[ctuna]

Why the Logic 7 system is not that good.

https://www.e90post.com/forums/showthread.php?t=1144129

If you read the specs on the output chips contained in the above link as
pdf files you can see the at rated power the chips are a 10 percent distortion.

[Peter Morrin]

I also have the Logic 7 system with the MOST connection between the head unit and the amplifier. Based up the discussion Ctuna posted, it appears that the weakness of the Logic 7 system is predominately inadequate power to the speakers.

The Audiotec Fisher Match Up 7BMW amp/dsp (approx $1000 USD) seems like a good solution to those who want to retain their stock head unit and not disrupt the MOST system. It offer 5 channels @ 65 W into a 4 ohm load and 2 channels @160 watts into 2 ohm loads. (No mention of THD at rated output). It also offers a DSP and likely higher quality Digital Analogue converter than the OEM amp. It has the option to add in modules (at $150 each) for bluetooth from your phone or a USB digital input. The amp/DSP is plug and play to the Logic 7 harness in the car.

While not cheap, this seems like an easy first step if one is not satisfied with the Logic 7 system. The add in modules would give the option of high quality bluetooth from a phone or an even better quality USB connetion for those who can live with a wire.

Once the amp/dsp was installed one could upgrade the speakers if not satisfied and add a trunk mounted sub with separate amp.

Are there other better options for those of us with the Logic 7 system?

[ctuna]

Mobridge makes a drop replacement for the Logic 7 amp that has quite
good specs and uses the Most Bus system without any add on's.

the trouble with everything else is you have to use a most to analog converter
and or reprogram for Hi Fi.
I think there was another company that tried to do something similar but I can't
remember who they where or if they where successful.

Mobridge also makes some other Most to analog pre amps .
Using these and then adding amps on top gets expensive.

https://mobridge.us/product/mobridge-most25-amp/
Kinda of expensive but you don't have to mess with the interface and
it's 8 channels with impressive power and a sub amp right out of the box.

[Peter Morrin]

Thanks Ctuna for the reply regarding MOST compatible interfaces. Before responding I would like to return to the post by mattanderson regarding sound deadening treatment. I would like to stick to treatment of the doors. Please correct any mis-interpretations on my part:

Constrained Layer Dampener (CLV):
This is the butyl rubber layer with one adhesive face and one exposed face. The exposed face can be a polyethylene (Dynamat) or aluminum (Second Skin). This is used to dampen large panels from resonating. Can this be used to seal openings in the door to create a "sealed" box. Where is it recommended to apply this product to BMW doors.

Mass Loaded Vinyl (MLV):
The product I have seen is made by Second Skin and comprises a heavy vinyl film with a 3/8"-1/2" foam backing. There is no self-adhesive layer so the material must be glued to the surface with contact cement. I do not know if this specific material has the structural integrity to "hang" across openings without being fully bonded. The vinyl surface did not appear to be compliant enough to form a good compression seal.

How should this material be best utilized with a BMW Door?

Foam:
This is availble in various densities, thicknesses, and porosities. How is it best utilized in a door. BMW provide a foam cover that seals off the metal inside face of the door keeping moisture off the back of the door panels. It seems to do a good job of this. Should this OEM liner be retained or discarded?

Other Fillers:
In home speakers, enclosures are lined/stuffed with all sorts of materials including foam, fibreglass, polyfill, wool, ???? Do any of these products have a role in a door "enclosure".

Speaker baffles:
Again looking to home speakers, great emphasis is placed on making the front baffle into which the drivers are mounted as stiff, dense, and "dead" as possible. Typically a minimum of 3/4" MDF or plywood is used. Are there sonic benefits to mounting drivers (particularly larger ones) to a solid baffle that is solidly anchored to the door. This obviously dictates a custom installation and likely a non-OEM interior finish.

Comments welcome.

Peter

[ctuna]

You need to take these kind of question to Absolute Sound or one of the High
End stereo Magazines or Forums. Consider that in a car you are having to over
come Road and Engine Noise there is a point where over engineering delivers
decreasing returns.

