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Conference hips::uk_audioo

Title:You get surface noise in real life too
Notice:Let's be conformist
Moderator:GOVT02::BARKER
Created:Thu Jul 28 1988
Last Modified:Mon Jun 02 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:550
Total number of notes:3847

430.0. "Dynamic Range reduction " by WOTVAX::MEAKINS (Clive Meakins @OLO) Tue Jun 22 1993 13:24

    Cross posted in AUDIO
    ---------------------
    
    A friend of mine has been struggling with his CD based system for 
    some time now.  It doesn't really matter what his equipment is, it's 
    all reasonable mid-range kit.
    
    No matter what other mid-range equipment is substituted into the 
    system, problems with harshness and tiring listening occur.  If low 
    end equipment is used, the problem to some extent goes away.  This 
    is due to the lack of information being presented IMHO.
    
    Now, I don't find some of the problems reported by my friend as so 
    serious, but they do exist, it's just I'm not as sensitive to them.  
    Then again it's not my system and I don't have to listen to it 
    continually.
    
    An interesting point is that CD's recorded to cassette then played 
    back sound fine.  I've sometimes found that the wide dynamic range 
    of CD a problem and that listening levels can become uncomfortable 
    at times.  Tape reduces the dynamic range to such an extent that the 
    musical peaks are less dramatic, but more comfortable.
    
    Recording all my friend's CD's onto tape and only listening via tape 
    seems a strange solution.  Is there some way to reduce the dyanmic 
    range of CD (to that of vinyl maybe), is this what some of the 
    after-market circuits do that are claimed to improve CD?
    
    Are we barking up the wrong tree, or could this be the source of the 
    problem that my friend has such a frustrating time with?
    
T.RTitleUserPersonal
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430.1Some ideas.....BAHTAT::SALLITTDave @LZO 845-2374Tue Jun 22 1993 13:4728
    Clive,
    
    Does the cassette machine have 3 heads, i.e. the facility to switch
    between source and tape whilst recording?
    
    If listening to either whilst recording a CD does not exhibit the same
    symptoms as when listening to CD "straight" then your friend may have a
    very esoteric problem, maybe around installation of the CD machine, its
    mains supply, grounding, etc. 
    
    Don't ignore "Belt" treatments (don't laugh....), your friend may just
    be more sensitive than you or I.
    
    If listening to the "source" setting while recording from CD sounds
    the same as CD on its own, you could add interconnects to that list.
    
    If it was my system, I'd start by verifying mains and earthing. It may 
    just be that the amp's requirements for these is less with tape than with
    a demanding source. Remember, when recording it may be that none the
    amp's line level circuitry is used.
    
    Then again, maybe your friend's speakers are too good, and are showing
    up deficiencies elsewhere that are masked by the way cassette
    compromises the signal.
    
    Or maybe his expectations are too high.
    
    Dave 
430.2Compress it or check it...YUPPY::AMERRTue Jun 22 1993 16:4510
    An alternative although not cheap approach would be to employ a high
    quality compressor to gently take the edge off of the worst transients
    that your friend seems to be suffering from. However we are many
    hundreds of pounds here...
    
    It would be interesting to try a couple of double blind tests (not too
    dissimilar to .-1 to identify exactly where the "fatigue" is being
    introduced.
    
    R
430.3Why dynamic range?FORTY2::SHIPMANMOGWed Jun 23 1993 09:1729
Are you sure it's dynamic range?

I have this problem with CD replay in general.  I don't mind any aspect I can
identify of the sound of a CD, but whenever I put one on I have an urge to
leave the room.  Staying is hard work.  CDs recorded to cassette, and to a
lesser extent Hi-Fi VCR tape, are not as bad.  LPs don't have this problem at
all, whether digitally recorded or not.

I'd suggest you try other types of CD player before messing with any kind of
purpose-built audio limiter.  Start with the extremes to see if this approach
is worth pursuing.  I'd suggest trying out two kinds: relatively high-end
players, and players known to have a response deliberately tailored to sound
'warm' or 'LP-like'.

