SPL Meter & SPL Calculator website -Techie Query

When I say can I go to 100, I mean MAX reading of 100 with average about say 88-90 db on the SPL meter.

Trust your ears not the meter or calculations - if it sounds uncomfortably loud at 90 db SPL (average) then you already have loads of distortion so back off the volume. In all liklihood as you crank it further you will not increse the metered SPL output at all ...all you are doing is making it "perceptively" louder by making the system distort horribly.

Here is an experiment - try cranking up typical small satellite computer speakers. I epxect you will find that you can make them sound perceptively uncomfortably loud as they quickly become terribly distorted. However, you will find that their output is actually modest when measured with an SPL meter.

Loudness is a funny thing. Real live music with extensive dynamic range will sound effortless and "perceptively" much less loud than an overworked and distorted audio system even when peak SPL's are closely matched with an SPL meter. It seems our ears use distortion/compression as a way to sense loudness...the more distortion/compression - the more perceptively loud. This is why banks of great big speakers and racks of hugely powerful amplifiers are needed at concerts to create enjoyable clean dynamic sound that is not uncomfortable until average levels approach 105 db SPL
Of course , even a concert is not meant to be played continously at this level because hearing damage occurs after a few hours at these levels...your ears need a break...so artists play a mixture of some softer pieces interspersed with loud pieces - it is the contrast or dynamic range that creates a large part of the excitment of a live event.

If you enjoy live concerts and seek to reproduce the same exhilheration at home then it is worth pursuing a system that can reproduce loud levels cleanly. 250+ watt amps and fairly imposing (often very heavy) three way speakers are the typical arrangements that work best. You may sacrifice a bit of soundstage with a bigger box speaker although this is not always the case. Accuracy in bass reproduction and effortless dynamics is where bigger systems pay off in spades. Good Luck!

Thanks Shadone for the input. Very usefull stuff. I should mention I dont think its uncomfortably loud, it's just loud too loud for what I normally listend too. As I could tell, everything was coming in clearly, just a little luder than I would have normally listened to.

When I said uncomfortably loud, I was merely trying to excersize a point that it was louder than I expected, wrong choice of words on that one.

Now, roughly speaking how loud can someone listend to an 85 watt amp driving 90db speakers from a listening point of about 12 feet? The amp is (I think) a High Current 85 watts using dual power supplies rated collectively at 320VA

Is that considered "high current"? Also, the specs on the amp say it can go to 130 watts into 4 ohms.

Thanks again

Roughly speaking I would say a maximum average of about 90 db SPL (leaving 10 db of headroom). A lot will depend on the source music and speaker design and its inherent dynamic range as to whether the sytem will run out of head room or not. Most large floorstander speakers can handle about 100 db SPL continuous at 1 meter with 10 db of headroom, which is equivalent to what you are asking from each speaker.

(Your upper limit is not entirely determined by the sensitivity and power, as it depends on the speaker design and what it is capable of....for example once the driver is driven to exceed Xmax, the linear operating range, then you are heavily into compression and harmonic distortion, heat is another factor as drivers get hot and their impedance rises significantly which reduces their output. Compression horns, for example, can play a lot louder than conventional drivers because of their inherent high sensitivity but they also have power limitations depending on design)