If you don't have quality speakers engineering there enclosures is a waste of
time.

Just and opinion.

[Peter Morrin]

Ctuna, Your opinions are always carefully considered! I also hear what you are saying about over-engineering and performance matching components.

In my case I have knowledge and DIY skills, but am a little cheap. I can build a custom enclosure, door board, or tweeter pod so don't need to pay a shop for their time to do this. I can't build a mobile DSP or 8 channel amp, so would have to buy that type of item. My car is also 16 years old so retaining "stock OEM" look is not required. This gives a lot more flexibility in driver choice, location, and aiming. Also with 30 years of after-market car audio tinkering, I have a selection of "free" drivers, amplifiers, and electronic cross-overs. I think in some respects I am an "older" version of the OP with his initial questions.

Based on your comments and those of others, it sounds like the E90 platform requires more power from the amplifier, and a DSP to tune the sound to the specific environment. This could likely be said for almost all oem platforms today. The offerings from Audiotec Fisher and Mobridge actually seem to offer a lot of value for the $1000-$1600 cost of the Amp/DSP. A lot of money, but we are not driving a K-car or a base Honda Civic. I am going to assume that anyone following this thread is starting from the proposition of upgraded amplification and a DSP.

Given this starting point, we turn to the mid/upper frequency drivers. If we constrain ourself to oem locations we are limited to a 4" mid-base crossed at 160 Hz and a 1" dome tweeter crossed at 3000 Hz. I think we are asking a lot of a 4" driver, mounted 75 and 35 degrees off-axis, on a flimsy pressed cardboard baffle. It is still a lot to ask of even a really good driver like the Morel.

My proposal is to use a 1" soft dome tweenter, an angled 3.5" mid base in the upper door and a 6.5" driver in the lower door mounted to a custom baffle secured to the door. With a 7 channel amp the tweeter-mid base would need to be on the same channel with a passive cross-over. With an 8 channel DSP, the tweeter, mid-range, and mid-base could all be individually amplified and controlled. Both options require running new wires into the doors.

I still don't understand how the underseat base drivers provide as good sound as they do, but many people are very pleased with them. With the additonal power and DSP control the option is always there to upgrade the OEM under seat woofers to Jenherts or others. There is also the option of a trunk mounted sub using the low voltage out from the DSP with an extra amplifier.

After this diatribe, I guess I am interested in whether people feel a 3 way active front stage (tweeter/3.5 mid/6.5 mid-base) paired with the 8" OEM underseats with good power would be better than a top quality (Morel or equal) tweeter-4" mid passively crossed, paired with upgraded underseat mid-woofers. All of the above driven by an upgraded amp/dsp.

Peter

[tankertoad]

An active three-way will offer potentially better sound. But at what cost in fabrication and labor? Dropping in a quality two-way set can yield outstanding results.

I have an e82. It came with the base system and a prior owner added sails with Bavsound tweets and mids. No amp so it left a lot to be desired.

I am not a DIY-er so I selected an off-the-shelf option from Intergral Audio and then gave it to my installer because the kit was for an e90 and it needed to be tweaked.

After install and tuning, I decided the Integral tweeter wasn’t keeping up with the rest of the system so I switched it out with an installer supplied set. The finished system consists of:

Alpine HD-149BT single DIN CD (discontinued but chosen for its clean signal and high voltage outs)

Arc Audio (Integral branded) PS8-50 DSP amp in the trunk

DLS UP-1 tweeters in the factory sails

Integral Audio custom passive crossovers

Integral Audio 4” mids (made by Scanspeak)

Integral Audio 8” underseat mid basses (maybe Scanspeak?)

Discontinued audiophile 8” shallow sub in the passenger footwell from a prior install. It sounds amazing but the 10” JL in a Musicar NW enclosure in my daughter’s e90 moves a lot more air). I will say if I turn down the sub, the underseats do an admirable job so I don’t think a sub is absolutely necessary.

Heavily deadened doors

Electrical fuse to beef up the fussy BMW system.

This was NOT cheap nor was it as pricey as other systems that don’t sound as good.

