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[Alan Scobie]

Hi Guys,

I have two g4's running side by side with OSX on one and 9.2 on the other with cubase SX and VST 32 respectively.

I have the units physically side by side and I have developed a hum from the soundcard of the os9 VST 32 machine that is directly related to the fan speed in the OSX machine. (dual 1.2 mirror door) sometimes when certain colours of pages are open on the OSX machine it changes the 'tone' of the hum from the other one.When the machine is off then the other one is silent!

Is this a known issue with mirror door fans being prone to interfere!

Any ideas or suggestions would be greatly appreciated.

I am just shifting over here from the Musicplayer forums amd it looks great here.

Cheers

Alan.

[bobkatz]

Oh my. I assume you're using the sound cards for analog in and out?

This fan-induced noise does not sound like it's caused by an external ground loop, but it is vaguely possible. I would try debugging by connecting a pair of headphones and/or an independent headphone amplifier directly to the analog outs of the sound card in question, and disconnect all other connections to the outside world, then slowly connect them in until you hear the problem again. This would probably be caused by a ground loop.

However, my ultimate suggestion would sound radical to you, but it is the best way around your problem, I think: Avoid usingng ANY analog sound cards...  I know you didn't want to hear that...  but the fact is that the polluting environment within a computer makes it almost impossible to design an analog sound card that is not affected by grounding, power supply, even fan speed interaction (as you have just noticed).

My guess is it would cost you far less in equivalent time and money to convert to an external analog in/out solution (external converters) and just use the sound cards for digital i/o. Either firewire, AES/EBU, or S/PDIF. This would avoid all the possible problems of powering and grounding a sound card within a computer.

If you insist on running analog I/O in your sound card, then I might suggest checking out the Lynx or RME brands, which have been measured as performing as well as or almost as well as external converters. However, watch out for ground loops between your video and other cables and your analog audio going into and out of the sound card. If you run balanced audio throughout you'll probably be all right.

Sorry for the bad news.

[Alan Scobie]

Hi Bobkatz,

Firstly, thank you for your reply.

I apoligize for my lack of clarity in explaining.

Both my units on both machines are MOTU 2408 MK 2's.

It may be strange but the MOTU from the computer that causes the noise is silent while it is the neighbouring Computers MOTU that has the noise??

Even with no external connections, the situation is the same?

Thanks for replying.

Cheers

Alan.  

[bobkatz]

[quote title=Alan Scobie wrote on Sat, 26 June 2004 13:34]Hi Bobkatz,

Firstly, thank you for your reply.

I apoligize for my lack of clarity in explaining.

Both my units on both machines are MOTU 2408 MK 2's.

Oh...  I tried... . but now that changes everything... These units' analog interface is NOT in the computer, and they're independently powered so they should be pretty immune to "deep inside the computer interference." The mystery gets bigger and bigger.  Is there a PCI card involved?

I would try process of elimination. You might want to exchange the PCI cards between the two machines and see if the problem moves with the cards. If it does, then you know that a card is the cause and not the computer or interface or external ground loops.

BK

[Alan Scobie]

Hi Bob,

Thanks, I tried swapping the PCI cards and no change

The cards are the PCI 324 cards that came with the MOTU's.

It does sound and feel related to the fan(s) in the mirror dorr G4. when it goes to 'sleep' and the fan slows down the tone changes. The general note of the noise is a 'G' which I think does suggest mains or motor interference but how it originates is a mystery.

On a completely different note, I followed your links and had a look round your site and work and it looks fantastic and I am happy to have someone of your experience and knowledge replying and posting on these forums.

I am producing an album of my own material for a Colombian girl band and I have been given a relatively small mastering budget by the management! It will be my first foray into this and I wondered what you think of Studio 1 or 5 here-  

http://www.hiltongrove.com/htm/audiomastering.html

Your opinion on this would be invaluable as I don't really know what I am looking for and I am putting quite a bit of faith in the 'house' engineers.

Thanks again.

Best Regards

Alan.

[bobkatz]

Alan Scobie wrote on Sun, 27 June 2004 21:48

Hi Bob, Thanks, I tried swapping the PCI cards and no change

Well, that probably eliminates the cards. So sorry.

Quote:

On a completely different note, I followed your links and had a look round your site and work and it looks fantastic and I am happy to have someone of your experience and knowledge replying and posting on these forums.

