Who here uses a pro amp to drive his speakers ?

[cjgeraci]

Hey, how do you quote someone, now? The forum design changed.

Anyway, in response to the deal about saying professional amps are good for production but not playback, that's sort of silly. Are you suggesting that the professional musicians use PA for their color. Let's see, if you get a QSC, you will get this effect, and if you use a Crown, you will get this effect and so on.... I don't think so. I think they pick the amp for its ability to cleanly produce music. The rest of the effects are in the gear, like pedals and so forth.

As to Mark's comments. I agree with what you are saying to some extent. I think you speak a little too down on PA amps, though. Granted, you have been reviewing all sorts of comments with an equally broad stroke (e.g. tube amps don't have authoritative bass). I guess you could consider your comments more pay-back. As far as the XTi, I've never heard one. I don't really go around searching for sounds all the time. Maybe it does suck, but I'd be a little surprised if it did. I think it is maybe more of a starter amp, though.

Now, how do you quote on this forum?

To quote, select the "Quote" button in the prior "grey" response area.

Is your practice kicking your rear end like my practice is kicking mine..........?

Welcome back, Jeff.

Carl.

[Jeff Matthews]

Hey, how do you quote someone, now? The forum design changed.

Anyway, in response to the deal about saying professional amps are good for production but not playback, that's sort of silly. Are you suggesting that the professional musicians use PA for their color. Let's see, if you get a QSC, you will get this effect, and if you use a Crown, you will get this effect and so on.... I don't think so. I think they pick the amp for its ability to cleanly produce music. The rest of the effects are in the gear, like pedals and so forth.

As to Mark's comments. I agree with what you are saying to some extent. I think you speak a little too down on PA amps, though. Granted, you have been reviewing all sorts of comments with an equally broad stroke (e.g. tube amps don't have authoritative bass). I guess you could consider your comments more pay-back. As far as the XTi, I've never heard one. I don't really go around searching for sounds all the time. Maybe it does suck, but I'd be a little surprised if it did. I think it is maybe more of a starter amp, though.

Now, how do you quote on this forum?

To quote, select the "Quote" button in the prior "grey" response

Is your practice kicking your rear end like my practice is kicking mine..........?

Welcome back, Jeff.

Carl.

Carl.

Thanks, Carl. I'm testing to see if this works. Also, thanks for the "welcome back." I'm used to busy periods and down periods. I get an even enough mix where I fel I get a nice balance of "play time."

What kind of practice do you do again?

[cjgeraci]

Hey, how do you quote someone, now? The forum design changed.

Anyway, in response to the deal about saying professional amps are good for production but not playback, that's sort of silly. Are you suggesting that the professional musicians use PA for their color. Let's see, if you get a QSC, you will get this effect, and if you use a Crown, you will get this effect and so on.... I don't think so. I think they pick the amp for its ability to cleanly produce music. The rest of the effects are in the gear, like pedals and so forth.

As to Mark's comments. I agree with what you are saying to some extent. I think you speak a little too down on PA amps, though. Granted, you have been reviewing all sorts of comments with an equally broad stroke (e.g. tube amps don't have authoritative bass). I guess you could consider your comments more pay-back. As far as the XTi, I've never heard one. I don't really go around searching for sounds all the time. Maybe it does suck, but I'd be a little surprised if it did. I think it is maybe more of a starter amp, though.

Now, how do you quote on this forum?

To quote, select the "Quote" button in the prior "grey" response

Is your practice kicking your rear end like my practice is kicking mine..........?

Welcome back, Jeff.

Carl.

Carl.

Thanks, Carl. I'm testing to see if this works. Also, thanks for the "welcome back." I'm used to busy periods and down periods. I get an even enough mix where I fel I get a nice balance of "play time."

What kind of practice do you do again?

You are welcome.

Civil litigation - at times, a little of bit of this and a little bit of that, you know...........

However, specialty areas include business & commercial, real estate, product liability, and intellectual property.

Carl.

