I finally managed it. I have flat response from 30 - 200 Hz in my room. And I hate it

Discussion in 'Archived Threads 2001-2004' started by Javier_Huerta, Jul 27, 2002.

  1. Javier_Huerta

    Javier_Huerta Supporting Actor

    Joined:
    Mar 9, 2002
    Messages:
    619
    Likes Received:
    0
    Hi all,
    I finally managed to setup my system for flat response. I have a huge hall (it must be around 11 or 12 meters high, 10 meters long, 13 meters high, open all around and with no parallel walls, so it was easy). I used a pair of MartinLogan Scenarios, a pair of DefTech ProSub 100's, and lots of time for moving the speakers, running sine wave tests and recording the results with my SPL meter. I elected to run the main speakers full-range, with the subs providing the lower end.
    The biggest deviation I have is around -4dB's at 100Hz. I'd say it's pretty good.
    And boring.
    Flat frequency response has to be the most boring thing I've ever heard! (no, I'm not trolling). It reminds me of my Etymotic Research ER-4S earphones - the sound is, to put it mildly, "out of this world", yet it's so unengaging and unergetic as to be dull and lifeless. I'm confused, then - why do people buy megawatt, 18" subs when flat frequency response at sane (around 105 dB's) listening levels can be had with small subs?
    Am I missing something?
    Should I *NOT* be aiming for flat frequency response? Whenever I switched on the "Phase correct loudness" [​IMG] button on my amp, I liked a lot more the sound.
    Yet...
    Once I loaded my MoFi discs (Queen's "The Game", Alan Parsons "Tales of Mistery and Imagination", Jean Michel Jarre's "Oxygen" and "Equinoxe") my perception changed. A lot. Those discs sounded PERFECT. The bass mix was simply perfect. The rest of the discs sound completely anemic.
    Which makes me think something else.
    Maybe engineers simply don't aim for a flat frequency response environment - yet the audiophile labels do.
    Now - what should I do?!? I finally manage to get flat frequency response, yet now I discover *maybe* this is useless, because of how music is mixed!
    I'm confused.
     
  2. rodneyH

    rodneyH Supporting Actor

    Joined:
    May 22, 2001
    Messages:
    844
    Likes Received:
    0
    my guess is that you are hearing something that you have never heard before, BUT it is the right way, not bloated with bass.

    I remember when I was a teenager and I had (2) 12" subs in my CRX facing towards my rear window, for a long time I really thought that that is what things were supposed to sound like. My dads audiophile home system sounded lifeless. After my ears have adjusted and I have done much more auditioning I now realize what it should sound like.
     
  3. Brian Fellmeth

    Brian Fellmeth Supporting Actor

    Joined:
    Jul 30, 2000
    Messages:
    789
    Likes Received:
    0
    I agree with Rodney. Stick with it and it will grow on you. What you are hearing is accuracy. If it sounds boring, that is because you have become used to having bass colored by lumpy FR curve. Wouldn't you rather listen to what the artist intended to lay down rather than have it arbitraraly mangled by your system ?
     
  4. Kevin C Brown

    Kevin C Brown Producer

    Joined:
    Aug 3, 2000
    Messages:
    5,712
    Likes Received:
    0
    I think that flat freq response is one of the holey grails of music/home theater. But, I could ask how you got there?
    RTA?
    Radio Shack meter with a discrete test tone disc? (What was the interval of measurements?)
    Did you apply the "correction" to your SPL meter?
    Do you have the phase correct between your sub and mains?
    I find it hard to believe that your mains would crossover to you sub correctly *without* applying a high pass filter (crossover) to your mains.
    If you don't like it change it, but before you you do, consider that *maybe* what you're hearing for the 1st time is what you're supposed to be hearing. [​IMG]
     
  5. Ned

    Ned Supporting Actor

    Joined:
    Feb 20, 2000
    Messages:
    838
    Likes Received:
    0
    Those subs are kind of "out of their league" compared to your speakers.

