A6-6T6 Build Quality (cont.) and Measurements

The speakers are 40" high with the tweeter about 36.5" off the ground (just a hair above my seated ear level). The sides are rounded which gives the speakers sort of a bloated look (that sounds worse than I mean it). I've had experience with a lot of different speaker designs and one thing I've found with the ones with the rounded sides is they tend to be less sturdy. With the carpet spikes that don't penetrate the carpet, my medium pile carpet, and rounded sides of the speaker, I ended up with a speaker that wasn't as steady as I'd have liked. I never got the impression that it would tip over, though, so unless you have really active kids or a Great Dane, you should be alright.

The back of the speakers sport a single set of five way binding posts in a plastic housing. This is pretty standard stuff including the binding posts which are of the gold plated post but plastic top variety. You'll recognize these as similar to the ones that are included on the back of most A/V receivers. At this price point, 5-way binding posts are most likely a cut above the competition which probably sport the spring type. At least you can use banana plugs with them. I also commend eD for restraining from putting dual binding posts on the back for bi-wiring. This would have been a ridiculous addition that would have added unnecessary cost to a budget speaker.

Opening the speakers, I noticed a few things. First, the two ports vent two different chambers of the speaker. The first chamber (from the top) includes the tweeter and first woofer. The second chamber has the bottom two woofers and the rest of the speaker length. The edges all have additional bracing. Each chamber has one other brace running horizontal. Since the top chamber is smaller, this makes that one much more inert than the bottom. This is borne out by the "knock" test which showed the bottom chamber ringing much more.

The woofers employ stamped baskets and small magnets. I was particularly surprised at how light these drivers were. The tweeter has an open back (something I haven't seen for a while) instead of a metal or plastic enclosure. Behind the drivers around the sides and back is a single piece of polyfil. The crossover contains two air core inductors, one for the high pass section and the other for the low pass section. Though they aren’t orthogonally oriented to reduce crosstalk effects, they are spaced far enough apart to minimize any audible effects. A polyester bypass capacitor is used in conjunction with two electrolytics for the HPF section of the speaker system.

Though the eD website claims the drivers are video shielded and even show the metal can usually employed for this application, there was no steel can encasing the motor. This should still provide adequate shielding if not placed directly on a CRT type TV’s. Glancing over the website, most of the information is accurate about the speakers design (including the technical drawings) though the claim that the widened base increases stability is dubious at best. If it is wider than the body, it is millimeters wider. If they really want to increase stability, they are going to have to substantially expand the base. Also, the drawing of the spikes in no way resembles what I received. In their defense, the picture of the base in the gallery clearly shows how wide the base is and the actual spikes you'll be receiving.

Set-Up

Inserting the spikes took a matter of moments. As I mentioned, the balls on the tips allowed the spikes to enter the carpet but not pierce it which meant that no fine adjustment was necessary. Using a few of my favorite test discs, I played around with placement. Imaging was significantly better with the speakers pointed directly at me but highs were tamed when they were pointed straight out (putting me off-axis). I compromised by toeing them in slightly. I placed the speakers no closer than 2.5 feet from any wall to reduce any bass boosting affects that close boundaries might provide.

Measurements & Testing

For laboratory measurements I used the Sencore SP395A FFT Audio Analyzer and a Sherbourn 2/75B amp, I measured the A6-6T6's in room on and off-axis frequency response with 1/12th octave resolution. Like most speaker manufacturers, eD lists the frequency response of their speakers on their site. Also like most speaker manufacturers, their graph resembles mine in a "had the same father but different moms" sort of way.

A6-6T6 1 watt/1 Meter Frequency Response (1/12th Octave) On Axis

A6-6T6 1/2 Meter Frequency Response (1/12th Octave)
Pink - On axis, Orange - 15 degrees off axis, Yellow - 30 degrees off axis

A6-6T6 Impedance

The Sencore consistently measures impedance one ohm low. From a close examination of the above impedance magnitude, it is clear the A6-6T6 low passes the woofer at 2000hz, while the tweeter is crossover over considerably higher, closer to 6000 Hz. This may be for a number of reasons, but the resultant frequency response both on and off axis clearly shows a significant droop in the overall output between 1000 and 4000 Hz. The problem with errors in this part of the frequency range is that human hearing is particularly acute in this region, and not terribly forgiving of mistakes.

The octaves on either side of 2000hz result in the greatest contribution to intelligibility more than any other two octaves in the audible range. As Paul Klipsch was known to say, “We live in the midrange”. A better crossover design would likely have minimized if not eliminated this problem entirely.