Algonquin Measurements & Analysis
Algonquin Impedance / Phase Measurements
System impedance dipped a bit below 6-ohms in the lower frequencies but considering the relatively high efficiency of the design, it's safe to rate them as 8-ohm speakers. The impedance minimum was located near the tuning frequency at around 52Hz. The system phase response maintained well under +-30 degrees which was to be expected considering the low order filter networks employed. This makes for a very easy speaker load to drive my virtually any home theater receiver available these days.
Algonquin In Room 1/2
Meter Frequency Response (1/6th octave smoothed)
Red – on axis centered,
Yellow – on-axis woofer
The Algonquins looked best when the measurement mic was at the height of the woofer's center. At this position, I measured a frequency response +-3dB from 70Hz to about 19kHz. There is a slight "oil can" resonant mode prevalent around 18kHz on the tweeter but this is pretty normal as far as metal domes go. When I placed the mic centered between the woofer and tweeter 1/2 meter away, the tweeter's output appeared to be a few dB hot above 10kHz. Thus I decided to take a more precise summed nearfield measurement to see what was going on.
Algonquin Summed Nearfield Frequency Response
Measuring the tweeter at 1 meter, I scaled the response to match the woofer and port nearfield measurements and applied a minimum phase transform to properly integrate all 3 measurements. Aside from the same null I found around 8kHz, the overall combined measurement seemed to correlate more closely with Axioms results from their anechoic chamber.
Algonquin 1/2 Meter
On/Off Axis Frequency Response
Red – on axis; Blue –
15 deg off axis; Purple – 30 deg off
axis
Given the rather ample tweeter output of the Algonquins, I recommend little to no toe-in. In fact, before I pulled any measurements and did some listening experiments of my own, I found they sounded best with no toe-in and with the tweeters slightly above ear level. This is pretty much how most people will use these speakers in an outdoor type of environment.
Frequency Response Comparison of the Algonquin vs the Klipsch AW-525
I was curious to see how these two speakers compared measurement wise so I pulled a quick 1/2 meter response for each. It's clear that the Axioms have superior bass extension, no surprises there thanks to the larger woofer in a ported cabinet. The Klipsch's measured about 5dB more efficient so although they don't have quite the same power handling (75 watts as opposed to 175 watts of the Axioms), they will still play about 1.3 dB louder at their rated power limits though that doesn’t imply they will sound as good doing it.
Noise Leakage Test
When I ran low frequency sweeps from 300Hz down to 20Hz, I found a minor cabinet resonance centered around 145Hz which actually became more evident when I placed pressure on the top side particularly on one of the cabinets. In comparison however, the Klipsch cabinet became quite noisy below 100Hz and even rattled in the 20-25Hz regions. However, this wasn't something that was discernable under normal listening conditions. Neither speakers are a direct substitute for a good old fashion MDF design, but both will surely stand up better against the harsh outdoor weather conditions. Thus the slight compromise in controlling cabinet resonance over durability is certainly a sensible tradeoff.