Higher-end players would include Roksan (my favourite), Linn, and Naim (haven't
heard this one though), but I don't think Meridian would do it: newer (<2yr
old) Meridians sound impressive but painful to me.  I can't give much help on
tailored players as I've heard so few, but anything with valves in the output
(eg the Musical Fidelity one) is likely to be worth looking at.  The only
reason I suggest looking for tailored players is that at home I use a portable
Sony D150 with a noticeably rolled-off high end, and I can listen to this far
more easily than most other players I've encountered, including my 'proper'
player.


For other ideas, could you post what other equipment you've tried swapping and
in what combinations?

Nick
430.4Oh sorry, I shouldn't have said that!TASTY::JEFFERYChildren need to learn about X in schoolWed Jun 23 1993 10:021
Or sell the CD player, and buy a nice record player!
430.5SympathyWOTVAX::MEAKINSClive Meakins @OLOWed Jun 23 1993 11:536
>>>Or sell the CD player, and buy a nice record player!
    
    That is what I would have recommended a few years ago when records were
    easily available.  I'm sure that a turntable / arm / cartridge
    combination could be found that suits.  The variation in sound that can
    be achieved with record decks is very diverse compared with CD.
430.6Glad I don't have this problemWOTVAX::MEAKINSClive Meakins @OLOWed Jun 23 1993 12:4353
>>Are you sure it's dynamic range?

    No, but I do feel it's a major factor with my friend who has the
    problem.
    
>>I have this problem with CD replay in general.  I don't mind any aspect I can
    
    I supect you have a good deal in common with my friend.
    
    
>>For other ideas, could you post what other equipment you've tried swapping and
>>in what combinations?
    
    The Pioneer CD is one that has tailed off treble.  Generally it sounds
    smooth, the treble sounds very little different to the Arcam Alpha Plus.
    Other CDs tried are, my Meridian 206 multibit which has been subject to
    POOGE4 modifications, so it's pretty good, Alpha Plus has been tried
    too as has a De Capo converter.
    
    The Amp is an Arcam Delta 90, this is a smooth sounding amp, some say
    too smooth.  This replaced a Pioneer A400.
    
    Speakers are Castle Chesters, whilst they do have their faults, they
    fair little worse in this system than many other speakers.  Other
    speakers tried include: Epos ES11 and ES14, Ruark Talisman, LS3/a,
    Mission 780, Tannoy (some big ones), and a whole host of others I can't
    remember.  The ES11s are smooth speaker with few HF nasties, though
    these are little better here.
    
    We've played with cables and fully understand the differences these
    bring in this system.  The cassette and Arcam tuner sound fine, no
    problems at all.
    
    We changed the resistors in the high pass section of the crossover
    (with Castle's advice), so we've a system with a CD that tails off HF,
    an amp that is very smooth and speakers with recessed HF and we still
    have a problem.  Indeed, disconnecting the tweeter doesn't even fix it! 
    Even the top end of the mid range manages to sound harsh.  The sound is
    reproducable in different houses too.  
    
    We're trying to fix this problem without masking dynamics and
    information.  With my own system I've carefully balanced it so that 98%
    of CDs sound fine to me.  To my friend my system is to harsh, a
    previous version of of was better for him.  We all have differing
    sensitivities and we're having trouble getting the right balance.
    
    Some of the equipment tried has helped in certain areas but been awful in
    others.  Nothing so far has fixed the problem.  It may be worth trying
    a current Meridian bitstream as these have a very smooth sound, though
    I know they don't match requirements for dynamics.
    
    We want to fix the problem, not cover it up, if you know what I mean.
    
430.7KRAKAR::WARWICKCan&#039;t you just... ?Wed Jun 23 1993 13:4913
    
    This seems like a pretty weird situation. I find it hard to beleive
    that *anything* can sound harsh through a pair LS3/5a's. Your friend
    may have become over-sensitised. When I had the Royd speakers that I
    eventually found too bright, it took me a long time to become
    desensitised to any harshness or sibilance, even with the ES11s.
    
    Perhaps you should get hold of a graphic equaliser, and use that to
    find out exactly which frequency range he objects to. That might give
    you a better clue as to what combination of components to choose, or
    maybe you could just leave the graphic equaliser in there.
    
