Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Stereo or Trifield ?

The only thing that makes me wonder about Trifield is the amount of information and the volume being sent to the center channel when in Trifeld.

One could suggest that the reason Trifield sounds so much better than Direct is because the ceneter channel, directly in front of you is being sent so much information snd at seemingly mucvh higher volume than the left and right. It has always seemed a bit odd to me that so much information would be distributed to the center channel. It also makes me wonder if Trifield would seem as impressive if the distribution across the three front channels was not so biased towards the center channel.

Check for yourself but I think you will be surprised at how much information is being sent to the center channel and at the relative volume across the front in Trifield.

Jnug,

you may have a point, however, whenever I have played with Trifield and the setup, it's the "snapping into place" trick that does it for me. When you achieve this, I think it is because the L/C/R are properly balanced. The centre certainly doesn't sound like it's getting more than it's fair share. I'd go as far as saying that when I sit do do proper listening (as opposed to back ground times), you can often actually forget about how many speakers there are or where they are. The soundstage or image becomes very wholesome and not especially directional....at least to me.

Also, when you think about how much difference a small parameter tweak can make to the image, one cannot expect Trifield to work perfectly out of the box without some sort of config for depth, width etc.

Therefore, you may hear too much centre channel if Trifield hasn't yet reached that "snap" position.

That my 2p for a wet Monday morning !!

Rgds

Nick

I tend to agree that Trifield requires some playing to get the setup right and does indeed "snap into place".

I found that the centre integration is best at about +1 to +1.5 in my system but depth setting is not the most critical factor. I found that the width setting makes the most difference and I use 1.2 for my room arrangement.

It is not surprising that a lot of information is put into the centre channel as this is where most information is in a lot of source material (e.g. lead singers). One beneficial effect is that the acceptable listening area is much bigger with Trifield using a real centre speaker as you are not relying on the created phantom image of 2ch stereo which is very dependent on room accoustics and listening position.

Malcolm

I find w/my setup that Trifield muddied the bass a bit vs. direct stereo, but I like it otherwise. This could be a function of my speakers. Have raised the crossover pt. for center to 80hz, but I think I'll do so further, to divert even more bass to the mains. Anyone else find this re: Trifield and bass?

Have VMPS RM40's (full range) for L/R and VMPS LRC, rated to 45hz or so for the center, it has two 5.5" woofers, but I think I'll get cleaner bass by keeping it away from it.

Interesting. I feel that the bass with Trifield is slightly less pronounced than with 2ch Stereo but amply compensated for by the improvement in everything else. I don't use subwoofers and have ATC SCM Actives as LCR (i.e. all the same drivers).

This may be due to room positioning of the speakers as (obviously!) the centre speaker is not in a corner and redirection to it may alter the perceived effect.

Malcolm

rblnr,
try this as an experiment. instead of moving more bass away from the center- try setting the center as large with protection and allow as much bass as possbile to go to it.

It may not improve things, but its worth a try.

Rblnr, I have found that the bass doesn't so much muddy as largely disappear with Trifield compared to Direct. Swings and roundabouts....you get improvements in other areas, but fullsome bass....ah well.

Cheers

George

rblnr,

You've highlighted probably the single point that stops me putting tri as my default....it loses the punch and clarity on bass. I spend most listening still at direct or stereo even though I like the mids and highs and especially voices that tri gives.

It does depend on mood, material and whether the kids have gone to bed !!

Nick

Trifield is utilize energy preservation decoding algorithm to redistribute th signal from the LR speaker into an LCR layout. That means, the total energy distribution between 2 and 3 speaker is always the same no matter where the source is panned in the LR soundstage and at what freq.

If they did plain (L+R)/2 or any other non-energy preservation algorithm, a left to right pan of a sound source would sound different with 3 speakers compared to when only 2 are used.

Also, Trifield utilizes wavefront reproduction algorithm so that sound from the 3 speakers works in unison to create a virtual spherical wavefront eminating from a virtual point anywhere between the LR speakers. That is why one need to fine tune Trifield's depth setting so that the wave launching from the 3 speakers's sums together properly.

Steered surround formats like DPLII and Logic 7 send the sound that is closest to whichever speaker is there, thereby, a speaker at a given position frequently would be the sole speaker playing that signal back. This causes individual speakers to become visually visible, but does not require as much fine tuning, since only gain riding are used for imaging between each of the LCR speakers. There is no attempt at wavefront reproduciton, which requires proper matching of the lauch wave and thus fine tuning of the center channel depth setting.

lwang,

very interesting and clearly put...thanks.

I think you have put the tech. behind what I described:-

"...you can often actually forget about how many speakers there are or where they are..."
=
"utilizes wavefront reproduction algorithm so that sound from the 3 speakers works in unison to create a virtual spherical wavefront eminating from a virtual point anywhere between the LR speakers."


AND,

"loses the punch and clarity on bass"
=
"....energy preservation....the total energy distribution between 2 and 3 speaker is always the same"

At least I think that if you spread a given bass peak over 3 speakers, not two, you will dilute the effect over a wider area. Whilst this may be good for some freq's, I think it loses the impact on instruments that by their nature probably should be tighter (e.g. bass kick drum)

best rgds

Nick

Has anybody experimented with the center channel EQ options? I know what they look like on paper but what is the intended application for each setting?

Nick,


And Trifield is recursive, meaning you could go from 2 to 3 to 5 to 9 front speakers (also, 4,6,7,8, but then they would not be equally spaced across the front).


Energy preservation means when you measure the sound energy output at the listening position, there would be no difference whether between 2 and 3 speaker setup.

In stereo setup, you are spreading the bass over 2 speakers, so there is not much difference between that and Trifield. It might be due to your center speaker lacking in low freq.

If you think bass coming from one speaker should be better, then switch your processor to DPL or mono mode, where the sound near the middle of the soundstage comes exclusively from the center speaker. You could then determine if that bass sounds better.