5teve Posted January 28, 2007 Share Posted January 28, 2007 Hi guys i finally got my ms stuff.... sounds great... apart from... my sub keeps cutting out.. and im thinking its the thermal protection kicking in... not good on a 4 day old sub first noticed it last night while watching the incredibles.. initially it sounded great, then i noticed it sounding a bit weak... turns out the sub was detecting a signal, therefore switching itself on (set to auto) but the sub wasnt actually working. to test i turned the sub test tone on on my onkyo 703, then i turned the sub on and off etc and just noticed a click when it was coming on (i assume a relay) and then a click from the speaker, but nothing else. it was auto switching on too... i unplugged it for a short while.. and after 5 minutes or so turned it back on and it worked again for a short while. repeated the above several times and it seemed consistent. The connection plate on the back was warm to the touch but not hot... and nothing like my onkyo amplifier gets. so if it is overheating.. then it must have a low threshold. It has also been warm here in perth too (40+) for the past few days but the house stays at no more than about 33-35. so i guess the question is... is this normal given the heat.. has anyone experienced this? and should i get the sub exchanged? (which i dont wanna do as they had to order it in specially... so took a few weeks) thanks in advance Steve Link to comment Share on other sites More sharing options...
Razr Posted January 29, 2007 Share Posted January 29, 2007 Sounds like thermal shutdown given your description. If the heatsink is only getting warm to the touch, there's a possibility that either the mechanical junction between the amplifiers output stage and the heatsink is bad, or it simply has a faulty component that's in thermal runaway, or the over temp sensor is plain faulty. Either way I'd be taking it in for a warranty check-up. Link to comment Share on other sites More sharing options...
5teve Posted January 29, 2007 Author Share Posted January 29, 2007 Sounds like thermal shutdown given your description. If the heatsink is only getting warm to the touch, there's a possibility that either the mechanical junction between the amplifiers output stage and the heatsink is bad, or it simply has a faulty component that's in thermal runaway, or the over temp sensor is plain faulty. Either way I'd be taking it in for a warranty check-up. thats the wierd thing... there is no visible heatsink.. just the connection / control plate on the back, i beleive they are class D amps in them so therefore dont produce much heat.. however the plate gets warm... just not hot... my onkyo gets that hot you cant actually touch it for more than a second... (mind you that is on a 42 degree day!) i think its is the thermal shutdown and im glad i have some agreement on it.. if i take it back to JB i will have to reproduce (which i may not be able to in the shop as its airconnned) plus it will take about 30+ minutes to reproduce... they will also have to order another sub in which will take about 2 - 3 weeks.... if i take it to a service centre they can turn it around in 10 days.. but then it gets repaired... if they can reproduce the fault... Bah.. i hate it when things go wrong.....! no-one experienced this problem with any other sub? Steve Link to comment Share on other sites More sharing options...
5teve Posted January 30, 2007 Author Share Posted January 30, 2007 well looks like the sub is hosed... i did more testing last night and it shuts down after about 3/4 hour.. green light stays on... but nothing is passed to the speaker itself... i fiddled about with the phase switch also at one point and a once or twice it caused the driver to boom.. and i mean boom! couldnt reproduce that tho... the interesting thing was tho... if i left the sub on with nothing playing through it.. it would heat itself up and then not work either.. anyway a call to qualfi has matters being sorted.. although not to my complete satisfaction.. they have no black subs anywhere and wont be getting any.. so im having to have it repaired.. not ideal.. but better than it not working. they are apparently sending a complete replacement amp for it to the repair shop.. hopefully that will be done quickly! i'll make sure that i make a note of any marks etc so that i know for sure that the amp has been changed.. i cant beleive that i was that lucky that i got a faulty one! most people i have spoken to seem quite surprised! oh well... i'll let you know how it goes... Steve Link to comment Share on other sites More sharing options...
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