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Conference napalm::commusic_v1

Title:* * Computer Music, MIDI, and Related Topics * *
Notice:Conference has been write-locked. Use new version.
Moderator:DYPSS1::SCHAFER
Created:Thu Feb 20 1986
Last Modified:Mon Aug 29 1994
Last Successful Update:Fri Jun 06 1997
Number of topics:2852
Total number of notes:33157

2688.0. "Spectrum Analyzers" by RICKS::SHERMAN (ECADSR::SHERMAN 225-5487, 223-3326) Tue Jul 23 1991 15:09

    Well, I just got back from a vacation in Idaho (my wife's folks are out
    there).  While there I picked up a 10-band graphic equalizer for $80.  
    Now, I really don't care about the equalizer because with my D70 I have 
    lots of control using digital filters.  But, this thing has a spectrum
    analyzer built into it.
    
    It occurs to me that the use of a spectrum analyzer is just the ticket
    for checking levels and such.  The "regular" way for me was to listen
    over headphones, listen on the stereo and listen in the car.  I'll
    still do that.  But, I'm finding that by running my outputs to the
    spectrum analyzer I can see things I can't hear.  It seems to be
    dramatically improving the quality of my stuff because I am now able to
    more intelligently set levels and control filtering.  Great stuff!
    
    I note that you can get one of these things at Radio Shack for about
    $140.  It sometimes goes on sale for $120.  (Now, you can see why I
    snapped up the one I found for $80.)  I suspect that these things were
    originally intended as a toy for the audiophile.  It's fun watching the
    lights move.  But, the store I bought mine at was blowing them out.
    I got the last one of two.  The other one had two 7-band analyzers in
    it.  Seems that these things are pretty much disappearing from the
    market.  It is becoming more common to have a 7-band analyzer built in
    to an amp rather than as outboard gear.  I think DAK has/had a unit
    that also included a white noise generator and a microphone so you
    could tune up a home stereo to have flat response.
    
    Anybody else added one of these babies to their setup?  Near as I can
    tell, by using it along with my headphones, stereo and car system, I
    can probably obviate the need to buy an expensive flat-response system.
    I was at first thinking I'd hold off on setting levels until I did
    mastering at a studio.  Then, I realized that this could get really
    expensive.  Far better to set levels with one of these before going to
    the studio.
    
    Steve      
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2688.1trust your feelings, LukeSALSA::MOELLERself censoredTue Jul 23 1991 15:168
     I've a friend with one of the DAK units.  I dunno..
    
    Recently I spent time transferring PCM to DAT and getting crazy
    watching the levels - it seemed that one channel or the other was way
    hotter than the other, but it did not sound that way.. the engineer at
    the studio told me to stop watching the meters and trust my ears.
    
    karl
2688.2Helpful for sound reinforcement, mixdown, I dunno, maybe?ROBOT::RYENRick Ryen 247-2552 TWOTue Jul 23 1991 15:4529
Some folks I know in a band started using a 31 band spectrum analyzer,
pink noise generator, in combination with a 31 band Graphic EQ. Their use
of the analyzer, and pink noise generator, improved the quality of their
sound reinforcement system by 300%. The pro analyzer cost them about $400,
including a special mike. The analyzer, along with a $30 Radio Shack sound
level meter were the best investments in improved sound that they made, even
though they had many thousands of dollars or equipment!

The 31 band eq was quite a bit more than $400, but it was very important to
have a precise level of adjustment, to match tha capability of the analyzer.
Every venue that you set up a sound system
in has different acoustic properties, and using an analyzer and EQ makes it
simple to compensate. They never had any problems with things like feedback,
and the sound was always crystal clear after they started setting up with
the analyzer.

So, for sound reinforcement, an analyzer is an excellent addition to any system,
including a home stereo. I never really heard of anyone using it for mixdown.
The rule of thumb that I've heard is the one that Karl mentioned, trust your
ears. Of course, if you monitors aren't flat, then your ears won't be
hearing reality in the first place.

