Thought from another thread...

[Griffinator]

Since the dynamic range thread is now a bloated mess, I figured I'd snip this out and discuss it elsewhere...

DVDs have a dynmic range of up to 144 decibels while CDs are limited to

96 decibels, if memory serves. This has profound implications for

headroom requirements.

Couple things I'm thinking about in relationship to the above...

1) Last I checked, 99% of the DVD/SACD/DVD-A players on the market are

incapable of delivering better than 110dB SNR - so that extra 34dB of

dynamic range is essentially useless, no? Hence the effective dynamic

range only differs by about 14dB or less, depending on the overall

quality of the delivery system. Furthermore, depending on the source

material, you may never actually access the extra dynamic range - if

your source was a 50's 1/2" tape, you'll be lucky to get a total of

70-80dB of range save on fade-outs, where dithering algorithms are

employed to prevent you from "hearing" the fade drop out....

2) The dynamic range of any audio delivery system is a definition of how far below

0dBfs it can reach - 0dBfs is still 0dBfs, it's just that the fade, the

quiet passages et al on a DVD are capable of being a lot quieter

than that of a platter or a CD. The problem I see with the whole

headroom argument in this case is very simply that the average level on

a CD, for example, is a lot closer to 0dBfs, so the casual user will

tend to turn up a DVD in order to compensate for this average volume, which is when the broader range becomes a loud issue rather than a quiet one. Someone let me know if I'm way off on this assertion.

[sfogg]

"Furthermore, depending on the source material, you may never actually access the extra dynamic range - if your source was a 50's 1/2" tape, you'll be lucky to get a total of 70-80dB of range save on fade-outs, where dithering algorithms are employed to prevent you from "hearing" the fade drop out...."

And even more importantly the system that the material is played back in (including the room) far more likely then not can't even handle that sort of dynamic range.

If one sets their playback such that 0dBFS (IOW the loudest peak they are going to get) hits 105dB per speaker to be able to 'fully resolve' all the dynamics even a 'lowly' CD is capable of the noise floor of the entire system must be below 9dB. That is including all the combined noise in all the equipment *and* the noise floor of the room itself. A typical room has a noise floor of around 50dB so in a typical room there is at most 55dB of dynamics anyway.

Only way to increase the dynamics is either raise the max volume or to lower the noise floor in the room.

Shawn

[edwinr]

Only way to increase the dynamics is either raise the max volume or to lower the noise floor in the room. Shawn

Good point you make there, Shawn. And it's not easy lowering the room noise floor. But if we did this, we would benefit in so many ways including increased perceived dynamic range, greater ability to discern fine musical detail, and lower average listening level to protect our hearing.

[sfogg]

"And it's not easy lowering the room noise floor."

The main way to do it (which is loads of work and expense) is a dedicated room that is built for isolation.

Or listen late at night when things tend to be quieter.

"we would benefit in so many ways including increased perceived dynamic

range, greater ability to discern fine musical detail, and lower

average listening level to protect our hearing."

Exactly.

Shawn

[Griffinator]

"

And even more importantly the system that the material is played back

in (including the room) far more likely then not can't even handle that

sort of dynamic range. If one sets their playback such that 0dBFS (IOW

the loudest peak they are going to get) hits 105dB per speaker to be

able to 'fully resolve' all the dynamics even a 'lowly' CD is capable

of the noise floor of the entire system must be below 9dB. That is

including all the combined noise in all the equipment *and* the noise

floor of the room itself. A typical room has a noise floor of around

50dB so in a typical room there is at most 55dB of dynamics anyway.

Only way to increase the dynamics is either raise the max volume or to

lower the noise floor in the room.

Shawn

And that, I believe, is the single biggest issue in the whole

"headroom" argument. If it weren't for the room noise issue, people

wouldn't feel compelled to crank their systems up to ear-damaging

levels (I have yet to hear a valid argument for this 30dB spike on the

Telarc 1812 CD that addresses the issue of major hearing damage at the

volume levels they're claiming to be employing) and thus the desire for

a megawatt amplifier to drive a pair of speakers that have a max SPL of

far less than what the wattage - dB - sensitivity formula would

indicate in such loud situations.

I also still haven't heard an explanation of the K-Horn's max SPL being

rated at 121dB, where the speaker is capable of handling power

sufficient to (theoretically) drive it upwards of 150dB. Anyone care to

give that a go?

[tkot]

the other way to lower the noise floor of the room

would to be to get a set of really good headphones, and add a sub that you can feel.

the issue that i have with that is that headphones make my

giant pile of speakers seem a little silly ;}

jay

[sfogg]

"

the other way to lower the noise floor of the room

would to be to get a set of really good headphones,"

Yup, and if anyone has ever taken a listen to Entoymotic Research

earphones they can attest to that. Those offer about 20dB of noise

isolation full spectrum when worn/used. Consequently the resolution of

those phones is amazing.

