Stereo Updates....maybe?

[dionphaneuf]

I've solved a bunch of recent quality issues on my w124 and am enjoying driving the car these days, especially on a fairly nice commute to work. I've got some suspension and other work to do in the near future (rear subframe bushings, front LCAs and strut mount rubber) but nothing urgent, and want to finally do right by the audio system in the car. In addition to the 500E I've been restoring an 86 560SEC. Its previous owner was an opera buff who had an upgraded Sony XR7400 head unit installed, along with two 10" subs in the rear deck under the medicine boxes and two tweeters added to the front of the door pockets. These are in addition to the 2x 4x6's in the dash and the two 6"s in the rear deck. It's not the most complicated system, but it sounds quite good playing CDs off its 10 disc trunk mounted Sony changer.

Comparatively the Becker 1432 system in my 92 system sounds worse in almost every way. I've made some half baked attempts to improve it with mild improvements;

• Add bluetooth to head unit and have becker refurb
• Upgrade dash speakers to Musway 120's
• Upgrade door speakers to Focal 165AS3
• Tried having my tuner refurbed or swapping in replacements

It sounds good playing some types of music (rock, classical, some jazz), but throw any bass at it and the doors rattle like crazy. I've also had a perpetual issue with intermittent crackling in the left channel that I suspect is related to the fader. All in all, I'm pretty tired of fiddling with the stock system and am ready to move on - even if I fixed the tuner, re capped the amps, fixed the fader, and really fixed the doors, the system could still not be what I'm looking for. To be honest, I've been pretty disappointed in this aspect of the 500E as there's just something about a great audio system that pushes my enjoyment of a car to the next level (as I'm finding on my 126), whereas rattles, poor sound quality, and the inabilty to play the music I like just leaves me feeling frustrated and doesn't 'spark joy' so to speak.

The main apprach I'm leaning towards is ditching the 1432 system for something different. I'm an audio neophyte so please bear with me as I stumble thorugh this and invariably make some foolish suggestions.

• My initial plan is to sacrifice the OE look of the 1432 and its 6 disc changer (which recently jammed btw) and find a decent head unit, perhaps with DSP, RCA outputs for F, R, and a sub. I'm not too picky but Bluetooth and quality are a must. Open to any suggestions here.
• Install a class D 4+1 channel amp in the trunk like this JL Audio HD900/5; many of these are close enough in size to fit in the space used by the tuner.
• I'm willing to bite the bullet and take a small hit on trunk space to add a sealed box sub, something like this that can easily make do with a ~1 cu ft box that should fit in the cubby behind the right rear wheel, above the battery. I looked at the Basser rear deck system but that box is pretty expensive and small, and I'm fine with this
• For wiring, I'd run one channel to each corner speaker and possibly leave the front doors disconnected. My 126 is an 86 car that lacks the door speakers (and 1432 style setup) of the 88+ cars, but like on the 124 these door speakers more or less fire into the side of the seat, and I don't think add a ton of value. That said, with bass duties passed to a sub these may be more useful and not prone to rattling.
  • Perhaps I could power these off one channel and drive the rear speakers off the head unit, assuming I find a HU capable of this?

Anyway, looking forward to documenting my findings here and taking any advice along the way.

 

[gsxr]

I think @Jlaa's epic thread may help you out (see links below). Depending on the level of bass you want, you might have to ditch the stock door panels and get Jehnert doorboards. The doors provide midbass, not sub/bass. A dedicated subwoofer will be a big help. Otherwise you are on the right track with the modern HU, DSP, etc. The door midbass will need dedicated amp channels so you may need a 6-8 channel amp, or multiple amps. I assume you will go crazy with Dynamat or other damping materials, if you haven't already, as this will also help. Eliminating rattles is tedious and time consuming.

