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Title: Yamaha LS9 input gain
Post by: Corne Stapelberg on September 09, 2010, 02:30:59 am
 Rolling Eyes

I need to ask this again, and forgive me because there is a few posts similar to mine already.
I am using my Yamaha LS9 32 for about a year now.  Last night I did a gig, the main act was only a acoustic guitar and vocal (SM58 Shure mic)
Very very good international artist.

Long story short :  During his last song he played a bit louder than during the whole show and sound check and I got digital distortion on the quitar channel ( -6 dB) on the channel strip.

I know -18dB is the way to go.

My dumb questions are the following:
1 :)Are the channel strip level indicator the same as the level when you "QUE" your cahannels to check the input gain?
2 Smile If you run into levels of say also -6dB FS on the outputs of the desk, will I also get digital disortion?
3 Smile Is it normal for a LS9 to give digital clipping at -6dB iput on a channel

Regards
Corne'
Title: Re: Yamaha LS9 input gain
Post by: Geoff Doane on September 09, 2010, 09:06:11 am
Are you sure the clipping is happening at the console inputs?

-6 dBFS shouldn't clip by itself.  The clipping may be happening at a later stage in the console (boosting EQ), or it may be the DI (assuming you're using one) overloading.  I use an LS9 regularly, and haven't had any issues like this, although I typically run the inputs a lot cooler than -6.

GTD
Title: Re: Yamaha LS9 input gain
Post by: Corne Stapelberg on September 09, 2010, 09:53:33 am
Hallo Geoff

Thx for the reply.  That is what is concerning me a lot.  My EQ was verry basic with cuts rather than boosts. How can I determine overload at other stages in my console?
I used a Behringer DI100 for a DI box.  No Pads active on it.  It does not have any overload indications on it, and I can therefore not tell if this is where my problem lies?

Regards
Corne'
Title: Re: Yamaha LS9 input gain
Post by: Andre Garver on September 09, 2010, 10:30:56 am
It had to be the D.I. - I used Bear-ringer D.I. a few times at a regular club gig of mine and have gotten the same thing on an extra-hot input.  A nasty spitty and crackling that is very ugly.  With two inputs on the LS-9 and no red lights showing I really doubt the board was clipping.

If you can afford it toss those in the bin and get a few decent D.I.s.  I like to have a few passives and a few actives available for different scenarios.
Title: Re: Yamaha LS9 input gain
Post by: Joe Brugnoni on September 09, 2010, 10:52:03 am
I have had the same issue with behringer Di boxes, I find that I must engage the pad in them most of the time unless it is very soft and constant.
Title: Re: Yamaha LS9 input gain
Post by: Mac Kerr on September 09, 2010, 10:57:17 am
Corne Stapelberg wrote on Thu, 09 September 2010 02:30

 Rolling Eyes

I need to ask this again, and forgive me because there is a few posts similar to mine already.
I am using my Yamaha LS9 32 for about a year now.  Last night I did a gig, the main act was only a acoustic guitar and vocal (SM58 Shure mic)
Very very good international artist.

Long story short :  During his last song he played a bit louder than during the whole show and sound check and I got digital distortion on the quitar channel ( -6 dB) on the channel strip.

I know -18dB is the way to go.

My dumb questions are the following:
1 :)Are the channel strip level indicator the same as the level when you "QUE" your cahannels to check the input gain?
2 Smile If you run into levels of say also -6dB FS on the outputs of the desk, will I also get digital disortion?
3 Smile Is it normal for a LS9 to give digital clipping at -6dB iput on a channel

Regards
Corne'



Is there some reason you feel you need to run the consoles levels that hot? Generally recommended levels are -18dBfs to -12dBfs as maximum levels. That is creating a level out of your console of +6dBu to +12dBu. On an analog console with analog VU meters they would be pegged in the red at that point. Turn down your input gain.

