Quote from: ajinfla on 2015-09-08 17:54:07

The larger speakers are not a waste, because you effectively have two spatially displaced "subs" to 40hz if you run them full range, thus will reap the benefit of the averaging vs a single sub. Using a single sub below 40hz is fine because the modes become quite sparse. Using a single sub to 80hz, yeah, good luck getting smooth amplitude there. So now 2 subs below 80hz? Well, that's more money....which could have been spent towards larger mains. I could go on, but oh well, use what suits you best.

Well and good, except I question when you are going to get two mains that have -3db @ 20 Hz

I use one large-ish sub, in a 5.1 system crossed over at 80 Hz,  same speakers all around, with Audyssey calibration tuned to my one sweet spot.  Works for me (though I wish the 'consumer grade' Audyssey had an option to *only* correct low frequencies), but I know the LF audio isn't as consistent for other listeners outside the sweet spot.  WAF and neighborly  concern prevents adding a second sub...for now.

50hz is fine too.

No nulls from 80hz on down? If you're not sitting on or next to the sub, you are one lucky man.

how can you explain that the most "cost effective" approach is to buy two speaker systems [...] ?

The typical stereo-enthusiast wants huge, full-range speakers left and right. Dedicated sub = evil. One person in a tight sweetspot.
The typical HT enthusiast wants (at least) 5 identical speakers (which need not be full-range; rear speakers might be dipoles) + (at least) 1 powered sub. Having left/right speakers which do not sound exactly like the center speaker = evil. Watching movies with other people is fun --> needs broader sweetspot.

Depending on your school-of-thought, these two worlds are more or less difficult to intersect.

[The resolution to this conflict directly leads to the scenario Rich described, where you have two dedicated rooms.

The idea is that you get two-channel dedicated systems, speakers etc for handling stereo - ie dedicated stereo system/dedicated HT system. Is there an argument for them handling two channel better than if one was just using a HT system?

I'm assuming that there are design differences between HT-style speakers and two-channel speakers? Or is that not true?

I *loathe* TVs mounted high on a wall.

Audioholics has attempted to make a "point system" to see if you would benefit from adding an amplifier:

http://www.audioholics.com/home-theater-co...p-to-a-receiver

Wrong! All it will do is add 3 dB, end of story. As long as the weaker amp is kept within its operational range for the entire program material

including the loud passages and peaks, then it will be audibly indistinguishable from the stronger amp.

The onset of distortion and full on clipping is rather quick with solid state amps, and although it is true you may only notice it on the louder peaks at first, as long as you don't dial it up to that point at which it distorts on anything, then you are good to go.

I wonder what his explanation is as to why science has never discovered a machine that can measure this elusive "extra adrenaline/clean sound" he speaks of, which for some odd reason disappears in DBTs

If one is distorting on the loud peaks, simply back down a dB or two on the volume knob and you're back in the perfectly clean, safe area.

Quote from: Gecko on 2015-09-08 12:21:24

But the sub will usually have a highpass.

Nope, that is rare. Variable lowpass is standard. Speakers already have an intrinsic highpass.

Jeez, where to begin.
Ok, single 80hz cycle is around 14', so less than the typical dimension of all but smallest room, 40hz is double, exceeding any room dimension, so you are less likely to have phase integration issues at lower frequencies. Further, there is no way you're getting phase integration with all channels at 80hz, so that's a complete red herring about different extensions on the center and surrounds,

plus they don't all get equal signals, plus....oh well.

The larger speakers are not a waste, because you effectively have two spatially displaced "subs" to 40hz if you run them full range, thus will reap the benefit of the averaging vs a single sub.

Getting swamped with indirect sound might be an issue, but apart from that, am I missing something?

I'm unsure how movie audio is assigned to the channels. I could imagine having ambience distributed across all (or most, maybe they skip the center) speakers, but I don't know. Therefore I wouldn't be so quick to dismiss the issue with the argument that the signals are different.

So, would you recommend setting the crossover frequency individually for each speaker according to its capabilities like I mentioned in the example?

Maybe don't crossover the mains at all if they go low enough?

My statement was specific to the scenario where all speakers share the same highpass of e.g. 80Hz. Would you still say that large speakers capable of 40Hz are beneficial in that scenario?

IOW, no one here including the OP who is busy munching popcorn, planning his next move.

You Born Again zealots are something else.

