85db Referance LvL is to loud

Discussion in 'Home Theater Projects' started by Luitz, Feb 24, 2004.

  1. Luitz

    Luitz Stunt Coordinator

    Jan 4, 2004
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    I just setup 5 freinds systems with a spl meter.
    They all have decent equipment.

    System 1 Yamaha RX-V1400 with Energy C5 fronts C-C1 Center and C-1 rears.

    System 2 Yamaha RX-V2400 with Energy C7 fronts C-C1 Center and C-3 rears

    System 3 Denon AV-R 3803 with Mission M-34 fronts, M3-C2 center and M-32 rears

    System 4 Kenwood VR-5090 with JBL E80CH Fronts,EC25 center and E30 rears

    System 5 Onkyo TX-NR900 with Heco odeon 600 mains Heco Odeon center Heco Bipolar rears

    All these systems had to have rears channels turned down by 2 to 3 db and centers down 2 to 4 db to gets a 85 db reading around the room at sitting postion.

    Now what I noticed was that at a 85db volume setting on the reciever all these systems would exhibit some distortion on heavy action sences.
    The worst being the Kenwood with JBL (just be Loud)system.
    Not sure if you all notice this on your systems. But from what I have heard and listened to this LvL is to much for most systems. Maybe a preamp amp combo may not exhibit this but these systems did.
    If I was to rate them in sound quality
    System 5 would win hands down smooth acurate nice presence.

    System 2 very close to system 5 but not as smooth sounding (little harsh/bright on top end). Standard Yamaha sound

    System 1 same as system 2 top end way to bright almost over powering.

    System 3 Smoother top end kinda raspy in the vocal department.

    System 4 Didnt like it. JBL is to forward sounding and has a very edgey sound almost tiring. Possible be better to use a different speaker. something not so raspy would like to try it on the systems 1, 2, 3, 5 speakers
    Basicly what i see is that at 85 db refernce LvL all these recievers are at 80 percent volume which is to much
  2. PaulT

    PaulT Supporting Actor

    Oct 28, 2002
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    I calibrate my system to reference level but very rarely will I listen to it at that level.

    Some will calibrate to the loudest they listen to and match the outputs of each channel at that level.

    It really depends on the room size, amp etc. Listening at reference on slightly underpowered amps will definately drain the system and start clipping the signals. I haven't looked to see what each of those receivers has for rated (published vs actual) outputs.

    ie. My old Onkyo 696 is rated for 100W x 5 however under testing it hits around 46W all channels driven. It would be rare to have that draw from all channels at the same time, however the more you turn up the volume, the more chance one or more channels will start to clip.
  3. Jeff Gatie

    Jeff Gatie Lead Actor

    Aug 19, 2002
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    I hope you are calibrating to 85 dB using Avia. If you are calibrating using VE or (most) receiver test tones, ref level is 75dB, not 85dB.

    That being said, reference level playback is easy to calibrate to but difficult to play material at, unless you have exceptional equipment and/or a small room. Personally, I am able to play Gladiator at reference in my small to mid-sized room with my Denon 3801, SVS 22-31 PCi and Cambridge Soundworks HTII speakers. YMMV.

    The good thing is, nobody *has* to listen at reference. My suggestion - turn it down.
  4. Guy Kuo

    Guy Kuo Supporting Actor

    Mar 6, 1999
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    Reference Level IS loud.


    Reference level is a term which really seems to confuse a lot of people.

    It boils down to this....

    By convention, max peak sound level during playback of the audio system as measured at the listening position is 105 dB SPL when the system has its volume set to "reference level." At that same volume setting, a signal which is 20 dB softer than max peak would measure (drum roll.....) 85 dB. A signal which is 30 dB softer than max peak would measure 75 dB.

    It really isn't a fixed dB level of 65, 68.343, 75 or 85 dB which is "reference level" but the setting of the system such that the measured volume at the listening position equals that of another system which is also at "reference level." This is usually accomplished by playing back test signals that have a known SPL level when played back on a system which is at "reference." You adjust your system so the SPL level is that same level and YOUR system is then at "reference level." This allows us to standardize what we mean when talking about how loud our systems are set during playback. In other words the same recording played back on different systems will have the same loudness (at the listening position) if all systems are set to the same setting relative to "reference level."

    So Joe can set his master volume to 10 dB below reference and tell Hank to also set his system to 10 dB below reference. If both of them play the same recording, they'll hear the same loudness level.

    "Reference Level" is commonly used to refer to the master volume setting on your system which placed it in such a state that its playback matches the loudness of other systems which are also set to be at "reference level"

    Most consumer test tones for setting SPL level produce 75 dB SPL if the system is at reference level. AVIA test tones are 10 dB louder, matching pro equipment practice, and consequently should measure 85 dB SPL if your system is at reference. Sound and Vision Home Theater Tuneup also follows this convention.

    Notice that this doesn't mean that all systems at reference level are generating the same amount of sonic energy. This is sonic energy measured at the listening position, not total sonic energy. If the venue is larger, greater wattage is needed to reach reference level.

    When calibrating your sound levels you are doing several things:

    1. Equalizing the relative sound levels of your various speakers so the channels are balanced relative to each other.

    2. Finding the master volume setting on your amplifier which sets your system to reference level.

    3. Recalibrating the master volume setting such that its dB markers read correctly relative to reference level. (This goal is not possible on many receivers)

    If you keep in mind those three goals and know what the dB level is of the test tones you are using, it is pretty easy to understand what seems to confuse a lot of beginners.

    Most receivers have channel level controls for the speakers. Those are used to get the channels balanced with respect to each other. You can also alter the overall volume of a system by moving all the channels up or down together. That gives you some ability to alter which master volume setting yields reference state.

    On simple receivers, set the channel levels to midrange, then use the master volume control to make one of the main front speakers read 85 dB SPL (assuming you are using Avia or SV HTT). This should set the main volume to a something at which you can go through each channel and have enough range to get all the channels to read 85 dB. Once all channels are balanced, mark or memorize the master volume setting. That setting now sets your system to reference level. If you want to hear your system at 10 dB below reference, you just decrease the master volume 10 dB. Notice that you can alter the setting at which the system is at reference level by tweaking the channels up or down together. This can sometimes let you make the number easier to remember. One caveat, not all low cost receivers have their master volume controls marked in dB. You might need to use your SPL meter to find how far down you need to turn the master volume to read 75 db SPL. Probably a good idea to check anyway.

    On more advanced receivers, the master volume and channel balancing acts in a more independent manner. For instance, going to channel balancing automatically presets the master volume to 0 dB attenuation. That automatically makes 0 dB on the master volume be reference level once all channels have been set to read 85 dB SPL. Other systems will even let you adjust the number readout of the master volume control independent of the volume setting. That lets you zero the number at reference level for our system.

    Because receivers differ in their implementation, you'll have to think about how the controls interact and work out how you can attain the first two goals. The third goal is not always possible.

    At any rate, once done you can listen to something at reference level and hear the same intensities as someone else using another system at reference level. This makes discussion of what you hear much more meaningful. Reference level IS quite loud. Indeed 10 dB below reference is also loud. Typically, I use my system at 17 to 15 dB below reference during films for comfortable hearing. You are not required to keep your system at reference level, but it is good to know where you are relative to reference so your comments about loudness and audibility have some basis for comparison.

    As I previously mentioned, the SVHTT disc has you target 75 dB SPL even though that actually sets your volume to 10 dB below reference. Remember it's a consumer disc so the instructions are simplified to match average consumer needs. You now now too much to simply follow those on disc instructions.

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