Hacking The Logitech Z906 Speaker System

The Logitech Z906 is a well-rounded 5.1 surround sound system. It’s capable of putting out 1000W in peak power, and can decode Dolby Digital and DTS soundtracks as you’d expect. It’s intended to be used as the heart of a home cinema system and used with a central command console. However, [zarpli] figured out the device’s serial secrets and can now run the device in a standalone manner.

As it turns out, the Z906 uses a main control console that speaks to the rest of the hardware over a DE15 connector (also known as the DB-15). [zarpli] realized that the hardware could instead be commanded by just about any device with a serial port. Thus, a library was whipped up that can be readily used with an Arduino to control all the major functions of the Z906. Everything from volume levels to effect modes and channel assignments can be commanded by microcontroller. As a finale, [zarpli] shows off the hardware playing a multi-channel composition without the console connected, with his own hardware running the show instead.

If you’ve got a Logitech Z906 or similar unit that you wish to automate, you might find this work useful. It’s also a good inspiration for anyone contemplating hacking away at the console ports on other hardware. Video after the break.

41 thoughts on “Hacking The Logitech Z906 Speaker System

    1. I was suspicious of that “1000W” too.i. I’m figuring it’s an exaggeration of an typo.

      It’s like those cheap “computer speakers” I found that had some outrageous claim, and the speakers were about the size of those in pocket transistor radios.

      I have a decent stereo receiver and a pair of Radio Shack Minimus-7 speakers as my “computer speakers”

      1. That 1000W is probably by multiplying the open circuit voltage with the pre-explosion short circuit current.

        Also, if there is anything that creates a kW of sound, I would not want to be closer to it then a few hundred meters without ear protection.

        1. “That 1000W is probably by multiplying the open circuit voltage with the pre-explosion short circuit current.”

          Sort of like Sears Craftsman horsepower?

          1. it’s the rating you should avoid going too long. some manuals indicate how many milliseconds the output can sustain. you’d want to avoid goig that far because it lowers lifetime of the device/speaker.

  1. “and can now run the device in a standalone manner.”

    I wouldn’t think speakers are very useful when used in a standalone manner, except perhaps as ballast.

      1. I bought a set of these way cheaper than RRP (£150) and I’ll be honest, they are far, far better than any PC speakers. I’m a huge music and movie fan, and other than missing hdmi there’s nothing to knock this as a budget media setup with a fair amount of quality at that price. At the current £400+ I’m seeing for these I’d say look at better quality, but if like me you can find a new set for literal peanuts, you won’t be disappointed unless your expectations are totally unrealistic.

    1. Ahh, yes – the old ILS (If Lightning Strikes) spec, it’s in the same IEEE reference as the PMPO measurements that allow up to 99% THD at .001 watt.

      Seriously these have a reputation for poor overall quality.

    1. If it’s the size of the old Mac monitor and PC joystick connectors it’s DA. If it’s the same size as a 9 pin RS232-C connector it’s DE. For that connector with more than 2 rows of pins it’s a High Density D-subminiature or HDE-15.

      1. Agreed, that letter is the size of the housing or backshell. A D-series connector with 15 pins is a DA-15, then DB-25, DC-37 and DD-50. The 9-pin was added later, so DE-9. The suffix letter is P for plug (or pin) versus S for socket, so an old-school RS-232 plug would be a DB-25P.
        The high-density H prefix versions came later, so a VGA-style connector with three rows of contacts is a HDE-15 in the same backshell size as a two row 9-pin RS-232 DE-9.

  2. And a great advertisement for a system that can’t be bricked by the manufacturer. Also a great open hardware paradise of inspiration for other ideas. Really good article.

  3. 6.0 inputs in pairs of cable, OK what else does it need to work? I’d call that standalone operation. The hands free thingies would be great on the bathroom or kitchen sink but why here.

  4. The smoke’s still in there? Must have done it wrong.

    All jokes aside though, what’s wrong with all the old stuff from the 70’s-90’s? I consider myself an amateur audiophile and will never spend money on a X.Y system again. Sound is sound, and it’s either good or it isn’t. For pennies on the dollar, anyone could do the same thing with analog hardware and a digital (or whatever floats your boat) frontend, with a pretty much implicit guarantee that the end result is going to be both better and cheaper than whatever the lowest bidder can put on the shelves today.

    I’m only 34 for gods sake – anyone else look at stuff like this and wonder when they got old?

    1. Could be an availability thing. Suppose somebody was giving this away or selling it for a fiver because he/she broke the central console and figured to just get a new system. Also, when it comes to the used market, some countries are suffering from PSTD – Post-Soviet Technical Deficiency. As in, over the post-war period where the civilised world was manufacturing good stuff, the Prison of Nations was mostly busy pouring resources into the military potential. The civilian manufacturing got what was left over, and due to quirks of a closed planned economy, a lot of the stuff that was made with that was crap, with the occasional gemstone in the middle – and telling the former from the latter isn’t easy these days, because the folks that figured it out back in the day consider it common knowledge, and won’t bother talking about it.

  5. I wonder if this could be used with the Z-5500, it uses a 15 pin connector like the Z906. I doubt Logitech would write a whole new command set for the newer Z906. Only thing is the inputs for the Z-5500 are on the control unit and not the subwoofer, so it makes me wonder how the inputs are passed through to the to the subwoofer via the 15 pin connector.

    1. Though in these times, you could run into “Wasn’t even made by the same contractor/supplier” issues between pieces of hardware that outwardly look like a uniform range.

  6. This is great. I have this speaker system, and I understand the ‘1000w’ is purely what Logitech claim, but thats by the by, it’s a great speaker srtup and I’m looking forward to messing with this
    The console that comes with the speakers has some awful limitations.

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