Focal Scala or Diablos with subs?

The Tact Millenium MK2 which I sold to one of my best friends I don't think it is that special. The latest Lyngdorf demo's were not that special. Wenn you look at depth, it is quite poor. Individual focus is okay but never stunning. Most important part the sound. It is not the best sounding amp. Even classical music is not that involving. In real in still sounds a lot different. We do every week new tests with Audyssey Pro and it is great. Sound is improving by Audyssey. Stage is becomming wider and deeper. I even had not such a deep and wide stage witht my Pass labs XP-20. Low freq go very deep, are tight with lot's of defined details. Focus is stunning. And there is a lot of air around voices. There is even a lot of black. I do not say that it is an easy system. There is no room for mistakes. And you have to work and think very precise. After that the results are great. I like the system a lot and it is so much fun to work with.

Bo1972, the Lyngdorf room correction system can indeed suck the life and emotion out of a system. However, IMO that happens only when the unit is misused, e.g. one has a lively room and runs the room correction procedure too many times in order to obtain a perfect response.

If I remember correctly the Lyngdorf room correction module lets one know how much correction have been applied. Of course, things will not sound good if 20 - 30 % corrections were applied. One should understand that room correction should be done as little as possible and only in the last stage of the set-up. That is, only after everything else was optimized properly.

In the past I sold Tact, to be unnest I never was convinced about the quality. The lyngdorf makes a big misstake. The sound is loosing it's emotion. People even call it dead. Audessey Pro give a more musical sound. The test I did with the Velodyne were all too slow. Buy Jacintha is her name. use track 6. The controbass need to be small in dimension also wenn you use the sub. Wenn it changes and voices and instruments become bigger or you image gets less focused it is too slow. For me it is that obvious. Scalas are even sols for less than 12000 euro. I still prefer the mid's of a three way system compared to a monitor. That is why I now use the Monitor Audio PL-200 with the PLW-15. This gives me stealth low quality starts from 16 hz. Speakers which can play to 117db without stress. And extreemly 3d holographic sound. It is stunning because with my Pass I play about 4 metres behind the speakers, mote than 1 metre beside the speakers. Even some recordings soms parts play beside and in front of you. This make the stage even bigger. But I even got an extreme sharp focus of voices and instruments within the deep and wide stage. Wenn you are in this business and yoy hear so many systems. My goal was: I want everything in my system. Wenn you use the right stuff at the end it is possible. Just use those tools who have the properties to make this happen!

Tubesrule, Scala seems to be very flexible. Not only it allows one to adjust the level of the bass and treble, but one can also adjust the position of the tweeter and midrange drivers to time align them at the listening position. IMO these are very important features that can make a huge difference if used properly. I do not think Viva has these features. Also, the Scalas go much lower than the Vivas.

Neuphonix, room correction systems can make a huge difference in the bass. However, electronic corrections should be applied only in the last step. Running the room correction procedure without optimizing the system first (i.e. place the speakers and subwoofer(s) in the best positions in the room) will almost always suck all the life out of the music.

I find it a bit hard to make a recommendation in this regard. I use an Accuphase DG-38 with great results. However, they are expensive and not that easy to use as the instruction in the manual are extremely vague (I know quite a few people who dumped them as they where not able to figure things out). Lyngdorf system seems to be more user friendly. However, I heard them doing both good and bad things, i.e. wonderful music when used with decently optimize rooms/systems or sucking the life out of the music when used in bad rooms. Probably your best bet will be to find a dealer that has some experience with room correction system and ask him to demo whatever he/she is using in your home.

Regarding your father comment about the price of the Scalas, I have found it very funny. However, I am not surprised at all. I get the exactly same comment every time a professional drummer sees my drum kit. Unlike we hobbyists, professional (drummers, sound engineers, etc.) can do their job just fine with much less expensive equipments. :)

Finally, it is interesting to see that dealers (all over Europe) have problems getting rid of the Scalas. I do not think it is their performance, just this bad economy. Most likely, getting rig of other large and expensive speakers is just as problematic.

