Mono Bass (summed channel) on Vinyl

Discussion in 'Music Corner' started by robertash, Feb 9, 2007.

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  1. robertash

    robertash Forum Resident Thread Starter

    Hey there everyone.
    A questions was posed on the Vinyl Asylum about vinyl having mono or "summed channel" bass. (below 60 Hz perhaps). If it did not, the needle would hop out of the groove - so vinyl mixes are always different from CD mixes.

    Can anyone here corroborate this info?

    Am I or my sources way off?

    Robert Mills
     
  2. Dillydipper

    Dillydipper Space-Age luddite

    Location:
    Central PA
    We discussed this here just in the last week; Barry Diament expressed that this was indeed one of the concessions made to make a master ready for cutting.

    Now, I don't remember if he told us this was done by the producer preparing the master itself, or if it was solely the responsibility of the mastering engineer at the pressing facility, so I don't recall at what stage this tweak was added.
     
  3. robertash

    robertash Forum Resident Thread Starter

    Thank you

    Thank you very much, I'll do some searching.

    Robert Mills
     
  4. bdiament

    bdiament Producer, Engineer, Soundkeeper

    Location:
    New York
    Hi Dillydipper and Robert,

    This is done during vinyl mastering. It doesn't have to be done. It just often is. Much as compression doesn't have to be done. It just often is. Neither is done on the very best records (despite some folks' belief that one or both must be done).

    I've known engineers that would mono the signal as high up as 150 Hz!

    !

    Best regards,
    Barry
    www.soundkeeperrecordings.com
    www.barrydiamentaudio.com
     
  5. R. Totale

    R. Totale The Voice of Reason

    What difference would it make in listening to music, though? Isn't the demonstrated non-directionality of bass information the basis of 50+ years of sub/satellite speaker systems?
     
  6. Graham Start

    Graham Start Forum Resident

    Location:
    Toronto, Canada
    Indeed, in practice it makes little difference as our ears can't tell where bass frequencies are coming from. Summing (or lack of summing) is really only noticeable on wide stereo mixes when listening in headphones.

    I have some LPs that are mono below 200Hz. Most are mono below ~100. But I have a handful that are wide stereo right down to 60, mastered by José Rodriguez.
     
  7. JBStephens

    JBStephens I don't "like", "share", "tweet", or CARE. In Memoriam

    Location:
    South Mountain, NC
    If heavy bass knocks the needle out of the groove, it's time for a decent cartridge! Although the cannon shots on Telarc's "1812" actually did cause that on a few systems. (You could actually see those cannon shots with the naked eye!)

    The bass is reduced dramatically during master cutting, and then boosted a like amount during playback by the RIAA section of the preamp. If this weren't done, the grooves would be so wide that an LP would only play for 10 minutes per side, not to mention the increased demands on the cutterhead and driving amp. However, that's done at the cutting stage, it's not done on the master tape. So there shouldn't be any difference between a "vinyl mix" and a "cd mix".

    Certain subsonic filters sum below 140 Hz to reduce subsonics since frequencies below that are perceived as omnidirectional.
     
  8. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    One of the first things I did when involved with a mastering project was to make sure the bass was not summed. As Barry mentioned this is strictly an optional process, but it was probably used more than not. It's a way to get a slightly higher overall level in the cut. Remember that cutting records deals with a lot of compromises. It's amazing that lp's sound as good as they do all things considered, but most agree that they can sound better than cd's where compromises are not as necessary. There are other optional mastering processes that are generally done, but that don't have to be, such as using the acceleration limiters. :eek:

    I am of the thought that low bass directionality can be determined. I have always been able to tell where a mono subwoofer is located, though obviously many aren't able to do this, or aren't experienced enough to do it. Listen to records with stereo kick drums and see if you can tell that they are split left and right. Granted there are some higher frequencies with the kick drum that may help with localization.

    Listen to 'Magic Man' from Heart's first lp where the bass is panned while it is decending in frequency. On a good full range system there can be pinpoint localization of it all the way down.
     
