HilcrRWise Posted October 19, 2012 Share Posted October 19, 2012 We have a couple of Mackie PA152 speakers, one of these has recently started crackling at certain frequencies (some music tracks play fine, it is most noticeable when using mics). the crackling appears to be coming from the top high frequency driver. Is it most likely that the HF speaker itself that has gone or could it be a problem in the electronics in the back? If it is the HF speaker what would be the chances of getting an exact replacement (I still need to finish dismantling it to get model specifics)? Even if I can get a part that will fit is it likely to match the sound of the existing speaker or would it be better to buy two and replace the one in the working speaker aswell? Link to comment Share on other sites More sharing options...
headoned Posted October 19, 2012 Share Posted October 19, 2012 sounds like interfernace, are all the cables plugged into the mic system correctly? as it could be a loose connection somwhere (or like you say could be the driver on the way out but not as likely if you say music plays fine) the only way to find out is to do some test and look around to see what could be causing it and check the connections on the mic set-up. New tweeters are genaraly available if it is the case and for most models of speakers you can just look up what make and model it is then hunt around your sure to find somthing. Link to comment Share on other sites More sharing options...
HilcrRWise Posted October 19, 2012 Author Share Posted October 19, 2012 I am almost positive the problem is within the speaker cabinet itself as doing a straight swap with another speaker resulted in no crackling. Not all music plays fine only some tracks (it is also possible that the crackling is there on the tracks that appear to play fine but are better masked by the music itself). Link to comment Share on other sites More sharing options...
headoned Posted October 19, 2012 Share Posted October 19, 2012 its not likely to be a problem with the internal wireing unless the speaker has been dropped or somthing. however driver do blow from time to time so its probably the more likely situation. check the owners manual for what drivers that speaker uses and see if you can get hold of a new one. Link to comment Share on other sites More sharing options...
handyandi Posted October 19, 2012 Share Posted October 19, 2012 Richard you are going down the right route by checking against a well known good cabinet. Carry on this route by swapping over the known good crossover board for the suspect one, if there is still a problem do the same for the known good HF driver. Once the problem goes away the last thing swapped is you faulty component. You will most likely need to remove the LF driver to access the crossover unless it is fitted direct to the rear input plate. Most HF drivers will have their component details on the rear. If not email Mackie sure they may supply you the details if not where to get a replacement. Recone kits are usually available to save purchasing a complete driver. Wembley are a good source of driver repairs. Link to comment Share on other sites More sharing options...
2ohmstable Posted October 26, 2012 Share Posted October 26, 2012 Hi there are these the mackie vision PA152 SPEAKERS. ?? I have had a major issue with 4 x of these which I own, internal x-overs have been a big problem, as they are mounted inside direct to the rear of the speaker with no shock mount they suffer major components starting to come loose. Had to have mine re- soldered and then hot melt on them to keep together. Aslo had a few issues with top end HF drivers. comps. these are very expensive indeed and the diaphram alone is around £70.00 each. Hope this helps a little Blue aran do the hf end. RCF N850. £191.00P EACH Think thjese comps are 90 to 100 watt each 2" diapharam is 3" Link to comment Share on other sites More sharing options...
vlfaudio Posted October 26, 2012 Share Posted October 26, 2012 How old are the boxes ? . According to the Mackie website they have a 5 year limited warranty. Link to comment Share on other sites More sharing options...
2ohmstable Posted October 27, 2012 Share Posted October 27, 2012 How old are the boxes ? . According to the Mackie website they have a 5 year limited warranty. Not sure I rekon these are poss 5 year old on mine. the mackie/rcf vision were never sold in the uk from what I was advised. they were install speakers and pro tour grade only through certain outlets only. I have had major issues with mine and to be fair the last repair bill on them was around 400 notes to put a pair of them right. with new top ends. and board repairs. Every now and then I get a crackle but have not yet found the fault. I'm thinking now that I will need to look at getting a set of decent x-overs for them as I do not want to go down the route of running them bi-amp as the x-overs do have the function to do this. Link to comment Share on other sites More sharing options...