Shawn

[sfogg]

"

I also still haven't heard an explanation of the K-Horn's max SPL being

rated at 121dB, where the speaker is capable of handling power

sufficient to (theoretically) drive it upwards of 150dB. Anyone care to

give that a go?"

Where do you get 150dB from??

K'Horns max power rating is 100w. Efficiency is listed at 104dB/w/m

1w = 104dB

10w = 114dB

100w = 124dB

But Klipsch lists max acoustic output at 121dB like you said. So either

the specs are a little wrong (efficiency lower then claimed or max

power lower then claimed), or there is some compression at 100w

lowering the acoustic output.

To continue the above on to 150dB....

1,000w = 134dB

10,000w = 144dB

20,000w = 147dB

40,000w = 150dB

Shawn

[Griffinator]

"

I also still haven't heard an explanation of the K-Horn's max SPL being

rated at 121dB, where the speaker is capable of handling power

sufficient to (theoretically) drive it upwards of 150dB. Anyone care to

give that a go?"

Where do you get 150dB from??

K'Horns max power rating is 100w. Efficiency is listed at 104dB/w/m

1w = 104dB

10w = 114dB

100w = 124dB

But Klipsch lists max acoustic output at 121dB like you said. So either

the specs are a little wrong (efficiency lower then claimed or max

power lower then claimed), or there is some compression at 100w

lowering the acoustic output.

To continue the above on to 150dB....

1,000w = 134dB

10,000w = 144dB

20,000w = 147dB

40,000w = 150dB

Shawn

Well, the 150 was a ballpark figure - but you did get my point. 400w

into a pair of K's would theoretically put out around 129-130dB, yet

the max SPL is 121.

[leok]

Nothing much to add here, just agreement. Loud isn't of much interest

to me anyway, but lower level timbres and acoustic ambience are

important. As I've reduced distortion and improved signal to noise of

both systems many recordings have taken on a three dimensional quality

creating a very stable sound space between and behind the speakers with

recorded echoes helping to establish instrument locations in that

space. To me, as has been said above, dynamic range starts with 0dB set

at a level I want to listen to and my system can accurately reproduce

and extends downward into low level detail.

I believe by choosing amplifiers that are close to their limits at the

volumes I prefer for 0dB, I am maximizing signal to noise and dynamic

range .. geting as much of the low level detail as the system permits.

Leo

[D-MAN]

It has always been a concern of mine that the DVD has much more dynamic range than any cd that I own, and some of those definitely apply some "stress" to the system like the cannonade(s) in "Master and Commander" and the gunfire in "Open Range", etc. In particular these DVDs caused some concern for the K33E's remaining functional. Due to the lack of musical information in these signals (mostly amplitude), fidelity is not a particular concern, so who cares how much "mud" there is? But when it comes to large signal fidelity, there is a definite problem.

I went to higher power handling speakers to cope. As a benefit, the stereo response improved. Previously, in stereo operation, the K33E would cause low frequency room overload at very low wattages (about 1w). The new drivers being balanced towards the upper bass rather than the lows allows for extremes of volume and no apparent room overload. This is entirely due to the woofers concerned. Now it remains clear at extremes of volume (30w+). Prior to the change, 30w was completely unacceptable due to "mud" (which I am calling room overload distortion).

The K33E is fine for low-level low-power work. For other purposes, I would go with a higher-power handling woofer which typically means the overall "balance" of the driver is tilted upwards rather than towards the extreme lows. The room overload point also seems to move upwards as well.

Friends have commented on the particulars in familiar music cds where the "mud" just isn't there anymore.

DM

[mobile homeless]

Nothing much to add here, just agreement. Loud isn't of much interest to me anyway, but lower level timbres and acoustic ambience are important. As I've reduced distortion and improved signal to noise of both systems many recordings have taken on a three dimensional quality creating a very stable sound space between and behind the speakers with recorded echoes helping to establish instrument locations in that space. To me, as has been said above, dynamic range starts with 0dB set at a level I want to listen to and my system can accurately reproduce and extends downward into low level detail.

I believe by choosing amplifiers that are close to their limits at the volumes I prefer for 0dB, I am maximizing signal to noise and dynamic range .. geting as much of the low level detail as the system permits.

I generally think this topic has been a sordid joke with more misinformation than anything else, especially in Ben's thread, which practically turned into an embarrassment as the overal picture was overlooked time and time again.