OWNER - jlaa (500E & w210 E320) | Owners and Their Cars

I had new cream-beige GAHH leather upholstery installed on the front seats. The first two pictures are "Before." The third picture is a GAHH picture after installation on the seat frame/cushion but BEFORE heating/steaming. The fourth and fifth pictures are the GAHH covers after...

www.500eboard.co

Installed: Blaupunkt Bremen SQR46 DAB + Jehnert doorboards & speakers | In-Car Entertainment (ICE)

Hi, Thought I'd share my experience with in-car entertainment on my 500e. I wanted something that sounds good but looks as original / 90's as possible, and one that has Bluetooth audio and phone calls, and something that's fairly simple. Ended up with Jehnert full system (4-way speakers and...

www.500eboard.co

 

[duuder]

The door speakers, while not large - add depth to the cabin. Wow, 2 10's would really hit!

 

[dionphaneuf]

Awesome, thanks. Yeah the 8 channel amps are a big step up in $$$ (>$1500, even used) vs the 4+1 (JL I linked can be had for $500) or even a 6+Mono. Even ignoring channel count, one item that came up in a discussion w @maw1124 was the power of the JL amp at 4x100W - the Musway's are rated at 75W RMS/150 Max at 4 ohm, the door speakers at 80/160, also 4 Ohms, so I may overpower them. The Alpine PDX-5 is a 4x75 plus 1x300W amp that may be a touch gentler but also gets good reviews.

From some googling and reading today these two HUs both rate well and seem to have DSPs, still looking for other options. The Sony has better built in amplification capabilities which may make it better suited to drive the rear deck and leave the amp channels to drive the dash and doors independently (not sure if this is possible).

Pioneer DEH-X8800BHS

CD receiver

www.crutchfield.com

Sony DSX-GS80

 

[gsxr]

Awesome, thanks. Yeah the 8 channel amps are a big step up in $$$ (>$1500, even used) vs the 4+1 (JL I linked can be had for $500) or even a 6+Mono. Even ignoring channel count, one item that came up in a discussion w @maw1124 was the power of the JL amp at 4x100W - the Musways are rated at 75W RMS/150 Max at 4 ohm, the door speakers at 80/160, also 4 Ohms, so I may overpower them. The Alpine PDX-5 is a 4x75 plus 1x300W amp that may be a touch gentler but also gets good reviews.

Don't worry about overpowering. You can adjust the levels as needed. Oversimplifying, you are more likely to damage drivers with an amp that is too small (pushing distorted signals) than an amp that is too "large". Unfortunately, you really need at least 6 channels... 2 dash, 2 door, 2 rear. The sub can either have its own amp, or use a powered sub box, if you go that route.

From some googling and reading today these two HUs both rate well and seem to have DSPs, still looking for other options. The Sony has better built in amplification capabilities which may make it better suited to drive the rear deck and leave the amp channels to drive the dash and doors independently (not sure if this is possible).

I can't help with HU's as I'm still using ancient analog Nakamichi CD-700 (or Becker TrafficPros, in the budget systems). However, I would never, ever use HU power for anything in a "good" system with external amps. HU power is severely limited, no matter what the spec sheet claims. You'd be far better off using a small, budget external amp for the extra channels, i.e. for the rear fill. Only need to run a pair of RCA's to the trunk / rear deck area for the second/small amp.

 

[dionphaneuf]

Awesome, thanks - good to know to not worry as much about power ratings, and yeah, 6 channels seems the way to go here and is probably far less work than the deck powered rear channel solution as everything for the amps and speakers is right there in the trunk - the wiring work actually doesn't sound too scary.

This seems like a good option, $400 open box special for a nominally $800 6 channel amp that would do well.
This is a decent mono amp that is available on marketplace near me that I might be able to get for $175 and does 200W at 4 ohm, right in the sweet spot of the sub I'm looking at that can do 75-300W.

I'll keep digging on the HUs - reading more Crutchfield doesn't seem to offer all the higher $$$ DSP capable single DIN options that get good reviews on DIYMA and elsewhere so I'll keep looking. To ask a silly question, most HUs I have seen have sub and then 4 normal channel outputs. Does this mean the 6 channel amp is taking these 4 channels and 'building' a >4 channel distribution of them?

