SamDram Posted October 1, 2015 Share Posted October 1, 2015 Morning all, After a horrendous amount of feedback caused by some chimps on the sound desk yesterday afternoon, one of my PA speakers has had a turn for the worst.The 12" LF driver is buzzing/distorting. On inspection, there are no obvious signs of damage. The cone is still in good condition and attached to the housing.This is about as far as my knowledge goes in terms of identifying what's wrong. Any ideas? http://www.blue-room.org.uk/public/style_emoticons/default/huh.gif The speaker in question is a Martin DLS12006 (8 ohms) from a Martin Blackline F12+ http://www.blue-room.org.uk/public/style_emoticons/default/rolleyes.gif Link to comment Share on other sites More sharing options...
pete10uk Posted October 1, 2015 Share Posted October 1, 2015 If you manually press in the cone (gently), is the travel nice and smooth and free from grating? You should have a nice free running motion without anything that sounds harsh or grating. If there is any resistance or sound then the cone has gone, you need to either replace or have the driver recone'd, I use www.recone.co.uk These things happen, normally at the hand of chimps. Link to comment Share on other sites More sharing options...
SamDram Posted October 1, 2015 Author Share Posted October 1, 2015 If you manually press in the cone (gently), is the travel nice and smooth and free from grating? You should have a nice free running motion without anything that sounds harsh or grating. If there is any resistance or sound then the cone has gone, you need to either replace or have the driver recone'd, I use www.recone.co.uk These things happen, normally at the hand of chimps. Yeah, I would say it is smooth running, nothing crunchy in there. From it's resting position, its depresses about 7.5mm.I tested a good speaker in the cabinet it came from, just to make sure there aren't any dodgy components, and it was fine, so the issue is definitely with the speaker somewhere.Puzzled http://www.blue-room.org.uk/public/style_emoticons/default/dry.gif Link to comment Share on other sites More sharing options...
pete10uk Posted October 1, 2015 Share Posted October 1, 2015 If you’ve swapped the driver from the suspect cabinet to another working cabinet and vis versa and the issue stays with the driver, then the driver has gone, 7.5mm doesn't seem much movement from my experience, but that it limited to around 10 different speakers. I've found a Martin price list from 2012 stating a replacement driver as being £210 +vat for this model. www.recon.co.uk normally workout sub £100 when you factor in postage etc, but I couldn’t find Martin on their list, you'll have to give them a call, I deal with Roy and he has never let me down on both quality and service and advice. Link to comment Share on other sites More sharing options...
SamDram Posted October 1, 2015 Author Share Posted October 1, 2015 Thanks Pete. I also noticed that recone don't specify Martin as a brand they deal with, but I will get in touch and see if they can help.If it's repairable, I'll try and avoid the £210 replacement for now, but if it comes to that then fine. Link to comment Share on other sites More sharing options...
pete10uk Posted October 1, 2015 Share Posted October 1, 2015 Just had a check and in 2011 I sent a Martin 12" to Roy for a customer, All in it was £80.00, I still deal with the customer and it hasn't given them any trouble since. Link to comment Share on other sites More sharing options...
kurzweil_dude Posted October 1, 2015 Share Posted October 1, 2015 Technically speaking then you didn't blow it... #beingPedantic Link to comment Share on other sites More sharing options...
Shez Posted October 1, 2015 Share Posted October 1, 2015 Slight hijack - I too have an unhappy F12 (not plus). Cone moves freely and silently but there's no continuity on the terminals. Is that indicative of a fried coil? If so, is that a full replacement job? It's only ever been used with a conservatively set limiter so I'd be surprised if this one is down to muppetry. Link to comment Share on other sites More sharing options...
SamDram Posted October 1, 2015 Author Share Posted October 1, 2015 Technically speaking then you didn't blow it... #beingPedantic Allow me to correct myself. A cretin has blown my speaker and I need to make it better Link to comment Share on other sites More sharing options...
pete10uk Posted October 1, 2015 Share Posted October 1, 2015 Slight hijack - I too have an unhappy F12 (not plus). Cone moves freely and silently but there's no continuity on the terminals. Is that indicative of a fried coil? If so, is that a full replacement job? It's only ever been used with a conservatively set limiter so I'd be surprised if this one is down to muppetry. If theres no continuity on the drive then yes the cone is fried or the connection from the cone to the terminal has come off. you can replace or recone. The limiter will help stop over driving which can make the coil hot and melt, hence the grinding, but a real muppet can send a square signal or a large pop which can force the cone past where it is designed to be and damage the coil it's self. Before we have some more pedantic comments this is a simplistic view. I've had both, once its gone its gone. Time to spend some money. Link to comment Share on other sites More sharing options...
sam.spoons Posted October 1, 2015 Share Posted October 1, 2015 Another http://www.blue-room.org.uk/public/style_emoticons/default/thumbup.gif for Roy (and his son) at www.recone.co.uk he's done work for me in the past and I've been extremely satisfied both with the price and the quality of his work. Link to comment Share on other sites More sharing options...
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