Dynamic Contrast and Limitations

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Wind Chaser

Dynamic Contrast and Limitations
« on: 2 Jan 2008, 10:20 pm »

In this small and mainly retirement community of 32,000 some one called me in response to an ad for a 2A3 amp I posted on the internet.  I told him unless he has at the very least 90 db efficient speakers it’s not even worth considering.

As it turns out he has a pair of Klipschorn’s rated 104 db crammed into an 18 X 12 foot treated room.  I brought the 2A3 over and with I left it with him, but not without sampling a few tunes first.  What really caught my attention here was the extent of dynamic range!  It was almost impossible to set the volume because the soft passages were very soft and the loud passages were incredibly loud. 

We weren’t listening to anything unusual in this regard; it was all stuff that I am very familiar with and yet I was caught off guard by the tremendous increase in sound pressure when the musical momentum surged forth and peaks soared even louder like a sudden thunderclap in close proximity.

It seems to me dynamic contrast is the dominion of high sensitivity.  The more efficient the speakers, the more liberal the dynamic range.  That’s not to say that a relatively inefficient speaker (measuring less than 90 db @ 1 watt) can’t sound dynamic, it will just be very limited and restrained by comparison.  What do you think?  What’s your experience with super high efficient speakers and how well do low efficient speakers handle dynamics in comparison?


Double Ugly

Re: Dynamic Contrast and Limitations
« Reply #1 on: 2 Jan 2008, 11:14 pm »
What’s your experience with super high efficient speakers and how well do low efficient speakers handle dynamics in comparison?

I own both, and IME it depends on what's driving the less efficient speaker.  A properly designed "low efficient" speaker will produce similar results when coupled to an amplifier capable of driving it properly.

FWIW, my 'less efficient' speakers are rated at 85dB (8 ohm), and the 100W Butler Monads drove them surprisingly well.  Achieving dynamics like those you describe was not a problem, but it's even less of a problem now that I have a 600W amplifier.  :wink:

satfrat

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Re: Dynamic Contrast and Limitations
« Reply #2 on: 2 Jan 2008, 11:55 pm »
I can say for a fact that it depends on the system, what Double Ugly said. In my system, i've got Odyssey Lorelei's, 87db@6ohms, running on 150watt Butler 3150's,,, lots of power conditioing, lots of Bybees and in a 11' x 17' room my Lor's can be made to sound like an echo chamber,,, all by the switch of a power cord. Believe it or not but I can make my lorelei's TOO dynamic to the point that it's just too much of a good thing just by placing this beta Gold Bybee power cord that I'm demo'ing for Bolder Cable. Only difference fromthem horns is you'd want to crank up the volume so to get totally immersed into the 3rd dimension, if that's where you want to go.  8)

AFAIC,it's not the effiency that dicates dynamics, it's the system itself.  :D

Cheers,
Robin

Tweaker

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Re: Dynamic Contrast and Limitations
« Reply #3 on: 3 Jan 2008, 01:13 am »
I found an interesting thread at the Decware forum discussing this very thing:
http://www.decware.com/forums/General/posts/3593.html
 You have to scroll down nearly to the end to get at Steve's comments so I'll save the trouble:
Quote
I guess my point is that any argument made on a singular piece of audio gear (speaker) will at some point have to be viewed from the perspective of the entire playback system. There is MORE dynamic range, and MORE information in the first watt by a factor of 10 than in any successive watt. If you put together a system where the first watt is irrelevant then you have a PA system, such as in my studio.
He goes on to elaborate:
Quote
Every time you increase the loudness level of a system by 3dB it required a doubling of amplifier power.

Simple example:

Using a 90dB speaker ~

Driven with 1 watts = 90 dB.
Driven with 2 watts = 93 dB
Driven with 4 watts = 96 dB
Driven with 8 watts = 99 dB
Driven with 16 watt = 102 dB
Driven with 32 watt = 105 dB
Driven with 64 watt = 108 dB
Driven with 128 watt = 111 dB
Driven with 256 watt = 114 dB

And so on.

Now lets go the other way:

Driven with 0.5 watts = 87dB
Driven with 0.25 watts = 84 dB
Driven with 0.125 watts = 81 dB
Driven with 0.0625 watts = 78 dB
Driven with 0.03125 watts = 75dB
Driven with 0.015625 watts = 72 dB
Driven with 0.0078125 watts = 69 dB (1/128th of a watt)
Driven with 0.003986 watts = 66 dB
Driven with 0.001953 watts = 63dB
Driven with 0.000976 watts = 60dB (about 1/1000th of a watt)

This gives almost 30 dB of dynamic range in the FIRST watt. The second watt gives 3 dB of dynamic range.

That should be fairly clear!
Cheers,

Steve Deckert

SET Man

Re: Dynamic Contrast and Limitations
« Reply #4 on: 3 Jan 2008, 01:52 am »
Hey!

   That's my friend is the power of Hi-ef speaker system :cool:

   My current speaker is my own home brew Single Driver with 94dB rated in TQWT driven by a pair of 18 watts monobloc SET. :D

   I've heard many speaker with low sensitivity of 87dB and lower. Sure they some of them sound good but usually they need to be play loud to sound a live. At lower level listening they sound dead and lifeless to me.

