wrote in message
...
Does someone have a .wav of such a tone so I can fine tune my amp gain
setting for my subwoofer (via oscilloscope or voltage meter)?

Thanks.

Why on earth would you need a 50Hz tone to set gains, and why are you
going
to try to do it with an o-scope??

I personally use tones to set my gains as well, 1khz for regular speakers,
around 50hz for the sub (can't remember the exact frequency I used last
time). A 1khz tone makes it easy to hear clipping.

An oscilloscope makes it easy to SEE clipping.

I personally use tones to set my gains as well, 1khz for regular speakers,
around 50hz for the sub (can't remember the exact frequency I used last
time). A 1khz tone makes it easy to hear clipping.

An oscilloscope makes it easy to SEE clipping.

If you set the volume knob on your head unit to no more than about 75% as
the "max volume" (ie the volume position at which a 0dB track would force
the amplifier to clip), you should never ever experience clipping of the
preouts. There's no need for an o-scope. It's not going to provide you
with any more information than you need.

Try this to make your own test tones...

http://www.hitsquad.com/smm/programs/SweepGen/

Kevin Murray

"[80s.fan]" wrote in message
.. .
Does someone have a .wav of such a tone so I can fine tune my amp gain
setting for my subwoofer (via oscilloscope or voltage meter)?

Thanks.

--
Please remove SPAM notice from my e-mail if replying directly.

and if you did SEE CLIPPING on the scope
what exactly would you do about it..??

Scott Badman wrote:

"MZ" wrote in message
...
Does someone have a .wav of such a tone so I can fine tune my amp gain
setting for my subwoofer (via oscilloscope or voltage meter)?

Thanks.

Why on earth would you need a 50Hz tone to set gains, and why are you
going
to try to do it with an o-scope??

I personally use tones to set my gains as well, 1khz for regular speakers,
around 50hz for the sub (can't remember the exact frequency I used last
time). A 1khz tone makes it easy to hear clipping.

An oscilloscope makes it easy to SEE clipping.

Lower the amp gains output?
I am curious to see how it looks theoretically and have the knowledge to use
a scope, meter, etc.

I know the by ear method is good enough for most but I can't always here
distortion on higher end amp/speakers so I want to measure the output.


"Eddie Runner" wrote in message
...
and if you did SEE CLIPPING on the scope
what exactly would you do about it..??

Scott Badman wrote:

"MZ" wrote in message
...
Does someone have a .wav of such a tone so I can fine tune my amp
gain
setting for my subwoofer (via oscilloscope or voltage meter)?

Thanks.

Why on earth would you need a 50Hz tone to set gains, and why are you
going
to try to do it with an o-scope??

I personally use tones to set my gains as well, 1khz for regular
speakers,
around 50hz for the sub (can't remember the exact frequency I used last
time). A 1khz tone makes it easy to hear clipping.

An oscilloscope makes it easy to SEE clipping.

Thanks. This is a good tool.

"MZ" wrote in message
...
I personally use tones to set my gains as well, 1khz for regular
speakers,
around 50hz for the sub (can't remember the exact frequency I used last
time). A 1khz tone makes it easy to hear clipping.

An oscilloscope makes it easy to SEE clipping.

If you set the volume knob on your head unit to no more than about 75% as
the "max volume" (ie the volume position at which a 0dB track would force
the amplifier to clip), you should never ever experience clipping of the
preouts. There's no need for an o-scope. It's not going to provide you
with any more information than you need.

so if you lower the amp gains if there is clipping
do you turn the gains so low that the amp cannot clip
even if the headunit volume is all the way up..??

Eddie

"[80s.fan]" wrote:

Lower the amp gains output?
I am curious to see how it looks theoretically and have the knowledge to use
a scope, meter, etc.

I know the by ear method is good enough for most but I can't always here
distortion on higher end amp/speakers so I want to measure the output.

"Eddie Runner" wrote in message
...
and if you did SEE CLIPPING on the scope
what exactly would you do about it..??

"MZ" wrote in message
...
I personally use tones to set my gains as well, 1khz for regular
speakers,
around 50hz for the sub (can't remember the exact frequency I used last
time). A 1khz tone makes it easy to hear clipping.

An oscilloscope makes it easy to SEE clipping.

If you set the volume knob on your head unit to no more than about 75% as
the "max volume" (ie the volume position at which a 0dB track would force
the amplifier to clip), you should never ever experience clipping of the
preouts. There's no need for an o-scope. It's not going to provide you
with any more information than you need.


You are generalising. Some cheap HU's will clip at 50% with a 0dB signal,
more expensive HU's with a good power supply won't clip even at 100%.