My installer did a wonderful job making the gear sound as good as it possibly can. My only complaint is the stage depth could be better but a 4” set is limited by the laws of physics and I want the OEM look.

[Peter Morrin]

Tankertoad,
Thank you for the description of your system and your comments. I did not see mention of the amplifier or is it build into the DSP? What is your wattage into each set of speakers? How have you configured the system with respect to cross-over frequency and slopes? With the base audio system, could you simply replace the OEM headunit without worrying about the MOST system?

Your comment regarding sound stage depth is the reason I am considering an active 3-way system. I just think we are asking too much of a 4" driver in a flimsy carboard baffle. This is perhaps supported by your experience and that of Ctuna as you are both using top grade drivers and cross-overs. Because I already have a 3-way driver system available (on my shelf), but do not have any cross-overs, I am leaning to a full 3 way active with an 8 channel DSP/Amp. The remaining channels would go to the underseat woofers.

Has anyone tried, or have an opinion, regarding wiring the underseat woofers to play in Mono? This would allow me to get away with a 7 channel DSP/Amp. My concern is that they are crossed at a high enough freqency that left and right may be discernable.

[ctuna]

Most modern OEM car systems are going for the lots of tiny speakers
and not much of and amp concept( no real power from these things and or
distortion when you turn them up ). This is why they don't have much presence
or depth. If they just had a single 5.25 in the front doors instead it would fill the
mid range much better. It's hard to go from a 4 inch to and inch and fill the midrange
Great speakers and DSP can help but the basic laws of physics and stereo
101 would say you need a mid size speaker to fill the gap.

[Peter Morrin]

Ok guys. I think we have this thread rolling. A lot of good discussion on the parts of the system down-stream from the source. I believe most people are using the OEM Head Unit with either the optical MOST output or an analogue low voltage (5v???) output.

What are people using as their music source? In my case I would have the OEM single disc CD, the 6 CD changer, my phone streaming connected via the 3.5 audio jack (analogue), and the OEM radio. I don't believe my pre-LCI Logic 7 system can communicate digitally via bluetooth or USB, but this is a feature of some of the DSP/Amps we have been discussing. I am mostly interested in high quality audio files and not terribly worried about phone calls. I would be interested in having the ability to play FLAC files from a USB stick or possibly from a quality Digital Audio Player.

So what is everyone else using as their music sources and do you like them?

[ctuna]

If you are in to high fidelity sound you will be throwing it all away using the AUX Input.
I use the Mr12volt adapter that runs through the Most Bus .
They have two levels now the cheap one and the one designed for idrive
which comes with android audio and carplay.

https://www.e90post.com/forums/showthread.php?t=1499808

https://www.e90post.com/forums/showthread.php?t=1002984

[Peter Morrin]

I have looked at the Mr. 12V systems, as well as the systems posted by Ctuna. I believe the Fisher-Technic DSP/Amp has a supplementary module that will accept a USB input and another module that will accept Bluetooth 5.0. The modules are $150 USD each.

The audiophile community generally poopoo Bluetooth from a sound quality perspective, but it is more convenient. I checked the Mobridge DSP/Amp and could not find a Bluetooth or USB input, but I might have missed it. Other DSP solutions may offer a high quality input.

I come back to the question of what people use as their audio source and how you connect it to your system?

Peter

[Captain Buumer]

OEM HU is fine as long as you keep the input digital.

I use Dension 500S BT (basically same as MR12 Volts but different interface/unit).

It simulates the external CD box.

Signal path is as follows:
Dension 500 accepts USB input (digital)
Dension 500 forwards digital signal to OEM HU via Optical (digital)
OEM HU sends out speaker level signal to DSP (Analog)
DSP (Alpine PDP-E802DSP) sends signal to all speakers that is processed.

The source files are .wav (from iTunes). They are much better than 128kbit .mp3 that lack clarity or any audio you could get from youtube.

I use speaker level signal because i have M-ASK OEM HU that has poor RCA output - it also sends out floor noise. CCC/CIC are obviously better with RCA output since they have upgraded design.

