RNS510 + DSP or Aftermarket Android with DSP?

[nermal]

I have an RNS510 with Dynaudio and would like to add an additional amp (Esotar2 1200 sub).

My original thinking was to run the line-outs through a DSP and then split back to the dyn amp and take a couple more lines for the sub amp. I've even spliced up a custom quadlock adapter to plug the head unit:


... but today, this head unit caught my eye and got me thinking. I'm sure this particular one is cheap Chinese garbage, but the idea of a modern head unit with a builtin DSP (and sub out) would simplify things a lot. Also, a 10.1" screen would help make the car feel newer. COIKA Android 9.0 System Car Radio Head Unit For VW Passat B6 B7 CC 1280*720P 4+64GB RAM 6 Core PX6 CPU IPS GPS Navi Stereo DSP|Car Multimedia Player| - AliExpress



Are there any high-quality options with DSP + sub out, Android and a large 9-10"+ screen that anyone can recommend?

[NinetySix]

Considering what you have now is widely regarded as having quite good sound, I'd be very cautious about taking any backwards steps.

I'm not aware of anything built into any kind of aftermarket head unit that would come close to the likes of a standalone DSP such as a minidsp, helix, mosconi etc etc.

It's getting harder and harder to beat the sound quality of an OEM head unit with something aftermarket, even from traditional brands once known for good car audio gear. Not saying it can't be done, and I can't comment on modernising the rns510 experience, but you should probably wash your mouth out for mentioning AliExpress in the same post as Dynaudio

[nermal]

Considering what you have now is widely regarded as having quite good sound, I'd be very cautious about taking any backwards steps.

I'm not aware of anything built into any kind of aftermarket head unit that would come close to the likes of a standalone DSP such as a minidsp, helix, mosconi etc etc.

It's getting harder and harder to beat the sound quality of an OEM head unit with something aftermarket, even from traditional brands once known for good car audio gear. Not saying it can't be done, and I can't comment on modernising the rns510 experience, but you should probably wash your mouth out for mentioning AliExpress in the same post as Dynaudio

Haha yeah, absolutely - AliExpress = "cheap Chinese garbage" (typically)

AFAIK - most of the Dynaudio magic happens in the amp. It has it's own DSP that is 'hard-coded' to the passat cabin and has built-in sound correction etc to help cleanup the RNS-510 signal.

An RCD 330+ would be a good option, but still a small 6.5" @ 800x480 screen - same as the existing RNS-510. There are a couple of Alpine and Pioneer units that look interesting in the 9" screen size range. Some have separate sub output and control over timings and frequency filters etc. The high-end Alpine options are comparable in price to a Helix DSP - not as good from a DSP perspective, but dunno if I actually need all of that with the current amp already tuned to my car.

I guess I was hoping for some definitive brand or model that was considered good quality - I'm seeing a bunch of new brand names pop up in this category that I have no idea about.. eg. Joying, Eonon etc - and you can't trust the online review sites ¯\_(ツ)_/¯

[NinetySix]

Couldn't help myself and had a little look into what might be going on on in Dyn DSP, and saw this page:

https://www.dynaudio.de/academy/2017/august/how-we-tune-the-hi-fi-in-your-car

It's mainly about the latest Dyn setup in the B8, and it's pretty vague, but it does talk a little about the Dyn B6 setup, and given its based around 2002 technology... That DSP isn't likely doing a whole lot by today's standards. Maybe some time delay, basic crossovers and however much EQ the processing power & budget back then allowed for. But the ace up it's sleeve is that it was tuned by somebody who knew what they were doing, and that's kind of a big deal 😎

I thought the RCD 330+ looked like a cracking good option, but from what I could tell it only takes one radio antenna in, where the 510 on my b7 has a diversity setup with 2 antennas. For me that's a deal breaker as I listen to radio a lot, in fact that's all I use my 510 for, anything serious I stream direct from my phone via a USB digital audio card to the standalone DSP. No idea what the actual audio quality on the 330+ is like, but I'll bet it's better than a joying or similar.

I reckon you had the right idea before you got "distracted" 😁 adding a sub or even subS shouldn't require reinventing the wheel, should be a well trodden path! Housing a sub is the hard part...

[nermal]

I reckon you had the right idea before you got "distracted"  adding a sub or even subS shouldn't require reinventing the wheel, should be a well trodden path! Housing a sub is the hard part...

