Chickadee – Dayton CX120-8 Coaxial (Pt 2)

Chickadee Crossover Revision

Fig 1 – Dayton CX120 Woofer Low Pass and Tweeter  High Pass • Baffle Width = 8″

The first response (Fig 1) has been bugging me. The woofer peak at 7.5kHz is too close to the tweeter. This interferes with the tweeter.

Fig 2 – New Woofer Low Pass

After sleeping over it, I decided to revise the crossover. The tweeter network remains the same but the woofer low pass filter was re-worked to attenuate the peak further. Fig 2 shows the woofer (Blue trace) with the new network. The peak is now suppressed by -10dB. This is a huge improvement over the previous low pass.

Fig 3 – Previous Response of Chickadee

Fig 4 – Improved Response of Chickadee

The two plots above clearly shows the improvement with the new low pass. In the previous summation (Fig 3), there’s cancellation in the tweeter from 5kHz~8kHz. With the revised crossover (Fig 4), the tweeter cancellation disappeared.

Fig 5 – Final Response of Chickadee

Fig 5 is the response of the Chickadee with the crossover updated. It is difficult to distinguish between the earlier response and this one but the cancellations are clearly visible in Fig 3.

Fig 6 – Previous Null Response of Chickadee

Fig 7 – Improved Null Response of Chickadee

Fig 6 is the previous null response with cancellations in the crossover passband. Fig 7 is with the new low pass filter for the woofer. This new null is narrower and deeper. 

Fig 8 – Previous Chickadee WaterfallFig 9 – New Chickadee Waterfall

In the new Waterfall (Fig 9), the artifact at 7kHz is greatly reduced. That’s the result of suppressing the peak.

Sound of New Crossover

The Chickadee sounds more intimate with this low pass revision. Vocals are clearer and more distinct. Best of all, the cymbals don’t exhibit that light brittleness as before.

Frankly, I am quite pleased with this crossover. There are only a total of six components – two for the tweeter high pass, two for the woofer low pass and a pair for the zobel. It’s not often I used so few parts and end up with a sound I’m proud of.

Summary

Initially, I was skeptical whether this Dayton CX120-8 Coaxial is of any good. Having corrected the crossover and living with her for a few days, she’s beginning to seduce me. The music is highly focused, as what one would expect from a point source. Projection is excellent too. This small 4″ throws the sound just like a horn speaker.

The Dayton CX120-8 is affordably priced at $32.98 (Parts-Express). For this level of sound quality, she’s fantastic value for money. 

Unless otherwise stated, all measurements were made in Full Space (4 pi) with the mic at 36 ins, tweeter axis. Impulse Window=5ms. No smoothing applied.