MX units used for surround processing?
 

I was just told that certain MX units are equipped with circuitry that's capable of processing stereo music into surround sound. I was totally unaware of this, so I researched the Mac compendium and, much to my surprise, discovered the following information under MX151 features:

....2-channel source material can be played back in stereo or processed up to 7.1 multi-channel using Dolby Pro Logic IIx or DTS Neo: 6 decoding....

My question is if anyone on the Mac board has experience with using this processing and, if so, what results did you experience?

Thank you for your time :D

Bill, I've done this with my Marantz processor.
I didn't like the result.
I prefer my music as 'natural' as possible.

I have the mx150 and it does this surprisingly well. Certainly not for an audiophile purist but depending on my mood and the music sometimes its fun to use. It's especially good when streaming tv shows on the HT system that are only in stereo. It gives a good surround sound effect. 99% of the time I listen to music on 2 channel system though.

MX units used for surround processing?
 

Mixed results here. Some 2 channel video sources are mixed and encoded to use with Dolby ProLogic decoders. If you have a lot of these in your library it makes sense to use Dolby Prologic to decide them.

For normal 2 channel audio sources it’s a crapshoot. The Dolby Prologc decoder will take ambient and out of phase info and steer it to the rear channels. It does this in a manner that is somewhat unpredictable. Try it, you may like it on some things.

Years ago, ProLogic was the only show in town. My Marantz will default to it if I don't turn it off. Like others say, it's a mixed bag unless you have a collection of legacy sources that used ProLogic.

Is this a joke?

Older MX units
 

McIntosh has been making units that will convert analog stereo signals into 5.1 ever since the MX118 and the MX130.
On the MX130, some units even have Dolby Processing and THX certification. I realize these have been left in the dust by current digital technology, but when they were first produced they were "top of the line."
Remember, these units were produced BEFORE digital was available at any reasonable cost to audiophiles.
I have an MX118 in my office system, and an MX130 in my home system.
Just remember - THESE UNITS ARE TOTALLY ANALOG! True, there was some minor digital circuitry in the early THX standards, but it was nothing like what is available now.
I use the MX118 at the office because of size limitations, and I do not play vinyl at the office. The MX130 is a larger unit (i.e., taller) and has phono inputs. It is the "brain" of my home system now.
The early MXxxx units suffer from a bad reputation because they were first marketed as Audio/Video units - at a time when all video was analog. Shortly after they hit the market, digital video hit the market - all of a sudden analog video units were viewed as worthless. McIntosh addressed the digital audio problem with the introduction of the MAC3 DA converter. But solving the video was not worth the expense.
Just ignore the video in these early units. Think of them as outstanding analog audio units. In that arena, they can hold their head high.
At age 76 I do not know that my ears could tell the difference between current leading digital products and my older analog system. But, to me the sound is pleasing from both units (MX118 and MX30). I like the MX130 because of its flexibility. Short of having a rack mounted patch panel, it is one of the more flexible units I know of from an input/output perspective. You can choose from 13 inputs and route them to any (or all) of four recorder outputs. It also has dual channel capability (i.e., I recorded 200 vinyl LPs to 192/24 digital files at the same time as my wife was using the other "channel" to listen to Oprah and Dr. Phil on the TV running through the MX130 system. There was absolutely NO cross talk!).
Although my "day job" was a CPA, in my early years I longed to be a jazz musician. I spent enough time in an orchestra pit or on a band stand to know what to listen for (I learned very early that unless one reached the "top echelon", the life of a musician is very much a "hand to mouth" existence - being CPA paid a lot better and very much more dependable).
As an illustration of knowing what to look for, I finally found a pair of KLH Model Nines (early full range electrostatic system - that I first heard in 1970) that have OUTSTANDING definition and "air" in their presentation.
So, my inability to tell much difference between my old analog 5.1 units and the newer digital units is a function of my decreased hearing ability due to age. I am not saying which is better - just with my present hearing I cannot tell any significant difference.
As an illustration of my hearing in the past, about 40 years ago I was at a venue after a musical group rehearsal, and the sound guys were trying to set up the system. They set a microphone up in the center of a venue (huge round building with cement block walls with cement floor and a domed roof (big enough to hold 10,000 people) - an acoustical nightmare) and turning up the gain on the system until they got a feedback squeal. They could not identify it - I recognized the squeal as approximately an "A" somewhere above middle "C". They had an equalizer in the system. I told them to cut back on 800 HZ (since "A" is 440 HZ - an octave up would be 880 HZ). The squeal stopped! All of a sudden they thought I was a genius with perfect pitch. But it was just that I had spent enough time "trying" to play music that I had decent recognition of relative pitch.
I do not know if I could still do that at age 76.
I do not know everything about music or acoustics, but I spent enough time as a player, conductor, and substitute recording engineer, in my early years, that I have learned a little bit. At my age the older analog McIntosh MXxxx units still sound great!.
So, do not dismiss the early analog MXxxx units for audio until you listen to them.
Thanks,
Jim

Hi Jim!
 

I'm a bit younger than you are, but your words still make great sense to me. In fact, much of what folks find to be "a giant leap forward" these days makes very little sense to me. For example, we've owned and enjoyed a Mac MX130 for many years and, quite frankly, it still sounds damn near as good as anything else we've ever heard in 2-channel stereo mode. If it weren't for the fact that we have a keen interest in creating our first 5.1 surround system -- in a new listening area -- we would still be smiling away as we allow our MX130 to run the stereo show.

By the way, my dear departed father was a CPA, so your thoughts are especially well-taken by the folks up here on the mountain. :D

Theta Digital developed a proprietary matrixing capability for their Casablanca III and newer preamp/processor, along with multiple Dolby and DTS ones. Their proprietary one is simply remarkable in its ability to stabilize placement without degrading the sound quality. Most of the time, I listen to streaming in 7 versus 2 channel. It simply seems to sound better.

I do not do anything fancy, just listen to 2 channel music. Would I be better off with something like a C28 over an MX130. I can afford either one, but the C28 is a little higher

Thx
Rick ( Chino Valley, AZ)