Boxsterfeet

Guys,

I've read about the benefits of Logic 7 providing 7.1 audio compared to the normal hifi upgrade which I'm presuming will simply provide more power at the extremes, but be basically in 2 channel stereo. As I won't be using any DVD Audio discs (in my autochanger) can anyone think of any other reason to go for the Logic 7 ?

530E60NL

Superb sound, even when listening to the Radio. Today I had a station on with some club music and it sounded as if I was listening to a CD.

subterFUSE

The Logic 7 is not a "7.1 channel" system. It is a system which has processing to direct certain sounds to certain speakers, but it cannot playback discrete recordings (such as DVD audio). 7.1 channels is a reference used for the newer Dolby Digital and/or DTS surround decoders found in high-end home theater components. It is also a recordng standard, where the sound is separated into 8 discrete channels which are directed to speakers independently. 7 main channels (Front left, Front right, Front center, Back left, Back right, Left-center rear, Rightcenter rear), and the .1 channel is a sub-output.

Normal CDs do not allow for 7.1 encoding. They are recorded in stereo (2 channel) Only DVD audio offers 5.1 or better recording, at this time. The BMW system does not allow for DVD audio playback currently. Only the Acura TL & RL have this feature, to the best of my knowledge.



The Logic 7 uses a processing more closely related to Dolby ProLogic surround, found on early home theater preamps from in the 1990s. Dolby ProLogic processing allowed a stereo audio source to be analysed and then direct certain sounds to certain speakers based on the frequency of the sound. ProLogic offered front left, front right, front center, and then monoaural rears. However, these were not discrete channels (ie sound completely separated between speakers).

Logic 7 uses something similar to this. It analyses the music and then directs certain frequency ranges to certain speakers.... for example, human vocal sounds fall in a midrange which Logic 7 directs to the center channel speaker. But, other sound which are in the same range as the human voice may also get directed to the center channel, even if that is not supposed to be the correct soundstage location. This is where the advantages of discrete audio become apparent. If you were listening to a recording and there was an instrument playing which would have been located on the left side of the soundstage, but that instrument was playing notes that happen to partially occupy the same range as the human voice.... those sounds would get directed to the center channel on the Logic 7.... but on a discrete recording and playback, the sound would come from the appropriate location because the recording had that data specified for a certain location.


But there are not many discrete channel recordings available today. So even if the system could play DVD audio, you would not have much use for it.

UUronL

Actually, SACD is multi-channel now as are many DTS and Dolby Digital audio-only recordings. Dolby Pro Logic II and IIx are most similar to Logic 7, and provide discrete surround decoding through steering logic. In fact, some video games and TV shows are recorded with "hints" that help PLII to do a more convincing job of steering the information. PLIIx adds support for more rear channels, but like so many "greater than 5.1" formats it isn't widely utilized. I've had all the above formats in my home for quite a few years now, when properly calibrated, it's amazing what can be done with plain old stereo. With that said, I doubt the enviroment in the car is taking full advantage of L7's capabilities.

saurabh

Doesn't the Logic 7 technically considered to be a 7.2 channel system due to the two subwoofer outputs it has. Thus, giving it that .2

Correct me if i'm wrong please.

UUronL

Generally, the effects channel is a single channel and does not carry any different information if multiple subs exist. Bass is non-directional so it doesn't make sense to do so. For this reason, multi-channel formats that contain an effects channel are only ".1" regardless of the number of subs being driven with the information.

Merv the Derv

Hmm, wish I'd got L7 now.

Boxsterfeet

Merv, did you get the hi-fi upgrade or do you just have the standard fitting ?

stream

I'll give you my non-technical answer--it sounds fantastic--best factory installed car stereo I've heard.

Here'a a doc describing the system (compliments of Iceman)--it's described as a 7.2 system.

Logic7.pdf

SinisterJ

Logic 7 Rocks Its The Best Stock System That I have Ever Heard