Arry74 Posted December 21, 2019 Share Posted December 21, 2019 Hi I have a problem that I am not sure I can fix. I have in-ceiling speakers that are very difficult to get to. When I had them connected initially, the company that installed them used speaker wire where the negative and positive wires look exactly the same as the outer sheath is the same. I recently purchased a new receiver and when I disconnected it I dropped the cables accidentally and now I do not know which is positive and which is negative. The grills on the speakers do not come off so I cannot see which way the cones are moving. I have watched YouTube videos on it but no one explains if / how you can check phase if you cannot see the speaker end of the connections. Any help would be greatly appreciated. Cheers Link to comment Share on other sites More sharing options...
Buffle Posted December 21, 2019 Share Posted December 21, 2019 There are some apps for mobile phone/iPad/etc. that test speaker polarity. Download, connect phone to amp, place phone mic near speaker and read + or -. You'll need to use a left or right speaker output from your amp. Mark cables and done. 1 Link to comment Share on other sites More sharing options...
BATMAQN Posted December 21, 2019 Share Posted December 21, 2019 Or you plug them in have a listen if they sound hollow crappy then reverse them you won't kill anything with a short test. A while back I actually ran one of my speakers out of phase for a few weeks without realising, it survived. 1 Link to comment Share on other sites More sharing options...
Arry74 Posted December 21, 2019 Author Share Posted December 21, 2019 Thanks very much guys Link to comment Share on other sites More sharing options...
almikel Posted December 21, 2019 Share Posted December 21, 2019 speakers don't care if they're connected "out of phase" - there's zero risk of damage... @Buffle's idea could work - I've never used apps like that... Can you get up on a ladder and shine a torch through the grille and see the driver? having the the room reasonably dark would help. If so get a friend to connect a battery (like a D cell or a 9V smoke alarm battery - not a car battery) to the terminals at the receiver end, and try to identify which way the driver moves. You want the driver moving forwards with the +ve lead connected to the +ve end of the battery. Don't leave the battery connected - have your friend connect and disconnect the battery while you adjust the torch to get a good angle to see driver movement...the driver will move forwards or backwards and stop each time the battery is connected, and go back to neutral when disconnected. If you can't see driver movement with a D cell (1.5V) try a 9V (ie smoke alarm) battery. Mark the leads at the receiver end... 2 hours ago, Arry74 said: used speaker wire where the negative and positive wires look exactly the same as the outer sheath is the same. just checking - sometimes there's a "tactile" ridge you can feel on the wire that's not obvious on a visual inspection...? ...given you didn't install the speakers I'd still go through the process to confirm polarity. cheers Mike 1 Link to comment Share on other sites More sharing options...
GregWormald Posted December 22, 2019 Share Posted December 22, 2019 Forget all the fancy stuff. Sit where the sound is best. Play. Reverse one speaker's connection. Play The connection that gives the best bass and musicality is (almost inevitably) 'in phase'. If you can't tell--don't worry, no damage will occur; and if you can't tell--it doesn't matter. Relax and enjoy. 1 Link to comment Share on other sites More sharing options...
gibbo9000 Posted December 22, 2019 Share Posted December 22, 2019 (edited) The other approach that may work, if you can't tell with your ears, is to use a Sound Pressure Level meter app for your phone. Set speakers up to reasonable volume (75db or so) on a piece of music you can repeat, ideally with a bit of bass and without changing volume try the leads each way around. In phase should be slightly louder. Should turn amp off between the two wiring scenarios, just don't adjust the volume. Haven't tried it exactly as above - but regularly do similar to ensure sub-woofers are in phase with main speakers using a test tone. Edited December 22, 2019 by gibbo9000 1 Link to comment Share on other sites More sharing options...
davewantsmoore Posted December 26, 2019 Share Posted December 26, 2019 On 23/12/2019 at 1:40 PM, steffanth said: most room correction software will also tell you if a speaker is out of phase This. Simpy run the run the calibration routine in your AVR with it's microphone, and all will be well. 1 Link to comment Share on other sites More sharing options...
