Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems 3x S/PDIF modded HD-DVD player in the works...

Vince,

"I think you'd still want the player to decode DD and DTS internally and output over the 3x SPDIF so your M pre/pro can upsample the PCM bitstream like a Meridian player."

When you configure a Meridian for a 3x SPDIF input will it even recognize a bitstream format on the 3 SPDIF inputs?

Shawn

Vince,

Glad to hear the XA2 arrived safely. The extra aluminum plates Toshiba put on its chassis surely makes it feel a lot more solid then the 3rd generation units.

BTW, wanted to mention that when you first power on the XA2 don't immediately expect a lock to the SPDIF outputs. The Toshiba has to boot for 20 or 30 seconds before it turns up its clocks and at that point my board will lock onto that and you should see a lock on the SPDIF inputs on the Meridian. Before it is playing anything the Toshbia defaults to 48kHz.

Have fun,

Shawn

Thanks, that is a good list. There are a few players there with 6 channel analog outputs but no Dolby THD decoding.

Shawn

Are there any sources of square waves in natural sounds? eg isn't that just some academic brute force test to show a "weakness" in the format?

And with Meridian speakers topping out their frequency range just above 20kHz (and with most of our hearing topping out around 16k) all we're essentially gaining from the 48/96kHz modes are increased dynamic range? We certainly won't be hearing any of the higher frequencies...?

Mark

Mark,

"Are there any sources of square waves in natural sounds? "

Not that I know of. Instruments all produce sine waves.

"eg isn't that just some academic brute force test to show a "weakness" in the format?"

It shows bandwidth (and timing), but one needs to really understand what a square wave is to understand why that is. Along with capturing the harmonics they also need to preserve the phase between the fundamental and the harmonics. If phase is altered that will show up on the scope too as a corruption of the square.

"And with Meridian speakers topping out their frequency range just above 20kHz (and with most of our hearing topping out around 16k)"

Right, a speaker isn't going to reproduce a 10kHz square wave at all, it would look horribly distorted. The speaker don't have the bandwidth or phase linearity to handle this you would just get the fundamental sine wave. And like you said even if the speaker could handle it we wouldn't hear the harmonics anyway as that is beyond our hearing range, we would just hear the fundamental sine wave at 10kHz.

"all we're essentially gaining from the 48/96kHz modes are increased dynamic range?"

The difference in 48kHz to 96kHz has nothing to do with dynamic range. It just increases the ability to capture from just below 24kHz to just below 48kHz. Dynamic range in the source would be increased by going to more bit depth... 16bit to 24 bit for example. Most people don't have systems (including the room and its noise floor) that can deal with the full dynamic range of a 16bit system and nobody has a system that could handle actual 24 bits of dynamic range. 24 bits of true dynamic range would be 144dB. To reproduce that if one had a room with a noise floor of 0dB and you matched the noise floor of the source to the noise floor in the room the loudest sounds would be playing back at 144dB. Very few speakers could play that loud and your hearing wouldn't last very long at all if one tried for this... roughly the same SPL as standing a few feet away from a jet engine. 16 bit gives 96dB of dynamic range. Again in the 0dB noise floor room the max volume would be 96dB which is possible. In a room with a 40dB noise floor if you don't want to loose source signal in the rooms noise floor the max SPL would need to be 136dB... again not really possible. If you limited playback to say THX Reference level of 105dB (per speaker) with that 40dB noise floor in your room your overall system is limited to about 65dB of dynamic range... about 11bits.

Best way to increase dynamic range/resolution of a system... lower your rooms noise floor.

Shawn

Vince,
Hope the attack subsides- feel better!

Shawn, that unreleased Pioneer 05FD looks like a great candidate for this kind of thing.

As to the compressed soundtracks, if its regular DD, I think Id prefer the Meridian to decode it but I think many discs will now feature the high res sound.............

One thing I like about my XA1 player is it will take a True HD track and downsample it to DTS 1.5 so it works over SPDIF to the 861. Sounds great when compared to the standard DD track.

best regards,
Jerry

Would be difficult - my noise floor is currently around 13dB last time I measured it... turn the Meridian system on and it gets worse at certain frequencies

WRT dynamic range an 48/96 - I was referring to the move from 16bit to 24bit recordings.

Mark

Thats awesome Mark. I wonder what mine is... I doubt its that low, but it might be...

best regards,
Jerry

"Would be difficult - my noise floor is currently around 13dB last time I measured it... turn the Meridian system on and it gets worse at certain frequencies"

Please...always room for improvement, I knew a guy with single digit noise floor and that was with his equipment on. Kidding aside 13dB is fantastic, what did you use to measure that? I do not know where mine is, none of my meters read low enough.

Shawn

Custom rooms can do wonders, but I'm scared to work out how much each 1dB lower cost me? At some frequencies the room is 0dB as long as nobody is in the room, but as you approach the bass frequencies things start to pick up. Pesky cosmic rays slamming into the acoustic treatments I reckon...

Mark

Jerry,

"As to the compressed soundtracks, if its regular DD, I think Id prefer the Meridian to decode it but I think many discs will now feature the high res sound............."

Will the Meridian accept/decode bitstream on its 3x SPDIF inputs? I thought it was basically expecting PCM when configured in that manor?

With my board tapped into the signal feeding the DACs you get PCM output all the time. If one really wanted bitstream for DD/DTS it would be easy enough to simply use the players stock SPDIF output into another input on the Meridian for that.

"One thing I like about my XA1 player is it will take a True HD track and downsample it to DTS 1.5 so it works over SPDIF to the 861. Sounds great when compared to the standard DD track."

Sounds better when you don't lossy recompress the lossless track at all though.

Shawn

Nice! Low noise floor makes a huge difference.

Measured mine using Earthworks M30BX mic, 1021 ZDT pre-amp and TrueRTA.

Mark