Anyone have any idea how the newer viva utopia may compare to scala at a very similar price point accounting for stands? Viva a contender if 2 channel is the main usage? They Are marketed as multichannel LCR products.

not sure why that last response didn't jump up the thread? try again

Hi all,

apologies for not responding earlier, hadn't looked at the thread for a while & didn't realise that there were more responses.

Quick update, the Scalas have been sold, so for better or worse that option is off the table. The dealer does have a pair of Watt puppies 8 for sale though, hmmm.

Over christmas I ended up grabbing a second sub, JL-F112 & was able to find a Bryston active crossover from a seller on here. Will eventually sell the smaller 10" sub & buy another 12.

In the end there were just too many little doubts to justify the expense of the Scalas.

So now for the process of getting the subs integrated as well as I can. The crossover is proving trickier than I thought, getting some really bad humming?

NVP: no offence taken at all. You're right I don't know much, that's why I came here to get thoughts and advice from people like yourself who do have more expertise. I'm here to learn.

I read your thread about the price on the Scalas & how they seemed to be pretty easy to buy at a greatly reduced price. The dealer that I bought my Diablos from in France offered to sell me his demo units for $12k euro. Not sure exactly why this is, probably just economic pressures, they're not selling well enough for dealers to have them sitting on the floor, perhaps overpriced/better options in this price range?

I should have noted that although my father is a qualified sound engineer he hasn't actually worked in that field for a while. One most definite thought that he did have was that i was totally crazy for even considering spending that sort of cash on a pair of speakers!!!

The testing process that we carried out was a definite eye opener, really highlighted for me the impact the room can have. I have been able to move the speakers out from the corner & away from the walls a little bit (they now have a little more than a foot of space behind them) & this has helped. Also spiked the stands.

So plan to try & spend some time over the next few weeks trying to get the subs dialled in. Have read the thread you posted (thanks for that) as well as another pretty good one I found by the sound doctor ( http://www.soundoctor.com/whitepapers/subs.htm#2SUBS ).

Unfortunately I'm pretty limited in where I can place the subs, have been able to build them into my unit so that they sit side by side under my front speaker. Will be doing the crawl test to find out where the optimal position might be, but for aesthetic/space reasons they probably going to have to stay where they are. This allows me to keep the Diablos on their stands.

Have been reading a bit about the Velodyne SMS-1 EQ & have heard rumours that JL might be releasing their own active crossover. Any thoughts on these or alternatives?

Should I be considering room EQ instead? Rives PARC, Lygdorf, Accuphase?

Bo1972, I agree with what you are saying. Electronic correction has come a very
long way in the last years. I use an Accuphase room correction unit for some
time now with wonderful results. IMO it is a must for SOTA bass and stereo
image.

Initially I though that we are digressing but not anymore. The OP should be
made aware of how seaming-less subs and monitors can be integrated these
days using room correction units.

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.

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). :)

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.

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.

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

You want to buy speakers which can give a wide and deep stage. But you use MF amp's ( I did demo's for MF and seold it many years. I owned a MF Nuvista)MF is a brand who are not good at 3d imaging. Brands like Pass labs are superior in 3d sound. MF are good in focus, but misses depth. Linn is also not so good in 3d imaging. 3 dimensional image is the most important and exiting property in highend audio.

Has anyone experience with the Utopia series III (MKii) or Limited edition which has a redesigned crossover for the Hong Kong Market which were produced in limited quantities and better than the standard series?

Ok will wait for measurements, if there sharp dip at 150hz ther ewill be a bump in lower octave, I am quite sure about that (acoustical physisc)

So far better investment in sonic would be not second sub but placement and smoothing 150hz. Diablo is not watt puppies- those are the racers, some stereo subs( even not speaking about single sub) can not cacth them.