As well as this, if you overload the amplifiers input, you will get
clipping, hence adjusting the gain, which FYI is not a volume control as
most people assume, rather, more accurately, a sensitivity control, to limit
the signal going into the amplifier.

IMO using a scope is a great idea. You would keep the amp gain low, and
increase the HU volume until the wave start getting flattened, then nudge
the HU back down. The bring the amp up, until the same thing happens, and
nudge back down. This will give you a rather wide dynamic range.

I prefer to use the listening method because a) I don't have an oscilloscope
and b) it takes into account the impedance of the drivers.

Eddie,

Tell you what, since I do know that you have 'fantastic' knowledge of car
audio (and you have provided feedback for some previous question I had),
would you have a few minutes to give your opinion on what I should do to
fine tune my system described he

Thank you for your time if you can.

1) Kenwood KDC-MP8017 Head Unit 47Wx4 (1800mV outs I think)
I tend to have the LOUD to ON and the Bass to 4 (out of 8), Treble to 7 and
Mid to 6. Do I do with set amp gains with these settings or at LOUD off and
EQ settings to 0?

2) PPI6600 Amplifier with QBASS Plus remote (see to max of 8dB out of 18dB
boost usually and varies depending on the song I listen to).
JL Audio 12W4-4 Subwoofer with custom fit sealed box

3) The other post I did the other day was the following (and someone
suggested I don't use boost at all for the sub):

I am trying to tune my PPI 6600 AMP for this setting. I mainly listen to
Techno/House/Dance type music.
Looking at the chart below taken from the users manual, what setting do you
think would give the best sound and can you give some explanation on why??
http://pages.infinit.net/edg/qbass.jpg

4) All speakers/tweaters wired in usual way and amp xcrossovers for front
and back to to about 64Hz-73Hz as suggested by my car audio shop (Infinity
5x7 5752cf (back) and Infinity 6802cf (front)). Sub is getting 200W rms,
back are getting 50Wrms each. Front are getting 50Wrms each but parallel
with extra tweeters.

5) I also have two tweeters in the front which I will be adding xcrossovers
for this week (set at 5kHz?).

6) I can forget using the o-scope and even volt meter if one says that it is
just not worth it.


"Eddie Runner" wrote in message
...
so if you lower the amp gains if there is clipping
do you turn the gains so low that the amp cannot clip
even if the headunit volume is all the way up..??

Eddie

"[80s.fan]" wrote:

Lower the amp gains output?
I am curious to see how it looks theoretically and have the knowledge to
use
a scope, meter, etc.

I know the by ear method is good enough for most but I can't always here
distortion on higher end amp/speakers so I want to measure the output.

"Eddie Runner" wrote in message
...
and if you did SEE CLIPPING on the scope
what exactly would you do about it..??

You are generalising. Some cheap HU's will clip at 50% with a 0dB signal,

Name one.

more expensive HU's with a good power supply won't clip even at 100%.

Name one.

As well as this, if you overload the amplifiers input, you will get
clipping, hence adjusting the gain, which FYI is not a volume control as
most people assume, rather, more accurately, a sensitivity control, to
limit
the signal going into the amplifier.

What's the difference? The input is merely a voltage divider and an op amp
circuit acting as a buffer. To most engineers, that's called an attenuation
device. In other words, a volume knob.


IMO using a scope is a great idea. You would keep the amp gain low, and
increase the HU volume until the wave start getting flattened, then nudge
the HU back down. The bring the amp up, until the same thing happens, and
nudge back down.

This would suck for "quiet" recordings.

This will give you a rather wide dynamic range.

Gain settings literally have nothing to do with dynamic range.

"[80s.fan]" wrote in message
.. .
| Does someone have a .wav of such a tone so I can fine tune my amp gain
| setting for my subwoofer (via oscilloscope or voltage meter)?
|
| Thanks.


Without getting into the discussions on this thread, here ya go...

http://www.ihearyou.com/testtones/

Knock yourself out

BTW - If I had a scope, that's how I'd set my gains too - but for most
situations, MZ's recommendations are "close enough." I don't think
anybody's right or wrong here...

"MZ" wrote in message
...
| You are generalising. Some cheap HU's will clip at 50% with a 0dB
signal,

snip

|
| What's the difference? The input is merely a voltage divider and an op
amp
| circuit acting as a buffer. To most engineers, that's called an
attenuation
| device. In other words, a volume knob.

