Setting up AV2 sound levels ?

Roy

I haven't got an AV2 , but I would expect these levels to work as on similar amps (I Have Denon 3802). So in your case -14 and 0 should be exactly the same as +7 and -7.

I don't know what the range of adjustment is on the AV2 (3802 only goes +-10db) but if -14 and 0 gives you the correct results don't worry.

Remember if you are using a Sound presure meter DON't point it towards each speaker as you adjust . You should keep it pointing towards the TV.

PS. - A Sub makes a massive differance for movies

Roy,
I don't have a definitive answer but my experience is that it is all relative.

It has taken me several months to get a balance I am happy with(by ear).
NAAP180>kef 104/2 front "0"
NAP175>kef 2QD surround "+6" kef 200c centre "-2"
NAP140> kef 104/2 rear "+4".
sub "+3"
It all makes the lounge looks a bit like a hi-fi demo room but the sound is awesome (on 2, 6 or 8 channels).

By the way what dvd test disc did you use please?

Further to greeny's comment a sub-woofer is an absolute must (I have MJ Acoustic Reference 100). I am thinking of getting a smaller one to supplement the front channel.(I might even hide one of them under the floor to get the cinematic rumble). The sub has been the hardest thing to set up. At high volumes >60+ I have too much and at low volumes <20 not enough. I guess it is a question of setting off the AV2 output level and the gain but I haven't got it quite right yet. I tend to manually adjust for music or DVD. Has anyone else had a similar experience or have a sub tuning suggestion?


Naim AV2
cdI
NAT02
Naim NAPV175
Naim NAP180
Naim NAP140
2 pairs Kef 104/2s
1 pair Kef 2QDs
Harmon Kardon DVD30
Panny 6.

You are right about relative levels.

You sound level meter must be pointed toward the corner above your telly (wall and ceilling) and place at your main listening position. It should be set at "slow" and "A weighing". The 14 dB diference looks too much, even if your Yams are more efficient than you Linn, but it depends on your room. Use the AV2 test tone first and your ears to confirm.
A center speaker is a must, before the sub.

Emmanuel

All opinions are my own, and reflect those of the organisation i work for, even if not stipulated.

Hi webrat,

The system you've got looks like it would sound awesome on films. How much of a difference does the 180 make on the fronts compared to the 140 ? As I've got a 140 on my fronts, I'm considering whether to move onto a 180 or perhaps 250 for them and would be interested in the difference.

The two things I've bought that made the biggest difference to my system were the DVD test disk and a sound pressure meter.

I bought a copy of Digital Video Essentials from Joe Kane Publications. You can get a copy at play.com for about 15pounds. It has details and walkthroughs of how to set your TV up, with a set of colour filters included. It also has a full set of 5.1 and 6.1 pink noise tones, full and limited bandwidth and full room sweep test tones.

Having used this, I get a much evener sound round the whole system. It is actually surprising that turning my rear channels down has made such a massive difference to the whole system sound level.

To set the levels, you also need a sound pressure meter. I got one for 40pounds from Cornwall Electronics, a Radio Shack digital one. I set it for Slow response and C weighting and then set a reference volume on the AV2 and set all the channels up to give me 75db at my listening point. It is important to hold the meter at your listening point with the microphone facing upwards, towards your screen. Very much like the picture on the Cornwall web site.


Manu - the one thing I find strange is that having set my system up with a phantom center. The volume level adjustment for this dissappears from the AV2 setup. Now, I know I don't physically have a center speaker, but that signal is now routed as part of the l/r channels and is encoded independantly. I actually find the center channel is 2-3 db lower than my l/r !

I do agree that the most important addition is a good center. But, space and funds permitting I'm getting there one step at a time. I need to get a new CD player next, my old Arcam Alpha to be replaced with possibly a CD5i or 5 ?

Cheers,
Roy.

Just to add a little controversy - I'd disagree strongly with "a sub is an absolute must" - I'd even go so far as to say you don't need one at all if your fronts are good enough.

<runs away with scorched back...>

Now the flames are out let me quantify that slightly. Obviously it depends on your room and listening environment but I borrowed a REL strata III from my dealer a while ago and it made no real difference to my system - that is to say there was slightly more bang there but not the 800 quids worth of cinematic seat-shaking rumble I was expecting!