Mac
Title: Re: Yamaha LS9 input gain
Post by: Bradford "BJ" James on September 09, 2010, 12:55:26 pm
This bugs me. So you have to monitor the input level on the meter to hit -18 max (I usually go a bit hotter). I guess I'm missing something....why doesn't the clip indicator light when I approach or exceed this level. I can see setting the IL a bit less to leave room for peaks, but -18 is less than halfway up the meter on an LS9 or an 01V.
Not whining, just looking for an explanation I can understand. There must be a reson.
BJ
Title: Re: Yamaha LS9 input gain
Post by: Tim McCulloch on September 09, 2010, 03:48:48 pm
You're operating in the Digital Realm that eventually gets turned in Analog Love.

With a 16 bit converter, 0dBFS is 1111111111111111.  That number corresponds to the maximum Analog Love Level, which is +24dbu at the output of the console.  That number means THERE IS NO MORE LEVEL, Digital Realm or Analog Love.  Headroom?  Zip, zero, nada.

You wouldn't run an Analog Love console at that level even at peaks.  If you PFL an input and trim the gain so that the peak signal is 0db on the Analog Love Meter, you are still about 20dB UNDER the maximum output capability of the mixer.

The Digital Realm clip indicator on the input is usually the "Out of 1s" indicator.  The actual analog electronics in front of the A/D converter doesn't clip until you're past the point of "out of 1s."

The gain staging you're used to in Analog Love consoles is implemented differently in Digital Realm mixers, and since we're long past the days of 8 and 12 bit words it is not necessary to use every available bit in an effort to keep things above the digital noise floor.

For the OP, I too suspect the DI or other piece in the signal chain as you were still below digital or analog clipping.

Have fun, good luck.

Tim Mc
Title: Re: Yamaha LS9 input gain
Post by: Corne Stapelberg on September 10, 2010, 02:05:28 am
Hallo Mac

I always run my board at -18 dBfs and try to peak at -18, maybe -12 dBfs at MAX scenario.  I just want to try and get the reason for this BAD SCENARIO.  Output on console was at -24 dBfs.

Regards
Corne'
Title: Re: Yamaha LS9 input gain
Post by: Corne Stapelberg on September 10, 2010, 02:13:56 am
Hallo BJ

The moment I heard the BAD SOUND, I instantly grab the channel input gain, and turned it down while I was also hitting the QUE button to monitor the input signal on the colprit channel (Acoustig Guitar through Behringer DI 100 DI).  The bad distortion was still there when I had the input gain level at -6 dBfs on the LS 9. -6 dBfs was the hottest the signal went at all.

This is why I am also asking the questio :
Is the led meter indication on each channel a true representation of the channel level that is the same than when you hit QUE and monitor the levels on the master output led meter.

I am also always using my laptop with Yamaha Studio Software running to monitor input levels

Regards
Corne'


Title: Re: Yamaha LS9 input gain
Post by: Corne Stapelberg on September 10, 2010, 02:28:02 am
Hallo Tim

Thx fotr the good info.  So just to sooth my mind ????
The desk was not reasponsible for the clipping sound.  If I Hit 0dBfs on the input that will be when the desk makes clipping sounds, not JUST above say -12dBfs.  It is the correct way to run the inputs at a peak of -18dBfs, but clipping will only be audible if you hit 0dBfs ??????

Am I understanding this correctly?

Regards
Corne'

"You are as good as your last show"
Title: Re: Yamaha LS9 input gain
Post by: Scott Helmke (Scodiddly) on September 10, 2010, 07:29:33 am
Those Behringer DI's overload easily - almost always need at least one of the pad switches turned on.

Plenty of analog devices overload with digital-sounding nasty distortion.
Title: Re: Yamaha LS9 input gain
Post by: Corne Stapelberg on September 10, 2010, 07:50:30 am
Hallo Scott

Thx for reply.  I am also starting to think the DI was the weakest link in my signal chain.
Pitty they do not have an indication on them of inpt gain???

