I ordered a center channel upgrade for crossovers and the speaker has a big null in the crossover range of 200hz if I wire all speakers in phase.
The speaker has two woofers wired in parallel crossed at 200hz with a big inductor only. So first order I think? They are two 6.5” drivers. The midrange is a 4 inch so distance is a bit compared to the 6.5’s
The tweeter and woofer measure very good together all ran through their crossovers and connected all positive to positive negative to negative. I flipped the + and - from the parallel woofers after the crossover so the negative goes to the positive of the branch and the negative going to the positive of the branch. This fixed the null in the 200hz range.
so does that mean the woofers are out of phase with the midrange? Should I flip polarity on the speaker when I run the software for my receiver for the sub to match up?
The speaker has two woofers wired in parallel crossed at 200hz with a big inductor only. So first order I think? They are two 6.5” drivers. The midrange is a 4 inch so distance is a bit compared to the 6.5’s
The tweeter and woofer measure very good together all ran through their crossovers and connected all positive to positive negative to negative. I flipped the + and - from the parallel woofers after the crossover so the negative goes to the positive of the branch and the negative going to the positive of the branch. This fixed the null in the 200hz range.
so does that mean the woofers are out of phase with the midrange? Should I flip polarity on the speaker when I run the software for my receiver for the sub to match up?
sorry a little unclear, is this three or two way?? and without more details of x-overs it's a little ambiguous...i would think that inverting the mid if it's three way, or the tweeter if it's two way would be the right solution...phase is tricky depending on order.
It’s a three way. Two woofers in parallel being cut at just over 200hz. The tweet to mid is crossovers around 2000.
6.5” woofers, 4” mid and 1” tweeter.
I tried flipping the mid first and it made both the woofers and tweeter dips in the signal so mid and tweeter do seem to be wired correctly
+ + - -
I talked to the designer of the crossover and they said they didn’t remember flipping the woofers after them being ran in parallel with each other. But I checked well over 5 times and tried different combinations and always come back to the woofers being flipped connecting back to the pile.
if everything is ran to each positive and negative out the dip is 15db or so in the woofers to mid transition.
Here’s the crossover schematic
Attachments
looks to be a mix of orders, is your physical layout the same as what the x-over is designed for?
the only thing that may help is making the woofer filter a steeper order to resolve/reduce the overlap region.
the only thing that may help is making the woofer filter a steeper order to resolve/reduce the overlap region.
They sum together fine with the layout shown. It’s just the woofers are running the way I said flipped polarity after the 8mh inductor. I don’t know if it’s common in parallel circuits to have it this way or not. All I know is the null it creates is pretty big if they are ran all to the +++ - - -
nothing to do with parallel, if the null is resolved with the bass section flipped then it's all good,no?
Because of the filter you will be getting phase shift around the 200 point and mid might not be phase shifted hence the cancellation ?
That is what I was thinking. It is important for the designer of the crossovers to know the actual impedance of the speakers at the crossover point. I agree that the woofers probably are out of phase with the midranges at the crossover point. It would be desirable to keep the woofers properly in phase by wiring them correctly in terms of the schematic since the only things which the woofers see are the 8mH chokes, and then reverse the plus and minus connections for the midranges and tweeters. Alternatively, simply reverse the negative and positive connections to the woofers since it sounds like the woofers and midranges are more than 90 degrees out of phase.
So should I be running the speaker flipped polarity from what I have now? As in they sum together good now with the woofers flipped. But when I run the software for the receiver should I have the whole speaker flipped coming out of the binding posts? I don’t know how audyssey handles marching a speaker to a subwoofer but I imagine the phase of the woofers matters but could be blended by the receiver with distance setting in the subwoofer.
Hello Elijahscott,
You mentioned that the woofers only have an inductor. So yes, this inductor produces a 1st order rolloff for the woofer. Yet the crossover for the midrange speakers is 2nd order. It normally is not a particularly great idea to mix 1st and 2nd order crossovers at the crossover frequency, yet this can be a good idea depending on the slopes of the speaker impedance curves around the crossover point if one curve is around twice as steep as the other. Just some info which you don't need to digest. Simply realize that choosing crossover points and the types of passive crossovers to use is a bit of an art, and that there are a few other factors to consider.