 

[gsxr]

To ask a silly question, most HUs I have seen have sub and then 4 normal channel outputs. Does this mean the 6 channel amp is taking these 4 channels and building a >4 channel distribution of them?

The amp can usually take one pair of inputs and use those to feed 2, 4, or 6 amp channels. So you don't need 6 channels in, to use all 6 on the amp. For example you could use 1 pair (L+R) inputs and then use the amps internal crossovers to feed 6 channels out (tweeters, midrange, and midbass) if you wanted. Depends how much you are using active (DSP/amp) crossovers, vs passive (external/speaker-level).

I'd start by selecting speakers first, then figuring out the best amps/crossovers. With Jehnert doorboards and two 6.5" midbass in each at 4 ohms, in parallel this is would be a 2-ohm load. That's fine for unbridged amp channels but most amps today can't bridge channels into a 2 ohm load. Doesn't sound like you are doing this, but something to keep in mind if trying to get more power to the doors.

 

[dionphaneuf]

Yep - I'm pretty happy with the speakers I have, I may swap out my door speakers for slightly different ones but it took a while to find ones that were slim enough to fit around the window regulators and could be trimmed to fit without too much issue. With a 6 channel, I'll likely bypass the factory passive crossover in the door as part of updating that wiring. I'm going to re evaluate my budgetting to see what the delta form my suggested approach to the full @Jlaa setup w door boards but it's probably the difference about $900 for what I'm planning on vs $2500 for the more serious one - pretty wide gap.

Is each rear deck group 4 ohms? Was trying to find that and didn't see it in this post here.

 

[gsxr]

Yep - Im pretty happy with the speakers I have, I may swap out my door speakers for slightly different ones but it took a while to find ones that were slim enough to fit around the window regulators and could be trimmed to fit without too much issue. With a 6 channel, Ill likely bypass the factory passive crossover in the door as part of updating that wiring. Im going to re evaluate my budgetting to see what the delta form my suggested approach to the full @Jlaa setup w door boards but its probably the difference about $900 for what Im planning on vs $2500 for the more serious one - pretty wide gap.

This partly depends on your desired bass level. The Jehnerts, with two really good 6.5" drivers, can put out a good amount of midbass. For non bass junkies, at non-reference levels, this may be adequate without a subwoofer. Adding a sub in the trunk to fill the bottom octave will help if you need more. A single slim door woofer will be of limited use, but may bridge the gap between dash & trunk sub.

Is each rear deck group 4 ohms? Was trying to find that and didnt see it in this post here.

I believe so. I would leave the stock rear deck speakers alone and just fiddle with DSP as needed to set them up for rear fill.

 

[JeffSpicoli]

The reason the HU has a sub channel RCA and the 4 other channels is because it has some level of DSP built in and it allows you to customize each output. All the outputs (maybe not the sub) will output full range. You have to separate the channels to control them independently. That generally means separate amps for lows and highs whether you go 4 or 6 channel (plus sub). As mentioned earlier, most amps have only one input and then do their own crossing. So as an example, you could run one mono amp with the sub out on the deck. Then another four channel amp to run the mid and high using the amp crossover for the tweets and then a third amp for the midbass. This lets you do your processing at the deck level and use the amp to "protect" the mid and tweeters.

Another option is to buy a 6 channel amp like this for example and just use one full range output from the deck, make all your adjustments at the amp. This offers much more detailed customization which might be great in the 124 because of how nice acoustically the cabin is. This particular amp can output to a mono sub amp and you'll have full control of it as well. You can find cheaper alternatives that in all reality will sound fantastic in most scenarios, and conversely, you can step up until you run out of money!

