Pros and Cons of built-in amps?

The PMC website is www.pmc-speakers.com. Meanwhile, try to pick up Hi-Fi+ Issue #30. The have several articles on active loudspeakers including separate reviews of the PMC AML 1's and the ATC Active 20. Then there is a separate article comparing the merits and shortcomings of both. This issue is indispensible if this is where your interest is. I hope this helps everyone.

Do yourself a big favor and find a PMC dealer. Then listen to a pair of properly broken in AML-1's with music with which you are familiar. I replaced Avalon Eidolons with these and, as fine as the Eidolons are, I would never consider anything other than transmission line bass with active dedicated electronics and no speaker cables.

Ryder, I never compared the AML-1's to any other PMC speaker. I would like to add two reviews if any of you are interested in the PMC AML-1's. The 6 Moons website did a very detailed review with a complete description of the construction and circuitry. It is in their archives and was posted in August, 2005. The other is in Audio Ideas Guide, a quarterly Canadian publication. They have a website and an archive section. The speaker was reviewed in Fall, 2001 and it has measurements. These reviews together should answer many questions. Check out Audio Circle under "Bryston" for even more information. There was a thread running there for these speakers with some pictures as well, it is about 4 or 5 pages in.

Hi Ryder: No subwoofer, not necessary. I am hearing all i need to without complicating the system. Frankly, the bass is equivalent in depth to the Eidolon's, minus about 2db. I have a dedicated listening room conducive to lower frequencies. Perfect bass integration with dissimilar cabinets and drivers can be quite illusive! I must note I listen primarily to Classical & Jazz.

Hello again Ryder! I should qualify the previous post. I measure to 30 Hz in my room at about 2 db down. The Eidolons ($25,000 with the Walnut Burl upgrade) measured 1 db down and 3 db down at 28 Hz in the same room. Now, you know the size of the AML-1's. They use a flat piston instead of a cone for the low frequencies. The motor assembly is about the size of the piston. This is feeding into a 5 1/2 foot transmission line from the rear of the piston. You cannot visually detect the piston moving at loud listening levels! The Eidolons weighed 150 lbs, were a 3 way with an 11" woofer and a vertical port with a very complex passive crossover network and a costly cabinet. I think the AML-1's are now about $10,000 due to the falling dollar. In this context however, they are still a bargain considering you get the amplifiers, electronic crossovers, equalizers and do not need to pay for the glorified fixed frequency tone controls called speaker cable. Plus, I feel the overall performance is improved. As a bonus, my friends need not fear a hernia whenever I decide to re-arrange the listening room where I now have more square footage left over!

To Paul: What about soundwaves traveling through air or floor hitting the tubes in free standing amplifiers? I do not detect any evidence of "shaking" electronics, Doppler distortion or distortion of any kind in the PMC AML-1's. I would assume any design requires proper implementation to succeed. Audiophiles just will not give an active speaker system a chance. Could it be that it is not about the music, as they are fond of saying, but the new equipment of the month that they are so passionate about? Find a PMC dealer. Listen to a properly broken in pair. Then fairly criticize if you can.

Mr Tennis: When you are about to purchase a loudspeaker do you try every amplifier in the market to test its compatability with it? Or, when you buy an amplifier do you do the same with every loudspeaker manufactured? If not, how do you know you are making the best use of your monetary resources? Maybe there is still a better amp or speaker out there you haven't tried and would sound even better in your system than the component you settled on. I assume the designer of the active system is a degreed and experienced engineer who wants to maximize the potential of his design and has taken the strengths and deficiencies of both the electronics and drivers he has chosen into account before that system is put on the market. Your freedom of choice is limited by geography, cost and experience.

Dave thinks vacuum tubes make the best amplifier designs. Two of the greatest enemies of the longevity of electronics are heat and dust. What do we have with tube circuitry we do not have with solid state designs: heat, dust, microphonics, phase shifts from the output transformers, weight, degradation of the tubes which will continue to deteriorate everytime they are powered never sounding the same way twice, tubes acting as RF antennas, tube replacement cost, bias adjustments, a rise of ambient heat in the room, poor damping factor because of those same transformers, limited high frequency response, questionable resale value due to a very limited market, among other things. Yes, it is too bad tube circuitry cannot be incorporated into an active design! I guess active designs must be inferior and poor value. I wish my computer had tubes. I have an empty room i could use to contain it.

For Bob Reynolds: I like the way you think. I am intolerant of those who condemn an entire design on belief and prejudice exclusively and not on research and experience. Ultimately, sound appeals to taste but many circuitry implementations are nothing more than glorified and expensive tone controls. Worship often excludes truth, accuracy and adherence to an objective standard.

This discussion should be helpful and fun rather than descend into a heated debate between the members of The Flat Earth Society and National Geographic!