In-Car DAB gets a new home

Bit of a break in posts, but my attempts at a coherent post on ILR haven’t worked so far… probably thanks to needing a few more decent sources to help make the points I want.

So I’m going back to one of my favourite topics and a quick break from my State of the Nation series…

One of the main issues regarding the planned DAB migration is the problem of in-car DAB. I previously blogged in January about upgrading the tape deck in my car to a DAB radio. And I’ve been very happy with it.

At least until my car broke.

After a failed journey to London (it made it to Maidenhead), the gearbox breaking 5th gear and a hydraulic leak, the car is, for want of a better phrase, beyond economic repair.

I’ve since replaced it and have had my new car for a month (bye-bye Australian travel fund savings) and it is, in pretty much every way, a better car.

This post is solely about my experiences with moving my awesome DAB car radio to my new car. Since the number of people that have fitted proper DAB radios to their car is pretty small, I’d guess that I’m probably one of the first to have moved one to another vehicle. So it makes sense to be the first to blog about it, to share my experiences of it and why it’s going to make DAB migration a little bit more difficult…

As I’ve already said, my new Mazda 3 is, in pretty much every way, a better car than my old Mazda 323. Though I’m mourning the loss of the much loved sun-roof. There’s also the small problem that DAB radios weren’t fitted as standard on 2005 model Mazda 3’s.

In case that wasn’t enough of a problem, I was faced with this:
Mazda 3 factory installed radio

Helpfully, it doesn’t have a standard DIN slot (officially, ISO 7736) to do a simple straight swap – a standard that’s existed since the early 1980s.

£180 later, and it looks like this:

To break down the costs:

  1. £40 to remove the radio from my old car.
  2. £35 to buy the faceplate with the all important ISO7336 slot (and a handy 2nd slot for storage).
  3. £15 for the electrical harness adapter – perhaps not a necessity but it certainly saves time installing the radio.
  4. £50 for a replacement DAB aerial (they start at £35 but as I’ve had good results from the identical previous aerial that came with the package I bought I’ve no complaints – other than DAB aerials are apparently only good for a single installation)
  5. £40 for the fitting to the new car

So not cheap. Especially after the £410 I originally paid to have it fitted to my old car.

(as a reminder, the original cost was £350 for the radio/DAB tuner and aerial package, £15 for the harness and £45 installation).

Obviously, that price is way beyond what most people would consider reasonable. For me, I can fully justify it as the radio in question is a highly functional Swiss Army Knife of Car Radio’s (LW/MW/FM/DAB with mp3/wma CD playback, Bluetooth and a spare USB port. Not to mention iPod compatibility (even if I’ve no intention of using it).

And – unlike in my old car – the hands-free part actually works for phone calls. Clearly the garage I used to install it are prone to mistakes (especially as this time round they’ve not connected the light cables for the heater controls or for the day/night colour modes for the radio).

More importantly though, I’ve found that even in South Wales it can be extremely difficult (particularly in eastern Newport where all the Cardiff & Bristol FM services collide) to find a clear FM frequency for FM transmission. My old phone had a built in FM transmitter which did a decent job but would always suffer from some kind of static. As for London…

So I thought it best to buy a full on head unit with a separate DAB tuner. This is what it looks like in bits:

The DAB tuner shouldn’t be too difficult to spot and isn’t much smaller to the full head unit. As with the average PC the microphone is connected to the pink socket, with the old harness still plugged in behind the main unit. The extra cable is the rear USB socket which has the Bluetooth adapter connected (the old aerial is on top of the head unit).

My concern with buying something like the much cheaper Pure Highway is that it doesn’t directly play the DAB signal – it pumps it out on an FM frequency. Since my attempts to play music over FM rarely work without some interference, it was worth the extra to have one combined unit that bypassed FM whilst also offering plenty of extra features.

What’s it like? I’ve already blogged that answer. But I’ve actually found my thoughts on DAB have shifted somewhat… and it’s all in the speakers.

