Problems Recording from Mackie CFX12 to Computer

[SampleX]

Hi gang,

I'm a n00b here and signed up to be able to ask a question of the wise who, no doubt, already have the answers to my problems...

I've been put in charge of modernising a church 'recording' system with a view to preparing audio files for a website, most specifically I'm charged with simplifying the work flow for this effort.

We currently have a very simple, very adequate setup and in the past have recorded to now-obsolete audio cassettes. We also have a Pioneer CD Recorder (consumer, not computer) in the stack where previously we have been able to take a CD recording and then rip to computer, remove track breaks and then edit down and resample for the net.

I wanted to go even simpler than this, recording directly into the computer, but I've had some bizarre and unexpected results.

First week out was the weirdest, about four weeks back...

Our setup runs pretty much like this:

All instruments and Mic's go into a Mackie CFX12, and for PA we use SRM-450's. We were running a 'tape out' from the Mackie to a tape deck, then the tape out of the tape deck was run into the line in of the CD recorder and the CD Out of the CD recorder ran into the AUX channel on a standard stereo amp (Sony) for playback in our overflow/creche through normal stereo speakers. The system worked perfectly for years and the signal flow was as follows:

Mixer (Tape Out) --> Tape IN (Tape Out) --> CD IN (CD OUT) --> AMP

I just need to emphasise again, that while whoever set this up originally didn't follow the 'best practice' rules, this setup really worked and we had some pristine CD and - ahem - tape recordings of a genuine representation of the sound board mix.

Now, if I were redoing this, I would run the Tape Out of the Mackie to the AMP AUX IN, and then run outputs from TAPE 1 and TAPE 2 of the amp to the tape deck and the CD recorder respectively, so that the AMP gets the first signal and the two recording devices get the same signal independently of each other. In fact, in recent weeks we've tried using elements of this signal flow as we mess around with trying to get the computer in on the signal.

So... the weirdness begins as follows.

I decided to use my ever-present Samsung NC10 (Atom Netbook) as my primary recording device for portability's sake, so I installed both Adobe Audition and Sony Sound Forge, as well as Audacity and tested that they seemed to work even on this low-CPU computer, and everything appeared to be fine.

Since we were not going to be using the CD Recorder if the computer was going to work, what we did the first week was to simply bypass the CD Recorder and cut out the overflow feed, which we didn't need that week, and so the signal flow ran as follows:

MACKIE (Tape Out) --> Tape IN (Tape OUT) --> Samsung NC10 Audio IN

Emphasis is that the TAPE deck was still the first device to receive the signal, and would be passing a signal to the computer, not receiving one from it. I make this note because I SO did not expect what happened next...

The Mackie was connected via Cambridge Audio premium RCA (phono) cables to the tape, the tape via the same cable type to a 'Y' adaptor to convert a stereo phono pair (RCA) to a single stereo 3.5mm jack into the computer.

With the Samsung Audio IN (which I now know to be a 'MIC IN' jack) plugged in, the REC LEVEL on the tape deck suddenly went through the threshold and into nearly constant red (signal clipping) and adjusting the REC LEVEL on the tape deck didn't alter that. The signal into the computer also went similarly hot and but levels could be normalised by turning the REC LEVEL on the tape deck way down, even though this didn't make the slightest difference to the tape deck itself. If I unplugged the cable from the computer rec IN, the levels immediately went back to normal and the REC LEVEL had to be turned up to give the tape deck a workable signal. This was the same whether the audio software on the computer was Sony or Adobe or Audigy.

Further tests and attempts to verify that the right cables were plugged in the right places yielded the same results, and I concluded that there was some kind of issue with the computer port being a MIC IN rather than LINE IN which was somehow causing some kind of surge in gain or something, don't know the science behind 'why', but would love to...

Nonetheless, by forgetting about the recording on the tape (which would have had the levels blown out I presume), by reducing the REC LEVEL on the tape deck until the signal monitoring on the NC10 produced a consistent signal within acceptable peak ranges, the computer picked up a perfect recording of the message that morning, maybe a little less rich than the soundboard mix itself, but as near as anything I've ever heard, all directly into the MIC IN jack on the NC10, which probably doesn't actually have the best sound card in the world anyway.

Anyway, I decided to move on to plan B and I remembered that I owned a Griffin iMic which was originally purchased to allow an Apple iBook (sans audio ports) to be used to transfer audio tapes into the computer for editing, de-hiss and digital conversion. The principle of the iMic is essentially an analog/digital converter to USB and the device is compatible, allegedly, with the Windows XP running on the Samsung Netbook as well as Mac OS X.

So the next week I went to set up the recording equipped with the iMic which, after a bit of fiddling, the NC10 recognised and would receive a signal from. The iMic is switched into LINE IN mode rather than MIC, and appears to cause no clashes. I also concluded that in the absence of a power amp in the mix, the MAIN OUT on the Mackie was basically the same line output as the TAPE OUT, just using different cables (TSR instead of RCA), so I decided that since the 'MAIN OUT' was not needed since the PA system was running on self-powered SRM450's on the MAIN OUT XLR channels, I cable-converted the MAIN OUT's TSR's to RCA's into the AUX channel of the overflow amp, and then ran an RCA pair from TAPE 1 OUT on the overflow amp to REC IN on the CD Recorder. This, incidentally, works perfectly. I was then able to use the TAPE OUT from the Mackie via the Y adapter to the LINE IN on the Griffin iMic into the NC10 by USB.