I am slowly starting to recall one or two previous cases with the same type of weard sound during two big outdoor shows with the same DI's, and at that stage I thought it could be a cable or something due to the much more involved setup, with multiple bands and up to 8 musicians on stage at a time. It was then more difficult to eliminate the culprit for that split second, but from the recording I made of the gig, it sounded if it was coming from the digital stage piano signal.

Regards
Corne'

Title: Re: Yamaha LS9 input gain
Post by: Kevin Maxwell AKA TheMAXX on September 10, 2010, 11:16:23 am
Very possibly a bad DI. But I have also had that distorted sound when an acoustic guitar with an internal preamp with a 9v battery that was going bad. I had one guy insist that he had just a week ago changed the battery. It turned out there was no on/off switch but was always on if the cord was plugged into the guitar and he had left it plugged in. He had to loosen the strings to get the battery out and didn’t want to but when he broke a string during sound check I talked him into checking the battery and it was very low. Changed the battery and no more distortion. But in your case I would lean toward that DI.
Title: Re: Yamaha LS9 input gain
Post by: Rob Spence on September 10, 2010, 10:43:32 pm
Corne Stapelberg wrote on Fri, 10 September 2010 02:28

Hallo Tim

Thx fotr the good info.  So just to sooth my mind ????
The desk was not reasponsible for the clipping sound.  If I Hit 0dBfs on the input that will be when the desk makes clipping sounds, not JUST above say -12dBfs.  It is the correct way to run the inputs at a peak of -18dBfs, but clipping will only be audible if you hit 0dBfs ??????

Am I understanding this correctly?

Regards
Corne'

"You are as good as your last show"

Yes, but understand that clipping in the digital world really sounds bad, not like the nice sound of analog clipping. You never want to clip in digital!
Title: Re: Yamaha LS9 input gain
Post by: Tim McCulloch on September 10, 2010, 11:07:35 pm
AT 0dBFS, you are out of everything, without exception, without headroom of any sort.  You *never* want to be there, and because all forms of input except sine waves have a crest factor, you need headroom.

If you're routinely hitting peak on an input, I suspect you have level reduction further downstream, either in a virtual or physical dynamics device, "gain reduction thru equalization", the system inputs are turned down or you just don't have Enough Rig for the Gig
Title: Re: Yamaha LS9 input gain
Post by: Michael J Brown on September 10, 2010, 11:28:29 pm
Tim McCulloch wrote on Fri, 10 September 2010 22:07

AT 0dBFS, you are out of everything, without exception, without headroom of any sort.  You *never* want to be there, and because all forms of input except sine waves have a crest factor, you need headroom.

If you're routinely hitting peak on an input, I suspect you have level reduction further downstream, either in a virtual or physical dynamics device, "gain reduction thru equalization", the system inputs are turned down or you just don't have Enough Rig for the Gig
Title: Re: Yamaha LS9 input gain
Post by: Dan Richardson on September 11, 2010, 09:36:44 am
Rob Spence wrote on Fri, 10 September 2010 22:43


Yes, but understand that clipping in the digital world really sounds bad, not like the nice sound of analog clipping. You never want to clip in digital!


When's the last time you actually tested that? Sure, in the dawn of digital audio,
clipping would wrap the waveform around and you'd get a full amplitude square wave.
Very dramatic tearing sound as your drivers tried to be two places at once.
I haven't seen a piece of gear do that in over a decade.
Somewhere along the way, they seem to have mellowed the math.

Way back when, I talked Klondike into letting me use an 01V on a gig. Klon had me bring it out to the shop.
The first thing he did was plug in a 58 and a monitor speaker, spin the input gain full up, and bark into it.
Sounded like analog distortion. Shortly thereafter, he started buying digital consoles.
Sure, clipping is a bad thing, but digital clipping doesn't have to sound dramatically worse than transistor clipping.

