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Hummingbird
Dayton DSA135-8 Aluminum Cone 5″ Midwoofer with Dynavox TD2801XL Tweeter
Active 2-way
This is the first time I’m working on Dayton’s Designer Series Aluminum Cone (DSA) woofer. From the Thiele & Small derived with my DATS, the DSA135-8 optimal volume is 7 liters for a bass reflex. It’ll be interesting to see whether I can get enough bass with such a small volume.
As for the treble, I’m testing out the Dynavox TD2801XL that I had for many years. I’ve never heard this tweeter before, so this is another unknown.
For convenience, the speaker is actively bi-amped with my Synergy amplifier. I set the internal DIP switches for 2.5kHz HP/LP at 18dB/oct. Microphone is at 24 ins, tweeter axis. Impulse Window = 5msec. No Smoothing applied. Frequencies below 500Hz are in Nearfield.
RAW Frequency Response of Dayton DSA135-8
Ported Box = 7 liters. Baffle Width = 8-1/8″
Fig 1 – Measurements below 500Hz are in Nearfield.
Crossing the Dayton DSA135-8 with Dynavox TD2801XL
fc = 2.5kHz • 18dB/oct
Fig 2 – Blue plot = DSA135-8. Red plot = TD2801XL.
Hummingbird Frequency Response
Fig 3 – Summed Response with TD2801XL wired in Reversed Phase
Hummingbird Toneburst Energy Storage (TES)
Fig 4 – DSA135-8 with TD2801XL. Crossover 2.5kHz, 18dB/oct
Hummingbird Harmonic Distortion
Fig 5 – Red plot = 2nd Harmonic. Violet plot = 3rd Harmonic.
How’s the Sound?
I like the Hummingbird very much. The DSA135-8 is exceptionally friendly to work with. It has a wonderful tonal balance. I did not have to use any Baffle Step Compensation network to tame the rising midrange. And best of all, no EQ is required to boost the bass. The midrange and the bass are perfectly balance, a rarity with 5″ midwoofers.
The Dynavox TD2801XL tweeter sounds excellent. It can hold it’s own when compared to other tweeters in the $35 price bracket. It would be fantastic if the manufacturer develops another version with a waveguide. That will solve the problem with the jaggedness in the treble response. Regardless of how flat the response depicted by manufacturers, all dome tweeters will suffer from by baffle edge diffraction when the tweeter is mounted onto a box.
This is another design that deserves a passive crossover. What I really love with the Hummingbird is it’s only 7 liters. It’s very compact for a 2-way. Great when space is a premium. |