I've been mixing thru headphones, not flat response monitors. I think that is 
reason that my mixes sound rather poor when they get moved to other systems.
I'd like to find some good used monitors, and after that look for
a spectrum analyzer for the 'live sound reinforcement'.

Rick
 
2688.3RICKS::SHERMANECADSR::SHERMAN 225-5487, 223-3326Tue Jul 23 1991 16:2615
    One thing I noticed some time ago was that my headphones were lying to
    me about the amount of bass I had.  I ran it through the analyzer and
    was able to verify visually that I had saturated the bass even though
    it sounded fine in the headphones.  I ran the D70 demo through the
    thing.  They really cranked up the bass for that, probably to give it
    the "punchy" sound.  That "punch" isn't always right, of course.
    But, the analyzer shows it.  In the end, I'm trusting Karl's admonition
    to trust your ears.  What this does is give me a quick indicator of
    whether or not levels are balanced.  I get the feeling that using this
    for helping with mixdown is kind of a new idea.  Guess time will tell.
    I might emphasize that I'm keeping the settings at 0 dB and not using
    the outputs of the thing at all.  When I go to tape I plan to yank the
    spectrum analyzer out of the loop.
    
    Steve
2688.4what was the topic ?SALSA::MOELLERself censoredWed Jul 24 1991 13:4324
    .2:
>I've been mixing thru headphones, not flat response monitors. I think that is 
>reason that my mixes sound rather poor when they get moved to other systems.
    
    Rick- I record thru headphones and mix with speakers- but it may not be
    that you have to have absolutely flat monitors.  Headphones have tons
    of imaging and detail lacking with speakers - thus you might have the
    perfect slap-back stereo echo on a part in 'phones, then find it
    disappears completely thru speakers.. this is also true of bright
    stereo reverb fields for me - what was maybe overdone in headphones is
    very subtle thru speakers, even great speakers.  So if you KNOW that,
    and KNOW how your headphones handle bass, you can, yes, even MIX with
    them on.
    
    Another issue is that I'd take my fave mixes on cassette over to
    friends' homes, only to think that I'd overrecorded the bass and lost
    the highs.  However, my friends all had their speakers on the floor -
    only good if your ears are on your knees - with the loudness control
    on, and had never cleaned the heads on their cassette dex.  Insert
    obligatory crappy Dolby 'B' decoding circuit comment here.   Trying 
    to mix for an environment like that gives one a screechy thin 
    irritating sound on anything else...
    
    karl
2688.5re .4ROBOT::RYENRick Ryen 247-2552 TWOWed Jul 24 1991 14:0622
I've come close attempting to mix with my headphones, after hours of 
experimenting, then moving the tape top other systems, my cars, boom-box, etc..
It always seems to loose something on each system. But, it seems that many
professionally mixed tapes have 'found the average mix' that works well across
a number of systems. I've read that the recommended method is to find some
good monitors. I've been looking for some, but they don't seem to be sold USED
very much. I guess when guys sell off their studio's, they keep the monitors
for their stereo systems.

The limitations of my mix really showed up on the last COMMUSIC tape. It
seemed to loose a lot in the translation from my 8trk onto the final tape.
The only thing that I can attribute it to is how I mixed it. Or maybe
it was contrasting my mix against the others on the tape. In any case, I was
less than pleased, and have been thinking about how to improve it.

Getting back to the original topic. I'm thinking that there might be some
utility in using a spectrum analyzer in mixdown, if nothing else just to add
an additional method of monitoring the final product. I don;t think I'd buy
one for that purpose, but I'd experiment if I had one.

Rick
2688.6Spectrum analyzers forever!RICKS::SHERMANECADSR::SHERMAN 225-5487, 223-3326Sat Jul 27 1991 14:1113
    A minor update.  I'm now nearing completion of a tune that I've been
    using with the spectrum analyzer.  This time, I did everything over
    headphones but relied mostly on the analyzer to set levels instead of
    the phones.  The results?  When I finally listened over the home stereo
    and in my car I heard *no* significant problems.  This is a first for
    me because I'm used to having to go back and tweek when one of them
    doesn't sound right.  Spectrum analyzers forever!  It beats the "lazy"
    way of using a limiter to get about the same effect but losing some
    dynamics.  Now, I can keep high dynamic range and avoid the need for a
    limiter.  When I recorded it was very easy to set the levels, having
    already adjusted levels using the spectrum analyzer.  I am pleased.
    