      Personally I will never ever buy a pair of speaker that is less than 90dB. Still there is more than sensitivity rating, the speaker must have relatively flat impedance also.. ideally not drop below 6 ohm. Simple xover with multi-way is a plus :D

   Than again there are always exception. I've heard some nice speaker with less then 90dB and some bad Hi-ef one also. :roll:

    Of course everybody got their own taste so that is just my own personal point of view. :wink:

Take care,
Buddy :thumb:

jlupine

Dynamic Contrast and Limitations
« Reply #5 on: 3 Jan 2008, 02:02 am »
In the world of conventional dynamic (cone-type) speakers, I've noticed that more sensitive speakers tend to have greater dynamic range and better bass at low loudness levels (say 70 dB average) than insensitive speakers even if the less sensitive speakers are connected to extremely powerful amplifiers.  Not always, just usually.  My experience may be distorted by hearing more systems in acoustically flawed hotel rooms than in scrupulously tweaked living rooms.  It could also be that this observation is most striking with very high-end speakers (e.g., Revel, Focal, B & W, Avalon, Wilson) that simply don't have their drivers balanced in loudness or dynamics until they reach a louder threshold than I'm describing.

And another thing:  increasing the loudness by 3 dB by doubling the power would occur only in the loudness range where the speaker system's sensitivity is linear.  I suspect that this is a more limited range--especially with some models--than many people think.       

Jan

NewBuyer

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Re: Dynamic Contrast and Limitations
« Reply #6 on: 3 Jan 2008, 02:17 am »
...increasing the loudness by 3 dB by doubling the power would occur only in the loudness range where the speaker system's sensitivity is linear.  I suspect that this is a more limited range--especially with some models--than many people think.       

Jan

Jan this is very interesting. Could you and/or others please elaborate a bit on this? What kind of linear ranges are common, and does it only correlate with sensitivity?

P.S. And doesn't this further depend also, upon the ohm-specification of the speakers?
« Last Edit: 3 Jan 2008, 02:45 am by NewBuyer »

satfrat

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Re: Dynamic Contrast and Limitations
« Reply #7 on: 3 Jan 2008, 02:36 am »
Looks like I interpret the word dynamic different than some. Looks liike the fans of high sensitivity speakers wanta look at dyanamic as what their loudspeaker will do at low volume whereas folks like myself with a 87db look at what can be accomplished from their loudspeaker in the right system. I can thruthfully say that the only time I listen to music at low volume is when i'm on the phone. That's not to say I'm up at 90db all the time but 70-80db is a realistic volume range for me. To me, the word dynamic means the 3dimensional depth perecption that can be accomplished with a set of loudspeakers at a realistic volume level. I have that in spades. As for having this same preseption at low volumes,,,, dunno,,,,, but i can easily see being outperformed by a system like Buddy's.  aa



Cheers,
Robin

SET Man

Re: Dynamic Contrast and Limitations
« Reply #8 on: 3 Jan 2008, 03:13 am »

As for having this same preseption at low volumes,,,, dunno,,,,, but i can easily see being outperformed by a system like Buddy's.  aa

Cheers,
Robin

Hey!

   Well, Robin you are welcome to hear my system. I don't know how or when but maybe someday. :D

   True that I like my system but it ain't perfect... it is not for everyone  :icon_lol: What's sound good to me could sound like shit to you :wink:

Take care,
Buddy :thumb:

Wind Chaser

Re: Dynamic Contrast and Limitations
« Reply #9 on: 3 Jan 2008, 05:48 am »
Dynamic range is commonly thought to be the difference in volume between the soft and the loud.  It's the vital force of music that emotes energy!  Think drums or loud crashing cymbals, the blast of a trumpet compared to a French horn.

I agree with Buddy's comment that inefficient speakers sound lethargic or "lifeless" at low volumes.  The bass is virtually nonexistent.  If not vitalized with plenty of power, they just don't wake up and sound sedated.

The other observation previously made in Tweakers post about the first watt is very interesting.  If indeed the first watt has almost 30 db of dynamic range and double the power is required for each 3 db increment thereafter, that would seem to me that the dominion of dynamics belongs to high sensitivity.

This is what made the 104 db sensitive Klipschorn’s so interesting and unlike any other speaker I have ever heard before.  One moment you are listening at a comfortable volume able to carry on a conversation with the person next to you, and the next moment you have to shout in order to hear each other because music isn't static.  It ebbs and flows.  IMO the best speakers are capable of relaying that energy without restraint.  And there is no such thing as too much dynamic range.

Any Avantgarde owners here?


rabpaul

Re: Dynamic Contrast and Limitations
« Reply #10 on: 4 Jan 2008, 02:12 pm »
There is actually a difference between speaker efficiency and sensitivity although I admit even I take them both to mean the same thing. Irrespective of the sensitivity rating e.g 105dB/W, I only consider a speaker as efficient if it has no minimum power rating e.g Klipshorn or Avantgarde. Such speakers will have a rather low max power rating e.g 100W.

Dynamics to me is about hearing not just the difference between loud and soft (contrast) but also about being able to tell that something is soft and something is louder at the same time e.g hearing the harpsichord in the background while string section of an orchestra is playing. IMHO this level of dynamics is system dependent and not really an attribute of the sensitivity of the speakers.