When you wired the woofers according to the diagram, you noticed a strong lack of bass around the 200Hz crossover point. This indicates that the woofers and the midranges are at least 90 degrees out of phase at the crossover point. You mentioned that when you reversed the polarity of the woofers, you noticed that the doing so fixed the null around the 200Hz crossover point. If you had the woofers at the same radial distance from you as the midrange/tweeter speakers, then this suggests that as originally wired, the woofers and midrange speakers are more than 90 degrees out of phase, and probably closer to being 180 degrees out of phase at the crossover point.
The simple thing to do is what you have already tried: Reverse the polarity of the woofers in order to get the woofers much more in phase with the midrange speakers.
I am not entirely clear about your original post. I assume that you ordered these crossovers in order to add center channel woofers to your speaker setup which consists of right and left channel 2-way speakers? If so, and after reversing the polarity of the wiring of the added woofers, you can then perform a trick to more finely tune the sound of the woofers so that they are much more in phase with the midrange speakers. As mentioned, the woofers originally were somewhere between 90 degrees to 180 degrees out of phase with the midrange speakers at the 200Hz crossover point. By reversing the polarity of the woofers, you noticed much stronger bass at the 200Hz crossover point. This means that, with the reversed polarity, the woofers now are less than 90 degrees out of phase with the midranges at the crossover point.
Now for the fun stuff...
Moving the woofers further back or further forward, relative to the distance of the 2-way speakers will now allow you to fine tune the phase relationship of the woofers relative to the 2-way speakers. So at 200Hz, how much distance corresponds for a 0 to 90 degree phase shift? The answer is a mere 34 inches in either in the forward or backward direction! Yet first, you need to fine tune the positions of the 2-way speakers...
Do the 2-way speakers have ports on the back of the speakers? If yes, then ideally the front side of these speakers should initially be placed approximately 34 inches from the wall behind them. Test moving the 2-way speakers up to twice as close to the wall or up to another foot further from the wall. Test by using an online tone generator set to 200Hz, and go for whatever distance produces the clearest 200Hz tone at your ideal listening position in the room. When you hear the clearest 200Hz tone (in terms of clarity, not volume) the position of the 2-way speakers from the wall behind them is now "dialed in."
If the 2-way speakers have ports on the front side of the speakers or no ports at all, then they can be placed close to the walls behind them.
After whichever of the above is done for the 2-way speakers, you can now hook up the woofers.
With the woofers now hooked up, you would then radially position the front sides of the woofers up to either plus or minus 34 inches relative to the radial distance of the front sides of the 2-way speakers in order to get the woofers in phase at your ideal listening position. Depending on whether or not you want to move the woofers further back or closer to you, you can experiment with either not reversing the polarity of the woofers or deliberately reversing the polarity of the woofers. Your room setup might not allow you to radially move the woofers further backwards for the best sound. Or perhaps your only choice is to move the woofers closer. This is why I mentioned that you might have to experiment with reversing the polarity of the woofers, or instead keeping the polarity the same as in the crossover diagram. Move the woofers in 6 inch steps and then continue to dial in the ideal position for the clearest sound from both the woofers and the 2-way speakers at the same time while listening to the 200Hz online tone generator. This is fun part of experimentation. You will quickly figure out what works the best.
The upshot is to experiment in order to see what works best for your room and the type of 2-way speakers that you have (front ported or back ported or no ports), and your chosen ideal listening position in the room. Some high end speakers are modular in which the midrange and tweeter speakers can be positioned either closer or further, such that the distance of the midrange speakers can be tweaked to within 1 inch and the distance of the tweeters can be tweaked to a fraction of an inch for ideal sound.
I hope that you are beginning to understand the concept of how radially positioning and perhaps the polarity of the subwoofers relative to the other speakers, in terms of distance from the room's ideal listening position, can dramatically reduce or nearly eliminate the perceived phase shift in order to prevent both dropouts and muddiness in sound around the crossover points for the woofers and the other speakers. As mentioned, listening to a 200Hz tone from an online tone generator will greatly help you dial everything in.
I generally am not a fan of center stage woofers, yet center stage woofers can sound very nice in a middle to larger sized room if the ideal listening position is perhaps a couch in the center of said middle to larger sized room. One might have to reduce the stereo separation (the distance between the pair of 2-way or 3-way Left and Right speakers) for the best clarity, or use a lower crossover frequency for the subwoofers (perhaps 120Hz or somewhat lower).
Best regards,
--GTP