HilcrRWise Posted October 29, 2012 Author Share Posted October 29, 2012 How old are the boxes ? . According to the Mackie website they have a 5 year limited warranty. The speakers are over 10 years old. I was on holiday last week so haven't had much chance to look at them again, however before I did go I was able to rule out the HF driver as I swapped them between the two cabinets and the crackling remained in the original faulty unit. I have little understanding when it comes to speaker electronics. In the back of the unit there are two separate boards (one orange with lots of capacitors, and one small green board which the speakon sockets, speakers and orange board are wired to and two sockets labeled BiAmp and Full Range (plug is currently connected to Full Range)). Could dry solder joints cause the crackling as I may just about beable to cope with doing a bit of resoldering, anything more will require a complete replacement or finding a professional to trace and replace the faulty component. Link to comment Share on other sites More sharing options...
Hilary Watts Posted October 29, 2012 Share Posted October 29, 2012 I had a similar problem last week where a speaker crackled intermittently - and on testing it only seemed to crackle when reproducing a frequency in a narrow band around 400Hz. The crossover incorporated a festoon bulb designed to protect the horn tweeter and I eventually discovered that one end of the bulb holder was loose resulting in an intermittent connection (it fell into two pieces when I took the bulb out and then replaced it!). I soldered the broken end of the bulb holder back together as a temporary measure and the speaker now works perfectly again. I'll replace the entire bulb holder next time I put in an order to CPC. I assume that the frequency around 400Hz was triggering a panel resonance which caused the crossover PCB to vibrate and showed up the faulty connection. On this basis I suppose a dry joint on a PCB panel could cause a similar effect. Link to comment Share on other sites More sharing options...
2ohmstable Posted October 29, 2012 Share Posted October 29, 2012 Hi. yep two boards. the green one is the board which you would swap over the loom plug to bi-amp to run the cabs off two amps thus bi-amped. yours should be connected to plug / loom full range. thus running the system 2 way stereo mode off one amp. the other board with resistors on and what you would consider to be like a transformer is the crossover or x-over board. think it has a 24v 100 watt lamp on it which is the protection for the hf top end. it is this board that may have some dry or loose joints on it. These speakers do have a right old good top end on them. I do have another spare pair of these sitting in my lock up if any one needs some. in black re powder coated black grills. nice looking All the best, good luck with repairs. Link to comment Share on other sites More sharing options...
HilcrRWise Posted October 30, 2012 Author Share Posted October 30, 2012 Thanks for the tips. I pulled out the crossover board yesterday and found that one of the inductors had come loose, the cable ties that were holding it on to the board had broken so it was only being held on by two solder joints. I put on a couple of new ties and even though the joints looked OK and felt firm I resoldered them anyway (aswell as the other joints). However when I restested it the crackling was still there and got even worse when I moved the board so I have come to the concludion that I need to replace the board completely. The PA152 spec sheet identifies the crossover as 1.6 kHz, 12 dB/Octave, looking on Blue Aran's website I found http://www.bluearan....semode=category, would this be an appropriate replacement for the original board (I have attached a picture of the two boards from the PA152, I assume this would replace the orange board and I would reuse the green socket plate board, is this correct)? Would replacing the crossover board affect the sound? ie: would I be better off replacing the crossover in both speakers so they match? http://img688.imageshack.us/img688/5974/img20121030083150.jpg Link to comment Share on other sites More sharing options...
HilcrRWise Posted October 31, 2012 Author Share Posted October 31, 2012 Another question, if the Eminence crossover replacement is what I am after, looking at a high res pic of it it has 6 terminal poles (IN+,IN-,W+,W-,T+,T-) however the existing crossover uses only 4. I assume this is because the 3 negatives are being shared, can I use this existing wiring with the new board, if so would I just connect the negative wire from the socket board to the IN- on the Eminence crossover or would I also need to daisy chain the three negative poles together aswell? Link to comment Share on other sites More sharing options...
jamesperrett Posted October 31, 2012 Share Posted October 31, 2012 You would be better off replacing the crossovers with the correct Mackie replacement as the crossovers should have been designed to match the characteristics of the particular drivers used. James. Link to comment Share on other sites More sharing options...
HilcrRWise Posted November 1, 2012 Author Share Posted November 1, 2012 You would be better off replacing the crossovers with the correct Mackie replacement as the crossovers should have been designed to match the characteristics of the particular drivers used. James. I would love to consider it however I have not yet found anywhere that can supply them (assuming they even still make them for such an old speaker) and Mackie has not yet responded to my query. It looks like I may have to go with the Eminence crossover and hope it will be good enough until we can afford some new speakers. Link to comment Share on other sites More sharing options...
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