Mind you my system probably looks slightly odd - an upgrade path from a nait3 has left me with an AV2/175 doing duty as my main stereo and AV system with the 175 on the front speakers and the nait3 powering the rear. Speakers are Acoustic Energy 109 at the front, 100 at the back and a Ruark dialog one center.

The AE109s are relatively cheap speakers (especially when I read what some people have in here!) but they pack a punch I haven't heard from anything else in the price range and I'm going to have to spend a fair bit of money to upgrade them in any meaningful way - hence my comment about the sub.

I would echo Manu's comment though - a centre is essential and make it a decent one. The centre speaker does the brunt of the work in films carrying effects and soundtrack as well as dialog - a good one can make a huge difference.

Cheers,

Marc.

quote:

---

Originally posted by Marc Evans:
Just to add a little controversy - I'd disagree strongly with "a sub is an absolute must" - I'd even go so far as to say you don't need one at all if your fronts are good enough.

---

The trouble is Marc that with movies, not only can the 5 main channel contain frequencies down to 20Hz (which most speakers can't reach down to), the .1 LFE channel can have even lower frequencies on it - in some cases so low that only the top subs can reproduce it.

So, with a few mega-expensive exceptions (Naim DBL's, PMC MB2's etc) if you really want to appreciate what's on a DD/DTS soundtrack then a decent sub it pretty much essential. That doesn't mean you can't enjoy a film and get good bass without one mind.

Matt.

I know that DD/DTS soundtracks can carry some extremely low frequencies well beyond the range of most speakers that's why I was surprised how little the strata did for me! I guess what I percieve is down to a combination of my room and speakers - possibly the room's too small to let the sub really go to work?

I've heard some great things come out of matched sat/sub speaker sets like the M&K THX set (can't remember the model). But the difference with a sub is less marked to me when you pair it with some floorstanders.

Hey, I can only say what I hear - perhaps I haven't heard the right kit yet!


Marc.

Marc, I'd agree that probably the most important speaker in a 5.1 system in the centre speaker. This is where all the main dialog is routed when the film is mastered. The l/r channels take some of the effects and merging the center with these makes their jobs very hard. I am fortunate that my system has quite good positioning and I can fire my speakers towards my listening position, otherwise I think without a center my system would some awful.

The Keilidhs I have do a good job on lower bass. Running test tones through them, I get a good response in the 40-80Hz range. They kick in about 25Hz, but with nothing like the power required to put good low bass out. I may get a sub later on, but with a 140 at the moment and perhaps a 180/250 into them later, they are doing a good job at the present.

Roy.

Gents,

Adding the sub or ".1" in a home theatre system frees up the receiver/amps from having to produce those ultra low frequencies which take a lot of energy to reproduce. This should allow your fronts, small or large, to produce better sounds and reduces the strain on the electronics. I think people expect too much from the sub. However, once you take it away, you realize how much it actually added to the whole experience.

That's my 2 cents.

Roy,
Thanks for the set-up info. I will experiment in the new year. I don't think my set-up is quite there yet - I have noticed that at high volumes the front pair tend to dominate and "over power" the other speakers. At low volumes the centre dominates - so I will keep tweaking.

Re: "a little controversy - a sub is an absolute must" - just to keep the ball rolling, is there an arguement that says it is easier to compensate for a missing centre than a missing sub?

The sub's value imho is not in the the rumble and thump in epics movies which is good fun but in the re-enforcement of, and the more subtle depth given to, the bass tones of music dvds(5.1/DTS) whether it is Clapton or Tosca.

This has convinced me think that several small sub's would be better than one big one.

Webrat.

[This message was edited by webrat11 on SATURDAY 27 December 2003 at 22:44.]

Yes 2 small sub are esier to place and can compensate for room anomalies. The problem is the price, a small good sub is almost the same price as a big good one.
It is easy to compensate for a missing center if you live alone, if you sit at the sweet spot, but for others...

Emmanuel

All opinions are my own, and reflect those of the organisation i work for, even if not stipulated.

I'm curious as to why one should point the SPL meter towards only the front of the room when calibrating levels etc.

