…and put them in adjoining rooms, would the sound always be in sych? Or will the delay be slightly different on each and drive me nuts. FM radios in kitchen and utility now, but one has died and I thought of going DAB, I know DAB would be out of sych with FM.

A DAB radio isn’t really any different to an FM radio, other than the data encoding technique on the base carrier frequency. So, no, there will not be a noticeable delay. In fact, the largest delay will the relatively slow propagation of the sound waves from the speakers, at a tardy 300m/s odd. Compared to that, the approx 294,000 km/s propagation rate of the incoming radio signal is irrelevant…..

yup no worries, we have one in the bedroom and one in the kitchen, and standing where you can hear both, they’re in synch. I’net radio’s out by a second or more.

Whenever I hear two DAB radios close together, the sound is in sync. There is an appreciable delay (a good few seconds) from FM/MW to DAB though. DAB through a TV is even delayed a bit more IIRC.

DAB will be as they will be receiving the same signal, unless you have a massive house so there would be a delay, as in calling the USA from the UK, even the speed of light sometimes just isn’t fast enough.

if you decide to go dab, just remember who you friendly dab aerial salesman is………. 😀

Cheers all, just making sure the delay was consistent between two radios, I’ll probably get two of the same model anyway, let’s see what turns up in Black Friday deals.

if you decide to go dab, just remember who you friendly dab aerial salesman is……….

Can you supply kinetic dab car aerials?

Just to wee wee on your bonfire when I have my two DAB radios on at the same time in adjacent rooms there is defiantly something odd that goes on with the sound.

they won’t necessarily be in sync. even same model and manufacturer ‘could’ vary, though i’d expect them to be the same in that case.
depends how much buffering they do and ting innit.
if you want multi room get one dab and an fm transmitter or a proper multiroom system. or just try two dabs and see how you go. 🙂

Just to wee wee on your bonfire when I have my two DAB radios on at the same time in adjacent rooms there is defiantly something odd that goes on with the sound.

Different models; different decoding speeds?

DAB isn’t as straight forward as FM. There is decoding and error correction going on so they could be out of sync, different speeds of processing

Also as it’s MPEG Layer 2 encoding you might get stereo unmasking going on because there are two sources…..

I have a few DAB radios, 3 Pure ones and a couple of cheap supermarket ones.

1 of the cheap ones has a slight delay compared to the other 4. I would imagine it comes down to which generic chipset is used to do the decoding.

[imagines OP standing in the doorway seperating two rooms listening to the radio]

I tend to listen to the radio in the room that I’m in. Not the one I’m not in.

I would have thought that two of the same brand/model would be in sync as they’d be doing the same thing to the signal, but not necessarily of they were different ‘models’.

My bedroom used to be directly next door to my sisters. She had a little JVC ghetto blaster thing and I had a separates system with amp & tuner.
There was a consistent delay between the two systems of about a second or so. Couldn’t quite work out where such a large delay was coming from with an analogue system.

Why would both be on at the same time, surely the one in the unoccupied room would be turned off?

So long as you stood equidistant from them both 🙂

Often the so called “delay” is due to the interference patterns caused by the SOUND waves bouncing around your square (ish) rooms. As these waves travel slowly, your ears can be fooled into hearing a wave that has been bouncing around the room for a few hundred ms. The actual incoming waves are traveling so fast (~300,000 KM / sec!) that on a human scale this is irrelevant! (also, it would make listening to radio in the car a bit of a pain……..)

As mentioned the DAB decoding chips may use different buffer sizes between models, but as the incoming data stream is 128kbs, any actual processing delays (checksum, signal PPL etc) are not audible to the human ear.

So, if you buy two of the same model it will definitely work, but i’m still not really sure why you need two radios tbh?

Why would both be on at the same time, surely the one in the unoccupied room would be turned off?

I don’t live alone.

You can’t hear the one in the further room well enough to do without another set. Radio 4 (except on TMS days, obviously) on more or less constantly when cooking/cleaning/laundry/etc so moving between the rooms. Not going to go to the trouble of multiroom faffage or earphones for that sort of listening.

That’s a load of rubbish maxtorque. Acoustically, the direct sound from each unit will dominate over any reflections from walls. For an echo to become audible the delay needs to be greater than 100 m/s and be within 10-20dB of the direct sound. Unless you have massive rooms with highly acoutically reflective walls, this isn’t going to happen.

When dealing with audible frequencies, the human ear cannot distinguish an echo from the original sound if the delay is less than 1/10 of a second. Thus, since the velocity of sound is approximately 343 m/s at a normal room temperature of about 25°C, the reflecting object must be more than 17.15 m from the sound source at this temperature for an echo to be heard by a person at the source.

[url=http://en.wikipedia.org/wiki/Echo]Echo on Wikipedia[/url]

If I’m pottering around the house I’ll have a portable on upstairs and the stereo on downstairs – it sounds a bit like they’re just a smidge out of synch, but the impression it gives is of a slight echo, as though it’s one radio playing in the NEC or something. 🙂

Also DAB on Wikipedia

The signal is delayed by 2–4 seconds depending on the decoding circuitry used.