[Jeff Matthews]

Civil litigation...... Yep. Sounds like your practice is somewhat like mine, except for the intellectual property. I don't mess with that very much. I do increasingly more transactional, which I think is a practice whose volume is directly proportional to age. I used to enjoy litigation, and to some extent I still do. But the mechanics of posturing and screwing around to get to a result both sides know pretty much from the outset will be reached is increasingly a pain. In some cases, here and there you get some surprising results and the issues are quite interesting.

Hey, how's your Supreme Court over there? Ours over here is just fabulous! We have a few interesting opinions out of ours. It seems, more and more, the courts jump in and substitute their opinions for jury verdicts because of articulated desires to be more "scientific" or "logic-based."

Example: Slip and fall on ice cubes near a soda-dispensor in a convenient store. Plaintiff verdict. Supreme Court reverses and renders. Held: It wasn't the ice falling out of the machine over months and months that was the dangerous condition of which the store should have been aware. Instead, it was ice on the floor. So, though the evidence showed the owner knew the ice dispensor would not shut off and it would allow ice to routinely fall on the floor, this was not the condition in issue. There was no proof the owner knew or should have known there was ice on the floor at the time of the slip and fall. This shtick will just aggravate you.....

Example 2: "We have no idea why all the carriers paid out all those billions in mold claims and went to the Dept. of Insurance to threaten to leave the state if mold coverage was not reduced or eliminated..... Heck, there was never coverage for mold damage in the first place!"

Of course, these "opinions" are all by self-proclaimed justices who don't legislate from the bench; they just apply the law. Gotta run. Take care.

[Arky]

the mechanics of posturing and screwing around to get to a result both sides know pretty much from the outset will be reached is increasingly a pain

Settle more & stop screwing around.[]

[DrWho]

How about the "looks" of Bob's "bobbling" frequency response curves plus and minus 1 or 2 dB? Is that "look" meaningless too?

First of all, that graph you posted states 1dB/div, and the entire line resides inside a single 1dB division - kinda hard to swing 4dB inside that range. So really it's +-0.5dB, not +-2dB. It's probably closer to +-.3dB, but that's nitpicking. Second of all, there is a note at the top that says the test signal was 500mV of random noise. I am not familiar with Bob's particular test rig, but I know that you could feed a random noise signal directly into various different measurment tools and usually you will never measure a flat frequency response. Perhaps you know of a random noise generator that happens to hit every frequency all at once and all at the same amplitude over all time? I sure don't.

Long story short, Bob posted that measurement to show the high frequency extension of the amp went above 20kHz. I wouldn't trust it to within more than 1dB considering the nature of the test signal.

[DrWho]

Oh, I think I've interpreted a square wave or two.

Ever try measuring a square wave played back from a CD player?

[Jeff Matthews]

the mechanics of posturing and screwing around to get to a result both sides know pretty much from the outset will be reached is increasingly a pain

Settle more & stop screwing around.

Yes, I remember you well, Arky! You got me there....

[Islander]

Anyway, in response to the deal about saying professional amps are good for production but not playback, that's sort of silly. Are you suggesting that the professional musicians use PA for their color. Let's see, if you get a QSC, you will get this effect, and if you use a Crown, you will get this effect and so on.... I don't think so. I think they pick the amp for its ability to cleanly produce music. The rest of the effects are in the gear, like pedals and so forth.

I'm not a musician, but I'd think that what you'd look for in an amp for stage use, especially if you have to buy a stack of them, would be ruggedness, ability to run at near full power most of the time, and low cost. Very low distortion and noise might not be that important, unless you're playing acoustic instruments, where distortion is a less frequently used effect.

For home use, the priorities are different. Low distortion, low noise, pleasing sound (or not many will be bought), snazzy or at least expensive-looking styling, to name a few. Rack-mounting lugs are rarely required.

No amp can be all things to all people, so as Mark points out, the engineers prioritize what's most important to the intended customer and design accordingly. I'm generalizing, but that's the impression I have.

Jeff, to quote, hit Reply, then highlight the passage you want to quote, then hit Quote.

[TheEAR]

So lets do a filtering of all that was said....[]

At the end of the day my Tenor OTL amps are THE best sounding tube amps and THE best sounding amps for acoustic muisc,where each detail counts,where life like performance counts. With efficient horns ....no pro amp comes close.