    Trevor
430.8Speaker cable and interconnects.ESKIMO::BROOMFIELDWed Jun 23 1993 14:1112
    
    	  You don't mention having tried interconnect or speaker cable.
    	I was stunned at the difference between XLO type 5 and 6 speaker
    	cable.  The effect in my system was primarily in the base, next
    	high frequency, little change in the mid.  
    	  Well burned in (very important) interconnect can have a
    	significant effect as well.  
    	  I've read that many people consider that the final "tweaking"
    	to a system of well matched components should be done with 
    	interconnects and speaker cables.
    
    	  Mike
430.9This is after 18 months of tryingWOTVAX::MEAKINSClive Meakins @OLOWed Jun 23 1993 14:3425
>    This seems like a pretty weird situation. I find it hard to beleive
>    that *anything* can sound harsh through a pair LS3/5a's. Your friend
>    may have become over-sensitised. When I had the Royd speakers that I
    
    I didn't explain this piece very well.  I don't think LS3/a's sounded
    harsh, but I when partnered with the other smooth sounding equipment, the
    result was so boring that they couldn't be considered.  I didn't
    actually hear these speakers, so this is 2nd hand, I'll check, it could
    be important.
    
    I'm sure that my friend is over-sensitised, but that's how his hearing
    works.  The test with a graphic eq sounds like a good idea.  Thinking
    about it though, the cassette should be pretty flat and that sounds
    fine.  Whilst Rob's hearing may be sensitive in a certin way, I suspect
    he's senitive in a way the most vociferous and sincere pro-analogue/anti-CD 
    are.  Had he every owned a top flight record deck he would be in that
    camp IMHO.
    
    Re the question on cables.  He's tried various interconnects, Van den
    Hul, Deltec Black Slink, Chord, Audioquest, Kimber and heaps of others. 
    On speaker cable he's tried Linn K20?, Linn K400, QED, Mission Cyrus,
    serveral Kimber (4TC, 4PR etc) and again heaps of others.  They all
    make "fine-tuning" differences, but don't deal with the fundamental
    problem.
    
430.10WOTVAX::MEAKINSClive Meakins @OLOWed Jun 23 1993 15:4622
>    I didn't explain this piece very well.  I don't think LS3/a's sounded
>    harsh, but I when partnered with the other smooth sounding equipment, the
>    result was so boring that they couldn't be considered.  I didn't
>    actually hear these speakers, so this is 2nd hand, I'll check, it could
>    be important.
    
    I've talked to Rob about the LS3/a's.  It's not so much that they were
    boring, more they were all treble.  Not especially harsh, but due to
    their lack of bass they simply couldn't be considered.
    
    A pair of speakers that showed promise were the Alphasons with ribbon
    tweeters.  These use the Tonigen ribbon tweeter that is also used in
    the Hi-Fi World speaker kit that is due to have the concluding part
    published next month.  The Alphasons had by far the sweetest treble so
    far, the problem was that there is too much treble and it's quality was
    far better than the sound from the mid/bass unit.
    
    The problem doesn't just come from metal domes, soft domes can be awful
    too (eg Ruark Tallisman II's).
    
    I firmly believe Rob would love a good record deck, if only the records
    were available.
430.11LARVAE::IVES_JOne i-node short of a file systemWed Jun 23 1993 21:2219
    Clive,
    
    have you tried the old main-phase reversal trick ? My old phillips
    benefitted from it. If you have a telefunken type connector at the back
    it's easy. If the mains is captive you might have to reverse at the
    mains end which is rather more drastic but may prove a point.
    
    I would concur with mr sallits point about earthing potential. after
    messing around with my Kelvin DAC i sat down, found the sound awfully
    fatiguing and eventually found a 15v difference in the earth potentials
    between amp and cd player !
    
    Could there be a fault with the Amp ? Have you tried the CD player on
    the other line-level inputs such as TUNER ?
    
    As other have noted many CD's simply sound bad. I have a couple of well
    recorded CD's (mainly Hyperion) which if they sound bright/hard/bad I
    DEFINITELY know something somewhere is wrong (though of course it may
    be in my cinuses (sp) ).
430.12Action planWOTVAX::MEAKINSClive Meakins @OLOThu Jun 24 1993 10:5718
    I've mailed all the responses to my Rob.  We'll work on sorting his
    system out over the next few weeks.  Some of the things we'll try are:
    
    More CD players, especially the Musical Fidelity one with the valve
    section.
    