I don't know much about modern decks either because I'm either in a super modern can-bus system or completely old school at the moment

 

[maw1124]

Yeah, I’m just “old school” enough to want to control the sound at Source, and use the amplifiers simply to amplify that Source SQ. I see a lot of people using DSP amps to keep factory head units then struggling to “clean up” that [invariably inferior] sound via the amp. I’m somewhat sure that works just as well, maybe, but unless you’re keeping the factory head unit for provenance purposes (like a .036), I can’t convince myself that juice is worth the squeeze. I feel like even collectors forgive radios, exhausts and wheels as long as they’re tastefully done. And if they don’t I certainly do.

The one idea @dionphaneuf has unearthed here is using a 6-channel instead of a 4-channel to drive the cabin. The more I think about that idea the more I like it, provided the 6 channel can mesh with my current wiring, which is up front where the old school radar detectors used to go, instead of out back. If you’re doing it from scratch, you may as well put all the amps in the trunk (I like short wiring runs to the front sound stage but new time delay tech lessens that concern). Here, time is on your side, because just like with speakers, materials science is miniaturizing amplifiers as time passes.

maw

 

[Jlaa]

Yeah, I’m just “old school” enough to want to control the sound at Source, and use the amplifiers simply to amplify that Source SQ. I see a lot of people using DSP amps to keep factory head units then struggling to “clean up” that [invariably inferior] sound via the amp. I’m somewhat sure that works just as well, maybe, but unless you’re keeping the factory head unit for provenance purposes (like a .036), I can’t convince myself that juice is worth the squeeze. I feel like even collectors forgive radios, exhausts and wheels as long as they’re tastefully done. And if they don’t I certainly do.

The one idea @dionphaneuf has unearthed here is using a 6-channel instead of a 4-channel to drive the cabin. The more I think about that idea the more I like it, provided the 6 channel can mesh with my current wiring, which is up front where the old school radar detectors used to go, instead of out back. If you’re doing it from scratch, you may as well put all the amps in the trunk (I like short wiring runs to the front sound stage but new time delay tech lessens that concern). Here, time is on your side, because just like with speakers, materials science is miniaturizing amplifiers as time passes.

maw

I don't know anything about modern DSPs in modern headhunts - specifically how flexible they are or what the UI is.

I have experience with discrete modern DSPs (Audison BitTen & JL Audio TwK) and DSP integral with amplifiers (JL Audio VX Series) over the past 8 years or so, and please let me relate my thoughts:

If we flip the question around to a solutions angle, the question is, "What do I want to do?" The answer is:

• You want to route the output channels of your head unit to various amplifier channels
• You want to cross over drivers - whether with 6/12/18/24/48 db slopes ---- against audio channels
• You want to combine (add) or difference (subtract) L/R audio channels
  • Corollary you might want to phase shift channels when doing so
• You want to equalize audio output, both level and width of center-slope
• You want to move the sound stage left or right, which is not purely dependent on delay:
  • You want to increase the volume level of certain drivers (amplifier channels) relative to other amplifier channels, especially at the higher frequency spectrum, to move the sound stage.
  • You want to delay the audio signal to various drivers (amp channels) at other frequencies, to move the sound stage
• You want to eliminate null spots in the cabin architecture that mess up mid-bass response by introducing delay at certain lower frequencies

This is basically Software Defined Audio. You can see the results of the GUI/dashboard for the VX setup below ---- it's all done via your computer. I am using 8 channels to drive the cabin with no subwoofer. You can see that I'm taking in 4 channels from the BE1432 after the fader (2 front, 2 rear) .... and then through the input mixer, I am feeding:

• L/R to the front dash tweeters
• L/R to the front dash midranges
• L/R to the door midbasses
• L-R (subtract the center information by subtracting the common info that exists in both L and R channels) and feeding that to the rear speakers. The fader then acts as an infinitely configurable (expansive sound) rheostat. (see that I delayed this by almost 20ms to the rears)