The downside to this is that I haven't been able to set up live monitoring of the signal being recorded into the computer, so I've had no idea until now WHAT was being recorded. Nonetheless, for three weeks we've run this system, and sure enough not only does the CD record, and the overflow works, but the NC10 running EITHER Sony Sound Forge or Adobe Audition has been able to record single stereo tracks featuring the audio from the mix on the Mackie without any apparent issue. Audition simply records the track in 'real time', while Sound Forge gives me a 'monitoring' panel in which I can see signal levels on a live chart and in which they never 'red line' but seem to peak at about three quarters the available level, usually hovering around 50% on the meter. I noticed on the tracks as they were recording that I didn't have a big dramatic 'wave' to observe, but rather a very understated, seemingly muted, waveform, even when magnified significantly.

I started to wonder if I was getting a very low 'line' signal and would somehow need to boost amplitude in order to make it more listenable, but I couldn't specifically see any settings to let me do that 'live' or to preview it. Nonetheless, I thought it was simply something I could do later.

Until this week...

I came to sit down with the three audio files we had, and start to listen to them, edit them, work with them, and what I heard was simply horrible. It was very low indeed, even on headphones and the computer on full volume, and worse than that, it sounded hollow, stripped and like there was some kind of 'phase' fluctuating on the signal as even background ambient noise seemed to soar and then dip variously throughout the recording.

To be honest my first thought was 'is this what's been coming out of the mixer? is this what people hear? has someone 'dusted' the board and changed EQ settings? is this what we're recording?' and so I went down early today to find out.

What I safely concluded was that what the computer is receiving from the TAPE OUT on the Mixer via the iMic to USB is NOT what the mix from the Mackie actually sounds like live, nor is it what the Mixer is delivering via MAIN OUT (XLR) to the powered speakers, nor indeed is it what the Mixer is delivering via MAIN OUT (TSR) to the overflow amp and the CD recorder. In fact, it isn't even what the Mackie is delivering via TAPE OUT when the TAPE OUT connects directly to the overflow amp or even the CD Recorder.

The amp mix, the headphone monitoring on the Mackie, and the CD Recording made this morning all sound loud, clear, rich, and exactly what I would expect from my sound mix out of the Mackie.

In short, either the iMic is chuffing things up, or the computer is chuffing things up, or there's something I'm not doing/the equipment is all wrong.

Unless someone can tell me that the Atom powered NC10 is somehow so limited in power that it is the CPU in the machine which is injecting these problems, which I find hard to imagine because I've read on the 'net of other NC10 users using their pooter for digital audio recording in live situations, then I've got to go with either the iMic is unsuitable, or there's something else that I'm missing.

I remember in the 'old days' using a Digidesign AudioMedia 3 card and ProTools on a PowerMac to record from taped messages to computer hard disk, and because the Audiomedia 3 interface was a non-powered PCI card with RCA inputs we would have to run the tape RCA OUT into a Loom 4 channel 9v battery powered micromixer and then back out of the Loom into the Audiomedia 3 in order to boost the gain on the inputs so as to be able to give ProTools an adjustable gain level in order to set the input to just below the clipping threshold. I assumed that in the 'USB Analog/Digital Converter' days that signal was just signal and no such micro-mixer based gain'd input would be needed, especially as I'm currently unable to even undertake real-time monitoring of what the pooter is receiving. Is it this simple? Is that what I needed to do? That still doesn't account for why it isn't simply a low level signal that is recording, it doesn't account for the pinched, nasal, nasty-EQ phasey sound that I'm actually recording which sounds like robotic digital garbage.

Incidentally, today I ran both Sound Forge and Audacity recording on the iMic input simultaneously, and they both recorded the same crap, so the phenomenon is independent of the application. I did notice what appeared to be a live input gain setting on Audacity, which didn't discernibly alter either the quality of the signal, or for that matter have much influence on the level. The overflow amp system and the CD Recorder got perfect recordings

Is the NC10 the wrong machine?

Is the Griffin iMic the wrong external sound to USB adapter?

Am I missing a stage here?

The iMic has a setting to allow you to switch the input of the iMic from 'Line' to 'Mic', and I even tried setting it to 'Mic' instead of Line using the same TAPE OUT feed from the sound board to see if that yielded even a different recording, but it didn't make a noticeable difference.

The fact that the first recording we did sounded very good indeed using the plain old Mic IN on the Samsung but needed the TAPE REC LEVEL to be adjusted almost as if it were being activated like a volume/gain control reminds me of the faffing about with taking a signal from a tape deck into a micromixer and then into the Audiomedia 3 card on a Mac, but surely these external USB devices are designed to do away with that stage?

By default, all the recordings made so far (one good in a bad setup, and four bad in what appeared to be a good setup) have had the same 'default' settings in Sound Forge, using a sample rate of 44,100 Hz and a 16 bit-depth, stereo channel.