Many Thanks. But I feel inadequate trying to figure out your challenging problem! Mr. Klett is much better at this than I!

Quote:

I am producing an album of my own material for a Colombian girl band and I have been given a relatively small mastering budget by the management! It will be my first foray into this and I wondered what you think of Studio 1 or 5 here-   http://www.hiltongrove.com/htm/audiomastering.html

I try not to listen to mp3s... is this in PCM format? Is it already mastered material or a mix?

BK

[John Klett]

Hi

well - let's see if I have this right...  you have two computers and ONE of them has the MOTU card/interfaces while the other is running OSX and does not have interfaces...  and when the OSX machine is off the MOTU's are acceptably quiet.

in addition the noises change depending on various things the OSX machine is doing i.e. fan speed, screen activity, heavy drive access and stuff like that/

is that about it?

I've seen stuff like this and...  forgive me if you explained this already but I am scanning and not completely reading...  you have to look at a couple things

one is proximity of machine to each other and to interfaces... also look at cables being close to each other and so on...  just move things around relative to each other, lift cables away from each other and see if anything changes.

the other is power distribution...  I generally recommend, for small systems like this, getting outlet strips that have some filtering in them.  I've used tripplite with good results

http://www.tripplite.com/products/product.cfm?productID=2460

and - these isobar ones are filtered - which is where you might get some help with line noise related problems

http://www.tripplite.com/products/product.cfm?productID=114

also Belkin PUREAV™ Isolator Home Theater Surge Protectors

I'm not really a big fan of surge protectors in outlet strips because when they trip they often don't completely recover and then leak noise to ground or neutral...  but these seem to better than others and mainly I am going for filtering.

by the way - if you have a Home Depot nearby you should see if they have the big flat Belkin outlet boxes  - they are not filtered but they are well made and not expensive.

So - if you have line FILTERS on the OSX machine and it's associated monitor etc. you may see and improvement...  generally I like to see all the power distributed from one source in small systems where you are not pulling more than maybe 4 or 5 amps...  The quality of ground connections is also a factor.

Mainly it's going to take some detective work - moving things around and upgrading outlet strips...  see what changes etc.

[Alan Scobie]

Thank you guys for a detailed and clear response. John,  I will get busy moving and plugging/unplugging!!

Bob,

You may have mis-understood my request-

I will be mixing the album at what is considered to be one of only a few top end studios in Glasgow, Scotland (http://www.cavastudios.co.uk/) and the link I sent you was a link to the studio in London that will be mastering the album.

I was merely curious to see your opinion of the facility and of the general equipment level as I am a mastering novice and wouldn't know what to look for if it had a sign on it

The emails we have had from them indicate studio 1 0r 5 and they are on the page I posted.
Sorry for the confusion.

I wouldn't dream of sending unsolicited MP3's, I get enough sent to my studio to last a lifetime!!

Cheers guys,

Alan.

[bobkatz]

Alan Scobie wrote on Mon, 28 June 2004 20:20

Thank you guys for a detailed and clear response. John,  I will get busy moving and plugging/unplugging!! Bob, You may have mis-understood my request-

I'm definitely doing a good job of misunderstanding this week! Anyway, now that I got your drift, Alan, I visited the virtual studio. Can't find a mastering equipment list in any of the studios. I do think their website design is cute and impressive, which is probably a good sign. Can you point me to a list of their mastering equipment?

But actually, the mastering tools available should be well below the following:

----the empathy, talents and experience of the mastering engineer and his/her understanding of your music, your desires, and other music in your genre

----room acoustics and monitors

and finally
----the tools and equipment that they use

>The emails we have had from them indicate studio 1 0r 5 and they are >on the page I posted.

I visited all the studios and didn't find any great list of mastering equipment, only mixing equipment. It sounds like they "also do mastering" in their mix rooms, which generally should be a turnoff (I could get into the reasons why in another post if you like).

>Sorry for the confusion.

>I wouldn't dream of sending unsolicited MP3's, I get enough sent to my >studio to last a lifetime!!

I just made a very bad assumption on my part. Please forgive me for assuming that it was a link to a song. But as a mastering engineer, I regularly give free consultations on the mix of a song to my mastering clients so it is not unusual for me to evaluate a clients' mix before mastering, give suggestions as to whether it is "mastering-ready" and so on.

