TomTom 720 Faulty Speaker

benjones · Occasional Visitor Joined: Dec 28, 2006 Posts: 47

My unit was fine and then all of a sudden half way up to Scotland it got the crackling speaker / screen dimming problem.

PCWB are picking mine up and getting a full refund. Can't be bothered to be a TomTom beta tester. Poor show if you ask me. Going to wait for the new Garmin I think. Shame because the 720 had so much potential. Lack of phone over FM was a big minus also.

killarachris · Occasional Visitor Joined: Dec 08, 2006 Posts: 22

Same problem here - when set a maximum volume (or when noise dependent volume sets it to max) speaker distorts, screen flickers to match the distortion and pretty soon afterwatds the display shows a battery with an exclamation mark on it and shuts down even though it is nearly fully charged.

This is the second unit from PCW to do this (my guess is they will hace had a batch from TT that they have distributed to all their stores).

Should I hang on for a TT fix or keep returning it on the off-chance I get one without problems?

UPDATE - once connected to mains power the distortion disappears at max volume!

Looking more like a manufacturing/design problem rather than a 'fault'. Perhaps TT can fix this (probably by reducing max volume limit) at the same time they fix the problem with most of the preference resetting when connected to TT Home javascript:emoticon(' Sad

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TIA Sad

mrzipy · Regular Visitor Joined: Mar 10, 2006 Posts: 79

Well got mine at Argos last Friday, and I experience the audio issues at full volume, but no audio system I have ever had sounds good when the volume is on max - try it on your HiFi and TV!

This is an except from a review of the TomTom 720:

"Unfortunately, we have to say that the sound quality of the new GO is not as good as that of the x10 series. This will be due to the flat shape of the GO 720. TomTom cannot change the laws of physics: for a rich, warm sound, a large speaker and a resonant box is needed
...
As a result, all the TTS voices now sound much more 'tinny' and even crackle a bit at times."

http://www.yournav.com/content/review/356/GO_720_TomToms_new_do-it-all.html

So I think this is normal.

sneeks · Lifetime Member Joined: Feb 17, 2006 Posts: 99

I too notice distortion at 100% volume but only when using the computer voice Kate, Jane sounds clear even at maximum volume.

mikealder · Posted: Mon Aug 13, 2007 6:19 am Post subject:

I certainly won't be testing the HiFi at 100% volume as I value the windows in my house Cool

but what I cannot understand is the need to select 100% volume, the device can be connected to the car radio via the FM transmitter and you can play your choice of music from the device -

You can turn your car stereo up to 100% and I am sure it will distort if not blow up the speakers, but it won't be necessary to crank it up that far to hear the device.

Can you also check that you have the device powered up by the car charger when experiencing this problem? - at least one person has mentioned the fault goes away when powered by the mains, what are you powering it with in the car?

To be honest when comparing the sound output of my 910 with the 720 there is very little detectable difference, they are both about the same for that reason I have always coupled the devices to the car stereo it sounds so much better - Mike

killarachris · Occasional Visitor Joined: Dec 08, 2006 Posts: 22

OK - I have been using Kate as well, not tried Jane, wil give that a try. I can confirm it only seems to appear when using battery power, when powered via the ciggy lighter there is no problem.

100% is loud, but when batting along a dual carriageway with the top down it is very useful!! The main issue is that avoiding 100% volume can only be achieved if 'noise dependent volume level' is deactivated - a useful feature that I would prefer to use (after all it's on the device to be used)

None of this explains why the unit switches itself off when there is battery power available following distortion at 100%.

As for connecting through the car - could try that but would need to change from Kate - she's far too chatty!. I connect my iPod for choice of music, much better than an FM transmitter; plus I have my phone connected handsfree by bluetooth through my car stereo system.

Will try the FM transmitter - but why sell a unit that can't do what it's supposedly buil to do i.e. play at the max olume of the unit using factory settings?

Chris

mikealder · Posted: Mon Aug 13, 2007 7:00 am Post subject:

Why not connect the iPOD to the TomTom and let that control all the sound to the car deck via either the wired line output (connect to aux in on stereo) or try the FM Tx capability of the x20. The only slight problem with this set-up is the hands free for the phone which can only route sound through the devices internal speaker - it is well worth a try wired up like this, you will need a specific cable to connect the iPOD to the x20 and make sure your iPOD is on the compatible list first.

I think the reason you are hearing distortion then the device is shutting down can be explained as follows, firstly sound output goes to max power clipping the sound level by the internal amplifier, this is heard as audible distortion. The clipping is placing a high demand on the battery which causes the voltage level across the cells to drop. The voltage dip is detected by the internal power monitor and turns the device off in the same way as it does when you remove the ignition key (when powering the unit from the vehicle).

The device should be powered by the supplied in car charger lead when in use, I guess TomTom could have lowered the max volume available from the device to avoid this issue, but then people would have complained it isn't loud enough!! - its a no win situation as they will never please everyone - Mike

killarachris · Occasional Visitor Joined: Dec 08, 2006 Posts: 22

Mike, thanks for the power explanation it certainly makes sense.

Don't get me wrong, I think TT are great products having only just had to bin my original TT GO after a few years faithful service. I must confess to buying a Nuvi 350T before the 720 and wishing I hadn't - the interface is poor, route planning is a joke (only one waypoint allowed!), the volume is inaudible, the TMC receiver is mostly useless and the clarity of the visual directions is poor also (not to mention a liking for single track roads).

I don't use satnav every day so I will stick with iPod control and charging through my head unit.

What really needs fixing is the variable volume control so that it cannot reach (current) 100% when not connected to power. I don't want to hardwire the TT (if I'd wanted a dedicated unit I'd have bought a head unit with it integrated) so the prospect of trailing a power lead from my 'auxillliary power socket' for every journey doesn't appeal, especially as the device flaunts battery life in excess of 4 hours!

From all this discussion my conclusion is that the max volume needs reducing to allow the noise variable volume option to function properly without distorting the speaker and causing a power down. If the software can be written to distinguish a unit on battery from a unit on charge then everyone will be happy.

I've posed these problems with TT so will let you know if they have anything further to add.

Thanks, Chris

mrzipy · Regular Visitor Joined: Mar 10, 2006 Posts: 79

Another thought is don't forget speakers have to b run in, which with a HiFi is much easier, I would suggest looping a song on the TomTom to loosen the speaker up a bit.

mrzipy · Regular Visitor Joined: Mar 10, 2006 Posts: 79

vroomfondel · Posted: Mon Aug 13, 2007 11:26 am Post subject:

PeteT · Posted: Mon Aug 13, 2007 12:21 pm Post subject:

mrzipy · Regular Visitor Joined: Mar 10, 2006 Posts: 79

I have just done some more testing and this issue is far worse with the computer voices, it's almost normal with the human voice...

So I think this is an issue with the quality of the computer voices, think I will have to use the computer voice for only reading aloud street names and not for the directions. Although saying that I have set a computer voice for reading aloud street names, but the option is greyed out and does not work.

I also note that if you put your ear to the speaker when no sound, there is a lot of hiss saying the amp is not very good quality.

mrzipy · Regular Visitor Joined: Mar 10, 2006 Posts: 79

It's started to bug me now so I returned my TT720, my TT ONE v1 is much better sound quality so I think I will stick with that.

Skwark · Regular Visitor Joined: Jan 30, 2005 Posts: 86

Just used my 520 for the first time and it suffers from the same problem - volume on 100% (still not as load as the 510 could go) and screen flickers and audio crackles.

Looks like I'll have to return it then.... Crying or Very sad

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