In article , Triffid wrote:
Neil Jones pibbled:
http://www.yeodoug.com/resources/faq...iselevels.html (Near the
end)

Bloody hell. 128dB in front of the bassoon! Am I wrong, or would your ears
go into 'self-protect' mode at this level, possibly hugely affecting the
performance of the musician?

Threshold of pain is said to be 130 dB on that scale. The conclusion
of http://www.symphony.dk/sektion2/audiograms.htm is a qualified:

"Based on the measured audiograms it may be concluded that musicians
can not expect to achieve pronounced hearing losses from playing in an
symphony orchestra. ..."

--
John Phillips

On Thu, 26 Aug 2004 23:09:51 +0100, ruffrecords
wrote:

John Phillips wrote:
To pursue an academic thought (rather than a desire to annoy the
neighbours) I was thinking about whether "orchestral" sound pressure
levels can be reasonably achieved at home.

I think the answer is yes, from just personal listening experience in
the concert hall (classical orchestral music, not normally closer to the
stage than 10 metres) and listening at home. However the more academic
answer depends on at least two factors:

1. What peak SLPs are achieved in a reasonably good seat in a concert
hall where an orchestra is playing, say 10 metres from the front
centre of the orchestra?

2. What reasonable (relatively undistorted) peak SPLs will normal but
good quality home audio kit produce?

The answer to 2 looks fairly simple. Peak SPLs about 109 dBA seem
theoretically achieveable at 1 metre from an average sensitivity
loudspeaker (about 89 dBA for a nominal eight-ohm Watt, I think) driven by
a 100 W amplifier (+20 dBW). I think also that a reasonably good modern
loudspeaker could, in practice, go up to to 109 dBA on occasional peaks
(is this correct?).

Compensating for (i) being, say, 3 metres away from the speakers, but in
a non-anechoic space, and (ii) having two loudspeakers, I think that 109
dBA probably comes down to 103 to 106 dBA peak SPL at the listening chair
(still VERY LOUD, nevertheless).

However, the answer to 1 ("orchestral SPLs?") has eluded a quick Google
search. Yes, lots of SPL figures can be found for an orchestra but they
vary widely and so far none I have seen is adequately qualified to answer
the question.

Are there any good references to orchestral SPLs in the auditorium? The
best references I have found are to SPLs in the context of the exposure of
the musicians themselves to high SPLs but I don't think these measurements
are easily translatable to SPLs in the hall.

I've seen 'front stalls' figures quoted between 105dB for an 'average'
symphony orchestra up to 118dB for very large ensembles performing
massive works by Mahler and Wagner.

It's also the case that several 'high end' speaker systems are quite
capable of hitting 120dB peaks in domestic listening rooms, combining
500 watt power handling with 92-94dB/w/m sensitivity. Horns such as
the Avantgarde series with over 100dB/w/m can of course hit similar
levels with ease.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Thu, 26 Aug 2004 23:11:09 +0100, Eiron wrote:

ruffrecords wrote:

I have never heard it expressed in SPL but a long time ago I read that
the peak output from an orchestra is about 70 watts of acoustic power.
You should be able to work it out from that.

Domestic speakers are about 1% efficient.

That would be about 89dB/w/m, but bear in mind that some designs such
as the Avantgarde Trio horn can achieve 103dB/w/m - and horns don't
obey the inverse square law!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

In article , Stewart
Pinkerton wrote:
I've seen 'front stalls' figures quoted between 105dB for an 'average'
symphony orchestra up to 118dB for very large ensembles performing
massive works by Mahler and Wagner.

Given the lack of precision in most of the sources I have seen, I think
those figures are within the band of consistent peak orchestral levels
for front-row seats (e.g. not the Royal Albert Hall's stalls - maybe
the arena, though).

I think I conclude that for peak levels, normal but good domestic kit
probably does not quite have the ability go to full concert orchestral
levels unless you are accustomed to sitting some metres away from the
front row and/or attending the "average" symphony performance.

It's also the case that several 'high end' speaker systems are quite
capable of hitting 120dB peaks in domestic listening rooms, combining
500 watt power handling with 92-94dB/w/m sensitivity. Horns such as
the Avantgarde series with over 100dB/w/m can of course hit similar
levels with ease.

However the higher-end kit probably does have the ability to create
front-row peak SPLs for all reasonable orchestral music (annoyed
neighbours notwithstanding).

--
John Phillips

John Phillips wrote:
In article , Neil Jones wrote:
http://www.yeodoug.com/resources/faq...iselevels.html (Near
the end)

As you say, these are measured in the orchestra rather than from the
audience, but since you are using theoretical extrapolations for 2)
rather than measurement, why not do the same with the figures for the
violin, for example?

Many thanks - some useful figures which are very helpful. However,
as with other measurements taken within the orchestra itself, I know
of no way to extrapolate near field, essentially single-instrument
SPL figures to a SPL for the entire orchestra in the far field region
(i.e. within the audience).

I wonder to what extent the measurements results from the individual (ie
the near-field) vs the sound from the rest of the orchestra.