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View Full Version : VT[4] Audio Levels.....



kleima
02-07-2005, 04:48 PM
The consistency of VT[4]'s audio levels is DRAMATICALLY improved! For instance, if I record test tone at 0db, it will actually hit 0bd on the VTEdit meter.

But, I am wondering why, if I plug the 0db test tone into one of the inputs, I have to reduce the input volume by 10-12 db in order for that input level to be at 0db, then I have to increase VT input volume by about 4 db in order to have the VT output meter showing 0db.

Am I missing something??

radams
02-07-2005, 10:49 PM
Nope NewTek set the analog input levels to -10 db...instead of +4...(on the XLRs)
I have bugged this but the more voices telling NT this the better.
Note that the miniphone jack level is -10db thou the SX-84 should have the XLR's be allowed to input and output at +4 for broadcast gear and signal runs (using an internal pad)...

But for some reason NT didn't put that in the VT4 software...I hope they will set this up to work again ASAP.

If you need to, go get a pad to connect your +4 sources into and then feed that into the VT....then you can keep the whole signal run at unity...other wise run it thru a mixer and setup the mixer to 0db units setup your levels then drop the master output from the mixer to a -10db level...Mackies have this marked on the mixer...(note the mixers's meters will read low but the input into the VT will then be fine).

But NT, these are workarounds that should NOT be necessary!!! And are additional costs to the system.

Cheers,

JReble
02-08-2005, 05:19 AM
Agreed. It needs to be fixed. We've had to deal with sub standard, and quite frankly, amateur audio handling on the vt since the beginning. It wouldn't appear to take a rocket scientist to make the analog ins and out subscribe to the same analog standards as other equipment we use.

kleima
02-08-2005, 01:49 PM
Actually, I was getting the -10db on the RCA connectors, not the XLR. (I didn't try on the XLR.)

So, are you saying that it is industry standard to have a 0db signal input into an XLR be at +4db?

That doesn't make sense to me either - but then, I'm not an audio engineer.... :confused:

radams
02-08-2005, 02:53 PM
Well if you are using the BOB's RCA connection then of course you will get -10 db that is standard....it is only with Mackie and some other PRO gear that output +4 thru RCA's....but RCA's are considered consumer NOT PRO...thus work at -10db normally...BALANCED XLR's on the other hand normally work at +4 db....for Unity.

How are you coming into the VT with a signal Gen with RCA's??? it should either be with 1/4 inch phone jacks converted to XLR or XLR to XLR...

I'm confused...what test gen are you using? what is its reference level?

Cheers,

chribba
02-08-2005, 03:13 PM
I think Newtek should always use the "pro" standards that is set to be. If anyone want to connect any consumer equipment itīs up to them to deal with the problems that comes along. Please give me "pro" all the way please...

chribba

radams
02-08-2005, 03:31 PM
Hi Chribba,

NT had given us some of both...and did allow us to mix both together...but with this latest build we lost the +4 db unity input on the XLR's...

Now the BOB has mostly RCA's which can be used but are more for consumer gear than Broadcast...but to be honest if you go into most stations you'll find both...

Now do you work with DV at all?

What reference level so you use...

-12db or -20 db?

It depends on the gear but most PRO DVCAM and DVCPRO stuff works at a digital unity reference of -20db...while the more common DV prosumer to consumer works at -12db...ALso note: that those are digital paths which act differently than analog (VT uses an analog motif to work with both digital and analog).

You can get great audio in/out depending on your setups and signal runs...
So don't discount the RCA's but understand the limitations to better implement your signal runs and setting and working with a reference unity.

ALso realize that the actual connections on the VT card are 3.5mm phone connections...which like the RCA are normally -10 db...for unity...

Good Luck to all ;)

Cheers,

kleima
02-08-2005, 06:44 PM
I have a Horita Black burst generator which also outputs 1K 0db test tone via RCA.

ScorpioProd
02-08-2005, 11:19 PM
As I said long ago, and I'll say again, I think the audio connector decisions made for the BOB are odd, to say the least.

