Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems G68 volume: How does it work?

My understanding of Sonos is the same as Ian's. Sonos' digital output is 24 bit, providing -48dB of attenuation without loss of information to a 16 bit signal. This has been confirmed by a variety of sources. So no need to rush out and buy a Bose system just yet. Returning to the point of the thread...

Having narrowed my preference down to 86 or 87, I did some listening to see if I could hear a difference, compensating for the difference in level by adjusting the Sonos volume. I could be wrong, but 86 seems to be a little less distorted on dynamic peaks. So 86 it is.

I'm still curious to know how the G68's volume is implemented...

Bryon

You don't get 48dB of attenuation even if it's 24bit. That's only true if the DAC were perfect, which doesn't exist.

At the listening position your lucky if you get 18 bits. So you have about 2 bits of headroom (12dB of attenuation before you start tossing information).

All bits in the DAC are not equal either. So when you shift bits down your shifting towards the lower end of the performance of the DAC.

Digital attenuation is bad. People keep thinking they have 48dB of attenuation. Try my DAC Resolution test in the WiKi. Oops that won't work on Sonos because it does not support 24 bit audio files.

That's why I use a Duet Controller because it can browse my music and control the Meridian Volume from one handheld device. Not as slick as Sonos UI but it squeaks out everything I paid for from Meridian. Meridian Sooloos solutions do it the right way as well.

I understand that the 48dB of attenuation I mentioned is theoretical, and that in practice it may be significantly lower, perhaps as low as the 12dB you mention. A few things...

-12dB is more than enough attenuation for my needs.

-Several state of the art DAC manufacturers use digital attenuation, including Weiss, Berkeley, and Wadia.

-I am perfectly happy with the SQ I am getting with my Sonos + Empirical Audio reclocker + G68.

-This whole discussion is irrelevant to the topic of this thread, which is...

G68 volume: How does it work?

Bryon,

The truth is no one outside of Meridian really knows how their hybrid digital/analogue attenuation is implemented.
I believe that George�s hypothesis is very close. If we knew for sure; you would have found the answer in the archives.

Regards,
Carl

But I remember George did some test and found it retained Max signal to noise ratio's!

That click sound shifts depending on where your speaker level offsets are set too.

Did you try the trick I use on my 568.2? Drop all levels to center around -4 to -5?

I forgot about all that testing. What nut would do all that testing.

http://www.meridianunplugged.com/wiki/index.php?title=RMAA_Tests

You da man George!

Thank you, gentlemen, for your help. I understand that there may not be a definitive answer to my question. Still, it's valuable to be able to discuss.

Ron-- As it turns out, I already had my offsets set low, so that the highest level was at -3. I can't recall exactly why or when I did that. It's quite possible that I read about it here on HH, or I could have stumbled on the idea independently, not sure which. In any case, I haven't yet had a chance to listen with the offsets calibrated "normally." I will report back when I do.

George - I followed your link and I have to say I am impressed at the extent of your testing. It's a valuable asset for curious folks like us, and it reminds me why I enjoy these forums so much.

Thanks again to all.

Bryon