Part #300-455 MK402 Crossover Question

[FredT]

Product description: "The crossover featured in this design utilizes a 2.5 kHz, 2nd order low pass and a 3rd order high pass, both utilizing acoustical slopes". The user manual: "Crossover: 2.5kHz, 1st order low pass, 2nd order high pass". I assume this describes the electrical crossover. When I look at the actual crossover board I see a 0.45mH inductor, a 4uF electrolytic capacitor, a 0.33uF poly capacitor, and a 1 ohm resistor. There are no other parts hidden under the circuit board. So how does one get a 1st order low pass and a 2nd order high pass with one inductor, two caps, and one resistor? What am I not understanding? https://www.parts-express.com/dayton...-pair--300-455

[thekorvers]

http://techtalk.parts-express.com/fo...62#post1352262

[FredT]

OK, thanks.

[FredT]

I was hoping to use these speakers in a small system at my condo, but the upper treble is distractingly bright.

[Chris Roemer]

You could experiment adding a little series resistance ( 1 or 2 ohms, to taste? ) in front of the tweeter's filter (on amp end).

[Whitneyville1]

Chris R, are the pair you have broken-in enough to give me an idea of how your's sound? With my HF roll-off in my hearing, they might be just what I need for computer speakers (pushed by a Dayton DTA-100 amp). Thanks in advance-Ricky-Pooh

[FredT]

You could experiment adding a little series resistance ( 1 or 2 ohms, to taste? ) in front of the tweeter's filter (on amp end).

I thought about that. It would be easy to replace the 1 ohm series resistor with a 2 or 3 ohm. The overall sound of this speaker is very good except for the tizzy upper treble. Measurement indicates reasonably flat response up to 7kHz, and then a rise in the response between 7kHz and 16kHz. The 16kHz peak is about 4 or 5 dB.

[johnnyrichards]

That sounds like it could just as easily be a poor crossover on the woofer - don't be surprised if a resistor mod doesn't do as much as you want it to do.

[FredT]

This is an attempt to post the Omni Mic frequency response. Have never tried to post a bmp file before, so the picture may not appear. If you can see the photo it will be clear this speaker is well behaved up to 7kHz. There's a peak at about 60Hz that some purists might not like, but it sounds very natural and pleasant at reasonable volume levels. Unfortunately, that upper treble peak doesn't sound so natural. The speakers have only about 10 hours playing time, but I don't expect the peak to go away with more time.

[FredT]

Could the rising frequency response of the tweeter be controlled with a notch filter? See my photo above.

[johnnyrichards]

I think it would be beneficial to see individual drivers before talking fixes.

[FredT]

I think it would be beneficial to see individual drivers before talking fixes.

OK, I'm headed out of town this morning, but I'll measure the drivers separately when I return next week.

[fbov]

...The overall sound of this speaker is very good except for the tizzy upper treble. Measurement indicates reasonably flat response up to 7kHz, and then a rise in the response between 7kHz and 16kHz. The 16kHz peak is about 4 or 5 dB.

Sounds like a job for the "treble" knob...

You're among the many here who might not appreciate the "very airy top end" or agree that it "create(s) a beautiful ambiance" to quote the product highlights. Expectations must be tempered when talking about a $70 2-way, ready-to-use speaker. A little EQ may be a quick and effective approach. It's hard to dial in a resistor value with hardware, and I don't believe there are any simulations of this XO/driver combo available.

Have fun,
Frank