I'd much rather listen to an LS9 clipping than a Behringer DI clipping.
Title: Re: Yamaha LS9 input gain
Post by: Mac Kerr on September 11, 2010, 10:35:04 am
Dan Richardson wrote on Sat, 11 September 2010 09:36

Rob Spence wrote on Fri, 10 September 2010 22:43


Yes, but understand that clipping in the digital world really sounds bad, not like the nice sound of analog clipping. You never want to clip in digital!


When's the last time you actually tested that? Sure, in the dawn of digital audio,
clipping would wrap the waveform around and you'd get a full amplitude square wave.
Very dramatic tearing sound as your drivers tried to be two places at once.
I haven't seen a piece of gear do that in over a decade.
Somewhere along the way, they seem to have mellowed the math.

Way back when, I talked Klondike into letting me use an 01V on a gig. Klon had me bring it out to the shop.
The first thing he did was plug in a 58 and a monitor speaker, spin the input gain full up, and bark into it.
Sounded like analog distortion. Shortly thereafter, he started buying digital consoles.
Sure, clipping is a bad thing, but digital clipping doesn't have to sound dramatically worse than transistor clipping.

I'd much rather listen to an LS9 clipping than a Behringer DI clipping.


Since the introduction of the PM1D at least, Yamaha has been designing their consoles so that the analog mic pre clips before the AD converter. You should have a hard time clipping the input digitally. It may be easier to clip the internal path at some point with too many gain stages. I assume that other responsible console manufacturers follow the same philosophy. This is not a theory I have felt the need to test. I'd rather keep the levels reasonable.

Mac
Title: Re: Yamaha LS9 input gain
Post by: John Roberts {JR} on September 11, 2010, 10:55:42 am
Mac Kerr wrote on Sat, 11 September 2010 09:35



Since the introduction of the PM1D at least, Yamaha has been designing their consoles so that the analog mic pre clips before the AD converter. You should have a hard time clipping the input digitally. It may be easier to clip the internal path at some point with too many gain stages. I assume that other responsible console manufacturers follow the same philosophy. This is not a theory I have felt the need to test. I'd rather keep the levels reasonable.

Mac



It seems we are constantly re-fighting old (won) battles.

Digital word wrapping is just how digital math works. While it is pretty straightforward to prevent it at the original conversion it must also be managed at every gain stage and operation where signal streams are summed and the result could overflow. This is very old news to digital designers and not something the user should worry about.

A properly designed digital path should act just like a similar analog path in response to overload. With the exception that cleverly designed digital paths could tweak gain structure on the fly to correct some intermediate stage saturating.

JR

Title: Re: Yamaha LS9 input gain
Post by: Rob Spence on September 11, 2010, 04:28:09 pm
Dan Richardson wrote on Sat, 11 September 2010 09:36

Rob Spence wrote on Fri, 10 September 2010 22:43


Yes, but understand that clipping in the digital world really sounds bad, not like the nice sound of analog clipping. You never want to clip in digital!


When's the last time you actually tested that? Sure, in the dawn of digital audio,
clipping would wrap the waveform around and you'd get a full amplitude square wave.
Very dramatic tearing sound as your drivers tried to be two places at once.
I haven't seen a piece of gear do that in over a decade.
Somewhere along the way, they seem to have mellowed the math.

Way back when, I talked Klondike into letting me use an 01V on a gig. Klon had me bring it out to the shop.
The first thing he did was plug in a 58 and a monitor speaker, spin the input gain full up, and bark into it.
Sounded like analog distortion. Shortly thereafter, he started buying digital consoles.
Sure, clipping is a bad thing, but digital clipping doesn't have to sound dramatically worse than transistor clipping.

I'd much rather listen to an LS9 clipping than a Behringer DI clipping.

Smile

I guess I learned not to do it before the mellowing out of digital.
Showing my age I guess.  Very Happy
Title: Re: Yamaha LS9 input gain
Post by: Tom Boisseau on September 12, 2010, 02:53:15 pm
Okay, correct me if I'm wrong, but I seem to remember it is possible to have the channel meters set (deep in one of those menus) so that they read the channel output level and NOT the pre fader level.  This could explain why the signal was distorted even though the meters were only showing -6dB!