Of course better sub would not hurt either. :) But first and most matter-placement on room problems solving plan would be best.

About diablo placement on subs- you will get some vibrations from sub , sonic will suffer(imaging in first place) placement speakers on sub would be more benefit that harm only if sub works up to 120-150hz. Diablo have quite strong uppr bass so sub need to work only up to 60-70hz.

Hi Washline,
until I heard the difference of the speaker in the corner to the open side I might have questioned your statement. But after the other day I think that you are right.
I always felt that the Scalas are going to be a bit OTT for my room, but the deal is tempting & who knows if I ever move to a different place the room will most definitely be bigger.
But it is a lot of money to spend on a maybe.
Starting to think that it might be better spent on a second sub / room treatments & some other tweaks instead.

Hey Kzhtoo,
I'm just waiting to get PDFs of the tests so that I can give some more detail analysis on the side by side results. In short though, Elviukai was on the money when he said the Diablos dropped of quite sharply below 70hz. The sub did go a long way to lifting things up again below 40 but there was a dip between 50hz & 40hz that I couldn't smooth out. But we didn't have enough time to play around to much with the sub placement / set-up.
At this point I'm leaning towards the second sub for a number of reasons, budget being the big one.
Will try to post the results over the week-end
=)

I think that if your speakers have to be up against the walls, you should probably stick with the monitors. Large floorstanders up that tight against the walls will certainly get boomy and you'll have a lot of trouble with image and staging. The Scalas will need some space to perform their magic.

Hi Neuphonix,
Please keep it posted. Looking forward to the details. :)

Hi Washline,
thanks for your thoughts, I will definitely have a look at the Cardas website for the set-up method.
Unfortunately given the room size/layout the speakers have to go up against walls/corners.
I did some room testing yesterday which I will post in more detail later, but it was very interesting.
I hadn't had the chance to listen to the speakers separately. WOW. The left channel which is hard up in a corner was extremely bass loaded, the right which is on the open side of the room sounded so different, much leaner.
Some sort of room treatment is on the cards for sure.
If I do use two subs one will be set-up very differently to the other which could complicate matters..
Perhaps the adjustable nature of the Scalas may help to compensate for this?
Will post findings in more detail later today.

I have a room that's a bit larger than yours and run the Alto Utopias. I've also run them in smaller rooms than yours. Obviously they do better in larger rooms though not too large. I think that given the modest power of your amp, and assuming you can get your speakers away from the walls, add in some room treatments, especially some absorption above and in the corners and diffusion behind, the Scalas should do fine in your space. Trying to dial in the subs with the Diablos is going to be a difficult proposition. I'd use the sub for watching films, assuming you do so with your system. Meanwhile, trade up for the Scalas if you have the opportunity. You'll be happy you did.

By the way, I would strongly recommend if you are not doing so to use the Cardas method for setting up your speakers. That system will help you align them properly in relation to your walls. You can get the details at the Cardas website.

try that link again:
http://www.hifigear.co.uk/media/uploads/AMS35p-brochure.pdf

just thought that I would put this link up showing the specs on my amp if anyone was interested:

http://www.hifigear.co.uk/media/uploads/AMS35p-brochure.pdf

"The AMS35p drives most loudspeakers easily. We do not recommend speakers with a sensitivity below 86dB, unless you are using them in a relatively small room. Apart from that, the AMS35p will handle any loudspeaker without problem or strain.
Because of its high peak current (over 100 amps peak to peak), the AMS35p is, in real life, a really big amp.