I'm sure that someone is going to tell me (and I can make clips of these different audio recordings if you want to message me, so you can hear what I'm talking about in terms of the difference between the 'good' recordings without the iMic, and the bad recordings with the iMic) that I'm an idiot, and that the answer is elementary, and it probably even has something to do with the theory behind what is a 'LINE' level signal and what is a MIC level signal, and what should be attenuated, and yada yada... I didn't go to sound engineering school... I know computers, and I know how to create music with instruments, and I even know a tiny bit (evidently) about how to do some rough mixing with the Mackie and get the sound levels right in our premises. This is just beating the stuffing out of me right now, so be gracious.

I'm sure its very easy to someone, and I'll probably go 'oh, what a doughnut...' but I'd love to know WHAT it is that I'm doing wrong, WHY it is wrong, and what to do next.

Is it as simple as the iMic being duff? Should I be using an M-Audio Transit? I can handle having to replace a piece of kit if and only if that's definately what it is... I wouldn't want to go out and buy 'better kit' because of someone's theory that the Griffin iMic is crap and should be binned, only to find that it makes no difference at all.

I also have, available to hand, a Mackie Spike Recording interface, which I could try. The reason I haven't started out with the Spike on this project is simply portability and convenience.

Can anyone please help me with this?

I've tried to give as full an account as I can, sorry if I bored you, but I'm sure that someone out there knows either from experience or because they have impeccable Digital Audio knowledge EXACTLY what this problem is and why...

Please help.

Thanks,

S.

 

[mixsit]

Ok, first off I wouldn't even try to advise on the computer/interface gear, but basic trouble shooting... Define and isolate problems. This might help writing about this stuff too. Pare it down to the clear specifics -skip the filler.

What I safely concluded was that what the computer is receiving from the TAPE OUT on the Mixer via the iMic to USB is NOT what the mix from the Mackie actually sounds like live, nor is it what the Mixer is delivering via MAIN OUT (XLR) to the powered speakers, nor indeed is it what the Mixer is delivering via MAIN OUT (TSR) to the overflow amp and the CD recorder. In fact, it isn't even what the Mackie is delivering via TAPE OUT when the TAPE OUT connects directly to the overflow amp or even the CD Recorder.

After my eyes cleared..
a) What the hell was that? Is the signal(s) out of the Mackie good/the same or not? Clear up the questions on the analog side- Simplify, and/or break down that goes'inta/out'a chaing until your clear what's what.
b) Settle on a way to get the computer end working. A simple CD player out -that would be line level- (but may be slightly lower than what the mackie puts out) in to the recorder' as a tester.

With the Samsung Audio IN (which I now know to be a 'MIC IN' jack) plugged in, the REC LEVEL on the tape deck suddenly went through the threshold and into nearly constant red (signal clipping)..

None of you chain is mic level' -that is a very low voltage compared to 'line in.
c) Along with the digi' trouble shooting- poor/wrong gain staging would typically mean distorted or very weak signal with high noise. 'Hollow sound is something else.
Again, break it down to simple (and successful) pieces, then add things (the variables) back in.

 

[mixsit]

..I've tried to give as full an account as I can,

Actually, although I almost gave up half way through.. most guys' do the the opposite needing info dragged out of them piecemeal it seems. Better this than that!

 

[SampleX]

Ok, first off I wouldn't even try to advise on the computer/interface gear, but basic trouble shooting... Define and isolate problems. This might help writing about this stuff too. Pare it down to the clear specifics -skip the filler.

After my eyes cleared..
a) What the hell was that? Is the signal(s) out of the Mackie good/the same or not? Clear up the questions on the analog side- Simplify, and/or break down that goes'inta/out'a chaing until your clear what's what.
b) Settle on a way to get the computer end working. A simple CD player out -that would be line level- (but may be slightly lower than what the mackie puts out) in to the recorder' as a tester.

None of you chain is mic level' -that is a very low voltage compared to 'line in.
c) Along with the digi' trouble shooting- poor/wrong gain staging would typically mean distorted or very weak signal with high noise. 'Hollow sound is something else.
Again, break it down to simple (and successful) pieces, then add things (the variables) back in.

Well, I WAS trying to break bits down. That's how I narrowed it down to 'either its the hardware, or its a part of the process that I'm missing. In general, someone with experience of both these types of problem should be able to immediately work out which one it is.

If the device is wrong, then quite simply its wrong.

If someone says 'yeah, you can't run a line out from a mixer or a tape deck into an iMic on a computer running Sound Forge and expect to get a good recording, instead you should be running that signal into some kind of a device that can boost gain because the iMic does actually respond to gain on the signal rather than just 'normalising' it as an entirely line level device', then that's something too.

With respect to the difference between 'distorted or very weak signal with high noise' being different from 'hollow sound', not really... This is the crux of trying to explain what I'm experiencing. I wouldn't know what 'distorted or very weak signal with high noise' sounds like specifically, but 'hollow sound' is something I can wrap my head around which might be one and the same thing...

I should probably make sample clips available.

