What are the major differences between Logitech Z906, 2010 and 2016 revisions?

[Ferather]

So my father decided to copy my desktop speaker system for computers (he will also be using a TV as a monitor). He got the Z906, but it seems to be a much newer revision.
I could instantly tell the main unit seemed lighter than my original 2010 rev, I also noticed it no longer uses a 2 pin plug-in power lead, and instead fitted.

The newer manual is also a bit different, while the main specs remain the same, the main text is now 'Ultimate THX', not present on the front of the older manual.
I did a little Googling, but did not find much, ideally I wanted a list of what's changed. I did find some videos related to sub changes.

I also noticed the site specs for the optical ports specifies up to 1080p, which can only be for HDMI passthrough (1080p applies to HDMI).

Old vs New Logitech Z906 Subwoofer Comparison (Stary vs Nowy Subwoofer) - YouTube
Old Logitech Z906 and New Logitech Z906 subwoofers bass - Youtube


Does anyone have any more detailed info between the two?

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[Lucky8]

Went to L's support. They said new revision is just THX certified . So he just Google it. Then I thought maybe he is right anyway. Maybe the latter revision got some differences in the crossover in order to tweak the accuracy . The only way to know for sure is to measure the sound output in both systems while playing THX content as source

 

[wino]

Older version is also THX certified.

 

[Ferather]

It is, but the newer version says Ultimate THX (manual), older just says THX (manual). Would be nice to have a 2023 version, with 6 channel SPDIF PCM support, maybe a PowerDAC too?

ESS ES9038PRO (Page 42) | Cirrus Logic CS42528 | Both are 8 channel DAC's, in this case it would be a 6 channel one.

 

[Lucky8]

Older version is also THX certified.

I know. That's why I can only assume the first release didn't follow up some technical strict guidelines to be fully certified. As THX is only a quality standard it would be rare if there are substantial upgrade on it for 2023. If so, maybe ( and helpe me out here ) full sampling per-channel?

 

[Ferather]

That standard probably changed, or they changed the LFE to suit a change made by THX. The first revision Z906 is full THX, but an older revision of THX my guess.
Confusing when the OEM does not really say anything about it. There is probably also more digital parts, or better-newer parts.

I am going to hold back from upgrading my older revision for a while, hoping for a newer revision.


Thanks guys.

 

[Ferather]

So my Dad got the latest version, and it 'sounds' like it has had a few other improvements (amp-dac), although not drastic, it could also be due to my unit is 13 years old.
I installed my DTS DCH drivers, and I quote the response ended up as: "The best quality I have heard", he is 65 and used to buy all pioneer.

I convinced him to go all optical, no analogue, and with DTS Interactive out.

He is using optical from PC to Z906 optical in 1, and from Samsung TV to Z906 optical in 2. Optical HDMI 2.1 from devices to Samsung TV.
The Samsung TV has built in DTS and Dolby Digital encoder, the DTS also has upmix, DTS sounds much better.

He also has the option to use just PCM out, and then use the Z906 to upmix 2ch to 5.1.

 

[Lucky8]

I'm up for that amp-dac .
Hey, it seems that Logitech got your dad's seal of approval . Pioneer, if you are old enough as me, was one of the king in those days.

So, if you father went all digital and now has ( technically ) a more advanced audio unit than yours... does this means you'll start drinking wine and walking on slippers ?

 

[ixi]

Better two ADAM Audio T8V/T7V/T5V monitors and logitech can be put in graveyard. Later on buy wladoooooh (aka subwoofer) and enjoy music how it was meant to be enjoyed.

 

[Ferather]

@ixi, not at £227 a speaker, or up to $1000 per pair. Z906 hold its price @ around £300 with 5 sats and a LFE. You would think for the price those ADAM would be significantly better, but it also uses class-d.
The only thing I would bother comparing is 1 channel THD and stereo THD, price means nothing (higher price does not mean better audio output), if THD is worse.

THD and THD-N is ultimately the measurement of pure audio (without change), frequency range and amp means nothing if THD is too high.
I have seen high grade amps doing 10% THD 1 channel, and 0.08% over two, those ADAMS are 1 channel driven.

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Not super shocking, although I would prefer to see Ohms and sine wave stats. 10x worse though.
You will be surprised how many people like colour in their audio, I don't myself.

Some mastering techniques include clipping to get the output to 'Sound like that'.


0.5% THD(+N) at 8 Ohms, as far as I know, is also worse than 0.5% THD(+N) at 4 Ohms.

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My upgrade path is purer audio (True Sound), so something like the DMAS, no amp or buffers. Working with a PowerDAC means its all PCM up to then, PCM stats are amazing for THD.

It also possible for Logitech to make a 8 channel DMAS, since its an all in one kit. With 8 channel SPDIF.