    If the bottom end sounds "flat" or "boring" you should consider that many people believe that a rising response is the ideal with the shelf at ~32hz. If your response is actually flat down to 30hz then it may be too thin in reality.

    Are you sure these measurements are in your actual listening positions?

    Lots of things to consider for this topic.
     
  6. Javier_Huerta

    Javier_Huerta Supporting Actor

    Joined:
    Mar 9, 2002
    Messages:
    619
    Likes Received:
    0
    Kevin,

    I burned a CD with sine waves, starting at 20 hertz and using a 10-hertz gap between frequencies all the way to 200 hertz. I'm curious - I've never seen the "correction" curve for my SPL. I used a C-weighted curve, a tripod mounted *exactly* on my listening position, and I did check on phase (actually, that was the first thing I did).

    As I said, the sound I got is pretty much identical to what my best earphones sound like (the Etys are supposed to be one of the most accurate headphones ever made) so I *suppose* I got it right. Bass lines are perfectly audible, yet not "tactile" - simply defined, but without "presence". As you said - it might be the first time I listen to a perfectly calibrated system. I'll give it some time (I didn't like the Etys on first listen, either).

    And Ned, the subs are *Definitive-ly* outclassed when it comes to the speakers. That's the reason I chose to run the speakers full-range (after comparing the bass notes coming out of the subs and the bass notes coming out of the speakers, I decided the subs should complement and not replace the low end on my system, so they are barely audible). I have a Velo sub I will use with the Logans, but due to a couple of factors I can't use it (yet).

    I'll try giving the system a slight rise at 30 Hz. Still, do you know how many dB's I should be aiming for?
     
  7. Scott Oliver

    Scott Oliver Screenwriter

    Joined:
    Aug 30, 2000
    Messages:
    1,159
    Likes Received:
    0
    You hit the nail on the head at the end of your first post. Major record labels produce Cd's designed to be heard through boomboxes, mini-systems, car stereo, and BOSE.
    None of those are made to play pristine highs and ultra low base with flat frequency responses. With the low end I would imagine most music is recorded with a 100HZ boost in mind. For example, kick drums can be absolutely exciting on a good recording, but throw in a major label rock typical rock album and they sound like someone took the air out of the room. Nothing, they don't go low they aren't powerful, nothing. Yet take that same CD to say my car and that mix can quickly start sounding like it has bass on it.

    Personally I wouldn't go back and there is a lot of good music to be had that is recorded well out there.

    By the way the worst recorded rock album in recent years to me is Bush's Sixteen Stone. I used to think that album had incredible bass and really cool strong driving beats. Then I get a hi-fi system and the album sounds like mush. So dissappointing.
     
  8. Andrew Pratt

    Andrew Pratt Producer

    Joined:
    Dec 8, 1998
    Messages:
    3,806
    Likes Received:
    0
    Do a search on "house curve" and that should help get you back to a sound you enjoy.
    Also if you aren't correcting that SPL meter then you really aren't flat since the RS SPL meter is very inaccurate down in the low bass freq's. This Thread on BFD's might help you understand where I'm coming from.
     
  9. Brian Fellmeth

    Brian Fellmeth Supporting Actor

    Joined:
    Jul 30, 2000
    Messages:
    789
    Likes Received:
    0
     
  10. John F. Palacio

    John F. Palacio Supporting Actor

    Joined:
    Jan 6, 2002
    Messages:
    575
    Likes Received:
    0
    Just a though! After all if you're not happy, you should change it:
    A -4dB drop at 100 Hz might be enough to to remove some of the "ooomph". That dip might be wide enough, let's say 85 Hz to 115 Hz, to be significant.
    Where are you crossing over to the sub?
    It is my opinion that if need be, there's nothing wrong with "goosing" the sub to get more "slam".
    [​IMG]
    While I am at it, and in reference to the headphone comparison; Earphones cannot duplicate what a good, low sub will do. A lot of what a sub outputs is actually "felt" and this is something no earphone can do.
     
