Crossover frequency/order question

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I am building a 3 way WMMT using a Dayton RS270. I am crossing over to 2 mids that are 6 1/2 and can handle low frequency pretty good. So I was thinking 325/350hz first order between W/M. But now that I think of it, the Dayton is an aluminum cone. Should I go second order? I prefer to stay first order.
 
Hi,

Your not really asking the right question, why on earth would you need
two 6.5" midranges for a 10" bass unit, you simply don't at all in reality.
One 5" is fine at that sort of x/o point, and far better than two 6.5".
Given baffle step midrange and treble need to be 85 to 87 dB.

rgds, sreten.
 
The point of crossover is good ;)
And you can stay first electrical order. Just put a notch/trap to remove the break up peak.

I'm not shocked by 2x6.5" for polar response reasons if MTM but MMT :confused: . One 6.5" is enough if MT and you should not go below 6.5" (130cm²) because of the 300Hz point of crossover frequency. A 5" below 500Hz is not ease. But 2x5" could do things good :)
 
If you cross at 350 and notch at 1200 where the nasty breakup is, you are in effect creating a Chusser eliptical.
Cross at 600 with the notch at 1200, and you should be able to tune to LR4 Acustic. ;)
I have an OB with two RS270, and I get off them at 320 Hz, LR4 electrical (Active)
Great Low distortion drivers in their range.
 
Hi jimbones,

Drop the unnecessary extra mid-range as already suggested, and don't be afraid of higher order or most especially, mixed order crossovers. When you factor the effects of the baffle, the listening position, (most people actually always listen off axis), driver offsets and such, you will often get the best results with mixed order x-overs that creatively utilise components. Mixed order is, IMO, often the only way to achieve desirable symmetry and phase alignment in the real world.

If you would like help with the crossover, I'd be happy to help.

I will need the following:

Driver response charts and impedance charts (either 3rd party measurements that you trust, your own measurements,, or manufacture).

T/S and/or mechanical/electrical specifications of all drivers.

Box dimensions (for both the bass and mid-range units in this case!), and if you already have this planned, the driver positions, or better, allow me to select the best position on the baffle for the drivers based on simulation. I you have none of this planned, I'll provide input. I can't work on a crossover simulation until we have a box design and a good feel for box's relative position to various boundaries.

Intended listening position relative to speakers. (ear height and distance from speakers of a typical listener in the "captains chair" of the room).

Intended spacing between speakers.

Intended orientation of speakers (parallel with walls for cosmetics, or tow-in for on-axis listening at the "captains position?")

Regards,
Eric
 
Free Mids

Hi,

Your not really asking the right question, why on earth would you need
two 6.5" midranges for a 10" bass unit, you simply don't at all in reality.
One 5" is fine at that sort of x/o point, and far better than two 6.5".
Given baffle step midrange and treble need to be 85 to 87 dB.

rgds, sreten.

I already had the Mids from a prior project so I save some $. I can use just one.
 
The point of crossover is good ;)
And you can stay first electrical order. Just put a notch/trap to remove the break up peak.

I'm not shocked by 2x6.5" for polar response reasons if MTM but MMT :confused: . One 6.5" is enough if MT and you should not go below 6.5" (130cm²) because of the 300Hz point of crossover frequency. A 5" below 500Hz is not ease. But 2x5" could do things good :)

I think I will start with only one mid. thanks.
I never designed a notch filter though. link?
 
Hi jimbones,

Drop the unnecessary extra mid-range as already suggested, and don't be afraid of higher order or most especially, mixed order crossovers. When you factor the effects of the baffle, the listening position, (most people actually always listen off axis), driver offsets and such, you will often get the best results with mixed order x-overs that creatively utilise components. Mixed order is, IMO, often the only way to achieve desirable symmetry and phase alignment in the real world.

If you would like help with the crossover, I'd be happy to help.

I will need the following:

Driver response charts and impedance charts (either 3rd party measurements that you trust, your own measurements,, or manufacture).

T/S and/or mechanical/electrical specifications of all drivers.

Box dimensions (for both the bass and mid-range units in this case!), and if you already have this planned, the driver positions, or better, allow me to select the best position on the baffle for the drivers based on simulation. I you have none of this planned, I'll provide input. I can't work on a crossover simulation until we have a box design and a good feel for box's relative position to various boundaries.

Intended listening position relative to speakers. (ear height and distance from speakers of a typical listener in the "captains chair" of the room).

Intended spacing between speakers.

Intended orientation of speakers (parallel with walls for cosmetics, or tow-in for on-axis listening at the "captains position?")

Regards,
Eric

I have or can get most of this info. However Dayton doesn't publish frequency response curves :mad:. I really appreciate the advice that you and everyone on the board is giving me. I answered your response on PE forum also with details of design. Thanks All!!!
 
Breaking up is hard to do!

Whoa!!!:eek:

Had i seen that strange behavior past 1khz I may not have purchased this woofer!! looking at that spec makes my mids look pretty good!! :p

Ok so it looks like I definitely need a 2nd order (or more?) filter. the other alternative is Jerome posted a notch filter for me. So i could go first order with a notch. Trial the 6 1/2 mid on its own baffle and if it doesn't work get another driver.
 
Eric, when you say mixed order crossovers I assume you mean that for different xo points not at the same xo point. correct? I wouldn't have a HP 2nd order at 350hz and a 1st order LP at 350hz? :h_ache:

Mixed order means that you may very well have a high pass and low pass targeting the same "x-over frequency" that are different order slopes electrically, in order to produce symmetrical slopes, in phase, acoustically.

Eric
 
Old Dog learning old tricks

Mixed order means that you may very well have a high pass and low pass targeting the same "x-over frequency" that are different order slopes electrically, in order to produce symmetrical slopes, in phase, acoustically.

Eric

Great. When designing I sometimes needed to do that but for some reason I thought it was taboo. OK so put a steep slope on the Rs270 and a shallow one on the Dynaudios. Sent you PM
 
if you pick a big enough '1st order' coil to roll off the response slightly, around youre 6dB rate, you can always add a notch filter higher up, or maybe just a capacitor?

You should be able to get a drooping curve, with a breakpoint, after which it rolls off at a faster rate.

There are free crossover simulators, and other things around the internet. Others here far more than I about them, so perhaps someone can recommend?
 
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