Yes, there are a "mix" of pro and consumer connectors, but the pro connectors are minimal in number compared to the consumer RCA connectors. Certainly not enough balanced XLR connections for doing what I would consider any kind of real mix at a live event.

And I'd love to know how that makes sense even as just a BOB for the system, when you look at the video side and see component connectors. I've never seen a component deck without pro audio connections.

When I asked this question long ago, Newtek stated there wouldn't be enough room on the BOB to put XLRs instead of RCA connectors, so I logically suggested TRS balanced/unbalanced 1/4" connectors just like Mackie uses.

To that suggestion I was told there isn't enough depth to the BOB to fit them.

So again, like anything, it's just a design decision that controls these things.

radams
02-09-2005, 01:32 AM
Hi Eugene,

I think that both you and I were ones of several who pointed this out to NT...and even Paul Lara tried to get the Neutrik XLR/TRS connection put in....but the design had already been done and there was no going back at that time...

I hope that in the future...that NT will look at the REAL world workflows when designing the new systems....We now have AES, SPDIF, Optical, etc...besides the older analog...

But also the issues of signal routing of channels and functionity in the real world uses...needs to be addressed...

For now thou we NEED to have the XLR's work at +4 db as unity...

Cheers,

radams
02-09-2005, 01:43 AM
I have a Horita Black burst generator which also outputs 1K 0db test tone via RCA.

I went to Horita's web site but it did not give the reference settings for Unity...but from your discription...it sound like it is @+4dbu...so VT's RCA's are at
-10dbu...thus the difference...again I would suggest running thru an external mixer setup all your sources thru it...and first use the +4 to set all levels then move the external mixer's master levels down to -10dbu...or put a pad between the mixer and VT...

At least until the XLR's are fixed to be +4 dbu....

Cheers

ScorpioProd
02-09-2005, 01:46 AM
Except Newtek already had their shot at a full redesign YEARS later, with the SX-84, and this stuff didn't get changed.

I agree with the fixes that you mention as critical, but I am left pondering something audio related...

I honestly don't see the point of trying to use or make the "audio mixer" into a FULL audio mixer anyway... Without external control surfaces, I certainly wouldn't want to be trying to mouse critical audio level changes on multiple channels. My Mackie 1402-VLZ can certainly do stuff much better than anything I could manage in the VT[4], and that doesn't surprise me one bit. And it doesn't bother me one bit.

External, REAL mixers have their place, and in a live situation, I can't see why one would WANT to try and do this all with one little mouse in a system while you're trying to do the video switching with it.

I mean sure, basics for audio routing and such, but beyond that?

radams
02-09-2005, 01:59 AM
You and I have been on the same page for years Eugene...

I totally agree that for LIVE production the software only mixing is TOO limited also there is not enough Mic pres for most live situations anyway...

So you have to go with an external mixer...which even NT agrees with.
For me the audio part of the BOB is really only for routing of external sources rather than actual mixing...even for POST users...

We really do need some type of control head with REALTIME mixing functions down to the clip's sample level...

I've always used a mixer into and even out of the VT due to these limitations...& I know you do to.

I still recommend to anyone working with VT either LIVE or POST to have an external mixer. I prefer the Mackies but there are several options that are not that costly anymore.

I've even requested some time ago that we be able to work with control heads...for MANY VT functions....and even suggested the TASCAM FW1884 unit since it could be both an external mixer and control head while giving additonal digital and analog inputs....

Put nothing has been implemented.

Cheers,

Jim Capillo
02-09-2005, 04:47 AM
I am also running a Mackie mixer here.... and while the audio issues don't elude me, they are a very minor part of day-to-day operations, which is the way I like it.