Tom
Title: Re: Yamaha LS9 input gain
Post by: Dan Johnson on September 13, 2010, 12:09:45 am
Corne Stapelberg wrote on Fri, 10 September 2010 01:13

This is why I am also asking the questio :
Is the led meter indication on each channel a true representation of the channel level that is the same than when you hit QUE and monitor the levels on the master output led meter.

Tom Boisseau wrote on Sun, 12 September 2010 13:53

Okay, correct me if I'm wrong, but I seem to remember it is possible to have the channel meters set (deep in one of those menus) so that they read the channel output level and NOT the pre fader level.  This could explain why the signal was distorted even though the meters were only showing -6dB!

If you go into the main metering screen on the LS9 (where you see the meters for inputs 1-32 or 33-64 all at the same time), there is an option to view pre- or post-fader levels on the input channels and choose whether pre- means pre-hpf or pre-fader.  Whatever you set this to also affects what you see on the meters on the control surface above each channel fader.

When you cue a channel, the metering point depends on the setting that you have set in the CUE settings of the console which are reached by pressing the MONITOR button repeatedly until you get to the CUE setup screen (see page 149 of the manual).
Title: Re: Yamaha LS9 input gain
Post by: Michael Lewis on February 15, 2011, 02:26:41 pm
sorry want to delete this but got no idea how.
Title: Re: Yamaha LS9 input gain
Post by: Michael Lewis on February 15, 2011, 02:44:42 pm
Hey guys,

I have some questions on the LS9 input gain. Here's telling some background stories before my questions:

Recently I had some discussion with my friend regarding setting proper input gains. My friend would say that he prefers using the 'unity fader' method while I argue that that is not the right method. He would set all the faders at unity and then bring the gain up till it's loud enough which he sometimes find that the input gain will be too low and sometimes has problems with not enough level, especially on his aux sends (when his main rig is much more powerful than monitor rig)and so on. I believe his gain is not properly set.

I then did some research and found this article below:

http://www.churchtecharts.org/archives/2210

It says that there are two goals when setting gain:

1. Getting a good level into the preamp, good S/N ratio, best sounding

2. Getting a good output through the system at unity fader, best fader resolution

The latter is said to be achieved by using trim / VCA so that while the gain helps in setting a good level for the input head amp, the trim / VCA helps in setting the faders at unity for the desired volume output.

The LS9 doesn't have VCAs so my question is where are the trims on LS9? Can the trim at the EQ stage be used for that purpose?

When I first bought my LS9 I had the problem of the USB's input being too high. After doing some research, I came across some user comments that say I can trim the inputs by using the trim of the EQ. I now do a trim of about -20dB for the USB input.

My question is, in order to achieve both goals, 1st setting a good HA gain as well as 2nd making sure it's not too loud at unity fader, can I use the trim at EQ to achieve this? Is there any other way I can do that?

For analog consoles that have VCAs, is it wise to put all faders at unity and then gain up using VCAs? What about larger digital consoles that have DCAs? Would they have trims along with DCAs as well? Which one should I use?

One more thing is regarding pad switches on consoles. My friend told me that he prefers to pad and then bring up the gains on consoles such as the Midas Verona to get to sweet spots. He even does that when there's no real need to pad (the incoming is not too high) but he says it sounds better that way. Is there anyone here who understands why he does that?

btw, I too confirm the problem of Behringer's DI100 input stage cracking up without pad. I had it cracked up on me a few times when I had loud keyboard, loud acoustic guitar and also loud computer audio. After those 3 occasions, I leave it on -20dB pad most of the time. I never had problems with other DIs so I think they are really bad DIs and shouldn't be used for pro use.