I have to say that Leo's post above is one of the few reasonable takes on the issue with a balanced view of his own needs with a proper conception/understanding of the idea of dynamics, both macro and micro.

Well done, Leo (even if you are wrong about the Belkin with your MoonPaths...heh)

kh

[Duke Spinner]

Hmmmmnnnnnn....

what Amp is Leo using......????

it can't be .......CROWN .......! ! !

[mobile homeless]

Hmmmmnnnnnn....what Amp is Leo using......????it can't be .......CROWN .......! ! !

Good one. Even if in jest, several things are apparent. This is the lowest wattage Crown made, not the 150-1000w behemoths, and it was acquired by Leo because of its untypical SS behavior of exhibiting very low distortion ratings at very low watt levels, something that most SS amps DONT do (and an important attribute when dealing with high efficiency speakers). Two, Leo has FOUR amplifiers, and I am betting he is mainly referring to his 2A3 Parafeed SET amplifiers with probably have the sweetest top end and most open mids, also REALLY excelling at microdynamics, quite possibly over any of the other subjects.

Lastly, I tend to not hold hardly any weight with specs, definitely as much as Leo, who is a distortion hound. I dont like distortion either, but have ultimately found it a poor measurement gauge relating to sonics, just in my personal opinion. Leo has done a LOT of thinking about getting the lowest distortion at a fraction of a watt, again, this where most SS amps suffer.

One of the problems with simple discussion of dynamic range, headroom, etc, is that it has far more variables than most even take notice of, which is why stock figure quotes to define it often miss the boat when you weigh in all the factors. Add to that the basic misunderstanding here as to what dynamics really mean and you have a mess.

I usually side with Leo's take with amplification; as for the Crown D-45, I am willing to give him the benefit of the doubt. IT was reported by DJK that the earlier D series were quite different sonically. It's hard to remotely imagine the three Crown D-75 I had on hand even coming in a Top 100 of amplifers if looking at something like Microdynamics. I can only assume the D-45 Leo has is a different animal altogether.

kh

[Duke Spinner]

the spec's are the same as a D-75a..

it has one less BJT per channel

[pauln]

Previously, in stereo operation, the K33E would cause low frequency room overload at very low wattages (about 1w).

1 watt is not "low", its the low end of live rock concert level!

See proof in the court room battle of the infamous "Headroom" thread.

(yeah, the very one from which this thread is trying to improve).

[mobile homeless]

the spec's are the same as a D-75a..it has one less BJT per channel

One thing I keep forgetting about ye olde Klipsch forum... Half the time, anything over two lines in a post is wasted, as it's either not read carefully, or at ALL. Gets me every time.

kh

[edwinr]

Everyone talks about that magical first watt. Certainly, in tha past, most non- class A S/S amplifiers suffered badly from cross-over and other types of distortion at low wattages in comparison with well designed (SET) tube amps. A greater number of more recent S/S designs do not exhibit this behaviour. In this case the first watt is clean and musical. Just because an amplifier features S/S topology, doesn't mean to say it sucks.

Just another thought. As we wind the volume control up, our ears will start to shut out fine musical detail and such niceties as soundstage cues, imaging and depth. There is probably an spl where we can still discern this fine detail without our hearing shutting down. But this would vary from person to person.

[leok]

There does seem to be some improvement in recent ss designs wrt low

power performance. But maybe knowing where to look helps too. The D-45

was quite a surprise. As a result I am considering construction of an

amp based on the National LM2876 (smaller but similar to the National

ICs used in GainCard/Clone amps).

They all act like big, very high gain, op-amps using tons of feedback

with all devices turned full on (except the power transistors). Also,

the driver stages provide some or all low power output current

depending on design.

PWM design (Tripath for example) is a completely different approach to

the problem. Linearity is inherent in the algorithm and output to input

feedback is not used. But PWM does have its limitations and the

National specs. are significantly better at low power than the Tripath

(which itself is a lot better than very many older ss designs). I'm

curious as to whether or not I will hear an improvement. Of course, if

I don't hear an improvement it could be I've reached my own threshold

of low power distortion detection. If it's worse, that's another can of

worms, including my particular implementation.

As for the Crown D-75, It may be the D-45 and possibly the D-75A are

different in that Crown directly targets low power applications (they

refer to the applications as "medium" power). Some of their literature

mentions that these amps are appropriate for use with horn loaded

speakers.

Leo

[sfogg]

"Linearity is inherent in the algorithm and output to input

feedback is not used"

Tripaths use feedback. In the case of the 2050 chipset for example the

modulator stage has a feedback loop and the output stage has a second

loop. There isn't end to end though.

Shawn