From my past experience, I would also recommend an external mixer. Easy to use and label, no switching screens and per channel tweaking is a snap.

jcupp
02-09-2005, 08:41 AM
I think Newtek should always use the "pro" standards that is set to be. If anyone want to connect any consumer equipment itīs up to them to deal with the problems that comes along. Please give me "pro" all the way please...

chribba

I'd like to point out that not all pro video gear has +4dBm XLR connections. I have Panasonic DVC Pro, Sony High8 and Sony SVHS Professional equipment that all use -10dBV RCA connections for audio. All my pro audio gear is switchable between +4 and -10 why isn't this true of video gear? I've never understood this.

JReble
02-09-2005, 12:01 PM
Because there are only two standards with 90+ % of broadcast professional video gear, unbalanced RCA connections at -10dBV and balanced XLR connections at +4dBm. Any VTRs designed for studio and broadcast use including DVC-Pro, DVCAM, BetaCam, Umatic, etc. always include balanced XLR connectors running at 600 ohm +4dBm for proper impedance with other professional gear.

Over the years, most manufacturers have developed scaled back versions of their flagship models for desktop editing, automation, dubbing chains, etc. and this has tended to blur the definition of professional or broadcast, neither of which really had hard fast meanings to begin with. These middle of the road VTRs, cameras, and other components usually did away with a number of features that were present in their big brothers. These missing features were usually frame accurate edit control, high speed edit transports, several configuration options, and of course the balanced line audio connections. In these they used unbalanced RCA connections at the standard signal level of -10dBV which interfaced properly with other unbalanced gear.

That's not to say that the lower end versions of these professional formats are not good or professional, but they do not subscribe to the "professional" specifications required by other high end gear like the balanced audio connections at 600 ohm +4dBm. If Newtek's intent is to offer balanced line connections on the BOB, then they must provide them at the balanced line specs. Otherwise it is largely useless and may as well be another set of RCAs. Like many TRS connections on many mixers, inputs can be connected either balanced or unbalanced. In balanced only inputs, the signal must be at the proper level for proper signal handling. It shouldn't be selectable on balanced only inputs when balanced line signals have standard signal specs for which the inputs are designed? I guess VTR manufacturers could provide both balanced and unbalanced inputs, but most folks don't want to pay for that. Therefore it's not selectable by input.

chribba
02-09-2005, 12:13 PM
I'd like to point out that not all pro video gear has +4dBm XLR connections. I have Panasonic DVC Pro, Sony High8 and Sony SVHS Professional equipment that all use -10dBV RCA connections for audio. All my pro audio gear is switchable between +4 and -10 why isn't this true of video gear? I've never understood this.

I will start by saying that i am living in Europe and if you have lower standards in USA i really apologies for saying this.
I cant call SVHS and High8 as "PRO". Cant recall it ever has been or will be. It has nothing to do if you can switch +4 db -10db. DVC Pro is a "PRO" format, has anyone told you diffrent?

chribba

kleima
02-09-2005, 12:15 PM
Ray,

So, you're saying that I should bring my VT input down to 0db and increase the input with the test on it to -6db??

kleima
02-09-2005, 12:25 PM
Chribba,

I still have an old Panasonic broadcast camera (SVHS) that has, printed on it from the manufacturer (which is Japanese, not American), the words, "For Professional Use Only."
You may call it marketing or whatever, but it seems to me that your definition of professional is different than the manufacturers.
SVHS is "broadcast quality" and has been used in thousands (probably millions) of "professional" applications.
In the days of dockable camera VTRs, you could get an SVHS docking VTR for just about any professional camera. I can guarantee you that "consumers" were not buying these cameras and VTRs!

Jim Capillo
02-09-2005, 12:43 PM
I will start by saying that i am living in Europe and if you have lower standards in USA i really apologies for saying this.
I cant call SVHS and High8 as "PRO". Cant recall it ever has been or will be. It has nothing to do if you can switch +4 db -10db. DVC Pro is a "PRO" format, has anyone told you diffrent?

chribba

LOL...... here we go with the old "broadcast quality" argument. :p

I've still got a Sony EVO-9850 Hi-8 editing deck in the rack and it has XLR ins/outs. While certainly not the quality of BetaSP (Sony NEVER marketed it as such), it certainly falls in the category between "prosumer" and "professional". I usually call it "industrial".