Title: Re: Yamaha LS9 input gain
Post by: Geoff Doane on February 15, 2011, 02:48:58 pm
Michael Lewis wrote on Tue, 15 February 2011 15:26

 My friend told me that he prefers to pad and then bring up the gains on consoles such as the Midas Verona to get to sweet spots. He even does that when there's no real need to pad (the incoming is not too high) but he says it sounds better that way. Is there anyone here who understands why he does that?



When I was younger (25 years ago), I had much more experienced sound guys tell me the exact opposite.  "Don't use the pad.  It sucks the life out of the signal."  I think they liked to use the channel clip lights as "signal present" indicators.  These days, I take it all with a grain of salt.

The debate over "faders at unity or adjust PFL gain first" will probably never end.  Personally, I use a variation on "faders at unity" and it works for me, but it relies on having appropriate gain structure in the back end of the system (after the console).  The latter technique might be a holdover from analog recording days when the first priority was to hit tape with as much level as you could get away with, and then mix from there.

As for the sound of the preamps, I've noticed extra noise when padding the inputs, which isn't surprising, since you now need more gain.  JR has mentioned in the past that some preamp designs may inadvertently roll off low end at low gain settings, so in that case the pad may help preserve the signal integrity.

GTD
Title: Re: Yamaha LS9 input gain
Post by: Michael Lewis on February 15, 2011, 03:09:02 pm
Geoff Doane wrote on Wed, 16 February 2011 03:48

Michael Lewis wrote on Tue, 15 February 2011 15:26

 My friend told me that he prefers to pad and then bring up the gains on consoles such as the Midas Verona to get to sweet spots. He even does that when there's no real need to pad (the incoming is not too high) but he says it sounds better that way. Is there anyone here who understands why he does that?



When I was younger (25 years ago), I had much more experienced sound guys tell me the exact opposite.  "Don't use the pad.  It sucks the life out of the signal."  I think they liked to use the channel clip lights as "signal present" indicators.  These days, I take it all with a grain of salt.

The debate over "faders at unity or adjust PFL gain first" will probably never end.  Personally, I use a variation on "faders at unity" and it works for me, but it relies on having appropriate gain structure in the back end of the system (after the console).  The latter technique might be a holdover from analog recording days when the first priority was to hit tape with as much level as you could get away with, and then mix from there.

As for the sound of the preamps, I've noticed extra noise when padding the inputs, which isn't surprising, since you now need more gain.  JR has mentioned in the past that some preamp designs may inadvertently roll off low end at low gain settings, so in that case the pad may help preserve the signal integrity.

GTD


Thanks. Yea I do agree that some old school sound engineers, my dad's age like to see the clip light flashing (quite constantly) on louder signals.

As for the pad helping preserve signal integrity, I believe it is an older console thing? I believe the newer consoles don't have the low end roll off at lower gain settings that you mentioned. Correct me if I'm wrong. I too find that padding adds extra noise and normally avoid pressing the pad switch unnecessarily.

Care to share what is your variation on "faders at unity"? What about the article that I brought up? Is it a good method to adjust PFL gain, then use trim / VCA to set faders at unity?
Title: Re: Yamaha LS9 input gain
Post by: Geoff Doane on February 15, 2011, 09:41:39 pm
Michael Lewis wrote on Tue, 15 February 2011 16:09

 Care to share what is your variation on "faders at unity"? What about the article that I brought up? Is it a good method to adjust PFL gain, then use trim / VCA to set faders at unity?


I skimmed the article, but my general feeling was that the author was suggesting too many steps and adjustments, and over complicating the procedure.

To properly describe my method would probably take an article too, and I'm not up for that tonight.  So, assuming that the back end gain is OK, and you have an adequately powered system to work with, here's my routine.

1. Turn all the gains down to minimum, pads in, if there are any.

2. With the channels muted, set the faders to zero (10 dB in hand).  They won't necessarily stay there, but it's a good starting point.  The console's master fader goes at whatever level the system gain was set, typically between -10 and 0 dB.

