Best active speaker

ATC specs are conservative (freestanding in open space). You certainly do not get "quantity" from ATC bass - their design is only about quality and approaching the performance of electronics in terms of distortion. The 150's are probably around 0.3% THD from 30 Hz upwards at live concert levels in a moderate room whereas most speakers have about at least 10% and often approaching 50% THD in the LF range - even when played at modest SPL's.

Most people are very surprised at the "lack of bass" from such as large speaker. As you don't get all the LF harmonic distortion that is normal for most other designs and increases the perceptive loudness of the bass - it takes a while to get used to the clean sound of 150's.

Can't go wrong with ATC but you know that.

Consider also Focal Twin 6 - a real bargain in active designs and obviously a step up from the passive electra 1007 (but you lose all that pretty and very expensive cosmetics for better sound and more expensive stuff inside the box).

Large PMC's have clones of ATC's famous mid range (emulation = sincerest form of flattery). So that is another extremely good choice with more bass on PMC's than with ATC. Plus the excellent Volt woofers with external brackets/heat sinks look like something out of a Batman movie - very very cool.

Finally Barefoot MM27 may be worth checking out if you want an extremely small package that will have people picking up their jaws off the floor when you fire them up.

kers.
ATC is very good but I must say very energy wasteful. The heatsinks are hot to touch even when not in use.I read in HDD forum according to AVIhifi founder which is an ex ATC engineer that he finds ATC outdated being that they are spending way too much money on old technology that can't compete with the current on

The amps are heavily biased Class A so yes they are still using some of the best OLD technology (no digital amps or DSP processing like with Meridian actives). They are also massively over-engineered and expensive and play much louder than most people need. Ashley has some not unfounded criticisms of ATC approach which is slow to incorporate the latest technologies that consumers expect. To be fair though, in the pro market the relative stability of their tried and proven bullet proof designs are seen as an advantage.

how does genelec compare to atc?

Put it this way, when George Massenburg built his latest studio (after 30 years as a renown recording engineer, equipment designer and university lecturer) he installed BOTH.

Ninety tons of MDF were cut and milled to a final cut weight of 40 tons. Beginning with a room footprint of 36' x 25' x 27', the one-inch square MDF pegs come out of the walls and ceiling in lengths that vary from 6 to 40 inches — and no two of the hundreds of thousands of “tines” are the same length.

Somehow, I don't think he cut corners on the speakers - personal preferences may lean one way or the other but both are good.

You can read more here

Another factor you should look into is that ATC don't put a lot of emphasis on cabinet resonance control.

The freestanding set of ATC's that Pink Floyd use have additional bracing inside. Many studios soffit mount them.

What really bothers me is ATC's treble extension

Indeed ATC focus on the range up to 12 KHz with soft dome tweeter (preferring damped type drivers over rigid types) - this design definitely rolls off earlier than some metal domes like the Be dome or designs with super-tweeter.