Cab HiFi

A very satisfying project. How to improve the music in the cab. With a cheap ldi radio and tinny mismatched speakers things coudl only get better.

The Radio

I used to have cheap radios, like you get from Aldi or Lidl for £20 to £30. With the front cover broken I searched for a new one and was persuaded to up my budget to about £100. Excellent advice. Still a mean old git I bought a refurbished unit from used car stereo on eBay.  

SONY MEX-N7300BD / DAB+ / FLAC / Bluetooth / USB / AUX / microphone for  £89 

Great buy, and a good company to deal with (I bought another one from them for the camper).

Good points:

1. The sound is great
2. 55W per channel. I definitely need more than 30W in the noisey truck.
3. DAB radio that's a nice to have.
4. Microphone for hands free phone calls - I had not appreciated how good that would be.
5. Can load the CD without moving the fascia (that removes one frequent failure mode)
6. Takes input from high quality bluetooth codecs and Android mode.
7. USB charging built in

The Aerials

Well, it had a DAB receiver so I put the usual windscreen stick on aerial. Reception was variable from perfectly good to useless all on a local journey of 30 miles. To be honest, that's what I expected.

For the FM tuner I bought a new wing mounted aerial. The best I could find and went to the trouble of fixing a really good earth to the wing and the radio. Very disappointing.The only advice I get from my friends is that a bent coat hanger is quite good. 

And the best aerial of all: My phone I get quite a good 4G signal and that allows me to get all the radio stations. I just need the data allowance, which is not a problem at the moment.

To be fair, the overhead luton bed area overhangs the cab and its all metal skinned, so you might expect it to shield radio signals. Unfortunately there is no practical cable route for a camper roof mounted aerial.

The Speakers

The bast part of the project. I wanted to replace my two small tinny, mismatched door speakers with something bette. I had a plan. To get a pair from any decent car at a scrap yard. I figured that people buy the doors and engines etc, but the speakers did ot really sell and were therefore valueless to the scrap yard. I was almost right.   

The scrap yard took my £20,pointed to an old Audi and said I could take all the speakers. Wow!! the door speakers were enormous 6..5" , and four of them. Those were the woofers, there were also 4 midrange and 4 little tweeters. And they were Bose ones.

I had to cut away the door trim to fit them. At firs tit looked impossibel, but worked out quite well.Just need grilles on the front.

Surprisingy, no crossover network, just capacitors on the smaller speakers. Teh Audi had an mplifier, but I left that in the car. My Sony radio seems quite  capable of driving teh new speakers, even though I suspect the woofers are 2 Ohms impedance rather than 4. I had the problem of working out the polarities without tracing the wires back to the radio. It makes a substantial, rather strange difference, having the polarity wrong (The expression out of phase is often used, but that is technically wrong and only equivalent for a pure sine wave). I found a polarity checker app on my phone. That worked well once I had worked out where the phone's microphne was!

Insulation

Not done yet, but definitely needed behind the speakers. 

Music source

It is surprisingly complicated getting the best quality sound to the radio.

I now have a spotify account, I do highest quality downloads and preferably connect with a USB cable on Android mode. I can't hear the difference with Bluetooth as a wireless alternative. My old phone remains a backup phone as an insurance policy, but it is now primarily my music server.