Yeah, good point. There's been a lot of "distractions" on this project... I embarrassingly started it ~4 years ago and got distracted with a couple of house renovation projects. Just had some time recently to get back into it.

In terms of housing, I've already built a custom enclosure (fiberglass, MDF and carbon fiber/kevlar) and a custom grill - made a silicon mold from an old T2 Kombi badge (perfect size for a 12" sub once you add the ring).

Grill:


Enclosure - false floor that fits over the spare tire/mag wheel. I'm not happy with the carbon fiber finish, so am going to redo it:

Planning to sand back and smooth out the surface and then lay a top layer of this honeycomb patterned carbon fiber + kevlar weave (just arrived):


Also made a custom Esotar 1200 trim ring and added connectors, various sounds deadening and dacron stuffing etc. Got a pressure pack of R36 biscay blue too for highlights:


It's fully unpluggable (120A anderson plugs) and removable to get to the spare tire, but unfortunately weighs a ton!

[NinetySix]

Aye, 'tis the work of a true craftsman right there! Any idea what the internal volume is on the enclosure? A "woofer tester" is handy for fine tuning an enclosure, tho if it's sealed, it's hard to get it wrong!

I went a slightly different route, there's compromises with any setup, but it's nice to have cake and eat most of it 😁

Note the anti-theft spikes, still in the functional prototype stage.

[nermal]

Thanks =) Yeah, it's sealed and IIRC was approx 40-45L (incl raised top), when I originally measured it using foam beans - recommended size for the 12" sub is 30-66L : https://www.dynaudio.com/media/2530/esotar2_1200.pdf


That's a nice setup, and good thinking with the ski pass. Are those 2x 15" subs in open baffle? That'll suck the air right out of your lungs 😁

[NinetySix]

Thanks =) Yeah, it's sealed and IIRC was approx 40-45L (incl raised top), when I originally measured it using foam beans - recommended size for the 12" sub is 30-66L : https://www.dynaudio.com/media/2530/esotar2_1200.pdf


That's a nice setup, and good thinking with the ski pass. Are those 2x 15" subs in open baffle? That'll suck the air right out of your lungs 

That's a cracker of a driver there, and not bad getting 40+ litres in a stealthy enclosure! Clearly you've put a fair amount of effort In to get this far, and easily enough coin to show you're not here for a haircut so I'll reiterate that a setup of this calibre deserves to have the enclosure "tuned" before even thinking about any EQ or DSP.

Basically that means taking an impedance measurement of the driver, the driver in the box, and the driver in the box in the car. A couple years ago I bought a Dayton DATS V2 I think it was, for that purpose and it did the job nicely. I think it's been superseded by a newer model, and the are a few alternatives around, but most will be a couple hundred bucks and might not get much use unless you're a bit of a diy speaker geek!

There's a free option that isn't too much mucking around though, see here:

Impedance Measurement

Modelling a driver's response with a software simulator and even following manufacturer recommendations can only take you so far, especially in a car with so many variables. The shape of the curve determines your system Q (I think, been a while!) and more or less stuffing will adjust that, subtly. Can't recall what makes for an ideal target, but without knowing what's going on in there, best you can hope for is adding "some" stuffing and getting "some" result though probably the most useful aspect of an impedance measurement is that any resonances or defects or insufficient bracing in the enclosure will show up as a squiggle, and when you measure it in the car with doors and boot shut, you're going to see where the car itself is affecting things, and that could be a buzzing boot lid or number plate.

I wouldn't go too deep down the rabbit hole, but it's an easy way to spot something that might not be apparent, might not be hard to fix, and absolutely won't be fixed with EQ.


Yep, 2x Alpine type-S 15s, mounted in what I think the home theatre infinite baffle enthusiasts call a push-pull slot loaded manifold yeah it's got grunt to spare, but it also doesn't have to work real hard for "normal" listening, ie low distortion. They are wired to drive in opposing directions, ie signal + both comes move the centreline of the car, signal - both move away from centre. Reduces 2nd order harmonic distortion, if memory serves.

Bugger, went and wrote an essay 🙊

[nermal]

Thanks for the advice. I hadn't considered any enclosure tuning, but yeah that makes sense. I think I'll engage a professional for that part of the project!

Does your enclosure take up much boot space? Do you have a photo of the back?