The screenshots below are all from the last time I touched the settings which was in 2020 --- I know JL Audio has updated the software now to the next version which has more knobs and things to fiddle with --- I haven't downloaded that in order to "not touch what ain't broken"

You can also see how soooooo much configurability allows you to endlessly tweak. From my file list below, you can see that I started tweaking in August 2019 and didn't stop until May 2020 when I said "good enough". Anyways my point of all this is to say --- having software-defined-audio integral to the amplifier is incredible. I think it would be difficult to build in so much configurability into a head unit, although I might be wrong since I've never had a DSP headhunt. Ultimately if you are fiddling with active crossovers and DSPs, I think the best approach is not so much to do a deep dive into the hardware but to do a deep dive into the capabilities of the DSP implementation - ie the software / settings that you can tweak. If the software / settings meet your needs, then go forth with the hardware.

 

[nocfn]

just open the windows and sing, sing a song... Sing Out Loud, SING OUT STRONG>>>> {insert Elmo GIF here}

 

[maw1124]

Something else to consider, if you must have a '90's appearance... just hit my inbox... some AI must be reading my phone.

RetroSound Grand Prix M4HD

Digital media receiver styled to match vintage BMW, Mercedes Benz, and Porsche vehicles — does not play discs

www.crutchfield.com

This with a DSP amp is also a good choice IMO.

New options pop up all of the time which didn't exist when I did my stereo or even when @Jlaa did his, such is how fast this industry is changing. The longer you wait the easier it will become to accomplish what you want to do.

maw

EDIT... of course, for that money you have have time delay, surround sound, 88-band equalizers and all the crossovers you want built in from Alpine...

 

[nocfn]

Who is this masked moderator....

 

[tanger]

Has anyone tried the RetroSound? Am thinking of getting the one above (mostly for the HD radio) or this one

RetroSound Grand Prix M2B

Digital media receiver styled to match vintage BMW, Mercedes-Benz, and Porsche vehicles — does not play CDs

www.crutchfield.com

Crutchfield says it fits, but the RetroSound website and customer support doesn't have our E500 listed.

 

[gsxr]

Has anyone tried the RetroSound? Am thinking of getting the one above (mostly for the HD radio) or this one

RetroSound Grand Prix M2B

Digital media receiver styled to match vintage BMW, Mercedes-Benz, and Porsche vehicles — does not play CDs

www.crutchfield.com

Crutchfield says it fits, but the RetroSound website and customer support doesn't have our E500 listed.

It won't be plug+play, but could be wired up in place of a 1492:

 

[JwashE]

Did anyone try this out?

 

[JwashE]

Bumping this one....

 

[Jlaa]

You can see that I'm taking in 4 channels from the BE1432 after the fader (2 front, 2 rear) .... and then through the input mixer, I am feeding:

• L/R to the front dash tweeters
• L/R to the front dash midranges
• L/R to the door midbasses
• L-R (subtract the center information by subtracting the common info that exists in both L and R channels) and feeding that to the rear speakers. The fader then acts as an infinitely configurable (expansive sound) rheostat. (see that I delayed this by almost 20ms to the rears)

@dionphaneuf, this is what Left Subtract Right sounds like (blue) versus L and R regular (yellow).
Feeding L-R to the rear speakers, bandpassing, and delaying 20ms adds a very nice effect and ensures that there is no weird sensation of vocals coming from behind you.

 

[maw1124]

That actually sounds great (Yellow) @Jlaa !! Kind of shocking actually.

You can really hear the Jehnerts carrying the midrange and vocals.

Well done!

Cheers,

maw

EDIT... apparently that's just one hell of an amp... (see below)

 

[Jlaa]

That actually sounds great (Yellow) @Jlaa !! Kind of shocking actually.

You can really hear the Jehnerts carrying the midrange and vocals.

Well done!

Cheers,

maw

I'm sorry to say --- both yellow and blue were the rear speakers only .... Blue was L-R bandpassed, and Yellow was full range L & R ..... and the rear speakers are stock!!!