I also have one of the Tandy/Radioshack analogue SPL meters, and did the calibration first pointing towards each speaker in turn, but got a better result with the Mic just pointing straight up for some reason i.e. when balanced up that way, the sound was more cohesive and 'of a piece' than the pointing at each speaker in turn method, which at first I thought I should do, looking at the graph re the sensitivity and polar response of the mic of the meter.

So, are we talking pointing towards the front of the room, angling up towards the intersection of the front wall and ceiling?

What is the advantage in doing it this way?

Just Curious.

Best

John...

Populist thinking exalts the simplistic and the ordinary

John, you answer your own question.
The advantages? the sound is more cohesive.
It has to do with the omidirectional patern of the RS mike and the nature of the "suround" sound: it must suround you.

Emmanuel

All opinions are my own, and reflect those of the organisation i work for, even if not stipulated.

Thanks for that Manu. I got the best result, pointing the meter mike vertically toward the ceiling, whilst at the same height as my head/ears, at the listening position. I guess pointing the meter mike up towards the front wall/ceiing would achieve pretty much the same thing then.

Re a centre speaker: if, like me, you tend to listen alone in phantom mode, i.e. centre speaker less, focus etc is not a problem when one is in the centre axis of the main left and right speakers.

In that instance, would adding a centre speaker improve anything? And surely, it'd have to be a very close match to the main left and rights, - I should imagine one couldn't use 'any old speaker' without incurring some deleterious tradeoffs as well re timbre matching, phase, dynamics etc.

But, I haven't tried it. So what have people found in the pratical real world, as against the theory?

I've been contemplating getting an Naim Access to compliment my SBL's when funds allow, but if one could 'get away' with something cheaper for a centre speaker, that would usefully free up funds to spend on the two channel side of the system.

I'd love to hear of others real world experiences re centre speakers.

Best

John...

Populist thinking exalts the simplistic and the ordinary

I found that running in phantom centre mode can work pretty well as long as you are sitting in the sweet spot.

However, as soon as I switched the centre speaker back in there was far more focus and forwardness (in a good sense) to the sound. It must be said though that this was a good quality centre that matched the left and right speakers perfectly (i.e. identical size, identical drive units).

I'd therefore say that for movies, unless you really can't fit one in then a centre speaker is very important (and it must be a good one and matched to the left/right speakers).

Whether this is so much of an issue for multi channel music is another matter - I've heard SACD running without a centre and that was pretty good.

Matt.

Thanks for sharing your real world experiences Matt. It pretty much tallies with what I thought would be the case - sometimes there's no such thing as a free lunch - looks as if I'll have to keep saving for an Axcess then.

Still, quality is quality.

Best

John...

Populist thinking exalts the simplistic and the ordinary

I too have experimented with Phantom center mode and thought it was'nt too bad.

However for DVD-Audio, SACD and DTS music discs it is quite common for the mixing engineer to treat all channels as "full range" and place a significant portion of the mix in the center channel.
One particular example of this I have is a DVD-A disc by Brian Bromberg, a Bass player. He is coming out of the center channel and if you run this disk in Phantom mode all of the attack and verve in his playing just dissappears.
However this also shows that for music you really do need a high quality center speaker with full range frequency response.

The other comment I would make is that the sub is also quite important for music simply because DVD-A and SACD typically has to be decoded in the source player and then fed to the amps as discreet analog signals (there are now a few digital linked systems appearing). If you don't have a sub the output that the mixing engineer designated for the sub seems to be flattened if redirected to the main speakers and lacking the pace and drive required. The sub .1 channel volume setting is a bit of a grey area, especially since the relative dB level recorded on the disc varies for different formats by as much as 10dB. I set the .1 channel at -10db which seems to work for most music, but of course you have to set the gain at an active sub aswell which is another challenge based on a lot of experimentation

On the level setting thing. I use a dB meter and found by trial and error that pointing it straight up at the ceiling at my sitting position works best. However for music I find in my system it is best to back off the rear channels by 2dB and the center channel by 1dB from the measured setup. The other frustrating thing is that the "speaker delay" setting won't allow a center speaker that is further away than the front main channels, even though the recommended speaker layout for multichannel music has the speakers at points on an imaginary circle surrounding the listener which places the center channel further away than the fronts.

Geoff