But with M-ASK i can send out flat speaker level output which is fine since speaker level is less sensitive to noise.

I'm very satisfied with the quality, in the driver seat it feels like you have headphones on and after i've got the tuning almost perfect i found so many rubbish quality songs i had in my library (i have fully active system).

The OEM speakers aren't that bad(still weak yes) if you DSP them but one of the underseats popped after i cranked up volume so i got new 3 way set anyway with dedicated corner subwoofer.

[ctuna]

I use the bluetooth in the mr12volt to stream ytube music it's pretty decent although
I when I did comparisons the usb was better and I use 320 bit mp3 .
The decent sound system will clean things up quite a bit so it won't sound
like a one transistor portable radio from the 50's

There are lot of different kinds of bluetooth now that promises HD of some kind.
But it requires that both ends have the hardware and codec to support it.

some sources like Tidal promise Hi Fi high bit rate over the air.

[tankertoad]

My Alpine head unit has USB-in and BT. USB sounds better. I use Apple Music as they have completely converted their content to “lossless” (up to 24bit/192kHz). Tidal may be better but I already was an Apple Music subscriber. To me, it sounds better than Pandora, SiriusXM, and even Spotify. YMMV

[Peter Morrin]

Tankertoad,
To clarify for me (non Apple user) you stream Apple Lossless from your phone to your head unit using a wired USB connection? Do you know which Bluetooth codec your phone and head unit use? I understand they are getting better, but was not sure whether the latest versions were up to hard-wired quality.

Since the connection to the phone is over USB, is the D/A conversion performed by the Alpine head unit?

[ctuna]

Although my Sammsung note 20 has one of the new codec capable of
what they call the HD bluetooth the makers of the Mr 12 volt do not list
what there codec is.
I believe they also have the option of wi fi over there better unit.
I know the quality of the music was slightly better with usb , usb containing
the same 320 bit mp3 files I was streaming from my phone.

I use the high bit rate ytube music setting when streaming from ytube it seems
pretty good . Better than sources I lived with for decades while going through every
format known to man .

The aux problem is discussed a lot on that airplay thread and many other times
on this board.

[tankertoad]

Yes, a USB cable runs from the rear of the Alpine into the cabin. The iPhone uses AAC for Bluetooth and the Alpine uses 2.1.

The lossless protocol is ALAC. I believe the Alpine’s 24 bit DAC is controlling

[Peter Morrin]

I travel a lot in places where I do not have unlimited data, so streaming is not an option for me. I am looking at getting one of these high resolution Digital Audio Players that can store FLAC files and has a decent internal DAC (not active if output via USB). In areas where I can stream, I would simply connect my phone via USB.

I think the best route for me is to find a DSP that accepts a USB input. What I am not yet clear is how the USB input is selected at the DSP.

[ctuna]

Why not avoid all that and just use a USB stick.

Doing multiple digital to analog conversions is a loosing game.

If a manufacturer has a direct digital input you would have to
go to that manufacturer to find out how it works.

[tankertoad]

Aside from a hard drive with your entire music library, the USB stick is the next best thing. I have one with many 12V industry demo discs and audiophile test discs to put my system though its paces.

[Peter Morrin]

If I retain the OEM headunit of the Logic 7 system, how would I connect a USB with Flac files to the system? I don't believe the Mr. 12V base system supports lossless files.

If I buy a new head unit, I could get USB input, but there are few head units that will integrate into the MOST network. The Dynavin looks nice, but the DSP functions are not as good as a stand alone DSP or DSP/Amp. Are there any other ways to use an aftermarket Head unit with the MOST system?

If I buy the Match DSP/Amp with the add-on USB module I would have a digital input directly to the DSP. What I have not yet determined is how the Match DSP/AMP controls the USB input. I am guessing control would have to be done at the source, which would mean a USB stick is not likely going to work, and I will have to be careful with volumne control.

I believe this system would do the D/A conversion once at the new DSP/Amp. Match note that they use Burr Brown chips which have a good reputation, but implementation is important. It would possible to get a higher quality external DAC, but it would be mitigated by the analogue input jack and A/D/D/A conversion.