The Andromeda, or building a reference speaker
By Tony Gee
02 Apr 2000
The result
Positioning.
These loudspeakers where not designed to stand on a bookshelf or in a corner, they need some space. Placing any loudspeaker close to a wall or furniture will alter the tonal balance.
I have a listening-room of 36 square metres where my favourite listening seat is placed in the middle. The front of the loudspeakers is 120cm from the rear wall and the outer corners are 110cm from the sidewalls. In this position there are hardly any noticeable room resonances in the bass. Fig. 14. My listening-room
Was it worth it?
I suppose by now you are wondering what they sound like. Well, everyone who has heard them so far is left speechless! Usually when people listen to a new set of loudspeakers they say things while they are listening like: "Wow, that is impressive bass" or "I never knew that was on the CD". But when they hear these loudspeakers for the first time they say nothing until after listening to about three tracks of various CDs they finally come back to earth. Of course I am biased, but they are very good! They radiate a sort of authority and calmness.
At first you might think there is not much bass, but the sound is totally free from the boom and boxiness that you are used to with ordinary designs. But when the T-Rex from Jurassic Park breathes, the doors and windows rattle!
Stereo imaging is excellent. The sound stage is wide and deep. You can pinpoint the players in an orchestra, not only in depth but also in height. The sound does not come from two loudspeakers, it is just there.
Hearing the differences between cables or between CD-players is easy. The amount of detail is amazing. Not only in the treble but also all the way down to the low bass. There is no preference for bass, mid or treble, it all melts into one.
The total impression is one of a very natural and neutral sounding loudspeaker with a large bandwidth, a big sound stage and excellent dynamics. There is just one big problem! I will have to trade-in my Denon PMA-860 amplifier / Marantz CD-67 SE CD player for a Mark Levinson set to be able to hear what these speakers really can do!
Measurements.
Here are three graphs showing the amplitude output corrected for 1watt/1meter showing an efficiency of about 90dB slowly dropping 1,5dBs up to the upper treble suggesting a warm sounding loudspeaker. Fig. 17. SPL output
The impedance curve is very smooth creating an easy load for any amplifier. Fig. 18. The impedance graph
In the voltage output you can clearly see the suck-out at 2kHz on the woofer that mirrors the peak caused by cone break-up. Fig. 19. The voltage output graph
Epilogue.
All in all it has taken me more than a year to build these loudspeakers and I am very pleased with the result. They are the best loudspeakers I have ever built and I would love to be able to compare them with a Wilson Audio Watt/Puppy or a JM Lab Utopia. But for me loudspeaker building is a never-ending story in which I keep asking myself, can I make something even better than last time? So I am going to sell these loudspeakers and start all over again. How about two Focal Audiom 13KXs, or maybe an Audiom 15KX? Then I would need an 8-inch mid-woofer, the Eton 8-472/32HEX looks interesting, then I could use a separate upper-mid driver, maybe something from Thiel or what about the Dynaudio M-560D Esotar? If I used a dome for th............
NOTE: This design is strictly for the home enthousiast and not to be used professionally without my permission!
Tony Gee
The Netherlands
|
Top