What I'm describing, as I tried to say, could possibly be very well construed as 'distorted or weak signal with high noise.' It certainly isn't a strong signal, the volume is incredibly quiet and the sound is distorted, almost digitally garbled, there seem to be digital 'artifacts' in the sound, noises that could only come out of the digital process. The audio range sounds pinched together, compressed, lacking depth and richness, 'hollow', tinny.

The first recording, taken straight from the tape deck into the Mic IN on the computer, once adjusted for gain using the REC LEVEL control on the tape deck, recorded perfectly in terms of audio quality.

For whatever reason the recording of the same sound source (Mackie desk) into the same computer and the same software via direct Line input into an iMic has not yielded remotely acceptable results.

THAT is the problem. I can't think of how to narrow it down any more than that without replacing the hardwares involved UNLESS someone with experience can say 'your setup is missing a stage' or 'the hardware is wrong' or something else affirmative.

Thats why I posted for help.

I appreciate the effort, but I plainly know that this is a process of elimination and it might involve trial and error to work out 'what' exactly is wrong... That's why I came to a forum of experts.

With regard the 'what the hell was that' comment, I don't know how else to explain it clearly... What the computer is recording is NOT what the soundboard is outputting, it is a corruption of it. In other words, the signal out from the Mackie is consistent in its output, therefore the problem HAS to be in the workflow from the iMic to the computer, to the recording on the hard disk. In other words, 'it definately ain't the mix on the mixer, or the outputs on the mixer.'

I'll give it a try connecting a CD player to the computer directly, and also via the iMic, and then I will probably try rectifying any problems I find with that by experimenting with the LOOM micromixer to give me an adjustable gain in the signal path.

The reason I posed the question is that somewhere, on this forum, is someone who already knows whether this signal path from mixer to computer needs an adjustable gain boost in the path, or whether it should just run straight to the iMic, or indeed whether there is another device than the iMic which WOULD do the job. It might not be practical in the long run, but I'm looking for this setup to be simplicity personified so that a monkey could actually run it. Incorporating a micromixer and experimenting to set levels every time there is some degree of change in the sound mix is a PITA if there's a solution whereby someone can say 'buy an XYZ AudioMagic USB Box' and it will do everything you want with little more than just the signal from the mixer's 'tape out' channel.

Anyway, thanks for the input. Certainly gives me plenty to work through.

 

[mixsit]

What I'm describing, as I tried to say, could possibly be very well construed as 'distorted or weak signal with high noise.' It certainly isn't a strong signal, the volume is incredibly quiet and the sound is distorted, almost digitally garbled, there seem to be digital 'artifacts' in the sound, noises that could only come out of the digital process. The audio range sounds pinched together, compressed, lacking depth and richness, 'hollow', tinny.

The first recording, taken straight from the tape deck into the Mic IN on the computer, once adjusted for gain using the REC LEVEL control on the tape deck, recorded perfectly in terms of audio quality.

For whatever reason the recording of the same sound source (Mackie desk) into the same computer and the same software via direct Line input into an iMic has not yielded remotely acceptable results.

In that case, i.e, if the only difference is level- then reducing the output from the mackie should be a good test of the whole chain, and whether your distortion or 'hollow is due to something else going on in software (compressed', pinched together'?).

With the Samsung Audio IN (which I now know to be a 'MIC IN' jack) plugged in, the REC LEVEL on the tape deck suddenly went through the threshold and into nearly constant red (signal clipping) and adjusting the REC LEVEL on the tape deck didn't alter that. The signal into the computer also went similarly hot and but levels could be normalised by turning the REC LEVEL on the tape deck way down, even though this didn't make the slightest difference to the tape deck itself. If I unplugged the cable from the computer rec IN, the levels immediately went back to normal and the REC LEVEL had to be turned up to give the tape deck a workable signal. This was the same whether the audio software on the computer was Sony or Adobe or Audigy.

For instance this is fairly bizarre.

Also do you not have the info you need on how your sound cards and software work?

 

[oretez]

OK, to keep things really simple

Did you record a tape from the Mackie? Are the levels on that tape appropriate?

Have you tried recording to the computer directly, without daisy chaining through the tape?

Rather obviously I'd recommend removing tape deck from the chain while you are diagnosing the issue.

(as an opinionated aside even a low rent onboard soundcard is going to have higher signal to noise ratio then a cassette deck so, particularly if you are primarily interested in spoken word material, I'd suggest either recording in parallel or A/D card first then the D/A to tape deck (if you need the cassettes)

(another great example of 'if it aint broke . . . Just what is it you were trying to fix?')

 

[SampleX]

In that case, i.e, if the only difference is level- then reducing the output from the mackie should be a good test of the whole chain, and whether your distortion or 'hollow is due to something else going on in software (compressed', pinched together'?).

For instance this is fairly bizarre.

Also do you not have the info you need on how your sound cards and software work?

Thanks for your efforts, but really... have you any idea the configuration of the equipment that I'm talking about? Are you even reading what I'm trying to be as descriptive as possible about.

I write 'the level is very low and the sound digitally garbled, the range compressed, the EQ hollowed out, and you come back with 'in that case if the only difference is level.....'

