407 RD4->RD45

[robertel99]

I still have poor bluetooth sound... phone is an iphone 11 pro. tried tuner settings etc but there is a popping sound in the dash tweeters that i cannot get rid of unless i use the fader on -2.
I ordered a usb cable from aliexpress, but can I use that to stream from phone? or only usb stick? cannot seem to find anything online, and I can't find a manual or something from a peugeot/citroen that came with a rd45...

It's weird because radio is crystal clear and has bass and everything but bluetooth is dissapointing...

EDIT: Forgot to mention I have also tried 2 other phones and the sound is the same, it's listenable at max 20 volume with the right bass/treble settings but nowhere near radio quality.

[xantia_v6]

My guess is that you have a faulty RD45.

[robertel99]

My guess is that you have a faulty RD45.

Could be, I will wait for usb cable to arrive and try out ipod mode and then if that is also crap then either 1 din aftermarket stereo or just live with it lol.

[robertel99]

just found out, if I turn mono audio off from iphone settings, the sound quality is absolutely crap, it sounds like a phone call, mind you, the streaming source is spotify premium on highest quality, so thats not the issue. does anyone know what bluetooth protocol the rd45 uses, or why it only sounds acceptable on mono mode? any way I can see any parameters of the headunit, or is there any fix?

[GiveMeABreak]

Hi, these characteristics are not specified, but bear in mind the RD45 is ancient now by today's standards and as the RD45 is generally not firmware updatable by the consumer, you are stuck with the original Bluetooth protocols, so these won't have been updated to keep pace with later smartphones.

Although most smartphones should work to some degree, the 407 system was only shown back in the day as compatible with iPhone 3G!

[xantia_v6]

I don't have any sound quality problems with modern Android phones connected to the RD45.

This is the only spec sheet that I have found: https://citroens-club.ru/applications/c ... p?id=85366

[GiveMeABreak]

I do have some info that I've just dug up, but not sure it will help any.

Bluetooth SW Architecture
Bluetooth SW architecture includes the following Bluetooth SW component
CSR unified stack 2.1 EDR:
QDID B013295 unified Stack 2.1 EDR

iAnywhere BT stack:
QDID B014592 BlueSDK 3.x and profiles (AV SDK, MT OBEX, BNEP, HFP, HID,PBAP, SAP)
QDID B015048 BlueSDK profiles (AVRCP, A2DP, BIP, BPP, HCRP, HSP, SAP, BNEP)

[robertel99]

well. back with a new problem. bluetooth streaming is BAD. it makes music distorted, however, when I turn on mono audio, its better but still not usb like. I have an iphone with apple music so the usb port turns on ipod mode so i can stream from my iphone no problem, but id like bluetooth. what could be the issue? anyone ever faced this ? why would it sound distorted on stereo but fairly decent on mono?
EDIT: also, tried it with many phones, same outcome. its been like this since I put it in the car, but I just now broke my usb cable and am forced to listen to bluetooth.

[shtu]

I suspect that head unit is faulty.
Have you tried an Android phone, or an Old Nokia Brick?

[robertel99]

I suspect that head unit is faulty.
Have you tried an Android phone, or an Old Nokia Brick?

Don't have an old phone, but I tried an android phone, an s10, and the sound is the same. Very distorted mids and highs, ok bass, and when on mono audio its significantly better, not distorted, but still poor quality.
I am looking to buy a newer software one, 4.x, as mine is 3.0. I hope that will fix it. Can't find anything online on it.

[robertel99]

Ok so I got my hands on another RD45, a bit higher sw version, it was a 3.2, but issue persisted. distorted sound without mono on. so my unit is not faulty. i guess i should either try a very new one, from a c-elysee, or just forget about it and use it on usb, since audio quality is as good as can be. only downside is usb will only work with iphones.