I've edited linear on Panasonic DVC Pro equipment and I don't consider it a "professional" format because I can't hear the audio when incrementing the tape frame by frame.

Just goes to show that everyone's experiences and preferences vaildate whether they consider a piece of equipment "professional" or not.

chribba
02-10-2005, 05:53 AM
Quote:
Originally Posted by kleima
I still have an old Panasonic broadcast camera (SVHS)

Quote:
Originally Posted by Jim Capillo
Sony EVO-9850 Hi-8 editing deck in the rack and it has XLR ins/outs.

I cant help but noticed that thease are antique! Both SVHS and Hi8 are dead formats for video recording for anything but home or casual use. Please consider to archive the material on some other format for future use.

As for the quality of the picture i can understand that you still think that they are broadcast when it is in NTSC or as it called "Never The Same Color". With PAL we have to have better formats than SVHS and Hi8 to able to call it broadcast.

Have i not heard that USA is to end NTSC broadcasting somewhere around 2006?

Quote:
Originally Posted by Jim Capillo
I've edited linear on Panasonic DVC Pro equipment and I don't consider it a "professional" format because I can't hear the audio when incrementing the tape frame by frame.

DVC Pro have an analog audio track that was intended just for better audio scrub? or did you mean somthing else?

Chribba

JReble
02-10-2005, 06:51 AM
Getting into an argument about what it professional or broadcast quality is a futile gesture. There is no single specification that can be used to compare formats or components. Even comparing a single spec like lines of resolution is pointless because the technology changes such that improvements in sampling or frequency response can make one format better than another with more lines of resolution. Here's some good reads on the subjects:


http://www.videouniversity.com/format1.htm

http://www.adamwilt.com/DV-tech.html

http://www.dvcentral.org/DV-Beta.html

From where I sit, there have only been a few rules in practice: If you can broadcast it, it's broadcast quality. If you can make money with it, it's professional.

Now as gear is concerned, I think most will agree that professional equipment is limited to gear that has professional connections, i.e. BNC instead of RCA video connectors, XLR instead of RCA or 1/8" audio connectors, actual meters and indicators instead of on screen displays, etc. etc. etc.. Industrial equipment is usually the scaled down versions of professional formats built to perform specific tasks like automation, dubbing, etc.. Prosumer is normally the equipment designed with typical consumer use features but having higher quality technical specifications than most. The bottom line is, you can buy whatever you want, and whatever you do with it is up to you, but specific features offered in the equipment you choose must meet the technical specification standards for those features. That's why we're here about the XLR levels.

jcupp
02-10-2005, 12:45 PM
I will start by saying that i am living in Europe and if you have lower standards in USA i really apologies for saying this.
I cant call SVHS and High8 as "PRO". Cant recall it ever has been or will be. It has nothing to do if you can switch +4 db -10db. DVC Pro is a "PRO" format, has anyone told you diffrent?

chribba

My Panasonic AJ-D230H DVCPro deck has -10dBV RCA jacks for audio I/O.

I stand by my comment that not all pro video gear has +4dBm audio I/O (even non-antique equipment).

radams
02-10-2005, 12:53 PM
Okay guys enough of the spitting contest...

all of this is just different standards that are used in various ways for various reasons...nothing is more or less pro/consumer...just those more used or offered to work with...

To be fully to date there is AES, SPDIF, Fiber-Lightpipe, ethernet..(yeah there is now a standard for audioi over ethernet)...

So please enough is enough...get back to creating or helping with positive solutions or needs you have rather than this spitting contest..

Cheers,

chribba
02-10-2005, 01:34 PM
My fault that i did not look on the viewing deck. sorry!

But to get to future format and support, why is not Newteks name here?

https://eww.pavc.panasonic.co.jp/pro-av/sales_o/p2/partners.html


Chribba