It isn't the only difference. I've said that already.

Then you said 'reducing the output from the Mackie...' It's a LINE OUT. A LINE OUT, even in my limited knowledge is good for two things - either a) inputting into a line level recording device or b) outputting to a power amp to amplify the signal. It's a Mackie CFX12 with a 'MAIN OUT' or a 'LINE OUT'. There isn't a volume control on it to adjust it... it's just a Line Out.

http://www.mackie.com/home/showimage.html?u=/products/cfx12mkii/images/ZOOMED_CXF12mkII.jpg

The only gain controls on the mixer are those which affect the actual mix itself, and that's not what I'm trying to do. The Line Out works just fine to a CD Recorder or to a Tape Recorder or to an external power amp. It just won't work into the Line In Jack of a Griffin iMic for the purposes of computer recording.

And that big 'why?' is what I'm trying to get to the bottom of.

The distortion and 'hollow' CANNOT POSSIBLY have anything to do with some other setting in the software because the software is unchanged between a good recording and a bad recording - the issue is introduced as a result of the change of signal path through multiple devices which all need to feed off this signal and the change SHOULD be a no-brainer because it is now utilising the most direct path from mixer to computer that is imaginable, but something is either not handling the job correctly, or I've missed a stage or principle in the whole process. Right now all evidence points at the iMic being either the wrong device, or the means of using it being more complex than I first thought. Someone, somewhere can tell me exactly which, because they've done it themselves, and kicked themselves for getting it so wrong in such an elementary fashion...

As for how the soundcards and software work...

Yes. I have a Samsung NC10 with built in Realtek Sound Card. It has a jack marked 'mic in'... that's no use to me. So I have a Griffin iMic which has a Line In jack and connects via USB. It's instruction sheet can be summed up as 'plug it in, connect device, is it in the right socket, whoopee!' As for the software, the software is a receiver of a signal. Crap in, crap out. The recording software isn't the mystery. Why the equipment chain is turning a good signal into a crap one is the mystery. Software can't change that or make it better any more than changing your tape deck can fix the fact that it is receiving a crappy signal.

 

[SampleX]

OK, to keep things really simple

Did you record a tape from the Mackie? Are the levels on that tape appropriate?

Yes and yes.
Also recorded to a CD Recorder.
Both devices have the on-board 'REC LEVEL' which I'm starting to guess is actually a gain control to boost the signal rather than a 'gate' to limit the signal unless anyone can correct me on that.
I can't say that the 'levels were appropriate' without knowing whether the 'REC LEVEL' control is reducing, or boosting gain. I don't have a tape deck or CD recorder WITHOUT a REC LEVEL control to test what the signal sounds like just from a straight recording.

Have you tried recording to the computer directly, without daisy chaining through the tape?

Yes. It has been the only way I could get a pure signal, which of course I would need to have in order to be troubleshooting.

I'll reiterate... when the signal was passed to the TAPE IN on the tape deck and then the computer MIC IN was connected to the TAPE OUT on the tape deck, which is a common practice in setups which use both CD Recording and Tape Recording, certainly in my 'field' of recording, the REC LEVELS on the tape deck slammed through the roof, into red zone, and the only way to get the one good recording we have on the computer was to use the tape deck REC LEVEL control like it were a pre-amp gain, dropping it right down gave the computer a really nice signal, but was, of course, no good at all for a recording on the tape deck.

We felt that this 'daisy chain' setup should have been the most logical way of sharing the signal because we assumed that one 'line' device is like any 'line' device. Clearly there's something in the theory and practice of recording devices that I'm missing.

We began to work on this new (purer) method using the iMic BECAUSE of the unexpected incompatibility in the signal path, and because of the understanding that the computer's own 'line in' was actually a Mic IN and therefore not suitable for direct connection.

I should add, then, that the latest attempts to record, which I mistakenly assumed were all good for a period of 3 weeks, are indeed on a pure signal path, no other devices in the mix, just mixer, iMic and Samsung NC10. That same signal, using the same cables and the same mixer output has been PROVEN to record perfectly well in tape deck and in CD Recorder, but the computer recording for some reason just ain't having it...

Rather obviously I'd recommend removing tape deck from the chain while you are diagnosing the issue.

As stated from outset, already done...

(as an opinionated aside even a low rent onboard soundcard is going to have higher signal to noise ratio then a cassette deck so, particularly if you are primarily interested in spoken word material, I'd suggest either recording in parallel or A/D card first then the D/A to tape deck (if you need the cassettes)

We've made use of the 'TAPE OUT' on the mixer as well as a 'MAIN OUT' in order to separate and isolate two 'parallel' paths. The MAIN OUT goes to our 'analog' recording set up (consisting of a stereo amp (to overflow facilities) and two 'TAPE OUT' channels, one of which is received by tape deck, the other by standalone CD Recorder) and the TAPE OUT (LINE OUT) goes directly to the computer and the iMic LINE IN. We get a perfect recording on the analog stack, and we get this digitally noisy, garbling, warbling, gasping, pinched, hollowed out low-volume rubbish on the computer. We can swap the signal paths over, and yield exactly the same result, proving that both signal paths from the mixer are good, and the 'difference' has to be related to the computer hardware, either machine or iMic.