The better the mix that you do, the better that I look  . In the ideal, a mastering engineer might have to do absolutely nothing to a song; that's what the mix engineer strives for. I have a regular "competition" with a superb mixing engineer who keeps on sending me great mixes and they keep on getting better and better----and whether I can find any way to further improve it and not take it downhill. It challenges my imagination---it's getting close!  

Cheers, too...

[Alan Scobie]

Hi Bob,

I am expecting bad news from you on this one!!

The main equipment onthe website is-

B&W 801 Nautilus monitors - offering 20Hz – 20kHz monitoring.
Chiswick Reach Stereo Compressor – Vintage valve compression
Lucid and Audio Design digital convertors.
SADiE Hard Disk Editor - Industry standard audio editor.
Large, acoustically designed day lit studios
TC Electronic System 6000 - high resolution digital audio
mainframe providing EQ, compression, limiting, noise abatement and surround sound processing.
Green Room Stereo EQ - Custom analogue four band parametric equaliser.

In my heart I think I already know your response but please surprise me

If this equipment list and those rooms are the 'mastering' (note it is now in qoutes)rooms, could they enhance my mixes sufficently or are they not 'real' mastering tools.

Cheers for all the advice Bob.

Regards

Alan.

[Alan Scobie]

hi Bob again,

If it is a "we also do mastering' then I would love you to expand on that a bit.

Cheers

Alan.

[bobkatz]

Alan Scobie wrote on Tue, 29 June 2004 13:52

Hi Bob, I am expecting bad news from you on this one!! The main equipment onthe website is- B&W 801 Nautilus monitors - offering 20Hz - 20kHz monitoring. Chiswick Reach Stereo Compressor - Vintage valve compression Lucid and Audio Design digital convertors. SADiE Hard Disk Editor - Industry standard audio editor. Large, acoustically designed day lit studios TC Electronic System 6000 - high resolution digital audio mainframe providing EQ, compression, limiting, noise abatement and surround sound processing. Green Room Stereo EQ - Custom analogue four band parametric equaliser.

Not so bad at all, Alan! I don't know why I couldn't find that equipment list when I went into the site. Anyway, the impression I get is that it is a serious mastering room with dedicated mastering equipment. I could get into questions of whether their complement of equipment is large enough and versatile enough to provide the sound quality that you need, but let me summarize:

1) if the music that you need requires compression or limiting, it seems they are reasonably well equipped, though they do not have the most versatile range of analog or digital processors

2) If the music you need requires very subtle processing or even upward expansion instead of downward compression, then they may not have as large an assortment of tools as they could.

However, a talented mastering engineer working with the equipment above would be able to produce a decent-sounding master with a good source, no doubt in my mind. I could work with that complement! I dont' think I could produce an "exemplary" master with every source I could imagine might come in.... they're missing a few key pieces in my mind, but to repeat, I agree it is a good assortment of tools!

[Alan Scobie]

Bob.....Thank you ....Thank you.

You have made my day  

I was fearing the worst.

The album is 3 girl pop a la Sugababes/ Atomic Kitten/Liberty X
But it has no heavy RnB influence and is more Song-y than programmed. It mixes Real Piano, hammond, guitars, bass with  some programmed drums and perc.
A few tributes to Nile and Bernard on there as well!!

Cheers for all your help

Alan.

If I dare, one more quick question.

The girls will be performing 'live' on some TV prom stuiff in South America and doing a bit of a schools tour as well. They will be singing live over the Backing tracks with some backing vocals still on place. Does the same mastering process apply to these tracks as well. If the album master is completed is it simply a matter of applying the same processing to the no-vox track?

Cheers

Alan.

[bobkatz]

Alan Scobie wrote on Tue, 29 June 2004 14:29

If I dare, one more quick question. The girls will be performing 'live' on some TV prom stuiff in South America and doing a bit of a schools tour as well. They will be singing live over the Backing tracks with some backing vocals still on place. Does the same mastering process apply to these tracks as well. If the album master is completed is it simply a matter of applying the same processing to the no-vox track? Cheers Alan.

Oh, dare, dare! Well, I always question whether it is necessary to master the no-vox tracks at all; when there's a tight budget I simply recommend they take the raw tracks and cut a CDR and play it over the PA system. But it can be the icing on the cake, and some clients want everything mastered. Nine times out of ten the same processing that I do for the full mix works for the no-vox (track), or with a tiny adjustment or change in EQ, perhaps.

[Alan Scobie]

Thanks Bob,

My mind is at rest.....you made my day

Cheers to you

Alan.