 

[BoNoFiDe187]

The manual change and power port change along with thx tweaking they spoke about up top, the physical box change from 2010 it was solid light blue to black and blue in 2016, improved console controller/subwoofer from the previous version with their freezing & circuit board issues. Those are the only things I’m aware of.

 

[Ferather]

There is only 1 bad thing to say, it seems Logitech rated this unit at maximum power output, rather than before the clipping elbow.
Many manufacturers down rate their power, to show better THD, but its not the units actual full output.

Supplies-amps start to clip and add distortion as they struggle to supply-add volts.


GaN-Systems-Advantages-in-Class-D-Audio_FINAL.pdf (gansystems.com)

I would guess at 400-450w RMS, would be more suitable.

 

[Laurijan]

I have the newer revision of the z906 with the fitted power cord. Can confirm that 4K 120Hz video from my PC to my TV with audio passthru in dolby digital works. Optical audio cable runs from TV to speaker system

 

[BoNoFiDe187]

Im having a blast with my revised version I just bought it’s def. better!! My old model kept freezing the console broke now the subwoofer took a crap. That’s why I had to buy the new one regardless.

 

[Bill_Bright]

Many manufacturers down rate their power, to show better THD, but its not the units actual full output.

Just to clarify, you are suggesting that is a good practice, right?

For sure, it is good. VERY GOOD.

Sadly, there are many manufacturers who do indeed rate their maximum power out well above what any normal listener would consider acceptable distortion levels. Same goes with some speaker makers. The published specs would suggest the speaker can handle a lot more power and/or produce much higher SPLs than they it really can - at least not without producing a lot more distortion or far from flat freq response.

 

[Ferather]

I am not sure about good practice, specs are all over the shop with many devices, but good point about the speakers.
With my 10 year old original, I start to notice THD just over half full volume (6-7 full lights), using SPDIF.

If I use analogue, I lose a lot of signal in Realtek DAC, which then needs an amp to be at the same volume as SPDIF.

Z5500 had an over boost feature, I think for the Z906 that's built into the main volume.
My default volume is two full lights with SPDIF input 5.1 DTS.

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I will guess that adding volume in PCM (before the DAC), increases the power output of the DAC.
I could put the amp into unity (add-takes away no power), and get an increase.

 

[Bill_Bright]

I am not sure about good practice

By "good", I mean in this case, "honest" and "realistic".

"Bad" practice would be where those companies and their marketing weenies would use "deceptive" tactics to advertise a stereo (2 channel) amplifier, for example, as being a 500W amplifier only to learn they were adding both channels together, using peak-to-peak, 10% THD, measuring with just 1 channel driven into a 4 ohm load over a frequency range of 300 to 10KHz ±10% - along with other power inflating tricks including outrageous S/N ratios, momentary (not continuous) power, etc. Now that "500W" turns out to be only 50W of [more or less] "clean" power - if lucky.

 

[Ferather]

I personally want rid of amps and the bullshit, I have even heard top of the line professionals state they can hear differences between amps, but then say its not enough of a difference.
What? If two amps are different which one is true sound (1:1 no change) and which ones is not? How can the difference mean nothing at all and not worth factoring in?

I am actually hoping Logitech will push out models with PowerDAC's, where the conversion to analogue already includes all the power (no amp).
Currently if I send my Realtek DAC say 144 dB of PCM, I DO NOT get 144 dB in power form, only after an amp which adds power.

 

[Bill_Bright]

What? If two amps are different which one is true sound (1:1 no change)

Too many variables to answer that - starting with the microphone and ending with the speakers, curtains, carpet, furniture, size and shape etc. in and of the listener's room, not to mention the listener's position, own ears, and own preferences.

 

[Ferather]

True but I would count them as after variables, If you did sinewave tests (+ other tests) and noticed the output is equal to input, you have 1:1 hardware.
With or without 1:1 hardware you will get the variables you mentioned. I still prefer the audio is not changed.

Edit: An AVR could put out 1% THD and another 0.1%, this is a noticeable difference, with variation (in this case constants) included.

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Here is what I designed to replace current systems, In this case with speaker PowerDAC's, and using lossless amplification-attenuation (PCM).
The idea of the PowerDAC in this case is to output the correct power (to speakers), to represent the digital input amplitude.

Lets say some PCM audio was coming in @ 60 dB, I add 40 dB via 32 bit float PCM, then it hits the PowerDAC which does 100 dB in power.
No power based signalling, using lossless optical right up to the speaker, with the speaker as the only variation in quality.

 

[Bill_Bright]

I think the ultimate goal (at least on the high end scale) is always to have 1:1 where the audio in equals audio out. I just don't think it is possible.

One day, when "Man" can manufacture 100% pure raw materials and use them to create perfection 100% of the time, then, maybe it will be possible. But, thus far, we mere humans are not capable of that sort of perfection.