  11. Sebastien David

    Sebastien David Second Unit

    Joined:
    Dec 4, 2001
    Messages:
    291
    Likes Received:
    0
    "Wouldn't you rather listen to what the artist intended to lay down rather than have it arbitraraly mangled by your system ?"
    No I wouldn't. But that's just me.
    [​IMG]
     
  12. Stephen Dodds

    Stephen Dodds Second Unit

    Joined:
    Aug 29, 1998
    Messages:
    354
    Likes Received:
    0
    One other question is the size of your room. I find it difficult to believe that either the Martin Logans or the Def Tech subs would have the sort of power handling to fill a room that size with accurate bass, especially at anything close to reference levels.

    And if you are listening at lower levels, the ear is very insensitive to bass, which is why a properly executed loudness control can be quite useful.

    Steve
     
  13. Wayne A. Pflughaupt

    Joined:
    Aug 5, 1999
    Messages:
    6,100
    Likes Received:
    33
    Location:
    Katy, TX
    Real Name:
    Wayne
     
  14. AntonS

    AntonS Stunt Coordinator

    Joined:
    Dec 18, 2001
    Messages:
    164
    Likes Received:
    0
    Javier,

    When I set up my first decent audio system no so long time ago (H/K AVR 8000 + Sherbourn 1500A amp + Studio 100s), I found exactly the same thing. Most of my CDs - and I listen mostly to art/prog rock recorded around early 70s, most of them are not even remasters - sound absolutely terrible on the new system. But newer CDs recorded in late 80s and 90s sound breathtaking. Also, music on DVDs is usually great.

    The verdict is - high end systems are very revealing. They can reproduce the source very truly, without taking anything from it, but also without adding anything. If the source is recorded or mixed badly (and most early recordings are), it will show up. There is no way around it but updating the sources. I found that I have to re-buy quite a few of my favorite disks either on DVD-A or at least remastered.
     
  15. Javier_Huerta

    Javier_Huerta Supporting Actor

    Joined:
    Mar 9, 2002
    Messages:
    619
    Likes Received:
    0
    Thanks all for your thoughts. I didn't expect such an unanymous response (about the fact that, indeed, a flat frequency response sounds different enough to a "boosted" one to be interpreted as "wrong"). I can't listen at high levels to my system because, being installed in my living room, it's subject to all kinds of high-frequency aberrations (the worst of all is the glass table on front of the speakers and the reflective wall behind them. At high levels, mids and highs become so strident as to hurt my ears).
    Anton, your post is pretty much on-spot, since I listen mainly to the same kind of music you listen to. Pink Floyd's earlier, non remastered CDs sound terrible, while MoFi's "Atom Heart Mother" and "P.U.L.S.E." are incredible - P.U.L.S.E. is the best recorded concert I've ever heard on my system.
    As I said before, I was just testing how flat frequency response sounds like. It sounds different enough to warrant further investigation - and to fix up a spare room I have, in order to get the speakers out of the living room [​IMG]
     
  16. Mark Seaton

    Mark Seaton Supporting Actor

    Joined:
    Oct 10, 1999
    Messages:
    599
    Likes Received:
    0
    Real Name:
    Mark Seaton
    Hello Javier,
    Steve Dodds went right to the first problem. The reason you can't listen at moderate to high levels is because of distortion and overdriving your system. Your room is very large compared to most home systems. The subwoofers don't stand a chance.
    Then we have to look at the measurements. Depending on the resolution used, I can make a speaker's response curve look like +/-1dB or +/-6 to 10dB... with the same speaker! My suggestion would be to check out TrueRTA from www.trueaudio.com . For the
     
  17. Javier_Huerta

    Javier_Huerta Supporting Actor

    Joined:
    Mar 9, 2002
    Messages:
    619
    Likes Received:
    0
    Mark, thank you very much for your post. It raised lots of questions (which is always a good thing).

    My system can be definitely overdriven. My amp is rated at 100 w/channel at 8 ohms; my speakers supposedly are 6 ohms (not true, I say) and I feel I don't have enough headroom with the amp, which is the main reason I don't listen at "reference" levels.