Hey Kzhtoo,
thanks for the suggestion, the Dynaudios do sound like an interesting proposition. Elviulai in his first post on this thread made mention that they do have some "thump" down around 40 whereas the Diablos do tend to drop off much sharper than that.
Certainly price wise they are on the mark. I might have to look into what dealer stock them here in Sydney.
Really the only reason any of the thinking about the Scalas is taking place is because of the price I think I can get them for. If they were listed at RRP it couldn't happen.
That and the fact that when I did listen to them I was so impressed.
Thanks again for your input =)

Hey Elviukai,
I tried to PM you a reply but they blocked it because I listed my email address?
I'll do the measurements as you listed & let you know what I come up with.
I suspected you might say no to the sub placement idea. Again somewhat restricted about where they can go due to the size of the room. One can sit quite nicely next to the Diablo, two is too much. There are a couple of other spots where they could go and suit the asthetics of the room, but I doubt there will be the flexibility to have them placed in the ideal SQ position. We'll see.
Thanks again for your detailed response, much appreciated.
Talk soon

Hi Neuphonix,
It seems our musical taste are somewhat similar. I listen to a lot of electronics/ EDM (trance, house, etc). This maybe more like a lateral move. Have you considered Dynaudio C1 MKII/Sigs? I recently moved from Electra 1008 Be to C1 Sigs. Granted I've only had C1 Sigs for less than a week, but so far so good. I'm also using Pass XA30.5 (rated 30 watts class A) to drive the C1 Sigs in a 18x25 room. C1 Sigs' bass vs. 1008 Be's is no contest (all gears/cables the same). I hate to say this but it is what it is. Not sure about how it compares to Diablo as I haven't heard Diablo in my room with my equipment, my music. I have heard both Diablo and Scalas at shows and always been impressed, but then again, they don't play electronic music at shows. :D

Note: C1 Sigs are less efficient being 4 ohm and 86db speakers but my "small" Pass amp drives them quite well. They seem to love a lot of current though, which Pass can plentifully provide.

Best,

OK, If your father can do folowing measurements-
1) from 1 meter on tweter axis left
2)same but right
3)from listneing position right
4)same but left
5) both speakers from listening position

its important that sub would be switched off during those measurements.

I know diablos frequency quite well in 4 rooms , so it will be easy to see

As for midrange- midrange resolution comes diferently in Diablo and Scala. Diablo have most of it midrange resolution going from tweeter (that sparkle snap you hear on fast records) Scala most of its reolution in midrnage have from its midrange driver (Maestro- something between those two) . Plus that Scala behavour is more civilized than Diablo.

Placing Diablo on subs makes more harm than goood in your case(xover point is low) uncless its the only place in room where sub outputs are linear.When you father will be after Diablo he can heltp you with sub placement. turn of diablo, set sub aoutpu as high as possible (up to 300hz) mesaure sub from 10-20cm as reference , then keep microphone fixed and make some sub moovements and making meausrements, until you find region 30-80hz smooth without major peak/dip. of course you can adjust diablo+sub by ear.signal tones to be flat ( dues low fr. wawes canceliation with diferent phases) , but this way i described here are much better form origin.

having Diablo mesurement in your room will make green or red light for Scalas. Then comes personal preferencies.

Hi Raks,
unfortunately second hand Jl subs don't some up all that often over here is OZ.
If I was to consider two new JL-112 I'd be up for about the same as the Scalas.
Definitely a good option, but not sure I can make that work.
I would like to hear the step up between the 10 & the 12. The 10 is pretty impressive given it's physical size, I love it!

Hey Elviukai,

thanks for taking the time to come back to me. Not sure if you got my reply yesterday.

Questions no problem, I've done my best to give what answers I can.

My father is a sound engineer, he will be coming over tomorrow to run some measurements on the room so hopefully will be able to provide you with something by Thursday.

Listening room is around 4mtr x 4mtr. Brick walls front & rear. Glass door/window one one side (with drop down blinds). Open to dining room on other side. Carpet floors. Leather lounge opposite front speakers for listening.

Both lounge & speakers are hard up against front & rear walls due to the size restriction, nothing I can do about this.

So I would say that my room seems to make the Diablos sound leaner than I remember them sounding in the dealer. But that is just my ears so let me do the measurements & try to tome up with something more accurate.

