P38A Should I put a modern touch screen radio in my car? [. . . . and other questions]

MrGorsky · Thursday at 10:44

pwood999 said:
What's the screen angle like on that Sony in the dash ?

I've not had it all together yet, so I can't say 100%! Last night it was lying all over the passenger seat with wires all over the place. I tried an L pad attenuator circuit in front of the transformer to try and reduce the head output level a bit. The Sony outputs 5volt line outs, and the Clarion 0.125volt so I thought it's blow the doors off. It didn't though, so I don't think you need them. I don't know much about electronics though, so I might be wrong!

When I do final soldering etc I'll omit them, and just have the audio transformers with a 10K resistor accross the secondary windings. The stereo unit in a p38 is resessed about 30mm behind the cubby box thing, and the Sony unit has enough "reach" for 20mm, so I'm going have to work that out.... It tilts to 10 degrees up and down so I think it'll be fine. I'll let you know!

pwood999 · Thursday at 11:14

I did not use any resistors with the trransformers. Mine are 600ohm primary & secondary, so the load on the head unit and feed to the amps is about right. Normal volume uses about 25% on the head unit.

On my other P38, I have a Pioneer DAB stereo. This time, as the Pioneer speaker outs are fully floating (sort of balanced) I tried connecting direct to the door amps (no sub). It seems the high impedance inputs on the amps, causes the stereo output to be lower power, and simply works. Again normal volume requires 25-30% on the stereo, plus no hiss, buzz, etc.

MrGorsky · Thursday at 11:25

This is basically what I've built. Same stuff as you probably! I have no idea what that 10K resister does, but the guy on the internet that I nicked this design off has it.... so I'm going to too!

To quote from his website....

Using a 600:600 ohm transformer is the most common. Unbalanced audio impedance of consumer-grade electronics can vary anywhere from 270 to 470 ohms or more. The 10,000-ohm resistor provides constant loading regardless of what the unbalanced impedance. In this configuration, CMMR (Common-Mode Rejection Ratio) will be 55 dB at 60 Hz, but gradually decreases to about 30 dB for frequencies above 1 KHz.

pwood999 · Thursday at 11:50

The resistor is probably there to limit the impedance at high frequencies. The transformer is only 600ohm nominal, and will rise at higher frequencies, although most audio transformers probably dont need it.

I used the Z1604 transformers from RS components. Response drops off quite a bit above 10-12khz, but at my age I cannot hear the difference.

MrGorsky · Thursday at 11:52

pwood999 said:
I used the Z1604 transformers from RS components.

Great minds think alike!

Grrrrrr · Thursday at 12:21

Montyjohn said:
I really can't decide whether to put a modern Android touch screen radio in my 2000 P38 or not.
On one hand, I would really like a reversing camera, DAB radio, decent modern built in sat-nav and a Bluetooth connection to my phone for calls and music. Anything else it would offer would just be a bonus. Probably not going to be watching Neflix down the motorway.

On the other, I prefer an original looking car, and I really don't like cars that look like they've been butchered, or have things bolted onto them dangling off the dashboard. I like a clean OEM looking interior without the tat.

I normally avoid aftermarket radios, as the line-up from Halfords (or anywhere else) look terrible. They are all flashy epileptic inducing bling that just ruin cars.
The newer android units however blend in a lot better subject to how well they are fitted.

This is what I have in mind, fitting a shallow 9" units as space is limited (my interior is dark grey without the wood effect).
I have a 3D printer, so I would print the bezel and fill/sand and paint to match interior colour, so I think I could get a pretty tidy result.

My current standard radio works (although most of the speakers crackle so that would need sorting).
If I buy a spare black button console trim thing I should be able to make this reversible, but before spending the money I can't decide if it looks naff or not.
I struggle to know about such things until I've finished them, so looking for opinions.

View attachment 312308

No. Apart from anything else the lack of buttons doesn't seem safe to me.

I fitted parking sensors to mine. Easy enough. A phone using Waze is as good as any sat-nav.

pwood999 · Thursday at 15:35

The Android in my Green P38 must be over 5 years old by now, and no longer supports Waze. Google maps still works but definitely slower these days. Mostly I leave the radio on & use Waze on the phone !!

In Blue P38 I use phone & bluetooth to Pioneer stereo. There's also quite a nice Pioneer App for the stereo channel search & audio settings that's much easier than the Pioneer head unit menus.

MrGorsky · Thursday at 15:57

pwood999 said:
The Android in my Green P38 must be over 5 years old by now, and no longer supports Waze. Google maps still works but definitely slower these days.

One of the reasons I want Apple Car-Play I think. It'll always be up to date (so long as you keep buying a new phone), and I never go anywhere without my phone so I assume I'll always have it on me!

We've got Car-Play in the Passat and it works very well. Waze, music, phone calls, and for those terrified of loosing steering wheel buttons, or having to use stereo buttons you've got Siri. I just talk to the Passat and it does what I ask it. Even reads you out text messages if you want it to.

pwood999 · Thursday at 16:12

CarPlay is great if properly implimented, but often varies. It's great if you only use sat-nav & phone music, but problematic in some scenarios. I found two issues in the past.

1) Some manufacturers versions don't switch between radio, nav guidance & calls properly. Several rental cars I had get stuck on carplay after calls, even though I was previously using the radio.

2) Call Audio quality is often worse than bluetooth, mainly due the way the call audio is routed from phone to carplay to stereo & back to audio for the speakers. Also callers complained my microphone was too quiet & had echos. Bluetooth direct to stereo was fine.

Never tried Android Auto, so can't comment on that.

@Montyjohn maybe add the phrase " . . . . and other questions" to the thread title !!

P38A Should I put a modern touch screen radio in my car? [. . . . and other questions]

MrGorsky

Well-Known Member

pwood999

Well-Known Member

MrGorsky

Well-Known Member

pwood999

Well-Known Member

MrGorsky

Well-Known Member

Grrrrrr

Technician, Bodgit & Scarper Ltd

pwood999

Well-Known Member

MrGorsky

Well-Known Member

pwood999

Well-Known Member

Similar threads