    Check the earthing.  Swap mains polarity on the CD, this may need doing
    at the mains plug end.
    
    Already tried different inputs on the amp to no avail, also tried
    different amps, though I may take mine along to try.
    
    Valve line stage using various valves, I reckon Sovtek ECC88's
    (mil-spec) would condition the sound to Rob's taste.  I'll also try my
    Golden Dragon's and Mullard's.
    
    Any more suggestions?  The goal is to get an acceptable sound to Rob
    without slugging the sound so that it's flat and boring.
430.13FORTY2::SHIPMANMOGThu Jun 24 1993 13:0118
Well if you're going to try everything all in one go, also try a different amp. 
Not just any different amp: look out for one with a) serious control over the
speakers (high power but mainly high current delivery combined with good
bandwidth); b) high input overload margins; c) high tolerance of input
ultrasonic/RF noise.

I find I can tolerate CD sound better when the amp is in *very* firm control,
even when the sound isn't apparently smoother.

I suggest high overload margins because the input behaviour as you approach
clip makes things sound much more offensive.


This isn't a logical way of doing things but you might as well cover what you
can...  Has this guy ever heard a system he likes?  If so, try to work out
what's different.

Nick
430.14Helpful horacePEKING::GERRYTThu Jun 24 1993 13:514
    Cheapest solution for CD harshness.....cotton wool stuffed in the ears.
    
    I know.......not helpful!
    
430.15WOTVAX::MEAKINSClive Meakins @OLOThu Jun 24 1993 14:3419
>Well if you're going to try everything all in one go, also try a different amp. 
    
    I was planning the changes one at a time :-)
    
>Not just any different amp: look out for one with a) serious control over the
>speakers (high power but mainly high current delivery combined with good
>bandwidth); b) high input overload margins; c) high tolerance of input
>ultrasonic/RF noise.

>I find I can tolerate CD sound better when the amp is in *very* firm control,
>even when the sound isn't apparently smoother.

    My monoblocks fit your description, I'll see how they do.

>can...  Has this guy ever heard a system he likes?  If so, try to work out
>what's different.
    
    Yes, but it's either high-end record deck or low-end CD systems with 
    compromises that cover up information.
430.16My experience with connectorsRDGENG::FRYBrentFri Jun 25 1993 12:3826
I don't use my new ROTEL 925mumble CD much, but sounds good for CD . . .

Anyway, was having lotsa trouble with "consistency" and some "harshness"
of my turntable analog system.  Sometimes good, sometimes bad.  Frustrating.

I've got a LINN Sondek, etc.

I got some good contact cleaner / lubricant from Maplins, and sprayed
it on cotton, and gave ALL my connectors a real hard scrub, and some black
stuff came off, etc.  Not just a spray, but a rub-a-dub scrub.  And checked
them all for good contact, squeezing in the inner sleeve when necessary.
I think the standard RCA type connector is really naf, but there you go.

Result:  Staggering improvement in smoothness, detail, etc. and consistency
from one listening session to another. 

Moral:  Don't ignore your connectors.

On the other hand, may just be a harsh CD.  There are big differences!

There are CD filter adapters on the market, which I would be tempted to try,
hanging off the CD outputs.  Should "connect the dots", if that's the problem. 

Good luck to your friend.  Must be frustrating!

430.17A solution at lastWOTVAX::PC0905::MeakinsClive Meakins @OLOMon Jul 26 1993 13:0512
    This note started when I entered information on my friend who couldn't
    listen to his system for prolonged periods, he found it harsh.  Well,
    he's solved the problem.  We tried all sorts, but in the end to suit
    Rob he had to spend, spend, spend.
    
    He's just bought an all Linn CD system for 6 grand!

	System is: Karik/Numerik (new Numerik version that's out asap)
		   Kairn (no phono stage)
		   Klout
		   Kedilah (sp?)
		   k400 SPEAKER
430.18KRAKAR::WARWICKCan&#039;t you just... ?Mon Jul 26 1993 16:153
    
    I hope that he gave it an extended audition before blowing 6K ! It'd be
    a pity if he now found it "too muffled" or something...