A friend has a set of Diablos in a larger room with similar amps & they do seem to sound more open. Like most speakers I guess they like being away from walls.

Have been speaking with a friend on another forum who has heard the Scalas being run from a MF AMS35i integrated (same power as mine). He felt that it managed fine, in fact he thought that it might have even run the Scalas easier than the Diablos (higher sensitivity?)

At the moment I am using one JL-F110 10" sub. I have played around with freq response & phase a bit & feel that it is working OK. Just the volume tends move up & down a bit depending on the source material. Don't have it set too high as I would prefer it to sound seamless rather than overpowering & muddy.

I have the pre running into the power via balanced & the sub running off the pre via RCA. From what I have read an external cross over might be the best way to get it working together, but I would prefer to avoid this expense if I can.

Musical tastes are electronic/dance, blues/acoustic, reggae/dub, bit of rock, little classical but not to much. So you can see that bass is a fairly important component.

Listening volumes are typically soft to medium, don't often crank things too loud.

I just was so impressed with the extra midrange of the Scalas & the taughtness in the bass. My wallet is more than happy NOT to buy them however! Would be content to leave it at one more sub & be done with it. Just the deal on the Scalas with a trade in on the Diablos is worth considering.

One more question about placement of the subs. What are your thoughts about placing the Diablos on top of the sub? I was playing around with the idea of mounting the subs on some granite plinths with isolation spikes & then taking the Diablos off their stands & placing them directly on top of the subs again with isolation spikes. Bad idea?

Talk soon

Thanks again

Hi Kzhtoo,
The deal is tempting, but yes the room is the primary concern
Am going to talk to the dealer about a home demo, I doubt that he will be all that keen, but hey nothing ventured.

Before risking all with the Scala's, I think you'd be better off to flip the JL Audio F110 for one or two used JL Audio F112's to see if that does the trick for you.

At half price for Scalas plus an option to trade Diablo in? Sounds like a no brainer. The only thing you'll have to make sure is your room is big enough to reproduce all the goodies you heard at the dealer, or else Scalas will just sound pretty close to Diablo, which already sounds big for monitor size.

"Can I have my cake & eat it too!”

I never can, but good luck to you.

Given that the Scalas are sitting at the dealers at around half RRP, the deal is appealing. So the potential loss is not that high, certainly if the Scalas were new & closer to full price then it would be much more of a consideration.

I picked up my Diablos at a great price by importing them from a dealer in France. I have spoken again to him about a possible Scala purchase & his price is slightly better but there is no trade in option.

I will try to twist the dealer about a home demo. It would seem to be the only way to truly make an educated decision.
Had hoped to avoid pushing him on the service angle too hard so as to work him over on the price! Can I have my cake & eat it too!
Hmmm, much to ponder.

"This is after all a pretty significant purchase (at least for my budget)."

Okay, I understand... the Scalas got you excited. But without a home audition, there’s just no getting around the fact that you’re taking a chance. Therefore, I advise you to check into the price the Scalas are going for on the used market and ask yourself if you can justify losing the difference between that price and the price you’ll be paying... just incase it doesn’t work out. Hope for the best but plan for the worst :-)

Hey Elviukai
I have seen that on a number of threads on the site that you have a lot of experience with the Focal speakers.
I've just started a new thread about my Diablos & wether to add subs or trade in for Scalas.
Any input would be really appreciated.
Thanks heaps
michael =)

Hi Michael, I assume its this thread? OK I will try to help a bit(still not now- need more info). But I havesome questions(never ask question on A'gon from elviukai- you will not get answer but more questions on return :) ) -

