@panzrwagn wrote:
Also, regarding high efficiency systems, they benefit greatly from being properly gain staged so that you don’t hear noise when the system is idling. Ideally, you want your preamp/line stage to clip within 3-6 db after the power amps. It’s common to see preamps operating 10-12dB or even more gain than is necessary, and that robs the system of that much dynamic range and results like hissing horns at idle. Turn the amps input sensitivity down, and drive the preamp harder. That leaves the noise levels down.
In an actively configured context - i.e.: with the driver connected directly to an amp channel sans passive XO - the issue with hissing, high efficiency mids/tweeter horns isn’t necessarily due to improper gain matching, but simply that a very high eff. speaker element of (in my case above) +110dB’s amplifies and exposes the inherent, component related noise levels upstream; even with a proper gain match as outlined by you, noise and therefore horn hiss could still very well be prevalent here.
Input gain in this case could (if possible) be lowered in an effort to quench noise, and while that would likely pose no problem with regard to not having the full power capacity at hand, at least not with very a high eff. horn/driver, changing input gain (and thereby output impedance) can affect overall sound presentation/quality and thus may come with a proviso.
That is to say: in such an (active) instance and trying to get rid of horn hiss the outcome could actually be one of an inverse scenario where input gain must be set too low (i.e.: not properly balanced wrt. input/output) to compensate for an exposed, inherent noise level upstream - not that it might be a problem SQ-wise to do that.
Quite a few pro power amps have output volume controls for each channel, and if such an amp were to be used on a mids/tweeter horn actively, ameliorating noise from upstream could be done via volume controls here as well, but those also seem to have some impact on SQ when attenuated.
If on the other hand a passively configured high eff. speaker system has an issue with horn hiss, I would be inclined to take a closer look at the gain structure in addition to the S/N ratio of the components used.
So, any impeding the dynamic range of a properly gained, actively configured high eff. speaker setup comes down to where the noise floor sits and its origins here, be that either S/N ratio or mechanically induced noise from amp fans or other external sources of noise.
@ghdprentice wrote:
Thinking further along the line of low levels of background noise, I dawns on me that different systems have different presentations of low level detail. I am thinking of the recording venue. Let’s assume a symphony hall for the moment.
I used to listen at the symphony to just the reflections of the sounds. So, if the violas would abruptly start playing I could hear the sound reflect off the sides of stage left, then the ceiling and then blend from the same sounds reflecting at the back of stage. These are pretty sublet and only a small number of db above background.
Not quite sure I follow here. How would you "isolate" the reflections of sound in a symphony hall to that of its perceived totality, other than focusing on the reverberative nature of a venue and try to assess the decay time by ear?
One my major realizations were that many systems overemphasize the venue of the recording. So say these reflections were 5db above the background… my current system would represent them as about 5db. But a lot of systems… my last generation included would represent them as 10db above the background. This is what I consider details forward. An overemphasis on quiet detail. Thirty years ago, I would have chosen this as “better sounding”.
The source material dictates the "venue" and the overall nature of the recording, and of course from hereon acoustics and speakers in particular affects what’s received by the ears. If by "systems" you include acoustics of a given listening environment, then it makes a little more sense to me, but looking at the gear isolated I fail to see how it can manipulate the "venue effect" or lack thereof to the degree you claim or propose. Also your described XX dB’s "above the background" seems dubious to me. How would you quantify and arrive at those 5 or 10dB numbers?
My thought is that these two systems would sound very different in rooms with different background noise levels.
Different background noise levels would affect low level detail, perceived dynamic range and image focus in particular, but what distinguishes those two systems to begin with?
Assuming the same character of sound in a noisier room, one would probably identify the 10db venue as better balanced because the details would not be drowned out. One more variable in evaluating systems.
Sorry, I fail to understand this.
Better and better equipment tends to get better at presenting all sounds proportionally (I think… assume.. in general). So if you don’t make sure your audio environment is up to the challenge, you could be losing a lot.
From what I believe you’re going at here, my take is acoustics (incl. noise floor) and the speakers are the most important factors - much more so anyway than amps and source. As an example cross-over design choices can have speakers emphasize spatial aspects, but hardly significantly modify the nature of the recorded material you seem to propose wrt. "venue." It’s really about the implementation of the specific speaker design in conjunction with the acoustics that sets the bar most predominantly, at least from my chair. "Better and better gear" is the least of it, if anything that really affects proportionality in reproduction.
Maybe by accident, I have worked at more and more aspects of sound as my system has improved… so I now have the best quietest audio room I have ever owned.
That’s certainly what matters, kudos - whatever the reasons for the improvements are in your case.
Sorry for the lengthy post.