    I'll check out the link you sent, and, as I said before, I might begin thinking about replacing the amp (I have had my eye on the Adcom stereo 200 w/channel for some time).

    Can you suggest some books on the matter? I own the two basic books by Alton Everes - Sound Studio on a Budget (?) and The Master Handbook of Acoustics and I don't believe I saw so many specifics in it.
     
  18. jeff lam

    jeff lam Screenwriter

    Joined:
    Jun 4, 2001
    Messages:
    1,798
    Likes Received:
    0
    Location:
    San Jose, CA
    Real Name:
    Jeff Lam
    I tend to like things even throughout the entire frequency spectrum. I eq my subs to a point where when I play sine waves in my room, the 35Hz tone sounds at the same amplitude as the 80Hz or 100Hz tone. You cannot achieve this with a ruler flat system. The 35Hz tone will be barely audible, especially at low levels. I apply a house curve. I don't care about "How the artist intended to lay down the track", I would even highly doubt they get ruler flat response anyway. And to tell you the truth, I don't think any of us have recording studios in our homes with the exact same room/treatments, size, monitors, amps, mixing boards, etc. to just sit and listen.

    Like Wayne said... "you would need a 750,000 square ft. warehouse with 543 American and European recording studios, accurate down to the dimensions, acoustical treatments, electronics and monitor speakers."

    This just isn't practical.
    I feel bad for everyone that have ruler flat systems thinking they are getting in everything exactly the way the artist intended but I see just the opposite. I just see what they are all Missing!

    To add to this... Why do all of you (who look for ruler flat response and shoot for the exact sound that the artist intended) suggest when people ask for recommendations: to use their own personal ears to go to the store and listen and choose the amp/speakers that sound best to them??? A Denon receiver will sound different from a Yamaha receiver in the same room, which is "correct". Why aren't you telling them go get a Krell because that is what this Artist or that artist uses in their studio and if you want to replicate what the artist intended, you need to have this amp??? I just don't get it...

    Now I'm not here to start a debate or flame war. I'm just expressing how I feel with this "FLAT" response issue.

    As for me, I'll stick with my house curve and Wayne's recommendations/methods of achieving it thank you!
     
  19. Kevin C Brown

    Kevin C Brown Producer

    Joined:
    Aug 3, 2000
    Messages:
    5,712
    Likes Received:
    0
    Jeff- I will answer your question about using ears to detect differences between eqp at a store. [​IMG]
    I personally find this a ludicrous way of buying equipment, because:
    1) There is no way you can be sure components are matched to within 0.1 dB to guarentee that simple sound level differences between them aren't responsible for the "better" sound you hear out of 1 vs another.
    1a) There's also no way you can be sure that subtle things deep in the component's config are set up identically (parametric eq values, dynamic compression, even speaker levels, etc). Unless you have hours to spend going through each manual and each component's software with a fine tooth comb. Same with speakers and crossovers to subs, phase, placement, etc.
    2) I personally don't believe that the differences in sound between say a Denon 3802 receiver, an Outlaw 950 pre/pro, or an Anthem pre/pro, etc., are large enough that I couldn't make any one of them sound bad or sound very well just by setting up my system correctly.
    But everyone's mileage varies, and that's what it's all about...
     
  20. Martin Rendall

    Martin Rendall Screenwriter

    Joined:
    Dec 5, 2000
    Messages:
    1,043
    Likes Received:
    0
    I think it's perfectly reasonable to adjust the bass to whatever you find most appealing. After all is said and done, music is meant to please. Not be a source of worry of disappointment!

    Perhaps a good compromise is to leave yourself options, and switch between response curves depending on the source material?

    At reasonably low volumes, I have a fairly good flat curve when I want it, but I definitely enjoy the bass with about a +3 boost to the sub. I listen both ways, depending on my mood and what I'm listening to.

    Martin.
     

Share This Page