Help with under 300Hz for Monsoon MM-700 Planars

impedance of the planar panel

Monsoon-MM700-panelx1-imp.gif


dave
 

Thanks for the impedance curve. I measured it at 3 Ohms at static, and assumed it would 4 Ohm driven.
Bfb1963, do you plan using one sub under the table? Or two small woofers on the desk under the planars flanking the monitor?

I will be going with two small woofers under the planars and flanking the monitor. No subwoofer. The Monsoons have holes on their bottoms for the metal peg legs that I can use for dowels to connect it to the woofer module.

I originally was going with a 3rd order at 300Hz, because that is what the guy I bought them recommended. But if they were meant to be 250Hz, then I will go with the Bessel 3rd order at 250Hz you posted. I wont consider the Butterworth because one of the inductors needed is on backorder from PE.
 
I've never built a crossover from scratch before. Some of the inductor specifications are off a little. Is that OK? I do not want to do any unwinding since I can't measure inductance. And I understand that capacitors can be configured in parallel to meet specification.

L1 specified 1.58, available is 1.5
L2 specified 5.27, available is 5.0
L3 specified 1.05, available is 1.0
 
Well, if you are using two small woofers on the table, you can cross higher. Its totally up to you. If you cross higher, you can have lower order slopes, even just one cap for monsoons, utilizing more from woofers.
The whole point of steep crossover at lower frequencies was for sub not to be localized too much (which should still be much lower that 250/300, at least 150).
If you run two woofers higher, you save a lot on crossover. First, select what woofers are you going to use, then decide on crossover.
You can put inductors in series to obtain desired value, btw.
 
Well, if you are using two small woofers on the table, you can cross higher. Its totally up to you. If you cross higher, you can have lower order slopes, even just one cap for monsoons, utilizing more from woofers.
The whole point of steep crossover at lower frequencies was for sub not to be localized too much (which should still be much lower that 250/300, at least 150).
If you run two woofers higher, you save a lot on crossover. First, select what woofers are you going to use, then decide on crossover.
You can put inductors in series to obtain desired value, btw.
That was super informative. Like a light bulb moment. So, I have my woofers picked out, and just need a crossover point recommendation. Where would you like these planars to take over? And what slope would you recommend?
 
Looks like they would be happier at 500 Hz highpass.

Easy to do with 5 or 6" speaker for woofer.

I dont know the details of the brand.
Do they have a built in passive components?

Impedance curve on planers always impressively flat
so hard to tell what resonance is.
Looking at post #22 maybe about 230 / 240 Hz

basically double that to 500 Hz

or looking at measurements if their is passive
components in there, looks like blue channel has
drifted or anomaly/ reflection from measurements
 
Unless a speaker is measured in exactly the same way, it's hard to get the same results as someone else in a home environment. Or get identical results twice.

Are you proficient with in-room quasi-anechoic measurements? And the series of questions that go along with that:
What distance was the microphone from the speaker?
What windowing/gating was used? Was that sufficient to eliminate room reflections from the measurements? You seem to have a lot of resolution in your measurements, which makes me wonder.
Were the two units measured in exactly the same location with exactly the same microphone location?

The overall character of your measurements look similar to those shown at Liberty Instruments for a similar Monsoon product, other than the low end (which may be a result of your measurement method - it's hard to tell from here 🙂)
http://www.libinst.com/what_makes_a_speaker_sound_good.htm
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