[NinetySix]

I was kinda hoping you wouldn't ask that 🤭 but fair enough



As I said, setup is in the prototype stage, and especially shameful for somebody who just happens to be an electrician

The boot itself is the box as such, and is doing a pretty good job of it so far with just a tiny bit of deadener on the boot lid and on the back of the number plate, parcel shelf could use some reinforcement/sealing one day when I get around to it.

The box ("manifold") was taken straight out of my old Astra and straight into the Passat with little modification, and it could easily be trimmed a little to be less intrusive, though I can just get the spare tyre out without unbolting it, heaven forbid. Ski port is open when listening obviously, and in 2.5 years I've had passengers in the back maybe 2 or 3 times if that. The 40 split is still functional but obviously the 60 portion can't open with the box bolted on, otherwise there's not a huge amount of boot space lost, tho in this configuration it's going to be at least as wide as the woofers. A pair of 12s would probably be significantly easier to house with good performance still, but I regret nothing, write it on my tombstone 😁

The real magic in this setup, though, is the little black box mounted just in front of the battery compartment, partially cut off in the pic, minidsp c-dsp 8x12 DL with dirac live, and is easily configured and tuned by an enthusiast with a laptop and a USB mic in about 20 minutes and makes for a sound stage that was never meant to exist in a car 😳 with a panning drum test track you need a micrometre to measure the distance between where each sound comes from. It's not cheap at 900 USD but worth every penny and then some.

But obviously, as magical as it is, you want your enclosures working well before tuning

[NinetySix]

While we're on the subject ...



Not dynaudio, but something exquisite I had laying around with some 3d printed adaptors that have survived thru 2 and a bit summers in a black car. Clearance to the magnet is roughly just enough !


Scanspeak illuminator mid woofers (aluminium cone, not paper version) and tweeters, scanspeak discovery midrange. Got a set of 4.5" scanspeak revelator midranges that are probably a bit big without cutting any metal, and wouldn't work as well as the 3.5" disco's off-axis, but maybe one day....

[nermal]

w0w, that's some tiny clearance on the magnet there - does it rattle? May be worth a little foam on the back of the magnet.

I like the 3D printed baffle adapters, cool idea. Yeah, I guess heat would be the enemy ... I wonder what the melting points etc would be.

Once you've done prototyping the box, a basic carpeted backing plate across the box and covering most of the right-hand side would help protect all your components and hide the whole setup (assuming you move the DSP etc to that side). I'm curious about what the bottles are there for - are they acoustics related?

How does the Mini-DSP hold up? I've heard mixed reviews and was looking at one originally - got persuaded that a Helix is the way to go, but as mentioned earlier, I really just want to split out the sub output from the amp input by frequency and timing...

[nermal]

BTW - I was lucky that although my R36 only had the standard Blaupunkt system, it had the Dynaudio wiring - got the amp + speakers for only $1500 from the wreckers. Here's the retrofit I did when I first bought he car in 2014: R36 Dynaudio Retrofit Guide . I used some DynaXorb pads behind the main drivers, not 100% convinced on the science they claim around geometry etc, but I think the soft rubber material provides good dampening.

Here are some photos of the enclosure construction (original post: B6 R36 Passat - Dynaudio Retrofit)

Internal volume/structure - before the raised lid went on:



Construction of the raised lid:

(tried using fabric for the original contour, but had to cut it away after it wrinkled)

First layer of contoured lid - using core-mat (great rigid bulking layer with good acoustic properties):

Original carbon fiber (before glossing up):

I've just got back into it (been distracted with a couple of renovation projects over the years...) - sanded back the carbon fiber lid over the weekend and about to do a fresh micro-balloon (Q-Cel) fill to smooth out all the waviness.

[NinetySix]

w0w, that's some tiny clearance on the magnet there - does it rattle? May be worth a little foam on the back of the magnet.

Although it looks like it's fouling, it just doesn't make any contact with the window reg clips, and it's shown in the worst case scenario, with the window all the way down, which is rare other than when sticking a parking ticket into a machine 😁 so I figure anything I might stick in there would ensure some kind of contact. I did something for a rain shield, can't remember what now! Might have been a foil tape visor, or part of an ice cream tub.

I like the 3D printed baffle adapters, cool idea. Yeah, I guess heat would be the enemy ... I wonder what the melting points etc would be.