For the electronica I listen alot too...the high quality very high power pro amp does wonders with power hungry speakers. Each amp has its optimal application.

And with large horns I understand why tubes are so popular,plys horns will spit the harshness...tube amps soften up ...the synergy is total.

Now a serious question...I will be getting Klipsch Heritage series this year,I want a pair of new LaScala II mains for my Tenor Audio amps. I know the LaScala is bass limited(to ~50Hz),this is a non issue since I will play ONLY acoustic...guitar mostly.Remember I also have a few very high quality subs if I ever need output below 60Hz.

So what is the Klipsch congregation opinion of the LaScala II ?

[Coytee]

So what is the Klipsch congregation opinion of the LaScala II ?

Owning an original pair, wishing they sounded like the II's, I give them two [Y] [Y]

[mark1101]

I absolutely love my lascalas and they are not 2s. I heard the 2s sound fantastic.

[mikebse2a3]

So what is the Klipsch congregation opinion of the LaScala II ?

Heard them at Pilgrimage 2006 and would love to own a pair!

mike tn

[Audio Flynn]

Never heard the "IIs" yet.

Heard several origonals with better than stock networks.

I like the terminology Sam Tellig uses in his reviews, it is what I hear in Heritage speakers.

http://www.klipsch.com/products/details/la-scala-ii.aspx#specifications

I think the low end perforamnce is understated from lab test set up factors.

frequency response: 51Hz-17kHz± 4dB

[Daddy Dee]

Mark,

Thanks for your explanation. That makes sense even to my lay understanding.

BTW, From your avatar, I see that you have incarcerated one of your dogs. From his expression, I can see his keen sense of injustice. Or maybe he/she is just a little person in a dog suit.

[Jeff Matthews]

Mark,

BTW, From your avatar, I see that you have incarcerated one of your dogs. From his expression, I can see his keen sense of injustice.

That's funny! U're killin' me! [&]

[Don Richard]

Your view there is "frequency domain" dominant, whereas music is really time domain dominant. It is always tempting to fall back on an FFT or spectral content view, but FFT applies accurately only to periodic forms, not transient forms.

Different sides of the same coin. But when it is time to decode the audio information, the ear acts like an FFT. Basically, the eardrum transmits the vibrations caused by sound pressure to the hair-like cells located in the cochlea which in turn stimulate the auditory nerve which in turn sends electrical impulses to the brain that causes the perception of a sound. If you "unwind" the snail-like structure of the cochlea the hair cells will then be in a straight line that matches closely with the logarithmic scale used to plot frequency response. Thats right, each "hair" in the ear structure corresponds to a specific frequency. There has to be a "hair" that can detect a frequency in order for it to be heard. You cannot divorce rise time in a waveform from the frequencies used to create the waveform. All audio waveforms are combinations of sine waves at various frequencies. So in order for us to hear a certain waveform the frequencies that make up that waveform have to be able to be detected by the ear mechanism. The human ear can detect frequencies from about 20hz-18khz. This is insufficient to recreate steep fronted waveforms exactly. Thats why an 8khz square wave sounds like an 8khz sine wave to humans, and thats why steeper rise times cannot be heard.

Recorded sound does not include rise times anywhere near the steepness of an 8khz square wave. The microphones couldn't couldn't capture the information even if it were there, the electronics wouldn't pass it (its not there, remember), and the recorder couldn't capture it. Playback systems cannot reproduce the frequencies necessary to reconstruct an 8khz square wave. So putting a link in the audio chain that can recreate a square wave, or any waveform with a similarly steep rise time, just before a loudspeaker that has absolutely no chance of reproducing that waveform is superfluous.

And you can't hear it anyway.

People who operate, design, and manufacture professional audio equipment know all of this. That is why pro sound gear is bandwidth limited. These folks won't waste their time or money on things that make no difference in audible sound quality.

Don

Honk if you love Horns

[TheEAR]

Don,

Good post, however some will coninue to debate how this and that amp has to to in order to reproduce the inaudible and what is not even present on the recording. []

[Don Richard]

In short, the author shows musical instruments with SUBSTANTIAL energy out to 100khz. And, in the secondary analysis he quotes the Oohashi paper to support the idea that people can and do process this information in the brain, and know when it is "missing."

