Members RoboPimp Posted October 9, 2004 Members Share Posted October 9, 2004 Hello, I'm curious about speaker phase, phase cancellation between speakers out of phase and about how the polarity of the speaker connections should be established. I have a "two way?" crossover system now. The top speakers are 15" and horns, the sub speakers are 18" The sub is crossed over at 125hz and high passed at 40hz, The top speakers I had crossed over at 125 and it sounds good. When I was experimenting with rolling the frequency down into the sub range (to about 90hz) I noticed that it seemed to be having some cancelation in those frequencies, at least that's what I think it was because the volume at those freq. where the two overlapped definitely got quieter. Could I be right? Could this be result of the top speakers and the lower speakers being out of phase? If so, could I try reversing the polarity of the subs to check and see if it changes anything or should I do something like the "battery test" on the speakers to see if I can determine which way is what? Any help would be appreciated. Link to comment Share on other sites More sharing options...
Members agedhorse Posted October 9, 2004 Members Share Posted October 9, 2004 Could be three things from what I see... 1. are you rolling the sub freq down while leaving the tops at 125Hz? In this case, you may be making a big response hole. 2. Br rolling both freqs down, you may be approaching a point where the top boxes are rolling off faster than the bottom boxes are coming in due to effeiciency-bandwith issues. 3. It's also possible that there are some phase issues, but that's why I would suggest 125Hz as a starting point. It's best for a power-bandwidth solution usually. Link to comment Share on other sites More sharing options...
Members dboomer Posted October 9, 2004 Members Share Posted October 9, 2004 The battery test will establish the polarity of the speakers themselves but what is much more important is the actual performance of the speakers. Flip the polarity of the sub while playing music with a lot of strong low end and take a listen and then flip it back. The correct hookup will be the one that is the loudest regardless of how the relative polarity looks. Link to comment Share on other sites More sharing options...
Members RoboPimp Posted October 9, 2004 Author Members Share Posted October 9, 2004 Originally posted by agedhorse Could be three things from what I see...1. are you rolling the sub freq down while leaving the tops at 125Hz? In this case, you may be making a big response hole.nope, sorry I didn't explain that very well. I have the subs set at 125hz low pass, 40hz high pass. The top speakers are high passed at 125hz but I was experimenting and rolling the hi-pass down on the top speakers to 90 hz so it should be overlapping the subs. When I did this I noticed the bass response in that freq. area seemed to get quieter.3. It's also possible that there are some phase issues, but that's why I would suggest 125Hz as a starting point. It's best for a power-bandwidth solution usually. 125hz a good crossover point for the tops/subs is what you're saying? Flip the polarity of the sub while playing music with a lot of strong low end and take a listen and then flip it back. The correct hookup will be the one that is the loudest regardless of how the relative polarity looks. is this for the subs only? To determine which way they sound best on their own with regards to the polarity? What if that doesn't coincide with the tops speakers as they are set right now? trouble eh? edit: thanks for the advice so far Link to comment Share on other sites More sharing options...
Members dboomer Posted October 9, 2004 Members Share Posted October 9, 2004 Originally posted by RoboPimp is this for the subs only? What if that doesn't coincide with the tops speakers as they are set right now? Well it's for one OR the other only. Your choice is polarity the same or polarity reversed 180 degrees for the tops and subs. As far as that goes this also pertains to whether you electrically overlap or under-lap your crossover point. You are looking for the best sound ... that's the point you are shooting for. Nothing else matters. As far as underlap or overlap, this also changes with the relative drive levels to the top and subs. In other words you can make the same thing happen by (relative to where ever you are starting from) just turning up or down the amp driving the subs. As you turn up the level you are moving up the acoustical crossover point. Link to comment Share on other sites More sharing options...
Members agedhorse Posted October 10, 2004 Members Share Posted October 10, 2004 Rarely (or never) is overlapping a good idea. Too many phase issues due to the crossover filter's phase responses. Link to comment Share on other sites More sharing options...
Members RoboPimp Posted October 10, 2004 Author Members Share Posted October 10, 2004 Originally posted by agedhorse Rarely (or never) is overlapping a good idea. Too many phase issues due to the crossover filter's phase responses. I'm beginning to realize that... thanks for the help Link to comment Share on other sites More sharing options...
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