  9. OcdMan

    OcdMan Senior Member

    Location:
    Maryland
    A couple of additional questions for the pros:

    During cutting, does anyone ever sum the bass and then pan it (either fully or partially) to the left or right? Doing that would seem to defeat the purpose of summing. Doesn't bass summing usually mean you're going to have an equal amount of bass in each channel? There seems to be some dispute on another forum whether or not bass summing actually means mono, centered bass.

    Thanks!
     
  10. bdiament

    bdiament Producer, Engineer, Soundkeeper

    Location:
    New York
     
  11. OcdMan

    OcdMan Senior Member

    Location:
    Maryland
    Thank you. Yes, that's what I thought. :thumbsup:
     
  12. bdiament

    bdiament Producer, Engineer, Soundkeeper

    Location:
    New York
    Hi Doug,

    Amen! Bass localization is difficult when one is doing sine wave testing but music, like real life is comprised of transients, not steady-state sine waves.

    Our distant ancestors made use of this localization ability. If you're living out on the serengeti and there is a stampede coming, you'd better be able to tell which direction that rumble is coming from is you're to have a chance at getting out of the way.

    As to 2.1 systems with mono "subs", they are a compromise. Often, the .1 is really a woofer. The term "subwoofer" means "below the woofer" and should in my view really be reserved for speakers that reproduce the bottom octave. Most of the boxes (i.e. "boom cubes") sold as "subs" would be lucky to reproduce as low as 40 Hz on a good day with the wind behind them.
    ;-}

    Stereo bass sounds more like "Life" every time. It is also much easier to deal with room issues when there is more than one sub.

    Best regards,
    Barry
    www.soundkeeperrecordings.com
    www.barrydiamentaudio.com
     
  13. Curiosity

    Curiosity Just A Boy

    Location:
    United Kingdom
    Agree with you about so-called subs in 2.1 systems. There's no way the one on my PC is a real 'sub woofer'. More a common bass unit.

    Regards,
     
  14. Ken Scott

    Ken Scott Recording Legend

    A question that I think is on topic. Close anyway.

    When mixing Ziggy Stardust for 5.1 I made a conscious choice to keep the low end as it was for the original record. Which led to very little use of the sub. I have since received a few critiques of it sounding thin. Not what people are now used to.

    Do you all feel it better to bring something like that up to present day standards or keep it as it was originally recorded ?

    Cheers
     
  15. R. Totale

    R. Totale The Voice of Reason

    One vote for "as originally recorded".
     
  16. public image ltd

    public image ltd Member

    Location:
    Canberra
    Depends which recording you are talking about - the master tape, or the recording as ultimately realised on the vinyl. The former captures the original, uncompromised, creative intent best IMHO, although even there someone could have applied a sub-40 Hz filter on the grounds that the average system could not be expected to reproduce those frequencies.
     
  17. BeatleJWOL

    BeatleJWOL Senior Member

    On something like that, if there's not enough low end to kick the sub into action without significant level changes, leave it alone, like you did - I guess that would count as "originally recorded".
     
  18. His Masters Vice

    His Masters Vice W.C. Fields Forever

    Your Ziggy 5.1 mix is one of my favourite surround mixes, Ken! My theory is that some people have surround systems with speakers (particular the rear speakers) that don't produce anything much below 100Hz (except for the sub, of course). Since you put very little in the sub, your mix may sound thin on their speakers. My rear speakers go down to about 40Hz and the fronts go down to 20, so your mix sounds fine on my system... :thumbsup:
     
  19. Tim H.

    Tim H. Forum Resident

    Location:
    Cottonwood AZ
    I'd also like to add that most systems don't have proper bass management for SACD/DVD-Audio (at least mid - lower end systems) or people haven't configured it properly for their system. If the bass management isn't set properly to direct bass frequencies to the sub because the person's front &/or rear speakers aren't "full frequency", it would indeed sound thin. It's One of the issues I think kept (keeps?) the hi-res formats from really going mainstream.

    When I first got my sacd player hooked into my HK reciever, I was underwhelmed by the sacds I had (including Ziggy). But once I set my bass management up properly, that all changed. :agree:

    Another vote here for Originally Recorded/Intended.
     
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