Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems +3dB "LevelPerfect" Tweak Performance Improvement Poll

George,

I think we tried -3db at your place on your DSP setup and I couldn't hear the benefits I get with analog.

Like I said with the 518 if I set the 568 to zero or even +3 with analog and use the 518 to lower the digital level it doesn't sound the same as lowering it in the 568. Clearly analog is different!

I am surprised I never let you hear my system set to zero and -5.

To my ears it's less compressed set to -5 not less resolved with analog. I can hear where analog kicks in on the volume setting because of a slight click and set to -5 it clicks in +5 db higher on my volume setting. The actual volume hasn't changed. Only the 568's volume is 5db higher. It just sounds less compressed...more realistic...less like a recording.

Ron

I also remember with analog configs that some people had noise problems changing sources and presets with settings above zero. Dropping below zero it went away. It's hard to say what they are doing with analog setups.

Ron

I forgot about that.

There is no reason to compromise at all. My new tool is a "compromise" (you pick and choose which speakers you want full resolution and which you wish to risk clipping on), even if they supported what I did with the tool in MConfig, it's still a compromise. No reason why all speakers can't be full resolution. But you could (and probably should) still have an overall Master "Digital Gain" adjustment for the geeks.

I'm tempted to set all speakers to +3dB and move the furniture But the risk of clipping due to 2dB (over +3dB) in rears is pretty low.

By the way, as 518 states, occasional clipping is no big deal.

I never noticed it in my setup when I experimented above zero but maybe it changes based on distance settings and levels between all the channels. Everyone has different settings. Strange!

Remember when I changed my crossover frequency to 90Hz instead of 80Hz? I needed to increase my lipsync time on my 568 to match my display. I didn't expect that!

All I'm saying is that it's reasonable to believe that Meridian's own people Heard these same Differences that are being referred to on this thread

However, it seems that they they made a (likely Deliberate) decision to implement the current Defaults. I'd like to hear THEIR Reasons why

That does not mean that I will agree with their Rationale, but I would like to hear hear their side of the story and then people can make up their own minds

As Nick has fronted the Hitchhiker days in the past, is he the best person to ask for an official response??? Or you, as Forum Founder and Finder of this Tweak???

Perhaps a Private Message to the "Meridian" User on this Board, which we know was used in January by Bob to respond to various issues

I think many hear would like to hear Meridian's side of this and they can then make up their own minds

Trust me that would not send a Message Bob.

Basically what Meridian did, is effectively put a 518 on each channel and allowed the user to unknowingly adjust the Digital Gain on each Channel and capped it at -3dB to start. And to balance channels you have to throw resolution away (the loudest speaker losing the most plus the -3dB start). And this is on their DSP Speakers. I believe they it do right for analog speakers by controlling analog gain.

Keep mind there are really two issues here that folks may not realize.

The fact they use digital attenuation on each channel for calibration is the real concern here. Not the minimum of -3dB applied to all channels which is a secondary concern.

Would it ever makes sense to set the DIGITAL Gain in a 518 to -3 on the Left +3 on the right? You use Digital Gain to optimize the DAC receiving it. You use analog gain to please the listener`s ear for level.

I will try my contacts at Meridian if I don't hear from them soon.

I did one more test to prove to myself this is all working as I understand it.

I was concerned that possibly in 24/96 MHR mode (which I shut off for some measurements) Meridian may have done some magic with the DSP Speaker (they don't).

So with the system configured normally (24/96 MHR) and running +3dB.

I ran my resolution tests (low level FLAC files) to verifiy what level I could hear again.

I ran my tool and shifted things from +3dB to -9dB (-12db that's 2 bits).

Then reran my resolution test and sure enough I lost 2bits. I went from 20bits to 18bits.

I've updated the Wiki Article on this to reflect more recent tests and discussion.

http://www.meridianunplugged.com/wiki/index.php?pagename=How%20to%20obtain%20level%20perfect

And I removed "do this at your own risk". I'm quite confident this is harmless now.

I also have sent an email to Meridian.

Ok I've tried it for myself in my setup. At the beginning I thought I heard distorsion, but it was my own fear that I heard. When comparing these sequentially there was no doubt in my mind that I hard MORE of the signal with +3dB fronts.

Bravo George!

I'm ofcourse interested in what Meridian thinks/responds with, but until they do I will run with +3dB fronts gladly. DSP8000 and DSP7200HC with HD621+G68.

I just thought of where some secret answers may exist.

In a G91

The G91 has a dumbed down set of processing. Which includes NO adjustment for center channel boost. My hunch is, it will not have the 3dB offset. If this is true and it supports bass management, Trifield etc. it will help confirm that it's in there just for for allowing center boost in presets.

If the offset is there in HT mode, my guess is when you switch to 2 Channel mode it won't exist because Speaker Calibration is removed and everything will be proper dBFS. But I suspect it's not there in HT mode as well.

Problem is my G91 is at my Lake house and I may not visit there for a bit to check it.

I also think I figured out how Meridian can detect clipping in 518 or (newer) DSP Speakers. All that have to do is look for significant runs of "Flat topped" peaks.

Anyone could check this. You only need an SPL Meter and a reference source like a SqueezeBox and Compare levels through G91 in HT Mode with 2 Speakers(calibrated to 0) to Connected Direct to DSP Speaker. And also compare G91 in 2 Channel Mode. With DSP Speaker kept at the same level. My guess is they will all be the same.

Another test folks could do on normal processor and Matrix Display DSP Speakers is push the +3dB much further using my tool (say +12dB). Then put your processor in Party DSP Mode and see if Clipping lights come on. Then put it back to +3dB and see if the Clipping Lights stay off. Occasional is not a big deal. I only have Matrix Display speakers on my system at the lake house.

Hi Guys
Please excuse my ignorance but can someone tell me exactly where to go to change the speaker values? I'm looking in my 861 mconfig msl file and can't find it.
Thanks
Joe