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PostPosted: March 15th, 2021, 3:10 pm 
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I always thought that a positive pulse on the red or positive terminal of a speaker would cause the cone to move out, not in. I verified this with a quick search. The two different Dayton sub drivers I have are both marked backwards - a positive pulse on the red terminal caused the cone to move inward. Fortunately this is an easy problem to fix, especially if you know about it before you wire and mount the drivers, but I'm really surprised that it's the case. The two models I have are the UltiMax UM10-22 10 inch and the Reference Series RSS315HO-44 12 inch.

It's pretty easy to check. Using Audacity I created a single cycle 5 Hz sine wave and deleted the negative half. It's a second long track with the rest silence, put your player on repeat track and your finger on the subwoofer. Assuming your system will pass a signal this low you can easily feel if the sub is going in or out. You may also want to verify that the signal to the speaker is a positive pulse, if any of your equipment is inverting this should be accounted for.

I tried to attach the test track for your enjoyment but a .wav file is not allowed. PM or email me if you'd like a copy. I've also created a bunch of chirp tracks that I've used to check time delays at various frequencies. I'm happy to share them if anyone is interested.

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PostPosted: March 15th, 2021, 3:24 pm 
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This is interesting.
I have tried listening with wires reversed and sometimes I hear a big difference and sometimes not so much. I suppose it really depends on the music and how it was recorded. Also how far back your subs from the mains. I think we need a remote control phase reversal on the subs.


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PostPosted: March 15th, 2021, 4:00 pm 
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If anything the sub(s) should be in phase with the main speaker's woofers. When one rolls off the other finishes the job.

Blending should be "transparent" where you feel the main speaker's woofers are actually doing the heavy lifting.

If not in phase with the main speaker's woofers there will a null (cancellation) when both are trying to reproduce the same frequency -- and there will be overlap.

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PostPosted: March 15th, 2021, 4:07 pm 
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Walt is correct (but you didn't need me to tell you that), all drivers need to be in phase. I have the DEQX set to delay the top box 9.3 milliseconds, everything is time aligned with that setting. The chirp tracks really help see what's going on both good and bad.

I wonder how many speaker systems are out there with the sub's phase inverted because of this mis-marking that I wouldn't be surprised is the case with all Dayton Sub Drivers.

As it happens the ribbons were also marked backwards, but they may have been correct when they left the factory. You can flip the transformer on the back which would make the phase opposite of what is marked on the terminals. I purchased them used so who knows.

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PostPosted: March 15th, 2021, 6:29 pm 
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Some vendors but most notably JBL have some or most of their woofers pull in on the positive voltage on red.

Many people implementing subs never bother to verify whether their subs are in proper phase with their woofers. I've corrected that on many friend's set ups. It's usually pretty obvious. I've also caught a couple where the 2 subs were out of phase with one another as one had been wired incorrectly.


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PostPosted: March 15th, 2021, 6:50 pm 
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I should have said raw drivers, not necessarily in systems.


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PostPosted: March 15th, 2021, 7:01 pm 
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I guess I shouldn't be surprised. But a company like Parts Express that is clearly trying to make reference quality drivers marked contrary to convention is pretty shocking. The drivers are great, however the inattention to detail, or worse, the intentional incorrect marking of terminals is really disappointing.

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PostPosted: March 16th, 2021, 12:49 am 
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Some explanation of JBLs thinking on the subject at the time.
https://adn.harmanpro.com/site_elements ... iginal.pdf

If the drivers you're using were intended for subwoofer duty it really doesn't matter as you should always try both phase options when setting up subs. There are full range speaker systems whose woofers (by design) don't push out on a positive system charge and you might not know this until incorporating subs.


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PostPosted: March 19th, 2021, 7:51 am 
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Dave,

Problem could be in the crossover connections. Did you try connecting the positive terminal of a 1.5V battery to the positive terminal of the woofer directly?

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PostPosted: March 19th, 2021, 9:09 am 
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Cogito wrote:
Dave,

Problem could be in the crossover connections. Did you try connecting the positive terminal of a 1.5V battery to the positive terminal of the woofer directly?


No battery. I described how I checked phase in my original post. I verified that the voltage pulse into the driver was indeed positive.

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