Sonics of Soundlabs

Thanks all for your very thoughtful responses. The guy has told me he just installed new cores (is this the transformer that changes the impedence curve, making the speaker more efficient?). Are there any issues to look for when purchasing Soundlab speakers used? Are the newer production models different than the older ones in any other way or, is it just the cores that have been changed?

Thanks again........... I'll be going to check these babies out later this week.

Chris

The laws of physics are immutable (except for quantum physics which we'll leave aside for now). At sea level, at 68 deg. F., sound travels at 1127 ft/sec.

So the length of a 20 cycle/sec sound wave at sea level at 68 deg. F. in free air is 1127 divided by 20, or ~56 feet (that's for a full sine wave.) To realize the full intensity of this wave in an enclosed room, as produced by the speaker, the room must have at least one dimension equal to or greater than half that length (28 feet). This can be measured from a top corner (at the ceiling) to a diagonally opposite bottom corner (at the floor.)

If that criteria is not met, then the wave cannot develop fully, and although you will still hear the 20 cycle sound, it will require more and more bass boost (as the room gets smaller and smaller) in order to realize a flat room response (assuming the speaker is producing a flat frequencey response)

No amount of "treatment" can increase the physical size of a room. Judiciously placed absorption and traps can only kill unwanted reflections which compromise the soundstage image (particularly sidewall reflections). If you kill all the reflections (as in an anechoic room) then you are listening to the loudspeakers' direct frontal output (100% nearfield) just as if they were a pair of great big headphones.

These principles apply to all loudspeakers, not just Soundlabs. However most loudspeakers can't match both the output and frequency range of products like Soundlabs, Wilsons, etc. etc.

If you're going to buy a pair of speakers that can do what Soundlabs can do, then you owe it to both yourself, and the speakers, to provide them with an environment that allows them to "be all they can be," meaning to fully "breathe" in all directions. The optimum size (i.e. the opposite of an anecohic room) would be one in which the larger dimension was somewhere around that of a full 20 cycle wave, say 30x50 feet. Some people have even suggested that outside would be best, but that is incorrect. Outdoors, the sound just goes off in all directions and never comes back -- the same as in an anechoic room; and in both cases, the effect would be one of listening to giant headphones!

Keep in mind that the room dimension issues above apply to all speakers, not just Sound Labs. I have found that having the capability is more convincing regardless of the size of the room.

Also keep in mind that to drive Sound Labs you must use a tube amplifier for best results. If you use the VT 200, play with the taps on the transformer as you may be surprised by which taps to what to the sound. Generally Sound Labs, like most other ESLs, prefer a low feedback amplifier to get the most out them. This can get tricky as low feedback amplifiers generally will behave very differently depending on their output power and output impedance, but the speakers make it quite evident that taking this care is clearly worthwhile!

Atmasphere -- I believe I did mention that in my post :~)

These principles apply to all loudspeakers, not just Soundlabs. However most loudspeakers can't match both the output and frequency range of products like Soundlabs, Wilsons, etc. etc.

You guys have it backwards concerning room size. Once you get a wavelength that is longer than the room, you get what is termed room gain, on the order of 12db/per octave. (In an actual room it is less due to the walls flexing and losses through the walls, but the gain is there). Smaller rooms = more bass.