As i recal the way the quad is working is sort of cone principle meaning the panel is build not like a cohérent film but with a slight delay between sectors. I'm sure you can educate me here. But from what i heard Quad "colapsef" at that time (and my HiFi pusher discontinued carrying them - at least soon after).
Yes, that's correct.
When Quad first described their structure and dispersion pattern, I couldn't quite understand it until my Quad techie actually opened it up and showed me every inch of detail between the original UK version vs the Chinese version.
The original Quads have what are called concentric ring Anodes comprising of 3 - 4 rings per speaker. Quad stats are actually made of several panels wired together in series from top to bottom. Let's take the ESL 2905's for example: there are a total of 6 panels from the full length of the speaker. Starting with the middle two- this is where the mids & highs are generated and the last two at the top and last two at the bottom, are bass panels. So in total six panels wired together.
The signal originates from the centre then onto the rest of the panels like a ripple effect, mimicking a point source. The ripple effect is caused by the ring Anodes which cover the entire surface. In addition to this structure, they also use delay coils, so this type of dispersion pattern is very unique and is found only on Quad ESL's. This also allows the Quads to be placed closer to the front wall, if space is an issue. The further away they're placed from the front wall, the deeper the soundstage gets and it's truly awesome!
The stats simply disappear in an instance, leaving a floating image dead centre of the performance right in front of you. In fact, it's so palpable you can reach out and touch the musicians! Or even shake hands with them.
So when bought over by IAG, they obviously copied this design and wanted to better it, and they did! These new Quads look and feel amazing! Aluminium side panels, extra rigid bracing in the centre, heavy duty spikes, plus 10kg added weight plates that are bolted to the bottom. So all well and good BUT the weakness is what's inside. Very cheap materials used and very poor quality, I'm actually surprised that this stuff inside even passes basic quality control. Someone paid off someone big money to get the design approved and start manufacturing... just my 50cts guess.
Other types of stats or even full range ones, don't quite have this type of dispersion pattern of the Quads. For example ML doesn't use multiple panels or panels wired in series... rather it's one full panel, one full mylar from top to bottom, acting as a line source. **Note** in the case of the CLX's, it's double mylar and triple stators but only on the bass section.
The other thing with Quads is that they're much softer and light weight in tonal presentation, transients and dynamics. This is due to their covering structure, which sort of muffles the transparency of true stats. The Quads have 3 layers of cover:
1. The outer fabric cover, referred to as the sock.
2. The metal frame encasing the whole stat panel. Referred to as dust covers.
3. Transparent plastic sheet, like cling wrap on both sides (front & back) which further protects the actual stat panels. The sound can travel through this plastic film, thanks to it's extra thinness. But is very very fragile!
Only after these 3 layers are taken off, you get to the actual Quad stat panels. And this is also one of the reasons why they don't sound harsh, bright or over the edge at all. In fact, they roll off the highest frequencies, they can't reproduce those extended highs unlike ML's. You can hear this straight away when compared side by side. Also ML's have limitless dynamics, they can extend their frequency range with some serious transients! Quads are still limited and if pushed too hard, they still arc and go into protection mode. They're just designed this way. They can play loud but not too loud, they have limits. The only limits with ML's is your hearing! If your ears can handle it.
So, the most positive things with the Quad ESL design is:
1. They can fit into smaller rooms and simply disappear leaving a wonderful soundstage presence.
2. Since they're relatively flat response, no harshness whatsoever, this allows for endless hours of listening. You can actually just sit there and listen till the cows & kookabaas come home.
3. They really don't need a fancy mancy highend expensive amplifier to drive them well to sound any better. They're more like monitors, Quads are Quads!
1. Now take the ML stats for example, they have no covers! Absolutely nothing! This is why they are so transparent and pure to the original recording. Nothing is coloured. You can also see right through them.
2. ML's are based on Line Source dispersion, so in order to achieve that superb soundstage depth and presence, plus make the stats disappear, they require proper placement in much larger rooms. ML's can do their true magic only if given adequate space to do so. Otherwise it's a compromise. Small rooms will never work for ML's.
3. With the use of average to highend top grade gear, ML's can perform from your average / nice stats... to an awe-inspiring experience with supreme finesse! All depends on what type and make of gear you use to drive your ML's. The performance can shift gears onto another dimension in a blink of an eye!
Quads simply can't do that, they were never made to do this, so their fundamental design was to capture the original source signal, being the "the closest approach..." Yes, it certainly was back then when made in England. Definitely not now, no chance.
This is why the very passionate owners of Quads still own them as their pride and joy. They are wonderful stats but only if matched with the right gear and well looked after. Which eventually depends on the overall build quality and internal design structure. That part is lacking I'm afraid, and I'm not sure if the new mighty parent company is concerned about it. They seem to be more interested in sales & moving boxes... according to my previous Quad dealer (from whom I bought 6 pairs of Quads!)
Oh well, good luck and all the very best to them, I sincerely do wish them well.
With that said, cheers to Martin Logan!
One of a kind stats, simply marvellous!
Woof! RJ