    Steve
2688.7All You Need is EarsDRUMS::FEHSKENSlen, EMA, LKG2-2/W10, DTN 226-7556Mon Jul 29 1991 10:3911
    Frequency balance is only one part of the mix balance problem.  The
    most annoying problems I have had have had to do with ambient noise
    floors and their effect on perceived attacks and decays.  In one case,
    a mixdown that sounded great in the studio sounded catastrophic in the
    car because enough of the attack for one instrument (strings in this
    case) got buried in the ambient noise that the instrument sounded like
    it was coming in late!  A spectrum analyzer wouldn't have helped much
    in predicting or fixing this problem.
    
    len.
     
2688.8RICKS::SHERMANECADSR::SHERMAN 225-5487, 223-3326Mon Jul 29 1991 11:3830
    How did you fix that problem?  Sounds like in my setup I would probably 
    have tried working on the attack waveform of the strings.  BTW, I'm
    still using the headphones/home-stereo/car test as the final test.
    I'm not advocating throwing these out as a mixdown test.  What I'm
    advocating is using the SA to greatly reduce the time needed to get to
    a good mix.  For me, it finds problems that it would have taken a lot
    of careful listening and repeat mixes to find.
    
    One other benefit I notice is that I'm starting to be able to identify
    different instruments on the spectrum.  I think 10 bands is just
    enough to do this.  I suspect it would be more difficult with a 7-band
    SA.  Also, mine goes from -12 dB to +12 dB.  If I had the bucks, I
    would rather have about -48 dB to +48 dB or so with (since I'm dreaming
    here) 30 bands to really do the trick.  I'm finding also that once
    levels are set with the SA when I go to tape the levels are already set
    and I usually don't have to tweek the input levels on the tape as far 
    as its level displays are concerned.
    
    Visually, this thing also gives me a feel for how my dynamics are
    going.  For example, too much reverb and the lights don't jump much.
    You can usually hear that, of course.  But, it's good to get the visual
    feedback, too.  It's also interesting to see how well some instruments
    cover the spectrum.  For example, one of the snare drums I use really
    covers it, so I have to be careful with other instruments that cover in
    the same frequencies to keep from saturating at certain points.  If I
    had to, I could change to another snare with different characteristics
    so that a particular frequency doesn't get saturated.  That kind of
    thing might be hard to hear and diagnose, but it's easy to see.
    
    Steve
2688.9and cheap monitors, cheap I say.ROBOT::RYENRick Ryen 247-2552 TWOMon Jul 29 1991 14:4029
Hey Steve, glad that it's working for you. Now that you mention it,
it sounds like a good way to help look for colliding frequencies!
10 bands counds  kind-of marginal. I know that my 10 band graphic is 
almost a toy compared to a 31 band, but it is still useful. A practiced 
ear is probably much better than 10, or even 31, but...
I'm very much a visual person, so undoubtedly using this
sense to augment my ears couldn't hurt. 

I said before that I've wanted an analyzer to set up my reinforcement
system. Never thought of the possibilities as a mix-down aid. And you know
that I've just been looking for additional justification to spend more
money! 8^) 

I picked up some El-Cheapo 4' monitors. I just mixed a couple of tapes,
using these instead of my headphones. I was reasonably pleased with the results.
The tape seemed to work well in my car stereo, on my home deck thru headphones,
and on a boom box. Not perfect, but still preferable to use of the headphones
alone.

Got a good deal on a pair of wireless amplified monitors. List $269, 
normal 'discounted' price $159 (whatever that means), blown out as 
shopworn at $54. Regardless of the sticker hype, probably never 
worth more than $54, but they faithfully reproduce that cheap boombox
ambience, and I don't have to use an amp for mixdown.

Now, where did I see that Rane 31 band analyzer.... 

Rick