Selling Damaged Magicos
If there is a qualified technician in your area, you can just order new woofers from Magico, and have them installed. You didn't mention whether the damaged speakers are in your possession, but if they are, it's an alternative to shipping the entire Magico speaker there and back. There's got to be an alternative to selling them as salvage. Best of luck, Dan |
vgrubb Hi. This is tragic, there is a way the woofers could be damaged in transport, if they were dropped very hard, but both woofer is questionable. Seeing there was no external damage this is unlikely. The other way is if the buyers amp went dc on both channels, this will cook the voice coils of both bass drivers only, as the tweeter is protected by a coupling cap in the xover. If you can use a screwdriver? The only way is to take the bass drivers out, there are external screws holding them in, make a note of which coloured wire goes to switch coloured terminal + or - there are only two, and send the drivers only back to Magico for inspection to see if the voice coils have been cooked, they can do a re-cone (with voice coil) if it's needed I'm sure. If the voice coils were cooked, then you have a grievance to deal with the buyer. Or if you don't want to go through all this sell them as is and cop the loss on the chin, I'm in Australia wish I could buy them! Cheers George
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Yes, excellent advice from George. What I would suggest that you do first, though, assuming the speakers are in your possession, is to do some basic troubleshooting with a multimeter. If you don’t already have one, the cost of a decent multimeter would be fairly minimal, and it may prove to be useful for other purposes in the future. What I would do first is to measure the resistance between the + and - terminals of each speaker, with the speaker disconnected from the amp. Under normal circumstances I would expect to see a resistance of something like 2 or 3 ohms or so, given the speaker’s nominal impedance of 4 ohms. If the reading is an open circuit (i.e. an extremely high or infinite resistance), then remove the woofer as George suggested, but before disconnecting it prop it up on something and measure the resistance across its terminals. Again, I would expect to see no more than a few ohms. If you again see an open circuit it would be indicative of a blown driver, probably due to exposure to excessive DC as George stated. And, while the driver is removed, to whatever extent may be possible examine the interior of the speaker using a flashlight, looking for wires that may have come loose, or anything else that looks amiss. Good luck. Regards, -- Al |
Thanks for all of the advice guys. I will take the woofers out and test them with a multimeter. I have one some place. It does seem to me that both of them going out due to being dropped or jarred is pretty unlikely, especially with no external damage. jafant, I'm not sure what the damage is or how it occurred. All I know is neither woofer works and the tweeters work just fine. |
Yes, it does seem very unlikely that physical mishandling could have caused this problem on both speakers. But it would also be unusual, although not unheard of, for an amp to put out large amounts of DC on both channels. And if perchance it was a tube amp, in most cases it would be nearly impossible because DC would be blocked by the output transformer most tube amps utilize. So before sending the woofers cross-country it would make sense to make the measurements I suggested, which may provide added confidence in the diagnosis that is being presumed, or might point in a different direction. I found some information on your meter. The 200 ohm scale is the correct choice. As you probably realize, one test lead should be plugged into the black "com" jack, and the other into the red jack that is just above it (and not into the uppermost red jack). Also, look to see if "BAT" appears on the display, which would indicate that the battery should be replaced. Then touch the two metal ends of the test leads together. The meter should indicate "000" signifying zero ohms on that scale, or perhaps "001" which signifies 1 ohm but would be within the meter’s expectable accuracy tolerance. Then proceed as I indicated in my earlier post. Be sure to disconnect the amp from the speakers when making the measurements, as I indicated. Regards, -- Al |
Very easy test, take a 9V battery, touch it to the terminals at the speaker, + to the red/positive terminal and - to the black/negative terminal, this should cause outward cone movement, if no movement the driver is blown. In most cases of excessive power or DC to the voice coil the coil will delaminate or change shape slightly causing it to rub against the pole plate, it'll also have a slightly "burnt" smell caused by the lacquer melting because of heat. To test for rub place three fingers around the circumference of the dustcap and push in gently, the cone should move freely. Best of luck Peter |
What does the meter indicate on the 200 ohm scale when the test leads are removed from the meter altogether? Assuming the answer is something other than the very low numbers mentioned in your last post, but instead is perhaps an indication such as "199" or "err" signifying "error", given the limited resolution and rated accuracy of the meter those results seem likely to be consistent with a resistance of a couple of ohms or so. Which seems normal and NOT consistent with a burned out voicecoil on the woofer. But I guess the next step, if necessary beyond Peter’s good suggestions, would be to remove the woofer and proceed as I suggested earlier, without disconnecting it. Also, when you do that measure the resistance between the + terminal on the rear of the speaker and each terminal on the woofer itself, and also between the - terminal on the rear of the speaker and each terminal on the woofer itself. Regards, -- Al |
I put another battery in. The reading of 1 I thought I was getting is actually in the hundred place like 1 _ _._. I am getting various readings from 1.0 - 190.0+ when I touch the leads. When I touch the speaker terminals, it stays at 1_ _._. It kind of seems like there is not a connection and nothing is going through. I attempted taking out a woofer. The screws on the woofers take small allen wrenches. I put almost enough pressure on it to break the allen wrench and it didn't turn. This is when I get concerned about my DIY skills which have never been good. I sure don't want to damage anything worse than what it is. Someone could probably take these speakers and put a little effort and money in them and have a nice set of speakers at a low cost. |
The guy you sold them to could've had the same speakers and switched his defective parts into your speakers, happens all the time, where are you located? Maybe one of the members here that lives near you and knows how to work on speakers and diagnose the problem can help you out, It's simple to do and only takes a few minutes to figure out what's wrong with them. |
I am getting various readings from 1.0 - 190.0+ when I touch the leads.Then it sounds like something is wrong with the meter. It should read very close to zero ohms when the leads are touched together, and the reading should be steady aside perhaps for a fluctuation of 1 count in the least significant digit. All I can suggest at this point is to try the suggestions made by Peter (pbnaudio) and Paul79. Good luck. Regards, -- Al |
Hi VGRUBB, I am a Magico dealer in Vancouver and have helped solved many problem just like yours from a variety of speakers. Here is what I do; 1) I gently push the unit in and feel for rubbing or scratching which obviously means it is damaged and needs replacing because this means the voice coil has been damaged or burnt out. If the unit passes this step with no scratching I move on to the next test; 2) I test for continuity with a multimeter and look for approx 4 ohms - that is good, but if it reads "infinity" the voice coil is blown or open circuit, a blown voice coil could also create a short- which would read "0" ohms. So either infinity or "0" is bad. If you do not have a multimeter, here is a simpler test - just touch the terminals with a 1.5 volt battery. You will should a pop when you touch the battery - that's a good sign. If it does not respond either the lead-in wires are broken - this is an easy fix by a speaker repair shop. 3) An alternative to step 2; I remove the unit and connect the amplifier directly to the drive unit at moderate volume. A good drive unit will play undistorted, albeit with very little bass. Caution is advised in step 3 - do not inadvertently touch amplifier leads together - the amplifier might sustain damage - also ensure the connection is secure, then turn amp on - amplifiers do not always like being open circuit. If I can be of more help, look me up on google - Liquidsound |
