Realistic Volume Levels

Stereophile recently stated that they only review equipment in the context of realistic volume levels. I think it does make sense as basicallly, hi-fi equipment is designed to have a go at trying to reproduce the actual musical event. And for those who don't read Stereophile, they gave 2 reasons.

  • At lower levels, weaknesses in the equipment may be masked.
  • The ear has an uneven frequency response vs volume.

And if I may include:

  • For a lot of speakers, the woofer doesn't fully 'kick' in until after a certain volume level is reached.

    The Singapore Listening Room and Volume Levels

    In my 12'x13' listening room (or 12'x26' depending on whether my windowed and doored dividing wall counts), I find that that for recordings with vocals, my tolerance limit is about 85dB C weighted. For classical/instrumental music, my tolerance just goes a bit higher, up to 90dB thereabouts. One reason is that my hearing is just a little bit more sensitive than others (thats 1 reason why I need my own hi-fi in the office, to drown out the sound of all the sounds I keep hearing -- oh no, who's that playing 'Believe' again... [luckily, Celine Dion is banned 8^)] ).

     SPL (sound pressure level) readings. My measurements come from the ubiquitous Radio Shack digital SPL meter which I picked up from a Radio Shack in Palos Verdes. 'A' weighted readings are weighted towards 500-10,000 Hz and 'C' weighted readings are weighted towards 32-10,000Hz. 'C' weighting is the standard used to measure musical material. Oh yeah, this is volume measured at my listening position, 6'6" away."  

     Peak volume levels? For music with vocals its no big deal; IMHO theres no way you can listen to 85dB++ vocals continuously without ear fatigue (unless you have a really smooth system). I'm perfectly happy with 80dB thereabouts. But for Classical Music, the dynamic range and loudness becomes really scary. Take Beethoven's 6th with its aptly named  Storm movement. Before this, the music varies from about 70dB to 85dB with some 91dB peaks and you think, 'thats as loud as it gets', then suddenly, theres a totally scary 97dB peak out of nowhere. So warning: play classical music on the quieter side until you're familiar with all the peaks. Then you might want to note it down in writing so you won't forget :) 

    A second point about life-like levels is that even though your ears can take it (perhaps you've hearing loss from going to too many discos - seriously, permanent deterioration in hearing sensitivity amongst disco goers has been documented), your neighbours probably can't! I think that continuous loud music at 85dB for long periods may actually be unacceptable in Condominiums /HDB flats, not to mention 90+dB! My listening room is an renovated balcony which therefore adjacent to my neighbour's balcony, which is just a spare room, so I don't have get any comments/complaints :)

    So I think that for the average Singaporean, we're more concerned with how equipment sounds at 75-80dB (as measured in a large room, as the same output that produces 80dB in a large room may actual amount to 80++dB in a small room due to reflections) than how it sounds at 90-95dB.

    So why is 90dB measured in a large room different from 90dB measured in a small room?

    But of course, the main reason is the different frequency response of small rooms. Small rooms are often referred to as 'live' rooms because of an abundance of upper-mid and high frequency energy reflecting around the room. As a C weighted reading is an average across the a range of frequencies, a 90dB reading can mean a lot of things, as it doesn't tell you how much high frequency energy is present. With a Radio Shack meter and a CD that plays pure test tones, you can get a rough idea of the frequency response in your room. But in a small room, I think you can conclude quite quickly that there's an abundance of upper-mid/high frequency energy.

    The 2nd point about the small room is that a 90dB reading may also consist of a lot of reflected energy, such that the absolute loudness of the sound from the speakers would actually be less than if it came from the speakers in a large room. Clearly, speakers (and other equipment) in a large room have to work harder to produce the same volume levels. My McCormack amp is a lousy example as nothing seems to faze it, but my little Quad amp (84wpc, yeah right :)), while remaining cool in my listening room,  really warms up when trying to produce any sort of loudness on my living room system (said L-shaped living room being thrice the area of my listening room).

    Therefore, one of the aims of room treatment is to reduce the 'liveliness' of the rooms. This would in turn, make in possible to play music closer to life-like levels.

    First Conclusions

    • Performance of equipment in smaller rooms may be different from performance of the equipment in larger rooms because:
      1. Less power is used to produce any given SPL, so weaknesses may be masked, or THD may be higher since the equipment is not working in the optimal range. (as a side note, some pieces of equipment, like the SF Line-1, actually have minimum THD at very low output levels -- something to look out for! :))
      2. Smaller rooms are livelier, so a piece of equipment a Stereophile reviewer finds 'forward' or 'tipped-up' (they hardly ever use the word 'bright') in his huge tube-trapped room, be very careful...
    • Therefore, reviews of equipment in large rooms have to be re-interpreted in the context of small rooms. So the mark of a good review is if it actually gives you enough information to predict what it would sound like in a small room (of course, nothing beats listening with your own ears).
    • Not to belabour my point, but this is yet another reason why you should not rely too heavily on magazine recommendations per se, but to read the actual text of the review. Of course, standards of writing vary...
    Implications for Equipment Choice

    Ultimately, the piece of equipment that interacts most with the room are the speakers. When choosing speakers, you will definitely have to take your listening room into consideration. This suggests that you should choose your speakers first and then decide on equipment.

    Whether you need to tame any brightness, avoid any 'spot-lighting' of the upper-midrange, will influence your decision. Actually, thats why I recommend sticking with dirt-cheap cables first and only changing your cables after you've broken in your system and figured out what needs to be done.

    I do not feel that having a small room means that you must get extremely smooth sounding equipment. Sure, smooth sounding equipment allows you to play music louder without fatigue, but sometimes they may also be too 'slow' for your liking. You should investigate equipment that sounds good at lower volume levels (since thats about as loud as you can play without neighbours complaining). Fortunately, from what I've heard, most of the smaller 2 way speakers, whether floorstanding or standmounted, do sound good at lower volume levels. Though to be frank, no matter what, you have to pay the price in less bass (and I've said it lots of times, its a price we should be happy to pay :))

    the subwoofer angle: the above discussion seems to suggest that in a small room, we will not be getting optimal bass output. Whether or not this is a good reason to spend money on a subwoofer (and it has to be a good subwoofer, like REL), instead of spending money on your primary components is of course is something that you may have to consider.