Focal Scala or Diablos with subs?

If I were you I would try first to integrate your Diablo with your current sub before taking a final decision. Read this post for more info about sub integration:

SubWoofer Help ASAP...

If however, the upgrade bug has bitten you already, then I would proceed with caution. Please do not take this the wrong way, but for somebody into hi-end audio who's father is a sound engineer your knowledge is surprisingly limited. I will try to clarify my statement as it is not intended to be arrogant.

Firstly, there are three main advantages of sub-monitors combos over large speakers: 1) the ability to place the sub in the place that will give you the best bass response, and 2) isolate the monitors from the strong vibrations generated by the subwoofer, and 3) the ability to place the monitor in the room in the position that will yield the most natural midrange and the best stereo image. Placing the Diablos on top of the subwoofers will negate the first two advantages.

Secondly, unless your speakers are symmetrically placed with respects to all room boundaries (often not even then) the response of the two speakers will never be the same. The larger the speaker the more it will interact with the room. Now, because of this, and also because you mention that the position of the speakers and listening chair are basically fixed, it is more likely that a sub monitor combo will work better than large speakers. However, since every room is different one can never be sure of this. (The Scalas have the bass adjustment knobs so they are more flexible than "normal" speakers.)

My advise will be to try to convince the dealer to bring the Scalas to you home. Make a deal with him, e.g. if you do not keep the Scalas you will pay him by the hour. Also, I would not trade in the Diablo but try to sell them myself (but this depends on where you are located). The Diablo are rather rare on the 2nd hand market so chances are you will get a better price for them than your dealer will offer you.

Finally, I want to make a comment about (2nd hand) Focal Scala speakers. For whatever reason I have seen quite a few Scala on the 2nd hand market (here in Europe they go as low as 12k euros). I've even started a thread about this here on audiogon but did not find out much why this is the case. Probably just a coincidence...

Good luck and keep us posted.
Paul

I see you use an old Rel subwoofer. I sold these 10 years ago. For stereo they are much toooooooo slow. For stereo use subwoofers without bass reflex and the speaker unit should be single and placed in front. With Audessey pro I became fully stealth subwoofer sound with my speakers. Rel is always toooo slow. Wenn I use my own music you can easily here it is not synchroon with the speakers.

neuphonix - my comment might be too late, but just the same I'll share with you my experience. We have the same size of room and with it are focal scala speakers and pass labs xa 100.5 power amps. The latest addition to my audio equipment is the musical fidelity primo preamp. Having a tube preamp and a solid state power amp makes it a hybrid. The speakers and the preamp are still in the break in stage but I want to believe that it can only get better. Perfect match . . . almost any type of music sound with great clarity, deep and wide soundstage. I think the TT, cd player, interconnects, power cords and my room acoustic treatment contributed to the great sound as well.
I also took the risk with the scala . . . just got lucky.
Hope you made the right decision.

Bo1972, I believe your comment about the REL was address to me. Firstly, IMO the concept of slow subwoofer is a misnomer. Most often it is the resonances in the room that give one the impression that a sub is slow, i.e. bass notes hang into the room too long. This is most often a problem with the set-up and with the room. Secondly, while indeed a old subwoofer, the REL Stentor 3 is certainly not a bad subwoofer (I had great results with it with and without electronic room correction). Surely, there are much better subs these days, but this has nothing to do with the OP's original question. Finally, thanks for reminding me to update my system page.

Neuphonix, I have re-read me initial post. I am sorry for being so bold. I was probably not that happy to realize that in 10-15 year my daughter me also not know that much about drums or speaker set-up or things that I do for living (e.g. physics, math, programing). :)

I sold the more expensive Rel subwoofers in the past. The difference for newer subwoofers is quite big. Downfyring and bassreflex does not make is more easy. Bassreflex makes a sub always slower. Downfyring means bigger chanches for acoustic problems. The older Rel subwoofers are difficult to use in higher freq. like 120 hz. The become noisy and the sound is not that tight anymore. The use of Audessey Pro and my Monitor Audio PlW-15 makes is very easy to use to 120 hz. The integration with the speakers become extreemly stealth. To be unnest I never thought this would be even possible. To use it to 120 hz makes the integration go to a new level which most people never heard. Voices and instruments are so much better focussed and more 3d as well. I had a few highend systems always without sub's Like The Nautilus 800S. Now with Audessey pro and my Monitor Audio PLW-15 I have superior low freq starting from 16hz. Many of my clients with highend systems call my subwoofer voodoo. Because they are stunned about the stealth integration of the whole sound.