1)What kind of room(frequency response) do you have? Diablos are detailed in rooms which have tendency to absorb 150-400hz(this way 2-4khz shows up and character becomes more lean and detailed) , in other rooms they are quite "juicy" and even have excess of 400Hz- sound is liquid and well "spread in room" (good for choirs or small string quartets) I listen diablo with Ayre and pass Labs and with boths amps they are "liquid and juicy"

in 4x4 room you will likely to have a room mode arround 60-70hz, could be as high as +7-10db . in neutrall room Diablo goes strong up to 70-65Hz and then drops like stone. Sonus fabers doesnt do that, and some dynaudio monitors even have "thump" at 40hz. the good news that diablo can be integrated with subwoofer quite easy with measuring qeuipment/ears. if you have only ears it can take years to do this, so best to help with special cd tones- "learn" your room. Drop me mail and I will sent cd record which will halp determine if you have some room modes. Diablo with CORECTLY integrated sub can be heaven for most music genres (I think there is member who prefer diablo with subs over Grande EM) . But only ears will not help this. If sub integrated poor it will add soem excitement but no in long term listening then better turn off.

If you room have some resonant mode Scala will not work (and forget about Maestro, even in perfect 4x4 room it will have huge bass thump which will blow your socks off. the funny thing that maestro can be listened from 2meter with perfect soundstage projection and tonal balance, scala can not, Diabalo- more or less can)

2) What king of music do you listen? Diablo plays very nice on medium to low volumes, but on higher it starts to scream a bit on not so perfect records(smetimes even on good recoreds). Scala like some juice,and in HT mode at higher level Scala will win over diablo+sub easily. not because Scala will paly lower(it wont, even oposite), but because it will play louder, do not compress transients. if you listen for large orchestra , wind band, pink floyd or music like this on natural listening levels Scala will be better. BUTnot with 35w amp.

actualy its quite a tought situation here, and I am afraid that further advices can be only after you listen to special tones and draw each tone on paper with realite loudness schange scales. knowing this we can moove further. hope this helps, and sorry for typo(if any) quick typing on small laptop-neve read what I am typed.

Greets

No no, this is exactly what I want to hear! =)
Having already part way made up my mind I need to have others who are more objective throw ideas/questions at me so I reduce the chance of making a decision that I regret. This is after all a pretty significant purchase (at least for my budget).
The 2.5mtr listening distance is a concern.
I don't think that the dealer will allow me to demo the Scalas at my home, delivery etc. I could take my amp into their shop which would go a long way to answering the question about suitability. Given the synergy of the MF gear with the Diablos I think the sound itself will be OK, just wonder about having enough grunt.
Doubt that I will be able to do a home demo of a second sub either. But the one that I am currently using is sounds fine & I have been able to get it to integrate quite well so think this will work. As mentioned it would also add to the HT experience. This is certainly a better option in terms of money/size/added HT ooompf.

"What do you think about the second sub idea?”

I know this isn’t what you want to hear but, in my experience, subs are one of those personal preference sort of things. Some love em, some don’t. If I added subs in my system, I’d probably want to make use of some room acoustical measurements software. Have you talked to your dealer about letting you try both options in your space?

I still think that the 2.5 meter listening distance is likely to prove problematic for the Scalas.

Hey Phaelon,
thanks for your response.
Yes you're right, I do like listening to big speakers in big rooms!
I didn't explain the design of my room too accurately. The listening area itself is around 4mtr x 4mtr but one side is open to the dining room, so sort of an l-shape.
The listening position itself is pretty much set in stone which also means that the seat & the speakers are hard up against walls.
I was probably more concerned with the asthetic of the Scalas rather than their overpowering sound, they are quite a large speaker. Some of the reading about them on other threads on this site had indicated that they were quite well suited to small to medium rooms.
I had a set of floorstanders before changing over to the Diablos & one of the main drivers of the change was to tighten things up especially given the size of the room. But even though I do love the Diablos I miss that extra octave or so down low.
What do you think about the second sub idea?

I think that you’ll find that your room and listening position is much too confining for the Scalas. Big speakers in big rooms will always add a new dimension to the listening experience that many, and this apparently includes you, will find appealing. Don’t listen to big speakers in big rooms anymore and enjoy your system.

Anyone?