I used PETG filament thru a 1.2mm nozzle, which is quite coarse but it tends to come out quite strong, plus I went over it with a hot air gun with a narrow nozzle and extra filament (basically a plastic welder, with filament for filler rod) to reinforce any joins (printed in 2 pieces, midrange enclosure a separate piece, about 0.4L I think) and just to get them as air tight as possible, and knock on wood it seems to have held up with no signs of failure. Pretty sure about 80 degrees is considered the maximum temperature for PETG printed parts, as that's the glass transition point, and I fully expected they would end up failing but it's just not the case. On a 40+ degree down in sunny Melbourne in direct sun light I measured the surface of the dash at just under 100degC, yet anywhere out of the sun below the dash was a chilly 56deg C, and I wouldn't be surprised if it was a fair bit cooler under the door trims...

Once you've done prototyping the box, a basic carpeted backing plate across the box and covering most of the right-hand side would help protect all your components and hide the whole setup (assuming you move the DSP etc to that side). I'm curious about what the bottles are there for - are they acoustics related?

Lol, that's coolant and distilled water from when I did a radiator flush and fill, just incase there was an air pocket waiting to burp out. Probably not a great idea putting red coolant in a cordial bottle, but no kids so only have to worry about a car thief drinking it. As for getting it to look like a professional install, one day maybe, the 60+ hour working week (16 days straight so far ) makes it tricky to commit to.

How does the Mini-DSP hold up? I've heard mixed reviews and was looking at one originally - got persuaded that a Helix is the way to go, but as mentioned earlier, I really just want to split out the sub output from the amp input by frequency and timing...

I'm gonna have to declare a bit of a bias here, as I'm a bit of a minidsp fan boy 🤭 though I've heard much good things about helix gear. I had a c-dsp 6x8 for about 4 years in the Astra and then the Passat, never had any trouble with it, no noise issues despite the 2vrms output (very conservative compared to many flashy car audio brands if you ask me) and sold it on Facebook for $150 once I got the 8x12 DL. The Mrs car still has a 6x8 in it going strong.

I see the early 8x12 (v1) had some issues with noise that minidsp acknowledged, redesigned the PCB even did something in the way of a recall I think (how's that for integrity!). Either way the current version (V2?) is fairly mature now and the specs on the hardware are really quite respectable in anybody's book. The remote is pretty basic tho, just 4 presets, volume knob/mute and some complex way of adjusting sub volume that i don't use. Any tuning or tinkering is thru a laptop, and I think that's a good thing, what are you gonna whip up a biquad filter on a remote while you're driving? 😆

I only splashed out on the 8x12 when they added the DL on it, Dirac Live, read up on it if you're unfamiliar... Basically the only automatic tuning software that does an awesome job, it does a pretty good job of getting the frequency response to how you want it (tricky part is choosing what you want), absolutely nails the time delay settings and best of all, corrects the impulse response with some fairly clever software and proprietary magic that dirac don't like talking about much.

Many high end DSPs have enough processing power and tuning options to do what dirac live does, but you need to know what you are doing and even for pros (and btw, not all pros know what they are doing!) it's not a 20 minute job by any means. Manual tuning can land you in a real OCD rabbit hole, and not one I was willing to ferret around in again - spent so many nights tinkering with the Astra, took so long to get something that was nice but many things not quite right. When I got the hardware in the Passat I basically just used the DSPs crossovers and a little TA and left it at that, and it wasn't too bad.

So for me, it was dirac or nothing (except the untuned 6x8 ). There are alternatives to dirac, though I believe dirac is one of the more complete (and truely automatic) packages and the only one available in turn-key automotive hardware, and currently only from minidsp (could be wrong by now, and more will surely offer it eventually) for car use.

I'm kinda used to it now, but it had a tune that sounded about 10 times better than I expected it to (and I expected plenty for the money!) And another 10 times better than anything I cobbled together myself, and it took about 20 minutes and all I had to do was give it a target frequency response and move the mic around the car when it told me to - priceless for the time poor. 'Nuff said.

Fwiw, I heard that helix specifically ruled out offering dirac live as an option on their roadmap, could be bs tho. Really should put a TLDR on these posts, and that is: if you're ever in Melbourne, you're welcome to come see what your ears reckon 👍

[nermal]

Interesting... yeah, I was originally looking at a mini dsp - as I only need to split the sub signal out by frequency and timing... That was a while ago, so was probably while they were having the recall issues.

So back to the original dilemma... a new Alpine head unit with 9" screen will do that (with frequency and timings), while the current amp does the basic staging - professionally tuned (?by Dynaudio themselves?) for my cabin. A new big screen with modern functionality is tempting.