Arry74 Posted December 26, 2019 Author Share Posted December 26, 2019 Will Anthem ARC find the problem? Link to comment Share on other sites More sharing options...
davewantsmoore Posted December 26, 2019 Share Posted December 26, 2019 46 minutes ago, Arry74 said: Will Anthem ARC find the problem? Hmmm... Thinking about this some, I don't know. You can try it.... it can't hurt, worst case it "it won't fix it". One way to determine if you have the ceiling speakers in phase with one another, is to find a mode in your receiver which sends "stereo to all speakers". Then, disconnect all dpeakers ecept the ceiling ones.... and play music. Flip the phase of the speaker you're unsure about, and the difference should be obvious as you change it back and forth. One will be dramatically better. 1 Link to comment Share on other sites More sharing options...
TDX Posted December 26, 2019 Share Posted December 26, 2019 On 21/12/2019 at 11:17 AM, Arry74 said: Hi I have a problem that I am not sure I can fix. I have in-ceiling speakers that are very difficult to get to. When I had them connected initially, the company that installed them used speaker wire where the negative and positive wires look exactly the same as the outer sheath is the same. I recently purchased a new receiver and when I disconnected it I dropped the cables accidentally and now I do not know which is positive and which is negative. The grills on the speakers do not come off so I cannot see which way the cones are moving. I have watched YouTube videos on it but no one explains if / how you can check phase if you cannot see the speaker end of the connections. Any help would be greatly appreciated. Cheers Use a AA battery to test it use your wire touch both end battery see which way it works. Speaker will make some sound for you to test. 1 Link to comment Share on other sites More sharing options...
Arry74 Posted December 26, 2019 Author Share Posted December 26, 2019 36 minutes ago, TDX said: Use a AA battery to test it use your wire touch both end battery see which way it works. Speaker will make some sound for you to test. Tried that but how do you tell in phase or not? Link to comment Share on other sites More sharing options...
TDX Posted December 26, 2019 Share Posted December 26, 2019 Connect a 9 Volt battery to the leads of the speaker, positive lead to positive battery end and negative lead to negative battery end. If a pulse is generated in the speaker then the speaker is still functioning properly. my understanding is that if the positive/negative is wrong then the speaker won’t make sound when testing by battery. 1 Link to comment Share on other sites More sharing options...
frednork Posted December 26, 2019 Share Posted December 26, 2019 16 minutes ago, TDX said: my understanding is that if the positive/negative is wrong then the speaker won’t make sound when testing by battery. Not correct, there can be a sound (or not) both ways Apps are dodgy and will give variable results seeing the movement or listening and picking the better/louder are the simplest ways as mentioned previously 2 Link to comment Share on other sites More sharing options...
Arry74 Posted December 26, 2019 Author Share Posted December 26, 2019 1 hour ago, TDX said: Connect a 9 Volt battery to the leads of the speaker, positive lead to positive battery end and negative lead to negative battery end. If a pulse is generated in the speaker then the speaker is still functioning properly. my understanding is that if the positive/negative is wrong then the speaker won’t make sound when testing by battery. When I do this I get sound both ways. 2 hours ago, TDX said: Use a AA battery to test it use your wire touch both end battery see which way it works. Speaker will make some sound for you to test. Tried that but how do you tell in phase or not? Link to comment Share on other sites More sharing options...
gibbo9000 Posted December 27, 2019 Share Posted December 27, 2019 16 hours ago, TDX said: Use a AA battery to test it use your wire touch both end battery see which way it works. Speaker will make some sound for you to test. Forgive me if I have missed something here. I would have thought applying a DC voltage (AA battery) will drive a once off change in speaker cone position and unlikely to make any ongoing noise. What you are looking for as suggested earlier in thread is the direction the cone moves. If you have the correct +ve and -ve for the wiring then the once off movement will be in the same direction for both cones (out of in) Link to comment Share on other sites More sharing options...
afa Posted December 27, 2019 Share Posted December 27, 2019 Yes 1 Link to comment Share on other sites More sharing options...
afa Posted December 27, 2019 Share Posted December 27, 2019 Or use this https://www.audiocheck.net/audiotests_polaritycheck.php PS not for headphones :) 1 Link to comment Share on other sites More sharing options...
Recommended Posts