3. Start getting levels on individual channels by un-muting the channel and turning up the gain until it is appropriately loud.  "Appropriately loud" is a subjective thing, but I think of it as the loudest I'm likely to want that input (solo level).  After I've got the sound of the channel right, I reduce the level to whatever would be the normal level in the mix.  Guitars and horns typically will come down 5 or 10 dB, vocals will stay at unity, maybe being boosted 5 dB for leads.  Kick and bass might move up 5 dB too (or start there) since they're not likely to walk on the vocals anyway.

4. Then dial in monitors and FX, and mix on the faders for the rest of the show.  As long as there is adequate power in the whole system, there's no danger of overloading any inputs.

An added benefit for me, since I mix many different acts from gig to gig, is that dynamics parameters and send levels are already in the ballpark, once I turn the gain up to the "appropriate" level.  Generally only minimal tweaking is required rather than starting from scratch every time.

I use a similar technique for FX, setting the returns for "unity gain" before hand, and then just turning up the send until I get the desired effect.  I may not be driving the effects anywhere near 0 dBFS, but so what?  If it sounds good, it is good.  Modern digital has a noise floor so low that squeezing the last bit of performance out of a 12-bit converter is a thing of the past.

I don't expect everyone (anyone?) to adopt my methods, but since you asked, that's the general idea.  For me, it's a fast way to work that gives me consistent results.

GTD
Title: Re: Yamaha LS9 input gain
Post by: Jordan Wolf on February 15, 2011, 10:59:58 pm
Geoff Doane wrote on Tue, 15 February 2011 21:41


...here's my routine...

Geoff,

I tend to agree with and follow your method.  If something is particularly noisy (i.e. older analog F/X units), I'll squeeze what S/N ratio I can out of it, but normally that's not a problem.

My only question is: what do you do to compensate for EQ gain adjustments...if you add ~5dB of 800Hz to the bass guitar's channel, do you dial back the gain of the whole channel by ~5dB?
Title: Re: Yamaha LS9 input gain
Post by: Tim Padrick on February 18, 2011, 02:15:17 am
I use a combination.  I set the vocal gains for a proper PFL level, set the faders to unity, and open the master to the level I think I'll need on the vocals.  I then set the other faders to unity, and set the gains for the levels I think I'll need.  This seems to work well for me.
Title: Re: Yamaha LS9 input gain
Post by: Geoff Doane on February 18, 2011, 07:56:52 pm
Jordan Wolf wrote on Tue, 15 February 2011 23:59


My only question is: what do you do to compensate for EQ gain adjustments...if you add ~5dB of 800Hz to the bass guitar's channel, do you dial back the gain of the whole channel by ~5dB?


To be honest, I've never really thought much about that.  Since my method tends to give much more input headroom than is really needed, a 5 dB boost is unlikely to cause clipping.  Also, if a source needs a 5 dB boost, it's probably because it's already deficient at that frequency, so it still won't adversely affect the headroom.

GTD
Title: Re: Yamaha LS9 input gain
Post by: Tim Padrick on February 20, 2011, 02:03:15 am
Geoff Doane wrote on Fri, 18 February 2011 18:56

..... if a source needs a 5 dB boost, it's probably because it's already deficient at that frequency, so it still won't adversely affect the headroom.

GTD


It might if the PFL level was based on an input that was deficient at that frequency (which would read lower than if it was not deficient).  (I agree that it's not likely unless one has the PFL level way too high.)
Title: Re: Yamaha LS9 input gain
Post by: Scott Weidenfeller on February 26, 2011, 08:35:32 am
Are you saying 0 dbu is really +24 dbu coming out of the mixer? I have always run my 01V at peaks of -6 to -10 or so dbu, I don't remember when/why I first started that and I don't hear distortion and I also don't recall seeing any excessive signals on the meters; though I also have some compression, effects, EQ going on which clouds it a bit.

Bottom line is it sounds like I should be running it cooler than -6 and if fact closer to   -18? Is that correct?