Certainly sounds do exist above the range of human hearing.

How can these sounds be recorded for playback? ACO 7016 mics into a 24/192 PROFESSIONAL grade recorder? Perhaps.

Then how do you play it back? Well, a PROFESSIONAL grade 24/192 playback system would work. On the masters. Sample rate conversion to one of the home hifi standards will result in damaged information, and loss of this HF information.

What loudspeaker can reproduce these frequencies? IIRC, JBL and a few manufacturers of nearfield studio monitors have models that go to 40khz or so. These units are used in PROFESSIONAL studio playback systems with 24/192 capability. They don't go to 110khz or higher.

Who can hear all of this? Many studies contradict the one you mention. PWK ran his own experiments in the 70s where it was found that inserting a 30hz-20khz filter ahead of a wideband amplifier had no audible effect.

If one listens to live blues, R&B, jazz, rock, techno, rap, or hip-hop, you are listening to amplified instruments and sound reinforced acoustic instruments. You are listening to loudspeakers. Loudspeakers that do not and cannot accurately reproduce 20khz much less anything higher.

The study you cite miced the instrument under analysis at a close distance. HF is attenuated at a greater rate with increased distance and increasing frequencies. At long distances HF attenuation is severe at ultrasonic frequencies. At normal concert listening distances for acoustical events such as a symphony, these frequencies cannot be detected. They would have been diffused/absorbed/dissipated by that distance.

But don't worry. I just read in a certain audiophile magazine that the proper $2200 speaker cables will solve these problems. [^o)]

Right.

Don

Honk if you love Horns

[Jeff Matthews]

So putting a link in the audio chain that can recreate a square wave, or any waveform with a similarly steep rise time, just before a loudspeaker that has absolutely no chance of reproducing that waveform is superfluous.

And you can't hear it anyway.

People who operate, design, and manufacture professional audio equipment know all of this. That is why pro sound gear is bandwidth limited. These folks won't waste their time or money on things that make no difference in audible sound quality.

QUOTE: "Given the existence of musical-instrument energy above 20 kilohertz, it is natural to ask whether the energy matters to human perception or music recording. The common view is that energy above 20 kHz does not matter, but AES preprint 3207 by Oohashi et al. claims that reproduced sound above 26 kHz "induces activation of alpha-EEG (electroencephalogram) rhythms that persist in the absence of high frequency stimulation, and can affect perception of sound quality." [4]

END QUOTE

Here's the study: http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

In short, the author shows musical instruments with SUBSTANTIAL energy out to 100khz. And, in the secondary analysis he quotes the Oohashi paper to support the idea that people can and do process this information in the brain, and know when it is "missing."

Secondly, there is an alternative and much more logical explanation for why PA amps are bandwidth limited: lower cost and high reliability, the twin towers of pro design. So good engineering practice would dictate the LOWEST and SLOWEST that would be tolerated in the application. For PA work, that is really slow, and really low.

Just because there is a quote and a study doesn't mean the whole premise studied and reported is not utter quackery. I believe you found a quack. It seems these people congregate wherever there are masses yearning for improvement. I especially love the medical ones that claim "The cure for cancer the government does not want you to know."

Seems the last I knew, there were some very, very, very rich musicians - capable of purchasing the most expensive equipment available - buying up and using all this professional - LOW and SLOW - equipment. Sorry, but this is horsepuckey.

Perhaps there are some substantial sonic differences between these two classes of equipment - whatever they might be. But, I can assure you most of the time, you will find, regardless of the category, that there is plenty of junk in each and plenty of great stuff in each.

I don't think you can slap a broad brush argument against these amps based on an over-simplified categorization as has been attempted. Ten-to-one, I bet once you've spent $2,000 (cost new) on an amp, you'd find the odds of a person discerning which is which to be slim-to-none. If you A-B'd them back and forth about 10-20 times, you might be able to pick up some very, very fine distinctions. Before that, the distinctions were almost discardible, but now that an "afficionado" knows they are there, they become all so important. It's strange that way. Much like a $300 bottle of wine, when Beringer is a really good buy for the money.