[m4shifter]

I am looking to upgrade my current HK (S688a) 16-speaker setup but having read most threads here back and forth, I don't think there is a solution to my dilemma.

The challenge: I most definitely want to retain Logic 7 / HK-Amp. The reason is in a car setup with exhaust, road noise, etc., achieving home theatre grade audio fidelity, to me, is unfortunately a second priority compared to immersiveness of upmix surround sound (I'm sure many audiophiles will cringe at this). I'd argue that whilst I'm driving, I find it harder to appreciate the naunces of the audio but I can definitely easily appreciate some upmix surround music.

I don't think there is any aftermarket upmix solutions that provide similar results to Logic7 / DTS / Dolby Pro, especially with the MS-8 now discontinued with no clear successor.

Someone has done before:
https://www.educarmag.com/educar-mag...ic-7-in-a-bmw/

And the same guy also mentioned this in a subsequent, unrelated post here:
https://www.linkedin.com/pulse/new-f...th-ward-tejzc/

where an aftermarket amp (in this case Audison) takes upmixed hi-level input coming from the HK amp.

My questions are:

1/ Is this considered a viable / argubly sensible approach to retain Logic7?

2/ Is there any other aftermarket dsp/amp that does surround sound upmixing? Helix offers "RealCenter" but I'm more after surround effects.

3/ I'd still want a 1-seater and 2-seater tune though, not sure if this is possible while retaining Logic7.

4/ Separately, I am not planning to add a "party sub" but rather looking to upgrade the underseat woofer. Believe Billfitz has been advocating Earthquake as the only worthy upgrade if there is no additional subwoofer. I'm not sure if the relatively recently released Morel is also a good replacement now?

5/ Given the perference above, I'd imagine something like an Audison 12.14 BIT (getting high level input from HK amp) paired with C4D / M4D for the 2 underseat subs might make sense.

6/ I have read various bits and pieces on how Logic7 works, but I can't seem to find much information on how Logic7 works on BMW F-series? I am pretty sure I read somewhere that the upmixing changes in real time based on driving conditions as well (unrelated to ASD inputs)?

[Arthurrs]

You may want to have a serious look at the m0bridge K2 8.1.1 DSP amplifier as an alternative to the Audison. The beauty of this option is that it is taking it's signal source directly from the digital MOST bus, and does so preserving the Logic 7 signals, as well as all the vehicle warning sensors/navigation/telephone as separate "sinks" in the mix that you can assign to any output. It is a very unique option that offers this all in one box.

The challenge anyone faces in using the speaker level outputs as the inputs to an aftermarket system, is that any speaker correction processing that the factory provides within the amp, needs to be counteracted by any equalization that you wish to apply additionally to get a decent response from your after market speakers, should you choose to go this route. Less is more.

[m4shifter]

Originally Posted by Arthurrs

You may want to have a serious look at the m0bridge K2 8.1.1 DSP amplifier as an alternative to the Audison. The beauty of this option is that it is taking it's signal source directly from the digital MOST bus, and does so preserving the Logic 7 signals, as well as all the vehicle warning sensors/navigation/telephone as separate "sinks" in the mix that you can assign to any output. It is a very unique option that offers this all in one box.

The challenge anyone faces in using the speaker level outputs as the inputs to an aftermarket system, is that any speaker correction processing that the factory provides within the amp, needs to be counteracted by any equalization that you wish to apply additionally to get a decent response from your after market speakers, should you choose to go this route. Less is more.

Ah - I think I got confused - thinking the upmixing is done in the HK Amp, and the signal from MOST will be stereo (e.g. from CarPlay). Are you saying the signal coming from the MOST bus is already upmixed? So something like m0bridge or Match Up 10DSP will retain the Logic7 signals?


What you said makes sense re neutralisng the speaker correction processing from factory.

[Arthurrs]

Correct, the MOST bus contains not only the "unprocessed" stereo/multichannel audio coming from the head unit (with logic 7, graphic equalizer, tone control, and full fader control), but also all the car gong/chime/sink signals. Take a look at this adapter's installation manual for an excellent overview of what is possible:
https://navtv.com/products/NTV-KIT969/zen-25.html

But this assumes your car has the MOST bus in it for audio transport. Newer BMW's use a different audio transport, and your options seem to be rather limited.

[Billfitz]

The Morel woofer is better than the OEM, but it doesn't go as low as the Earthquake. It probably doesn't go as loud, but one can't be sure, as Morel doesn't list the xmax, which determines the maximum output. I haven't come across any other woofer that comes even close to the Earthquake's 23mm.

[NealfromNZ]

The logic 7 processing was developed lexicon in the 1990s. They made high end surround processors and this was in the days before true 5.1 formats in domestic audio where widespread. So they develop the surround sound algorithm for 2.0 & 5.1 formats that could produce 7.1 suround. They were also musicians so some of the settings variants where designed with live music performance in mind.

Harman Kardon brought Lexicon and JBL so incorporated the the algorithms into some of their equipment streams. So with BMW partnering with Harman Kardon it ended up in the amplifier products.

There are other upmixing algorithms from 2.0 such as Dolby Prologic 2 , DTS Neo. But not many car audio manufacturers implement those into dsp systems.

The Mobridge amp mentioned has 3 centre channel algorithms that can be used so you still get surround , but no so sure if it gets passed logic 7 from the idrive. You could check with them as they are really good and open on what their product does.

I’m not 100% sure but from what I understand the HK amps have two maps build in and it’s changed by the data stream associated with MOST ( surround toggle on idrive ). So my learning to date is that Idrive doesn’t send logic 7 audio. Just either 2.0 PCM audio or MPEG audio if from DVD source.

On the Mobridge I do run one of these and run Morel Underseat woofers. I do augment these with a trunk sub ( it’s not about doof doof btw more about having low distortion and headroom on sub bass frequencies ) The term sub is overused on BMW underseat options. The majority of aftermarket BMW solutions are just woofers.

The morels will do down to 20hz without issue or any eq at a reasonable output and I have seen over 112db on them to see what they will do. So that roughly 30 db about my M3’s 80db noise floor of road , exhaust, tire noise which is in the 20 -300 hz range. A colleague measured incar qtc in the low 0.7 range which used to be considered the ideal or perfect woofer response.

SWS will have more cone travel though

Anyhow. Have a look at the faqs here. Goes a bit of the way to explain logic7


https://lexiconpro.com/en/product_do...c7_adm_revbpdf