4.1 is... what? stereo? surround sound?

[Lemernis]

As I'm asking a question about my 4.1 system on another site, someone at that site is asserting that any signal coming out of an audio miniplug cannot be converted into anything other than stereo. He maintains that the two 1/8" miniplugs out from the 4.1 system, one purple and one lime, are for the rear front and rear speakers, respectively. In other words, the 4.1 produces stereo sound that is split between two sets of speakers. Unclear to me how the subwoofer figures into that.

I admit my ignorance and confusion about this. Is the 4.1 system essentially glorified stereo? Or does it offer true 'surround sound'? What's the difference?

[thxsubwoofers]

I would say in my opinion that its superior stereo. 4.1 systems are ment for music and 5.1 systems are ment for movies in my opinion. The difference is that 4.1, the speakers would play everything it signals, and 5.1 mostly all the voice comes out from the center channel. The surround speakers are ment for the explosion effects etc. If you listen mostly to music like me, I always keep my system on 4.1 mode instead of 5.1.

[Lemernis]

Thanks for the reply.

Maybe a better question is that if the sounds of a computer game or DVD movie are recorded in Dolby surround sound, how does the ProMedia 4.1 system handle that? (Assuming that the computer playing the product has the sound card and software to run surround sound.) Even if ProMedia 4.1 is technically stereo, are those five speakers able to reproduce the sound in what for all practical purposes will be 'surround' sound? (I.e. by splitting the center speaker channel evenly between the two front satellite speakers.

ProMedia 4.1 is THX certified, meaning that it meets the same rigorous standards that movie theatre sound systems use, and of course they are playing Dolby sound all the time. So I guess it is surround sound, no?

[thxsubwoofers]

ProMedia 4.1 is THX certified, meaning that it meets the same rigorous standards that movie theatre sound systems use, and of course they are playing Dolby sound all the time. So I guess it is surround sound, no?

Hmm maybe or maybe not. It could be also that THX has certified the Klipsch Promedia 4.1, for the Sound Quality.[]

[Lemernis]

As I understand it, THX certification for a multimedia system requires that the device exactly reproduces a Dolby digital soundtrack as it is meant to be experienced in a (THX certified) movie theatre. That is, in surround sound.

My rudimentary understanding of surround sound is that it is recorded with more than two channels instead of just two, as stereo has it. For example, a film might be recorded and it's sound mixed for a movie theatre that has 8 channels/speakers. Somehow the ProMedia's 4.1 four satellite speakers and subwoofer is supposed to reproduce that in a way that does justice to the movie theater experience. But it is not at all clear to me how it does that, given that it is using fewer speakers. And 1/8" miniplugs, which are supposed to be for stereo.

The manual that came with the system simply states, "... the ProMedia 4.1 has four channels and a subwoofer..." and refers to "...all four dedicated satellites..."

***

I'm asking the topic starter question more than just out of curiosity. It's not really clear to me yet how to set up the 4.1 system to get the best sound reproduction.

I have two different computers sharing the ProMedia 4.1 via a KVM switch which simply carries to the two audio lines out from the 4.1 system to ports on the back of the respective computers. (I.e., it doesn't split the signal, really. It just allows me to switch the two lines out from ProMedia 4.1 back and forth between the two computers.)

Each computer has an integrated digital audio chipset included on the motherboard*:

Computer 1

ASUS P4B533 motherboard

"Audio Controller. This C-Media 6-channel PCI audio chip supports legacy audio and HRTF 3D positional audio functions. The chip also supports 24-bit S/PDIF In (0.5~5V) and S/PDIF Out (44.1K and 48K formats) professional digital audio interface, and one MPU-401 UART mode compatible MIDI/game port."

http://www.cmedia.com.tw/product/CMI8738.htm

Computer 2

ASUS P4PE motherboard

"Audio CODEC. The ADI AD1980 is an AC'97 CODEC that allows 6-channel audioplayback. The audio CODEC provides six DAC channels for 5.1 surround sound, S/PDIF output, AUX and Line In stereo inputs, integrated headphone amplifier, greater than 90dB dynamic range, and stereo Mic PREAMP support."

http://www.soundmax.com/products/documentation/SMSPXUsersGuide.pdf

And on the back of each computer are three audio miniplug ports of which both manuals state:

"Line In: This Line In (light blue) jack connects a tape player or other audio sources. In 6-channel mode, the function of this jack becomes Rear Speaker Out.

Line Out: "This Line Out (lime) jack connects a headphone or a speaker. In 6-channel mode, the function of this jack becomes Front Speaker Out.

Mircophone jack: "This Mic (pink) jack connects a microphone. In 6-channel mode, the function of this jack becomes Bass/Center."

Near as I can figure out, in '6 channel mode' the ports (i.e., the three audio miniplug jacks) on the back of my computers accomodate

front left and right

rear left and right

front center and rear center

But since the ProMedia 4.1 lacks center channel things become a bit confusing. The 4.1 has a subwoofer, but my best guess is that it does not have a dedicated line. Not clear to me how the subwoofer's signal is handled between the 4.1's two miniplugs.

The ProMedia 4.1 has two lines out, one green miniplug and one purple miniplug. I'm guessing the green miniplug must be for front left and right speakers and the purple miniplug is for rear left and right speakers.

The manual states "Connect the GREEN plug to soundcard output number one, and the PURPLE plug to output number two"

This is not very helpful in my circumstance. Computer 2, for example, renders no sound when I connect the 4.1's purple miniplug to the audio chipset's light blue rear speakers port. But it does work when I connect it to the pink bass/center port.

Doesn't make sense to me, but at least I'm getting directional sound where it's supposed to be when I test with the audio chipset's demo software. Okay so far.

However, the software bundled with that computer's audio chipset doesn't even include a 4.1 speaker set option. Instead it lists

Quad Speakers (Multi-drive Surround)

Surround Sound Speakers (5.1 Surround)

And it doesn't seem to make a difference which I select.

I would assume that whatever I select from the integrated audio software will override the setting in Windows Control Panel/Sounds and Audio Devices/Volume/Speaker Settings/Advanced. There I currently have "Quadrophonic" selected, since it seems to most closely match what near as I can tell are the channel signals coming into the computer: front left and right, and rear left and right.

Any, all rather confusing. I'm not an audiophile, and only semi-literate as a computer person. Any advice will be greatly appreciated.

* I also had slots added to the mobos to allow me to install in my own soundcard if I wish.

[thxsubwoofers]

As I understand it, THX certification for a multimedia system requires that the device exactly reproduces a Dolby digital soundtrack as it is meant to be experienced in a (THX certified) movie theatre. That is, in surround sound.

Yeah, your correct. Still comes to me but, what about the Klipsch promedia 2.1. That is also THX certified.