… the chances are that gurrrrglegurglegurgle have gurgle a proper gurgllegurglegurglesqueak -nal. Not for any gurrgle-ference reasons butgurggle DAB gggghg is ick -ing crap

Slight thread hijack – when my car DAB radio has a weak signal (fairly frequently up here!) it often repeats the last second or (a couple of words) of a sentence. What’s that all about?

Got a Sony Hifi thing in the living room and a Roberts radio downstairs in the kitchen, no noticeable delay. Have previously noticed a big delay between radio via Sky box and the DAB in the kitchen.

We have a couple of DAB radios made by the same manufacturer but different models. There is a very slight time difference between them if they’re both on, but you’d have to try incredibly hard to get worked up about it (and this kind of thing usually drives me nuts).

midlifecrashes – Member

You can’t hear the one in the further room well enough to do without another set

That’s fine, if you can’t hear the other one then you don’t need to worry about them being out of sync

ohnohesback – Member
… the chances are that gurrrrglegurglegurgle have gurgle a proper gurgllegurglegurglesqueak -nal. Not for any gurrgle-ference reasons butgurggle DAB gggghg is ick -ing crap

I have a tiny little cheap Pure DAB radio at work, in a large steel-clad building, and reception is absolutely fine, only very, very rarely dropping out.
I also have a DAB in the car, with a stick-on film antenna on the screen. Apart from a dead spot of about half-a-mile in Box, I can drive from Chippenham to Bath with perfect reception, and all the way down to Burnham-on-Sea, with a small dead spot just past Avonmouth.
When I had FM, I’d lose the signal about a mile outside of Chippenham, and not get anything until I was inside Bath.
Pretty much the same driving to Bristol.
FM was utter crap.

Your cars aerial was crap me thinks.

I wouldn’t bother going DAB OP. Use a smartphone or tablet to stream internet radio to a bluetooth speaker. Much better quality and you also get to replay content from the excellent new bbc radio app.

I wouldn’t bother going DAB OP. Use a smartphone or tablet to stream internet radio to a bluetooth speaker. Much better quality

Yeah but its not really is it ? Not to mention a kerfuffle.

Any minor kerfuffle is offset by the choice of content. I do have a pocket size dab which I use via line in for when we leave the dog on his own. Rest of the time we bluetooth iplayer radio and spotify which is where the content choice wins.

Pondo’s echo +1 here

(cheapo DAB mono radio/alarm and a good DAB stereo receiver)

ohnohesback – Member
… the chances are that gurrrrglegurglegurgle have gurgle a proper gurgllegurglegurglesqueak -nal. Not for any gurrgle-ference reasons butgurggle DAB gggghg is ick -ing crap

I have had DAB since 2005. I have lived in 3 different areas since then, 2 rural and have never had a reception problem.

It’s excellent.

I also frequently have 2 radios on in the house, makes sense to me.

Got talking about DAB in the pub last night and found out some DAB stations are switching back to mono, which is a bit of a joke:

“Ofcom has given the green light for more broadcasters on the national commercial DAB digital radio multiplex to switch to mono and permitted Digital One to extend coverage into Northern Ireland, following a recent consultation.

Absolute 80s and Planet Rock will be changed from stereo to mono transmission to allow TeamRock to launch on the Digital One DAB multiplex next month. The move has been criticised by some listeners who increasingly dismiss DAB digital radio as being a serious replacement for FM in the future if most stations are in mono. Already, most stations broadcast in mono on the Digital One multiplex.”

link

Yeah,DAB is a bit of a joke. An antiquated digital system designed in the 80’s. It can’t compete with FM on quality. A few years ago the DAB brigade/BBC had their knuckles severely rapped by the ASA for claiming that DAB was CD quality. Now they use vague meaningless phrases such as crystal clear reception. DAB could be a quality system if the stations cranked up the bit rate,but that would cost more money and consume more bandwidth limiting the amount of crappy stations that can be squeezed in. As a result most stations have gone through a process of dropping bit rates and dumping stereo. Hardly a quality system. If you really want a DAB make sure it is a DAB+ compatible radio. Every other country is either closing down their DAB system or converting to DAB+. A DAB only radio will not work with DAB+. Eventually this country will have a DAB+ system.

trail_rat – Member
Your cars aerial was crap me thinks.

Nope, quality antenna on a Ford Puma, into a properly installed audio system using a Sony head unit and Genesis amp with Infinity Kappa speakers.
I’d get the same result on the factory installed unit in my Octavia when I got that, then with the Alpine that replaced the Octy factory unit, until I put the Kenwood DAB in. The only time I have issues with DAB is if I go towards Salisbury; once past Devizes, there’s bugger-all across Salisbury Plain, but according to a friend who has a new Focus with DAB, she gets reception nearly everywhere she goes, and her job requires her to cover most of the south of England.
The local BBC transmitter for FM runs at 2W, the DAB one, about three or four miles out of town is 85W.