My old car did a pretty good job of bass heavy music – but beyond a volume of 20 I had to drop the bass EQ settings to prevent speaker distortion – and even then going much louder would bring it back. I’m all but certain the new speakers are much better, especially as I can play dubstep tracks at 35+, on the hip-hop EQ setting, without any distortion (so far the only track that causes problems is the Caspa remix of I Remember by Deadmau5, and then only at 40+. Which is insanely loud – to the point that you can feel the bass resonating even at 50mph).

How does that affect DAB. Not in a good way… it sounds better than it did in my old car, of that there’s no contest as it’s generally brighter than before – but I am finding a slight dullness on both BBC R1 and Kiss 101 in the midrange compared to the FM frequencies – which is a big surprise as they both sounded better on DAB in my old car. Clearly, the quality of speakers makes a big difference – that and the electrical connections are all that have changed.

It could be worse though. Kerrang! on DAB in Birmingham is definitely far worse than on 105.2FM with some pretty nasty compressive sounds. But that’s down to the poor bitrate (64kbps mono rather than 128kbps joint stereo) which, in all honesty, didn’t sound much better than MW (complete loss of cymbals on the high-range being the most obvious on Suede’s Animal Nitrate).

To be clear though, in case anyone misunderstands me – the dullness I’ve heard is extremely subtle – you need to be specifically listening out for it to hear it. Worst case scenario, I’m finding in-car DAB  to now be equal or slightly worse than FM, compared to equal to or slightly better than before. The difference is clearly down to the improved quality of the speakers used in the car.

I’ll add that I’m not drawing too heavily on numbers, stats or general perception (except for Kerrang, but then it was obviously worse than the other stations on the same mux – MXR West Midlands if you wanted to know). I’ve based the above purely on my experiences with the unit and what I’ve heard – nothing more or less. Especially as it’s a significant U-turn on my previous thoughts on the sound quality of DAB (i.e. it sounds better than FM so I can’t understand why anyone would complain about it unless they’ve got an agenda of some kind. I can now genuinely understand the view-point. Even if I don’t agree with it – see this excellent post by James Cridland – I share the opinions he’s expressed).

Note that the above is about audio quality, not signal strength or breakup/bubbling of the sound due to poor signal. The new aerial is mounted vertically down the side of the windscreen (the old aerial was horizontally along the top on my old car ). Apart from the aerial being visibly more noticeable, the actual strength of the DAB signal hasn’t changed and is still faultless on BBC/D1 with some dropouts on the local CE Birmingham mux in the usual places in Birmingham (my old uni stomping ground of Bristol Road in Selly Oak being one example where it struggles for signal).

I’ve also found one minor advantage of DAB aerials – they can’t be damaged by a car wash…

I’ve got plenty more to say on DAB – I’ll leave the more general opinions for a dedicated post as part of my State of the Nation series (it’s definitely coming!). But the specifics of this post:

  1. My Mazda 3 dispenses with the ISO7736 standard and does something completely different for it’s in car radio – something that seems to be pretty common on most cars from the last 5 years or so. My old Mazda 323 (and the older 323 I had before it) both had them as standard (even my first ever car, an F reg Fiat Uno had one). Whilst £35 isn’t that much, it’s still an extra expense that should really not be necessary. Some Government intervention would be welcomed from me!
  2. DAB aerials are apparently single use – the one I bought with the package I bought in January is now in the bin. Whether it’s an issue specific to the type I’m using or a general problem of all DAB car aerials is another matter… hopefully I’ll find an answer
  3. It doesn’t matter how DAB aerials are orientated – vertically down the side, or horizontally along the top of the windscreen – the signal strength seems to be the same om both old and new cars
  4. DAB aerials have one big advantage over their FM counterparts – they can’t be damaged by a car wash.

Until I get my head around some ILR numbers…

One thought on “In-Car DAB gets a new home”

  1. In my experience, an external DAB antenna is extremely sensitive to orientation. DAB is transmitted in vertical polarisation only, so you really want to have a vertical antenna (and, of course, a sticky-on antenna on your windscreen can’t be vertical since the screen’s at an angle anyway).

    The requirement for an extra antenna is a nuisance; but the recent announcements from car manufacturers that DAB will be installed as standard soon should certainly assist here.

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