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#### Talley

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http://annhyg.oxfordjournals.org/content/55/8/893.long which shows some testing done on the SPL of musical instruments played by orchestra players. Much data shows averages and peaks. One interesting note is Peaks of horns are in the 132db range and double bass is 121db.... now you have to understand this is the SPL at the ear for the player.

What is the average distance you would listen to these instruments in a live setting? well... I listen to people play the upright bass at a distance of 12 feet. Thats what you want right? If your playing cello music from your speakers in your room you want it to feel and sound like it's really there right? Well plant that cello right between the speakers or from an SS&I situation say about 6 feet behind the speakers maybe? average listening distances are what 12 feet. So I dunno lets say 15 feet from the instrument.

Cello for example peaked at 121db in one ear and 124db in the other ear. Considering the cello sits around 3 feet from the ear we can use that as an example of peak level needed to playback right... but what is this at the MLP? well lets use this site: http://hyperphysics.phy-astr.gsu.edu/hbase/acoustic/isprob2.html you plug in the 124db with 3 feet (this is the music instrument to the ear as shown on table 2 of the first link and the testing performed) You transfer this to a listening distance of around 12 feet away and you now need peak SPL levels in the 110db range.

So now you need 110db peak... not constant... peak. What kind of amplificaition power do you need? Take my Ultras for example... they are "88db" sensitive based on the 2.89v/1m test so not sure how that transfers to the 1w/1meter but we'll use 88db as a calculation I use this site: http://myhometheater.homestead.com/splcalculator.html and it tells me at 12 feet and 125 watts I get 100db. This falls 10db short for the "peak"... 1000 watts gets me peaks of right at 110db at a 12' distance with a realistic playback of a cello peak at the same 12 feet away.

So realistic non distortion peaks needs 1000 watts.

So. Obviously all amplifiers can provide peak power above their RMS rating. How much more? Am I really thinking out of the box on this or would a 1000watt amp... say the Emotiva XPR-1 provide so much headroom that during realistic levels of playback and peaks would never be stressed to the point of distortion providing clean playback at all times. Another issue is who would listen to a cello at levels hitting peaks of 110db? I know when I listen to cello music my peaks only hit around 90db. What does this mean? Well... it could mean that I'm listening at a distance of 100 feet away from the cello which by that site above would be the right SPL at 100 feet if listening in a music hall.

however then the issue is the playback of your system and SS&I... what if that musical instrument sounds like it's only 15' away from an imaging point of view? Well then your system needs to be able to play those levels to match the SS&I interpretation of that instrument or it will never match.

Could this difference in SPL and SS&I lead to some kind of weird brain tricks... is it a mind thing where your brain hears the imaging of a close object but at a sound level of far away so your brain struggles to keep up with a smooth seamless playback?

Crazy if you think about it and again sorry it's another rambling on my part but seriously.... Don't you need 1000 watts to get realistic playback?

Maybe we should do the math for horns... which at a 132db peak for the musician we would now need more power from an listening point of view. Again... peak power is so much different than RMS and most of the continuous levels of playback based on that article on table 1 is around 88 to 98db. Putting you a need of 86db for 12' away from speaker and this only needs around 25 to 50 watts of amplification for an 88db speaker to maintain clean realistic playback during average levels....

...but for peak wow... you need some power!

#### Talley

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The other question is what happens during peaks?

If your playing back music through a 100watt amplifier (rated at 8ohms under thd levels) and your listening to 90db which is easy for an 88db speaker at 12 feet (~100db) with no distrotion

what happens when you change to the 1000w amplifier? Do those peaks automatically get louder or does the peaks stay clean since they don't go into distortion levels. The 100w amplifier would still play those peaks at those peak levels but with lots of audible distortion yes?

#### ellisr63

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Or really efficient speakers... My JBL 2360A horns with EV DH1A drivers are 112db with 1 watt, with my bass bins at 100db with 1 watt. I drive my bass bins with 250wpc, and the horns with 50wpc. I can hit your desired levels with little power. :T

#### Talley

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Or really efficient speakers... My JBL 2360A horns with EV DH1A drivers are 112db with 1 watt, with my bass bins at 100db with 1 watt. I drive my bass bins with 250wpc, and the horns with 50wpc. I can hit your desired levels with little power. :T
Well... I never said my desired levels... I listen to alot lower but it made me wonder what it would take for clean playback and realistic playback levels as if you were really there. It's quite surprising what is needed.

And yes... efficient speakers would be a huge improvement achieving this.

#### ellisr63

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Well... I never said my desired levels... I listen to alot lower but it made me wonder what it would take for clean playback and realistic playback levels as if you were really there. It's quite surprising what is needed.

And yes... efficient speakers would be a huge improvement achieving this.
We watch movies at 1 watt on peaks...when we want it loud

#### morca

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Film please if you test 1 kw on the SVS speakers.
And wear a helmet

#### Talley

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Film please if you test 1 kw on the SVS speakers.
And wear a helmet
I bet they would handle it. We are talking peaks. You only need ~50w for continous rms wattage for realistic levels during normal parts.... but the peaks, which could last up to .5 seconds can run up in the 600+ watts.

No way could they hold up to 120db constantly. not even sure if they really could hold up to the peaks.

...only one way to find out :hsd:

#### ellisr63

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Waiting for :hsd:

#### morca

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I think you will wreck them,beter sad: they will explode i think

#### Talley

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I think you will wreck them,beter sad: they will explode i think
Think so?

They are rated for up to 300w. I wonder what their peak handling capability is for the 200ms-500ms peaks that demand so much.

#### prerich

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Or really efficient speakers... My JBL 2360A horns with EV DH1A drivers are 112db with 1 watt, with my bass bins at 100db with 1 watt. I drive my bass bins with 250wpc, and the horns with 50wpc. I can hit your desired levels with little power. :T
I was just about to say the exact same thing that you have said! Although my Cornwalls are 101db, I'm driving them with a 200wpc amp (8ohm). Speaker efficiency is often overlooked when people talk about peak output, but high efficiency provides lower distortion at high spl's.

#### Savjac

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While sitting in the hall, the sound produced by the orchestra will never reach your ears at some of those levels. Things can reach say 100db during some maximum crescendos, however, that does not happen often. The problem with the recreation of the orchestral sound is not so much one of volume but one of moving air. It cannot be said that a couple smaller speakers can accurately portray an orchestra in mezzo forte.

Having said that, I did attend a concert of the Chicago Symphony seconds when they play out doors during the July 3rd celebration. For several years they played the 1812 Overture and instead of whacking on huge concert drums during the end, they used real canons to kind of drive home the thought of the piece. Now that far exceeded 100db and it was a beautiful thing.

#### morca

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Think so?

They are rated for up to 300w. I wonder what their peak handling capability is for the 200ms-500ms peaks that demand so much.
No i was partly kidding,because i think 1000 watt RMS /8 ohm is a lot of power for the most speakers.

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