I'm now trying to narrow down whether this is a hardware fault, or whether I'm being a dolt and the setup for this kind of recording simply cannot be as simple as I've tried to make it.

If I could frame a question another way, to get me closer to an answer, it would be this...

If the Griffin iMic, which gives a computer an external (therefore less noisy) LINE IN digital converter to USB, can accept a direct connection from a TAPE OUT on a tape deck in order to pass the tape's analog content into a computer (which is what the iMic is 'sold' as being capable of doing) WITHOUT having to use micromixers (external gain controls) to adjust/boost the input signal strength, then why can't the TAPE OUT from a device like a mixing desk do exactly the same thing?

Aren't 'LINE LEVEL' sources all equal? Aren't line level inputs all equal? Whatever I'm missing, unless the device is actually faulty, MUST be in this ballpark of discussion, it HAS to be the crux of the matter, surely.

I'm just trying to establish whether the theory and practice of these principles has precedent, experience, to tell me what I'm doing is right or wrong, before I conclude that the iMic is crapped out, and needs to be replaced with something better.

As it stands, until I understand what's going on, I could go out and buy another external DAC/soundcard/device to convert a LINE IN (analog) to digital signal via USB and get exactly the same results, because it isn't the device, it's the principle and practice of how I'm trying to get it all to work...

(another great example of 'if it aint broke . . . Just what is it you were trying to fix?')

But it obviously is 'broke' in general... I'm just trying to work out which 'bit'...

 

[mixsit]

Aren't 'LINE LEVEL' sources all equal? Aren't line level inputs all equal?

No. Ever hear of -10 and +4?

Which is why I was simply asking if you tried REDUCING the mackie out put level as a tesy to get it OUT OF THE WAY AS A VARIABLE. (and please, don't come back with 'there's no Tape out control. It's just a frikin temporary test.
jeez. Trying to help here.

 

[oretez]

Aren't 'LINE LEVEL' sources all equal? Aren't line level inputs all equal? Whatever I'm missing, unless the device is actually faulty, MUST be in this ballpark of discussion, it HAS to be the crux of the matter, surely.

no nominal input and output voltage tend to fall in general categories, classes but there is a huge range . . . but that issue is not your primary issue (in all probability)

trying to trouble shoot this stuff via distance communication is frustrating at best even if individuals are speaking the same language

I asked the questions I asked because, to me, the answers were not clear . . . and what wasn't broke, to all appearances, was what was working prior to changing things

to me it's obvious, for what I do (and in a general way I track audio in a similar way to what I interpret as your goal pretty much daily with a wide variety of equipment) the imic is neither the most flexible nor robust A/D tool for the job . . . but I have no experience with it so have no opinion concerning its ability, since you already have it, to accomplish your task

some if not most computers that only had two audio sockets (in and out) permitted the 'in' to be configurable between 'mic' and 'line' voltage via software if you haven't investigated that if might be worth the effort and try your preferred signal path with on board sound. It makes obvious, to me, perfect sense that if you plug a tape out into a mic in that you will clip downstream from that input . .. if using the imic with ostensible line input didn't help, can't say, but the first simplest explanation is that imic is not appropriate tool (but as that plays into my knee jerk 'gut' reaction to imic I would also be forced to reexamine the assumption more critically (if I were doing the trouble shooting)

if you have parallel outputs I would tend to not daisy chain but feed the cassette recorder via 'tape out' and the computer through mains (not through PA amp'd levels but pre amped mains . . . and it would not be unusual for nominal levels of those to be different) Most Windows audio software makes no effort to control input levels directly. That is controlled via OS (Windows 'volume' control) or console supplied with drivers for the A/D device making sure the computers input options are set appropriate can obviously impact your recording

Not saying that you can't daisy chain just not sure from the description of what you are trying to accomplish with that approach or why you would want to, generally speaking (very generally) with audio you daisy chain only when you have no other option . . . There are reasons, far beyond mere fashion, why people spend $600 on DI boxes and a simple 1 into 2 mic splitter starts at about $60 . . . Diagnosing anything daisy chained becomes multiplicaticatively more difficult. If you can configure you computer's on board to work at line level send a signal from mixer to computer via what ever the shortest route possible might be . . . Set appropriate recording levels then gradually increase complexity of signal routing from that baseline

Theoretically between cassette and computer the 'better' capture is going to be computer. If you need a cassette typically you are better off going from computer to cassette rather then other way around (there are variables, self noise of the computer hardware, that can influence that basic idea)

essentially you have a very simple set up that should not be producing the types of problems, if you are still experiencing problems, you seem to be having. looked at iMic in hope that somehow it was set up as telephony tool and that, that might somehow explain your issue

and to be quite honest I am a bit less certain concerning what type of response from the forum you're looking, following the last post then I was after the first

if you can get acceptable recordings from mixer to computer what's the current issue?

In any case good luck

 

[SampleX]

No. Ever hear of -10 and +4?