Bingo - I agree - but the problem is that some folks use the input gains as
a "volume knob" for the output stage... This is bad, since loud isn't
always better - but you already know that... It's a "volume knob" for
matching output (hu) to input (amp).


|
| IMO using a scope is a great idea. You would keep the amp gain low, and
| increase the HU volume until the wave start getting flattened, then
nudge
| the HU back down. The bring the amp up, until the same thing happens,
and
| nudge back down.
|
| This would suck for "quiet" recordings.

But he said he'd use a 0dB test tone to set it - although I'd use the scope
directly on the HU pre-outs first to find the point of clipping, make note
of it, then put the scope on the amp outputs, set the HU at the prior
reference point, and watch the amp output waveform while increasing the
input gain to the point of clipping - and back it off a tad. Tada - a tuned
system. Although for most cases, this method is overkill.

| This will give you a rather wide dynamic range.
|
| Gain settings literally have nothing to do with dynamic range.

Actually, optimizing the input signal will give you a wider dynamic range.
Reference (0) - Peak (2v) will have a narrower dynamic range than
Reference(0) - Peak (4v) by the inherent nature of the sine wave - will it
make a difference to your ears? It may and/or it may not.

Scott Badman wrote:

You are generalising. Some cheap HU's will clip at 50% with a 0dB signal,
more expensive HU's with a good power supply won't clip even at 100%.

Most I have seen NEVER CLIP... which ones are you using that clip
at 50%..??

As well as this, if you overload the amplifiers input, you will get
clipping, hence adjusting the gain,

Yes, pushing the amp past its voltage limit will result in clipping...
What do the gains have to do with clipping, unless you adjust the
gains so the amp plays SO LOW that it doesnt ever clip, which
in my expereince is NOT a good thing....

which FYI is not a volume control as
most people assume, rather, more accurately, a sensitivity control, to limit
the signal going into the amplifier.

it is a volume control, it is nearly EXACTLY like the one on the head unit.
I dont see why folks always say it isnt a volume control....???

IMO, if you think if the gain as a volume control just as the one on the
headunit, it should make it easier for folks to understand whats happening..

IMO using a scope is a great idea.

I have at least 5 scopes, I have used scopes for nearly 30 years... And I
would almost NEVER use a scope to set amp gains...Unless there were
some strange problem I wanted to *see* with the scope there would be
no god reason to use the scope to just set the gains....


You would keep the amp gain low, and
increase the HU volume until the wave start getting flattened, then nudge
the HU back down. The bring the amp up, until the same thing happens, and
nudge back down. This will give you a rather wide dynamic range.

How will that change your dynamic range..??

I prefer to use the listening method because a) I don't have an oscilloscope
and b) it takes into account the impedance of the drivers.

impedance of the drivers..???


Eddie Runner

Gary Rodgers wrote:

Bingo - I agree - but the problem is that some folks use the input gains as
a "volume knob" for the output stage... This is bad, since loud isn't
always better - but you already know that... It's a "volume knob" for
matching output (hu) to input (amp).

If you mounted the amp on the dash and had a knob on the gain
control so you could turn it easily, IT MOST CERTAINLY COULD
BE USED AS A VOLUME CONTROL INSTEAD OF THE HEADUNIT
VOLUME...!!!

But he said he'd use a 0dB test tone to set it - although I'd use the scope
directly on the HU pre-outs first to find the point of clipping, make note
of it, then put the scope on the amp outputs, set the HU at the prior
reference point, and watch the amp output waveform while increasing the
input gain to the point of clipping - and back it off a tad. Tada - a tuned
system. Although for most cases, this method is overkill.

If you get the amp to clip AND THEN TURN IT BACK A TAD, then
most folks would NOT be happy with those settings...

Eddie

| What's the difference? The input is merely a voltage divider and an op
amp
| circuit acting as a buffer. To most engineers, that's called an
attenuation
| device. In other words, a volume knob.

Bingo - I agree - but the problem is that some folks use the input gains
as
a "volume knob" for the output stage... This is bad, since loud isn't
always better - but you already know that... It's a "volume knob" for
matching output (hu) to input (amp).

I'm not so sure I agree. Using the gain as a "volume knob" in multiamp
systems is quite common. Short of adding external processors, it's usually
the only way to set the relative levels between different speakers. For
example, many people like the rears to be attenuated in comparison with the
fronts. Decreasing the gain of the rear amplifier is one way to achieve
this goal.

| IMO using a scope is a great idea. You would keep the amp gain low,
and
| increase the HU volume until the wave start getting flattened, then
nudge
| the HU back down. The bring the amp up, until the same thing happens,
and
| nudge back down.
|
| This would suck for "quiet" recordings.