If it were possible, then surely, every flagship model from Denon, Anthem, Onkyo, Marantz, Lyngdorf, Yamaha, McIntosh, you name it, would always sound exactly same to our ears, and have the exact same results as measured with our test and measuring equipment. The same would be said for speakers. But that's not happening. And surely won't in what's left of my lifetime.

 

[Ferather]

We can make it so only the speaker unit its self is the only point where 1:1 is lost. There is no such thing as 1:1 speakers or headphones, but we can do 1:1 up to them.
This is still a major improvement. PowerDAC's already exists now, its just took some time to develop it, and then make viable products.

HDMI and audio lag is still an issue. This day in age you would not expect any kind of audio lag. Extra read: What is True Sound?
Using a multicore mobile SoC without a buffer is also a significant improvement to an audio only DSP.

A Yamaha DMAS and a Denon DMAS rated-badged True sound 1:1, will be 0% different in output, just features other.

 

[Bill_Bright]

but we can do 1:1 up to them.

Nope. Sorry but definitely not true. Speakers for sure influence the sound more than anything else. But starting with the microphone and all the way through the electronics to the final digital to analog converter and last amplification stage, changes to the original sound will be made, regardless how slight. And perhaps more importantly, starting with the microphone, those changes that are made at each and every step of the way all add up. They do NOT cancel each other out.

We may not be able to hear the differences with our own imperfect ears, but those differences are still there.

 

[Ferather]

True if we talking about recording then playback, but I am more about the final file. I understand the mic will have lost quality, but we have a recording that we can compare input to output.
Another way is to produce a digital sound (not recorded), via software, then compare the input (PCM) to the output (PCM) of the 'playback' system.

By input I mean input to the playback system (output from computer), opposed to a microphone input to a computer-other.

PCM file > SPDIF out (check 1) > DMAS > PCM out (compare check 1) > Speaker.

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Good thing you point this out, my wording can be confusing.

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A DMAS (here's hoping for a Logitech DMAS), should be multi-mode, with the default mode of True Sound, it can also have user and OEM modes (DTS-Dolby-other).
This way if you like to add colour or even compensate via EQ, other, the user mode can be used as a custom mode that can be programmed.

In True Sound mode, there should be no additional processing (changing) of the audio, only amplification-attenuation.
No analogue or power based signalling means there is not much in terms of audio parts.

 

[Bill_Bright]

True if we talking about recording then playback, but I am more about the final file.

Huh? Fine "file"? Seriously, how does that make any sense at all? Of course the "file" will be identical. Changing 1 bit from a 1 to a 0 can totally alter, even corrupt a "file".

First, I would argue that "true sound" ("sound" being the key word there) is not some "file" created by some programmer on his computer.

"True sound" is clearly another example of an ill-conceived "marketing" term.

"Sound", by definition, is "a vibration that propagates as an acoustic wave through a transmission medium such as a gas (like "air"), liquid or solid."

Even an electric guitar is an analog device as the sound is first created through a vibration in the strings.

Sound is analog. Period. Full stop. There is NO SUCH THING as digital sound.

"Sound" is not a bunch of 1s and 0s residing on a disk in a file, or being carried by electrical current through a conductor. That's "audio" or an audio file. Sound and audio are NOT the same thing. Sound may be represented in an audio file by a bunch of 1s and 0s, but we can only hope it will be faithfully reproduced after that. And once it is reproduced, it again is converted into analog before we mere humans can hear it. Why? Because our ears (and brain) detect "sound", not a bunch of 1s and 0s and sound is always analog.

For that reason, there is no such thing as a "digital speaker" either - at least not in the practical sense. For klaxons, maybe. But not high-quality reproduction of sound. What are currently marketed as digital speakers are simply analog speakers housed in the same speaker cabinet as a DAC and amplifier.

In True Sound mode, there should be no additional processing (changing) of the audio, only amplification-attenuation.

In any "reproduction of sound", there should be no additional processing (changing) of the audio, other than amplification or attenuation. No argument there.

And make no mistake, if a programmer created the audio file you have saved on your computer, when you play it back through your electronics, what you hear through your headphones or speakers is analog.

I do understand what you are trying to say. I am not arguing for the sake of argument here. But folks need to understand there is a HUGE difference between "sound" (waveform vibrations we can hear with our ears - which is analog), and a digital "audio" file created by first recording the analog sound, then converting from analog to digital, or an audio file created entirely by via a computer program using digital means.

In ANY CASE, the final amplification stages will ALWAYS be analog. The final signal sent to the speaker drivers will ALWAYS be analog, and the waveform/sound that hits our ears will ALWAYS be analog too.

So again, to your point, the "sound in" should be exactly identical to the "sound out". But it isn't possible. If it was, every brand of amplifier and every brand of headphone would all sound exactly the same. But as you noted above, professional listeners with their golden ears can hear the difference.

But many would argue that it is those subtle differences that turn a good receiver into a great receiver, or a good speaker into a great speaker.