Icon Audio speakers

Regarding brightness both the Wharfedales and the Sansuis were designed prior to the outbreak of audiophilia nervosa and so have adjustment for mids and top.

The Wharfedale might not be sensitive enough. I mean they will work but depends what your average listening volume is. I rarely listen at high levels but I like to have the option to do that on occasion without any clipping on the peaks.

Your amp will probably just get a bit fuzzy rather than hard and nasty if it clips but you'll still notice a decline in fidelity even though it's not unpleasant sounding.

Id have reservations about that amp driving 989's or 63's.... You might get away with the 57's but I'd say 10w is about minimum for them really....

Lower power might work with a very high quality transformer but the Musical Paradise is a bit beyond its remit here for me.

I don't think you will have any issues at all, and if you do they will sell on very easily. They are still popular with the valve guys.

Indeed, if driven with more you can damage them with arcing etc depending on the current.

My room measure 8' x 12' and have my speakers firing down the longer length of the room, do you think being only 8' wide is enough for 57's I'm sure I've seen them placed fairly close together in a smaller room.

DO NOT!!! Touch 989s, they're to big for their flimsy frame so stress the panels. They will spend more time in the back of your car going backwards & forwards to OTA than in your lounge playing music.
Yes they sound wonderful, happy with 15w+ and have some bass but unless moved carefully, in their boxes, are way, too fragile.

Was similar with my 63's..... Not quite as much of a nightmare as yours I believe but still 2-3 visits each to both Huntington (Quad) and indeed OTA were enough to put me off....

The 57's actually seem quite robust by comparison and are a little simpler to work on too.

I have heard them sound wonderful in much smaller rooms than that. 

But if you do go for it get a well-sorted pair. Fixing problems with them is a nightmare even if you are well handy with stuff like that.

Yeah it's a head and heart (ears) decision. Anyone in their right mind wouldn't bother with a speaker so fraught with potential issues and they will need maintenance at some point, be that 1 or 8 years, you won't know unless you guarantee the age and spec of all components..... But when you've heard them you'll understand why people persevere .....

They're still not to everyone's liking though which I understand.

They can work in large and small rooms, large rooms just need a bigger amp and clamp board protection to stop them arcing with higher power, most of the rebuilt ones have this already.

(Referring exclusively to 57's (ESL's) here)

Looks like he's running a REL Strata sub with them, good choice.

That's some pair of Focals behind them too!

Just as a point of order there's a difference between an amplifier being able to 'drive' a speaker and being able to get sufficient volume and headroom out of them.

I appreciate that 'driving' is not a technical term but what is meant by that is that the amplifier is capable of maintaining voltage into a low impedance load with steep phase angles aka a 'hard to drive' loudspeaker.

If it cannot do that then you will get all sorts of deleterious sound issues - rolled off top-end, no bass, boomy, un-controlled bass and so on. The amp may even blow a fuse.

This is unrelated to how many watts the amplifier puts out. It's a function of how robust its power supply is. I am sure most of us have heard 100 watt (or more) amps that despite their wattage sound thin and weedy with many loudspeakers. This is why.

So a 6 watt valve amp will 'drive' the ESL just fine, so will a one watt amp. But maximum volume whilst maintaining optimum sound quality will be very limited. Whether that's a problem depends on the individual use case.

IIRC ESL will have sensitivity of 80db at 1 watt at 1 metre. 80dB is pretty loud and you have two speakers so it's effectively 83db for 1 watt.

Let's say you listen from 2 metres away, you will lose 3dB for every doubling of distance so you are back to 80dB at 2 metres.

ideally though you want at least 20dB of headroom above your 'normal' listening level because music is dynamic, it's not the same level all the way through. For each additional 3dB of volume you need double the power.

Let's say your base level for listening is 75db which is above 'background music' level but quite far away from 'blasting it out.'

So for listening at 2 metres distance from the ESL you need enough power to reach 95db (or close). That means a 30 watt amplifier. Which oddly enough is the power output of a QUAD 303.

It depends over what frequency spectrum you are calculating efficiency.

What I've outlined is a good 'rule of thumb', it won't be exactly applicable in every circumstance but it beats just trying things totally at random.

Like most guidelines in hi-fi it gets you in the ballpark, which is all that's needed.

You say that but I don't think you are.

it tends to be assumed that a bright or fatiguing sound is due to excessive high frequency output but it isn't. It's usually due to a peak in the area of 800hz to 3Khz. 

Ask Steve about the difference with his Zu speakers when we dropped the levels in that region by just a couple of dB. 

if you attenuate the FR above 3Khz all that happens is the sound gets dull and 'shut in.' You lose all the life and sparkle. 

Well I wouldn't mind that Macca, but if you are coming on the train it won't be easy carrying everything so no problem if you don't