OT: Surround Sound?

[Dave Plowman (News)]

Not so good as what? It's no different to any other broadcast audio - assuming a decent source.

[John Rumm]

On some of the lower bit rate DTTV channels, not as good as they used to be on Nicam.

[tony sayer]

Did the lower bitrate channels get onto NICAM anyway?...

[tony sayer]

Umm .. try listening thru some decent equipment that includes better equipment than 10 quid speakers;!...

[Dave Plowman (News)]

Possibly. But in NICAM days we were restricted to 5 channels anyway. And NICAM was fairly low bitrate too. (11 bit companded) Plus the fact that the source material was likely Beta SP or similar which had audio not dissimilar to that from a cassette deck.

[Dave Liquorice]

They ought to be "full range" though as each of the 5 channels is full range. This may or may not equate to "expensive" as what one person considers expensive might not be to another. The .1 is "Low Frequency Effects" and shouldn't contain anything other than the effects.

Most domestic 5.1 systems however have small speakers with limited LF response for the 5 main channels and use the "sub" to carry the LF that the main speakers can't reproduce.

You still need a decent amount of copper (2.5mm CSA) and copper ain't cheap. "79 strand" bell wire is 59p/m from TLC (44p/mm by the 100m drum) but that isn't heavy enough IMHO. Even the real "bell wire" is 15p/m.

[Dave Plowman (News)]

Although it will do no harm, 2.5mm is way oversized for most domestic installations - especially of the 'home theatre surround sound' variety.

[John Rumm]

Most did not exist on analogue, although ITV1 used to sound better IMHO.

[John Rumm]

Might be worth clarifying slightly that if all you are listening to is off air "stereo" fed through a prologic decoder, then the rear channel is slightly less than full range. However as you highlight, proper 5.1 sourced material however does not have the limitation.

[Dave Plowman (News)]

ProLogic isn't 5 channel, though - the rear 'surround' channel being mono, as well as bandwidth limited.

[John Rumm]

Tis why I said "channel" rather than the plural... ;-)

(having said that, its still normal to use two speakers for it to give a wider "sweet spot" in the room).

[meow2222]

So a) not going to multichannel loses some positioning info b) not going with decent speakers introduces frequency and linearity distor= tion c) therefore you conclude one must go with multichannel. Its not logical.

How's that possible? And no, its not what I claimed.

Are you suggesting using mid-quality front speakers and small budget driven= rear ones? It would certainly mess about with phasing, and likely change t= he relative frequency response too. The efficiency will generally be differ= ent too, not to mention the pattern of level and frequency response with li= stening angle.

How would choosing an active sub a) improve on existing 3 speaker systems or b) improve on larger better designed stereo speakers? Too much doesnt add up.

NT

[John Rumm]

Yes

b) not going with decent speakers introduces frequency and linearity

You will get distortion on any speaker obviously - going cheaper may (as an approximation) get you more of it.

c) therefore you conclude one must go with multichannel.

I would say its quite simple really - however, start by identifying your actual objective first.

If you want a system that will be used for music reproduction, and also surround sound. Then start from the baseline of a system that meets your quality requirements just as an audio system. Then add surround capability to it. That way you are not compromising your music reproduction.

If you just want a sound system for just AV use, then almost anything will be a big improvement over the tinny speakers in most modern TVs. So a even a basic surround system will achieve that. Also keep in mind that absolute fidelity is less critical for this application - what may ultimately not be good enough for "audio only" can be quite satisfactory for AV use. Obviously it depends on how critical of these things you are.

I would argue that for AV use sacrificing *some* quality against getting surround is a worthwhile trade off for most users, since the surround capability adds another dimension to the viewing experience and enjoyment. This is my opinion, and not everyone will share it - hence if unsure, go listen to a surround setup in your price range, and see if it does it for you.

Personally I am very fussy about audio quality, so went with the first approach on my main system - it was built as a stereo system first and foremost. Now using that for AV was a big improvement on just using the TV sound (even though my TV at the time actually had relatively decent sound). Some years later, I added surround to that and it made the movie watching *significantly* better than what could be achieved with just the HiFi quality stereo system on its own. Later still I added an active sub, and that was another improvement. Over the years I have tweaked bits here and there and moved things about etc. I now feel I have an music system that I enjoy, and a very good AV system as well. Now you could argue that if I took the total cost of all those components, and went back to square one, and spent it all on stereo components alone, I would have a better audio system. That is probably true, but I don't feel I would get either enough improvement[2] or as much enjoyment a few grands worth of upgrade on the music system on its own.

[2] the further up market you go, the more expensive the next improvement becomes, and the more subtle the difference usually.

I said "if you can get good stuff for free" and you said "most people can now". What was that supposed to mean?

That is quite workable - and phasing etc is not an issue in practice. For starters you are not feeding the same signals to each.

Again none of these matter that much since AV amps allow independent adjustment of levels at each speaker, plus adjustment of the delay to the rear effects (to allow for rooms size and positioning variation), and quite often other parameters as well.

Even variation between speakers is not too much of an issue generally. Left needs to match right certainly, and it helps if the centre is tonally similar to the main left and right. It also wants good clarity for dialogue. Front to rear match is less critical since the effects that are likely to pan front to back are more typically environmental sounds, and genuine effects (explosions etc) rather than musical sounds where a slight tonal difference will be objectionable.

Three speaker or three way speaker?

Either way the answer is by handing the content below the normal lower cut-off of the main speakers. Even a fairly substantial floor stander won't go down to where a decent (music optimised) sub will.

That's because you are using odd maths ;-)

Not everyone wants huge floor standers dominating a room. Going for a good quality and articulate bookshelf sized speaker for example can give very good HiFi reproduction with plenty of fine detail etc. What you compromise is the low end punch. Adding an sub (which can be tucked out of the way behind a couch etc) can add the LF performance that the speakers on their own don't manage.

[meow2222]

Exactly. That's easy for me. Most tv content is not 5.1, and I'm unlikely to want to watch the sort of stuff that is. I do OTOH like good sound quality.

Plenty of midrange kit is available free, but I've not seen anything first rate for free.

3 speaker normally means 3 amp channels driving 3 speaker cabinets

Modern compact subs tend to be resonant and/or bass reflex, they'll give plenty of bass, but its never going to be good quality.

Some of us already have better quality systems than little resonant subs

NT

[John Rumm]

Most TV stuff these days (well films anyway) will still carry surround information encoded with pro logic on the normal stereo sound track. So even if you have not got a decoder thatn ca give you 5.1 from a HD channel etc you can sometimes get reasonable results with the right equipment.

Even mid range will far exceed what a TV alone can do...

I was not talking about compact subs as such. One made with an intention of being usable for music as well as movies (the kind of kit made by Rel for example) will tend to include low and high level inputs, adjustable roll off frequency, and phase switching. The are often sealed cabinets rather than ported. So for music work you can set the roll off to blend nicely with the bottom end range of the main speakers (or for that matter, if the main speakers have a slightly flabby output at the bottom end - set the roll off a bit higher and flip the phase to cancel some of the main speakers "bass").

Indeed, and some have better subs as well ;-))