Which is why I was simply asking if you tried REDUCING the mackie out put level as a tesy to get it OUT OF THE WAY AS A VARIABLE. (and please, don't come back with 'there's no Tape out control. It's just a frikin temporary test.
jeez. Trying to help here.

By all means, tell me where that switch is on the Mackie CFX12.

If what you mean is 'if you turn the master fader all the way down does the computer still record digital garbage' then the answer is no. But of course, it might have sounded smart to quote a bit of rocket science at the dumb n00b, but it didn't actually prove a single thing did it?

Conclusion: if I turn the master fader on the mixer down there's less coming out of the PA system, there's less going into the tape deck, there's less going into everything...

As far as I remember the question didn't relate to whether reducing the level of the signal routing through the mixer would actually possibly reduce the level of signal leaving the mixer... the question was about why the signal records fine on the CD and tape decks, and not on a computer...

I'm of the thinking that you're overcomplicating this more than I am... That's why I said 'someone who knows this problem and knows the answer already could answer it', because if you don't know the problem and you don't know the answer, all you're doing is talking me through the same trial and error that I could put myself through...

So fine... I'll play. When I turn the master slider down on the Mackie mixer, there's less of everything, so yes, there's less digital crap on the recording, not that the recording is a damn bit of good to me using this as a means of getting rid of distorted and artifacted, compressed digital audio.

Can you explain to me how many paces forward I moved with that exercise?

 

[SampleX]

no nominal input and output voltage tend to fall in general categories, classes but there is a huge range . . . but that issue is not your primary issue (in all probability)

trying to trouble shoot this stuff via distance communication is frustrating at best even if individuals are speaking the same language

I asked the questions I asked because, to me, the answers were not clear . . . and what wasn't broke, to all appearances, was what was working prior to changing things

to me it's obvious, for what I do (and in a general way I track audio in a similar way to what I interpret as your goal pretty much daily with a wide variety of equipment) the imic is neither the most flexible nor robust A/D tool for the job . . . but I have no experience with it so have no opinion concerning its ability, since you already have it, to accomplish your task

some if not most computers that only had two audio sockets (in and out) permitted the 'in' to be configurable between 'mic' and 'line' voltage via software if you haven't investigated that if might be worth the effort and try your preferred signal path with on board sound. It makes obvious, to me, perfect sense that if you plug a tape out into a mic in that you will clip downstream from that input . .. if using the imic with ostensible line input didn't help, can't say, but the first simplest explanation is that imic is not appropriate tool (but as that plays into my knee jerk 'gut' reaction to imic I would also be forced to reexamine the assumption more critically (if I were doing the trouble shooting)

if you have parallel outputs I would tend to not daisy chain but feed the cassette recorder via 'tape out' and the computer through mains (not through PA amp'd levels but pre amped mains . . . and it would not be unusual for nominal levels of those to be different) Most Windows audio software makes no effort to control input levels directly. That is controlled via OS (Windows 'volume' control) or console supplied with drivers for the A/D device making sure the computers input options are set appropriate can obviously impact your recording

Not saying that you can't daisy chain just not sure from the description of what you are trying to accomplish with that approach or why you would want to, generally speaking (very generally) with audio you daisy chain only when you have no other option . . . There are reasons, far beyond mere fashion, why people spend $600 on DI boxes and a simple 1 into 2 mic splitter starts at about $60 . . . Diagnosing anything daisy chained becomes multiplicaticatively more difficult. If you can configure you computer's on board to work at line level send a signal from mixer to computer via what ever the shortest route possible might be . . . Set appropriate recording levels then gradually increase complexity of signal routing from that baseline

Theoretically between cassette and computer the 'better' capture is going to be computer. If you need a cassette typically you are better off going from computer to cassette rather then other way around (there are variables, self noise of the computer hardware, that can influence that basic idea)

essentially you have a very simple set up that should not be producing the types of problems, if you are still experiencing problems, you seem to be having. looked at iMic in hope that somehow it was set up as telephony tool and that, that might somehow explain your issue

and to be quite honest I am a bit less certain concerning what type of response from the forum you're looking, following the last post then I was after the first

if you can get acceptable recordings from mixer to computer what's the current issue?

In any case good luck

And now I'm more confused than I was before...

Where did I say that I was getting acceptable recordings from mixer to computer?

Where did I say that the devices were daisy chained?

I specifically stated that the 'acceptable recording' came from the practice of daisy chaining, and that the method chuffed up every device IN the daisy chain EXCEPT for the computer which only got an acceptable recording by chance because I discovered that I could use a control intended for onboard use on the tape deck to have a curious side effect of manipulating the levels of the signal so as to be recordable by the computers...

All latter (three weeks of experiments) recordings were made using parallel and seemingly identical signals, and the computer cannot make good recordings from this signal, in fact they're abysmal, while the other 'parallel' devices CAN. The analog path is not so much 'daisy chained', but rather set up appropriately, the signal passing to an amp and then to the appropriate active line-out channels for 'Record Out' from the amp to the devices. The computer (and iMic) is in a chain of its own.

