Car Radios


#161

No, it’s not exactly MER, I’ll try to make it easier to understand, hopefully I can explain it the right way un-technicallised, (yes I think I just made up that word). It gets very technical, both SNR & MER are different to C/N ratio, but are linked to it.

SNR relates to the signal quality, yes, but so does MER.

Both SNR & MER are mathematical algorithms that take a number of things into account.

SNR is the ratio between the rms value of the payload data and the reduced effective error.

MER is the ratio between the rms value of the payload data and the effective error without reduction.

The MER will always be a lower dB (worse) value than SNR.

For that Green SNR indicator to be at full value, I’d expect an SNR of 30 - 35dB, which would represent a reliable solid signal.

Having a strong signal strength (full green bar like you have), doesn’t necessarily mean you’ll have good reliable reception.

If the SNR was at full green bar, the signal strength could be at 2/3 full-strength & you could still have a strong reliable listenable signal.

One of the most important digital signal measurements, (which are generally not indicated on consumer items (digital radios or TV’s), is BER Post Viterbi or the number of bit errors after the error correction has been done.
This tells you the number of bit errors still left in the data after error correction & is what will be used to decode the signal.

If you’ve still got too many bit errors Post Viterbi (after error correction), you’ll have no reception, or if it’s borderline, you’ll get breakups & dropouts.

Sorry now I’m getting technical & pushing past most peoples understanding.


#162

Just got to enjoy DAB+ in my new ford territory and while it’s great to have added variety in suburbia, going to be doing lots of rd trips with new caravan
What’s the likelihood of DAB+ being available in rural/remote Victoria/NSW in the short term??


#163

None whatsoever :confused: unless you include ACT as part of that area.


#164

You’ll need one of these


#165

Just an update on my Mazda. The Mazda 3 is a great car overall, it was a good buy pricewise . I think I got it cheaper than the focus or the Honda with the dab radio.

The dab radio itself unfortunately has been a little disappointing with random drop outs in good reception areas, no dab text and hard to scan stations after a factory reset. Was disappointed with Mazda with the 1k service they did see the scanning issue but did not seem interested in answering my questions like do other demo cars have difficulty scanning new stations? do they have dab text etc. The drop out issue is hard to prove. Though sound of the dab radio is great when it works.

I will keep trying to see if I can get it fixed :grinning:. They did log a ticket with Mazda headquarters. But they said they don’t know if it will be ever fixed. Looks like I just need to followup.


#166

That’s disappointing. I’m 100% satisfied with my Focus DAB. And incidentally also 100% satisfied with the actual car LOL. I’ve clocked up over 25,000km in 12 months and it’s been a great car so far and no problems. With the mileage I do I appreciate the 15,000km service intervals too.


#167

Same here!
Love my Focus Sport too.
It’s a tad small in the back seat and the boot, but I guess I can’t complain given its less than 4.4 metres long (hatch).


#168

Yes true - that would be my only small complaint, it’s a little squeezy in the back seat but otherwise loving it :slight_smile: They’re a really nice drive. Ford service can be a bit hit and miss but I’ve been happy with my dealer so far. Free loan car for servicing too (tolls included!) which is a nice bonus.


#169

And the 1 other thing I would change, as the ride quality can get a little jiggly at times, I would like them to make the suspension a tad softer (I know it has “sports” suspension and that’s why it’s like that).


#170

Unfortunately cannot fix the problem with cut outs and dab text etc so my workaround in place. After 3 days of Mazda looking at it

At least the workaround only cuts out for a second rather than 7secs or so in the mazda. Dealer says they had scanning issues on a brand new car too.

First world problem I know.

I heard a traffic announcement whilst listening to dab via aux port. It was ad for gambling by triple m. How does that work? From gps? It was via the car not on 2ch. I pop up message came on mzd unit.


#171

Sorry to hear that you are still having digital radio issues with a brand new car.

I don’t understand your last question…I don’t see what GPS has to do with an advertisement or traffic announcement on your plug in DAB Radio?


#172

Yeah it is disappointing.

This is the rds system. Very strange listening to aux and I hear Dan from triple m giving an ad for a betting company lol.


#173

Ah ok, I thought you meant like a normal AM/FM radio traffic update you heard via DAB


#174

Yes but using the aux port.


#175

Gee very disappointing to have these issues on a brand new car! You’d think Mazda would be on top of it. No problems at all with the Focus and a friend has a new Lancer and the DAB works fine too.


#176

Yes if only I can turn back time.

The MZD unit comes with ADR (Australian design rules firmware). It’s concerning they also tested a brand new car and it had the same issue.

Would of expected some basic testing before releasing the dab hardware,

A) They can scan all dab stations first time if you can scan on a pocket radio.
B) They can decode dab text.
C) The volume is reasonable not excessively softer on dab.
D) The reception is steady when driving in a metro area.

Dab seemed to be an afterthought. Test driving the car I did listen a bit it was only 20 mins worth. The sound is generally good.

I won’t recommend a Mazda if you love your radio :grinning:. But if you do test drive one first do a factory reset and rescan. I would be very very interested to see the results. When I was on the hunt for a new car, I went to a couple of dealers they seem to be very reluctant you going alone and drive. Think it’s Mazda’s policy.


#177

Now the footy season has started and I listen to the ABC on the car radio , I noted no glitches at all… And thinking back its only the 9A/9B I ever get glitches with. 9c has been clear.

Did a bit of checking and researching what are the difference between 9A/9B/9C. Obviously the repeaters. I don’t think that would be issue. The break up occurs far away from the repeaters to have an impact.

However another thing too 9A & 9B some of stations deviate off the standard EEP. 9C was uniform see below.

9B
2SER uses EEP4-A
HOPE EEP4-A
Inspire Digital EEP4-A

9A
1SM/FUN/Gorolla/Zoo EEP4-A
2000 /2RPH EEP 3-B

9C
All EEP 3-A

So do you think that the less robust error checking of a couple of stations can actually throw the whole ensemble out and cause glitches ? For not all radios but for some (like my car radio). Or technically it does not make sense. Would like to see what my theory is to some who is an actual broadcast technician or knows a bit more than me which is not hard :). I am thinking of writing to ACMA on this. Anyway stations should be at 3-A. More people may think their digital radio is faulty with the inconsistency in error checking with the current setup.

As FYI ; EEP 4-A requires around 4 times the TX power to match EEP 3A to give the same signal strength. I believe, the international level of protection standard for DAB Terrestrial broadcast appears to be level 3.


Digital Radio
#178

So what is the curve of return if you move to level 2? Is there much improvement over 3A? How many capacity units do you lose for more error protection?

Would be interested to see a test with the highest level of error protection in a regional area to see if it throws the signal significantly better.

What was the highest level of error protection used in the Darwin and Canberra tests?


#179

I am not sure I would say it would be like the logarithmic. There is a big different between say 4A to 3A but going to 2 might not make much difference.

As FYI i have submitted a request to ACMA. I heard some one ring George and Paul and state that a brand new Sangean had issues with drop out with 2UE. I felt like asking her does it work on the ABC. My main point is they should standardise the error correction as they cannot control the firmware of all the devices out there. Maybe I should move this post back to digital radio :).


Digital Radio
#180

I updated Android Auto on my phone today, and I finally got Voice Control on my Ford Focus to work with the Tune In radio app.

So I just say “Play (station name)” and it seems to work!
Never had much luck with this before.