What if it isn't and is driven to clipping peaks? Still Wrong! ?

What DBTs does audible clipping disappear? Cite them please

" Keep in mind that doubling power will not only give you roughly 3dB more acoustical output"

He pushes the concept that a weaker amp kept below clipping at all times, is audibly inferior compared to a more powerful amp playing the same material at the same level.

Stay below that point where the weaker amp starts to audibly stumble and the two amps will be indistinguishable from each other. If you need more power, OK fine, then buy a stronger amp, but don't pretend more powerful amps have a sonic advantage over weaker ones, Mr. Audioholics, when the weaker amps aren't being asked to play beyond their safe, operational range. Stronger amps have no advantages in such situations.

Quote from: mzil on 2015-09-09 20:40:47

Stay below that point where the weaker amp starts to audibly stumble and the two amps will be indistinguishable from each other. If you need more power, OK fine, then buy a stronger amp, but don't pretend more powerful amps have a sonic advantage over weaker ones, Mr. Audioholics, when the weaker amps aren't being asked to play beyond their safe, operational range. Stronger amps have no advantages in such situations.

  [Oops. Spelling correction and minor edits applied in the above quote.]
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Boy I wish receivers still had rudimentary power level meters, common in the 1970/80s. Even just simplistic clipping indicators, quite common in modern pro gear, would be better than nothing. 90% of all this baloney would disappear if consumers had a nice visual indication of exactly when they are nearing/hitting the danger zone; instead we are left in a situation where the point at which our amps redline is nebulous to most folks so it can be used as a selling point to push needless power.  Without these visual indications to show what's really going on, it is so easy to scare consumers into thinking, to paraphrase:

"You may be distorting on the peaks but don't know it because you don't have the ears for it like I do. You wouldn't want to do that, now would you? Whatever power you have now is not enough; you need more. Here, look at this scary music sample I've selected where the peaks are 100X louder than the average level. THIS COULD HAPPEN TO YOU!"

Although there's a grain of truth to what they say and of course there are some people who clearly don't have enough power due to their particular room size, speakers' efficiency, seating distance, desired loudness level, and program material needs, I bet 90% of people would be shocked by:

A) Their actual, day-to-day power level needs, usually (but not always) measured in single digits if their bass is handled elsewhere (a powered sub employing bass management)

B) Their inability to hear large amounts of distortion if it is just fleeting, lasting a tiny fraction of a second (the quick, momentary musical peaks or "transients"), also usually pretty safe for the speakers themselves. So there's no rational reason to fear it; you can't hear it and nothing is being damaged.

That it's actually easier to avoid an amplitude null from a mains/sub phase mismatch at 40hz, than 80hz, in room. There is no way you're getting 80hz phase coherence all 5 channels with a single sub.

I think what you're forgetting is that the mainstream receiver manufacturers are just as guilty of trying to up-sell as the audiophile market. They will advertise the addition of an extra five or ten watts in their higher-end models, as if anyone could possibly hear that fraction of a decibel!

Born again?

Let me get this right. You are asking what if it isn't kept within it's operational range and is overdriven to the point of audible distortion on some parts of the song? Would it be audible then? You seriously need me to answer that? OK, here: Yes, over driven, audibly distorting amps are audibly distorting.

Did you read the Audioholics passage I quoted?

He pushes the concept that a weaker amp kept below clipping at all times, is audibly inferior compared to a more powerful amp playing the same material at the same level. He's pushing the lie that there's a difference besides that 3 dB higher output level before the onset of distortion. That is not true. You however believe it, I take it?

If you need more power, OK fine, buy it

I'm confused about something. It was said earlier that some AVR's can't completely disable DSP as some stereo integrated amps have a HT bypass function. So then that means they may sound different?

Quote from: Rich B on 2015-09-10 09:33:26

I'm confused about something. It was said earlier that some AVR's can't completely disable DSP as some stereo integrated amps have a HT bypass function. So then that means they may sound different?

Most receivers have a "pure direct" mode that bypasses all DSP.  However, you will lose bass management and your sub won't work in stereo unless you have it wired and crossed over externally from the receiver.  There should also be a less "pure"  direct mode that still includes bass management, channel delays, EQ, etc.

Some AVRs apparently cannot fully bypass the "correction" circuits despite "bypass" et al modes. While this may not equate to "bad", it certainly can represent a change to the soundfield, that would not be there with your integrated.