To try to narrow the issue, the iMic COULD be the point of issue. It was not in use when I got the 'good' recording, but equally the 'good' recording came from a 'bad' setup and I'm starting to suspect that the setup went bad because of some fundamental issue relating to the output signal being mismatched to a 'MicIn' jack on a basic netbook. I can find no controls which switch this from MicIn to LineIn. That said, the iMic HAS been used previously, on another computer, to connect a tape deck to a computer to digitise a standard analog audio source on tape. If the iMic IS faulty then it has become so suddenly, and if the iMic is unfit for this purpose, I can accept that, except that it is marketed the same way as every other USB based D/A converter (external sound card) and I can see no indications in online forums that this device shouldn't work. More to the point, I'm hoping someone can say 'ahhhh... I know what the problem is' and then proceed to tell me that the output of a tape deck is very different to the output of a mixer, and that I need to boost gain on the mixer output or something, in order to get a usable signal into the computer, and that this is something that the tape deck signal doesn't need to do...

As I've said before, I don't know the theory behind all this, or the practice, but to me 'line level' is 'line level' is 'line level' and should be the same for all devices with a 'line out.'

I understand a principle that in converting analog to digital the 'listening' digital device which is intended to make the recording must be able to 'hear' the signal properly to do so, and that this might be controlled by some kind of gain/volume control. Perhaps the computer is like the listener, and the mixer like the tape deck, the iMic like the speakers, but is needing an 'amp' in the equation by way of a micromixer or some other device which somehow 'injects' signal gain. If this is what the problem is, someone say so and give me an idea of the best way to fix it.

Forget the tape deck and the cd recorder for now. They were introduced to the story to illustrate the problem that I got by daisy chaining and using the MicIn port on the laptop, and then latterly to illustrate that the two devices get perfect recordings from a parallel identical signal from the mixer, therefore ruling out the mixer as the source of the problem.

It's as simple, now, as this: from mixer tape out to iMic Line in via USB to computer, I can't get an acceptable recording even though the signal quality is perfect for other devices...

Is there a reason why that signal path would cause problems, or is there a device that I'm missing out from the signal path which would fix the problem.

Bottom line is that someone somewhere has a computer connected via a device like an iMic to the line out sockets of a simple mixer for the purpose of directly recording audio messages, be they musical or spoken word... They aren't spending $800 on DI boxes, or special equipment... they're using very simple 'consumer-easy' setups, like I am... It's just that theirs is working correctly and mine has an issue that I can't explain, but someone out there CAN explain to me because they've experienced it.

THAT'S what I'm asking a forum of varied audio-recording/digital recording/instrumentalist enthusiasts...

I could ask it in an even simpler manner...

I have mic's and instruments running into a mixer which controls a PA system. I want to make a direct sound board recording of the mix. I have available a 'tape out' line socket pair and a computer with an external USB soundcard which has a line in jack and the ability to switch that input from 'mic in' to 'line in'... Do I need a powered micromixer between the line out of the main mixer and the line in on the computer in order to give the computer a good level of sound to record or should the setup described not require, in principle, anything more than it already has?

 

[BushmasterM4]

There is a +20db switch (actually a check box) in windows for your recording in. I would not think that would cause your items first in the chain to screw up too. But strange things happen.

 

[mixsit]

..If what you mean is 'if you turn the master fader all the way down does the computer still record digital garbage' then the answer is no.

..So fine... I'll play. When I turn the master slider down on the Mackie mixer, there's less of everything, so yes, there's less digital crap on the recording, not that the recording is a damn bit of good to me using this as a means of getting rid of distorted and artifacted, compressed digital audio..

Please, sorry I'm so thick- after all this- Does reducing the level make a clean recording or not? Yes or no?

“But of course, it might have sounded smart to quote a bit of rocket science at the dumb n00b, but it didn't actually prove a single thing did it?”

Let’s skip that. Damned if I can tell.

By all means, tell me where that switch is on the Mackie CFX12.

‘Utility Stereo Out' –with independent level control. Page 10 of the pdf.
Any two of the four buss outs- independent level controls.
Each capable looking like anything from ‘mic level (-50) to +20 db.
Plus loosing the need to daisy chain.

 

[SampleX]

Please, sorry I'm so thick- after all this- Does reducing the level make a clean recording or not? Yes or no?

No. The already low volume on the signal is simply made lower.

‘Utility Stereo Out' –with independent level control. Page 10 of the pdf.
Any two of the four buss outs- independent level controls.
Each capable looking like anything from ‘mic level (-50) to +20 db.
Plus loosing the need to daisy chain.

OK, can give that a try this week.

I presume I can conclude that what we're saying is that 'line out' from a mixer to a tape recorder or CD recorder works, because those devices effectively 'pre-amp' the signal internally, whereas straight to a computer isn't working because there's no independent gain on the Line Out channel because it is Line Level. Therefore we would seem to have identified our incompatibility, and whereas my audiotechnological yokel ass would have then used the Line Out into a micromixer to test the theory, you've revealed that I can, in fact, use the mixer in clever ways to have the same effect using on-board gain/fader controls...

Thanks, that's useful information and I've now downloaded the PDF for the Mackie because its a hell of a lot more detailed than the 'quickstart guide' that my predacessor seemed to have left me.