But he said he'd use a 0dB test tone to set it

Which is exactly my problem with it. What happens when you play a -6dB
recording? You can't get to max volume because your gain setting is acting
as a ceiling. This is why it's generally a good idea to leave a sizeable
cushion at the top end of the volume knob. A "loud" recording (0dB perhaps)
would reach max level at 60% or 70% up the volume knob. A "quiet" recording
could then be pushed up to 80% or 90% to attain the same volume level.

- although I'd use the scope
directly on the HU pre-outs first to find the point of clipping, make note
of it, then put the scope on the amp outputs, set the HU at the prior
reference point, and watch the amp output waveform while increasing the
input gain to the point of clipping - and back it off a tad. Tada - a
tuned
system. Although for most cases, this method is overkill.

In theory, you're right. But the fact of the matter is that every head unit
that I'm aware of doesn't clip nearly as early as what some are suggesting.


| Gain settings literally have nothing to do with dynamic range.

Actually, optimizing the input signal will give you a wider dynamic range.
Reference (0) - Peak (2v) will have a narrower dynamic range than
Reference(0) - Peak (4v) by the inherent nature of the sine wave - will it
make a difference to your ears? It may and/or it may not.

But you're not modifying the voltage level actually reaching the amplifier.
With the gain setting, it's being attenuated right at the front end. The
voltage reaching the preamp stage is the same under both circumstances.

"[80s.fan]" wrote:

Eddie,
Tell you what, since I do know that you have 'fantastic' knowledge of car
audio (and you have provided feedback for some previous question I had),
would you have a few minutes to give your opinion on what I should do to
fine tune my system described he

try this http://www.installer.com/tech/gains.html

Thank you for your time if you can.
1) Kenwood KDC-MP8017 Head Unit 47Wx4 (1800mV outs I think)
I tend to have the LOUD to ON and the Bass to 4 (out of 8), Treble to 7 and
Mid to 6. Do I do with set amp gains with these settings or at LOUD off and
EQ settings to 0?

I would set all the amp and xover gains with the headunit set to FLAT...
No EQ, no LOUD, no nothin..... Once the gains are set up you can
add those things to your taste.

2) PPI6600 Amplifier with QBASS Plus remote (see to max of 8dB out of 18dB
boost usually and varies depending on the song I listen to).
JL Audio 12W4-4 Subwoofer with custom fit sealed box

I would set that FLAT as well while doing the gains....

3) The other post I did the other day was the following (and someone
suggested I don't use boost at all for the sub):

I would start without the boost, if you need it then use it...
I would do the gains without boost, but you can also fine tune
the gains after you add boost if you want, its just harder to keep
track when you change something (totally up to you)

I am trying to tune my PPI 6600 AMP for this setting. I mainly listen to
Techno/House/Dance type music.
Looking at the chart below taken from the users manual, what setting do you
think would give the best sound and can you give some explanation on why??
http://pages.infinit.net/edg/qbass.jpg

Your gonna have to pick the freq where you want the boost.... Typicly
this might make the most impact for you if the WIDE is selected.... I
personally
would try to NOT use boost at all... But its up to you...

4) All speakers/tweaters wired in usual way and amp xcrossovers for front
and back to to about 64Hz-73Hz as suggested by my car audio shop (Infinity
5x7 5752cf (back) and Infinity 6802cf (front)). Sub is getting 200W rms,
back are getting 50Wrms each. Front are getting 50Wrms each but parallel
with extra tweeters.

Oughta sound good.

6) I can forget using the o-scope and even volt meter if one says that it is
just not worth it.

To use a scope, or a volt meter, you have to know what you are looking
at and what it means when you see one thing or another....Most folks look
for clipping with the scope, but in most decent systems the amps CAN
clip if turned up far enough and setting it so it CANT clip is usually very
low and most folks dont like the systems set this way....

So, use a scope you can see the system CAN clip, ok so now what???
DUH.... A scope really doesnt help you, since ALL decent systems
can clip, why use the scope at all..??

You could use a multi channel scope to set the levels of FRONT AMP
and BACK AMP precisley the same, and a scope could be a very
precise way of doing this...!! BUT AGAIN, WHY..??? The front
speakers and rear speakers are almost always different, if not different
sizes, then different mounting locations which effect their output!!

So adjusting amps precisely the same in this manner is usually USELESS!
Much better to adjust by ear to make the front and back play equally
to your listening spot.

It aint really all that hard.....
Folks dont like thinking of gains as volume controls but IF YOU DO
its easier!!

Just think, your in a room with 4 stereo systems, use the
volume controls on the stereos so that each one is the same volume
(by ear) to the listening area.... SIMPLE, any child can do it....

SO do the same thing in the car, adjust each amp so the level is the
same in the listening area... SIMPLE.....

Eddie Runner