Thanks for any help/clarity on this

PS I may have to go experiment with all this and a meter.
Title: Re: Yamaha LS9 input gain
Post by: Mac Kerr on February 26, 2011, 11:16:11 am
Scott Weidenfeller wrote on Sat, 26 February 2011 08:35

Are you saying 0 dbu is really +24 dbu coming out of the mixer? I have always run my 01V at peaks of -6 to -10 or so dbu, I don't remember when/why I first started that and I don't hear distortion and I also don't recall seeing any excessive signals on the meters; though I also have some compression, effects, EQ going on which clouds it a bit.

Bottom line is it sounds like I should be running it cooler than -6 and if fact closer to   -18? Is that correct?

Thanks for any help/clarity on this

PS I may have to go experiment with all this and a meter.


You need to be careful about what reference you are using with dB. 0dBu can never equal +24dBu because they have the same reference, and different values. What you meant to say is 0dBfs (dB full scale) on certain Yamaha consoles gives you a +24dBu analog output level. That is true. It is also a standard of sorts across several manufacturers. Sony professional video equipment uses -20dBfs as their "0" reference level. That is equivalent to +4dBu, which is a standard in the analog world for 0Vu.

Mac
Title: Re: Yamaha LS9 input gain
Post by: Scott Weidenfeller on February 27, 2011, 09:31:13 am
Thanks,... I think my head is about to explode  Shocked

I have got to figure this out/learn this crap
Title: Re: Yamaha LS9 input gain
Post by: Frederik Rosenkjær on February 27, 2011, 06:08:02 pm
Geoff Doane wrote on Wed, 16 February 2011 02:41

 here's my routine.



Well, just wanted to chime in and say how much that goes against my personal preferences and way of working. Plus I think it's as close to "objectively wrong" as you can get in the audio business (where it's "if it sounds good - it is good".)

IMO the purpose of the gain pot is to optimize the signal for the entire signal path - using it to it's fullest so as to not pickup noise, but without distorting, of course. This applies to both analog and digital consoles.

I'm running an LS9-based rig, though I'm normally using Riedel Rocknet preamps. These have less noise than the Yamaha AD8HR I used to use for inputs which, in turn, have less noise than the native LS9 inputs.

But even with these quite nice preamps I find a dramatic difference when using this approach (all faders @ unity) versus my own approach which is in principle to get the signal as hot as possible - in practice channels are regularly peaking around -6 dBFS.

I mostly operate the rig myself, but every so often I get hired to provide for a band with own engineer and on occasion the BE has been of the "faders @ unity"-school. I hate it - the rig gets so incredibly noisy, as mentioned even with very good preamps and going digitally all the way into d&b D12 amps feeding Q7-cabs, while running the gains my way, the system is just gorgeously "digital black" kind of dead quiet between songs which, at some gigs, is invaluable in my personal opinion and taste. I want to hear the music - not the system.

I've never heard an LS9 distort in any unpleasant way at anything below 0 dBFS. Neither with internal preamps nor AD8HR or Rocknet.

If you want the fader resolution from the 0dB-method, you should consider using the attenuator in the EQ instead of the gain pot.

Also, I have a pet theory that says that this could be the reason so many people dislike the LS9 inputs so much - maybe they should just run them a little hotter.
Title: Re: Yamaha LS9 input gain
Post by: Michael Lewis on February 28, 2011, 11:51:58 pm
cool.. I was also thinking of the attenuator in the EQ to bring back faders to unity
Title: Re: Yamaha LS9 input gain
Post by: Corne Stapelberg on March 04, 2011, 09:30:25 am
Hallo Geoff

Thx for your input.
I found the reason for my distortion.
It was infact the DI that clippped.
After I started to use a pad on them as a standard procedure - nothing like that ever happened since I started this post.
From there I run the LS9 sometimes a bit hot, but NO MORE FUNNY NOISES !!!!!

I also follow your way of mixing : Best possible input gain without clipping (with the correct EQ applied) and ANY posistion for the slider

Regards
Corne' Cool