English Premier or International (HiFi) - New signing at the back?

Hi-Fi Corner
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Hi @Innocent_Bystander , this could be a bit of a long read, but I’ll try to keep it succinct.

As a product concept, the design and specific implementation of the WB IGx seems very well thought out, with lots of advanced material and design approaches that should deliver significant benefits in the home.

First off, it is round like a drum, so one can ‘roll’ it into place.
Second, it has all the common control features of a sub bass for gain, variable corner frequency, variable phase and a phase control defeat switch so you can bypass phase control if you do not need it.
It also looks the part!

Unfortunately, for the version that I tried (which may have been an early prototype circulating amongst dealers) I had a number of issues which meant I never managed to successfully integrate it with my system. I had not expected to have it on loan as the dealer came in the morning and we all tried together to integrate it, but gave up late afternoon and they left me with the unit over the weekend to keep trying.

First problem was it had small holes drilled in the base. Don’t know why, maybe that was so they could get the 0.04% at 1W distortion spec?
Whatever, holes in subs do not help with integration!

The controls had no click or stepped markers (unlike REL which do) - this made it exceedingly difficult to conduct any repeat measurements.

The filter roll off is fourth order, not what I want with infinite baffle main speakers. But I guess they have matched the filter to their own range of loudspeakers for this aspect.

Next, the sub axis fires sound vertically. This is necessary because their construction architecture uses gravity as a way of solving lots of issues with conventionally constructed subs. However, even though this might not really be a problem in theory, in practice it was.

Finally, this wonderful concept of getting away with a smaller amplifier and motor, driving a very large, very stiff, very low mass diaphragm completely omits the fundamental fact that air has mass too. And if you want to accurately move and control a large volume of air at very low frequencies, you just need a bigger motor!

Of course, in other (untreated) rooms, with different main loudspeakers (ported) the results could be quite different.

Hope the above gives you the information you were looking for?

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Interesting because rather different from reviews I had read a few years ago on the Torus, the IGx’s predecessor! Regarding roll-off, I assume it is to match with main speakers having a similar rolloff, as you suggest probably with their own in mind. In terms of moving air, IIRC it is an 18” driver, with large excursion, which in all but the largest rooms should be quite capable - though as with any sub I’d expect a pair to be better than one. From the specs (of Torus) and reviews I expected it to do wonders (though only for music not cinema effects).

I’m unclear why upwards firing at such low frequencies should be an issue - I wouldn’t expect any difference from horizontal, my only reservation about that was risk if something were to fall on it (also dust pickup, but soon blasted off!). I suppose you could use on its side, with a couple of chocks to prevent runaway!

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Hi again @Innocent_Bystander . I really wanted to like this WG IGx.

The way I see it is there is still quite a bit of innovation going on in very low frequency sound reproduction. As a research engineer, I note the effort by WB to really change the landscape. However they have fundamentally fallen short in the electronic control and integration aspects with this product. In contrast, Linn, with their PWAB and digital DAC in their most recent top of the range floorstanding loudspeakers have something interesting.

Magico, with their American conventional sub bass concept and brute force approach but integrated intelligently with a fantastic DSP.

The DSP permits so much direct control over time delay, filter characteristics (choices of Bessel, Critical, Butterworth and Linkwitz Riley) along with filter order, (variously, 1, 2, 3, 4, 5 & 6 depending on filter type selected), corner frequency, gain AND, having done all of that selection, additionally an audio band graphic equaliser, each band with tuneable corrections of filter Q and centre frequency.

In contrast the IGx can only be limited down to 30Hz corner frequency, continuously variable gain and phase (that can easily be knocked out of position) and a semi random ‘ears’ based tuning approach - Ugh.

Now, combine elements of all three of the above, and maybe we have something useful!

PS: The IGx cannot be operated tipped on its side, but I am sure you knew that!:wink:

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Yes, I’m a big fan of DSP AXOs, and it was a bit surprising that WB use passive. Re tuning, as I know you know you can of course use a third party monitor like REW, provided the XO frequency isn’t too low for the mic.

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@Edmund-of-Essex, I just stumbled upon a sub I’d never come across before, which might fulfil your desire for air movement…

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Also called an Infrasonic Generator it is the Ascendo SMSG50. The driver is a mere 50”!

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Hi IB, wow, if only you had mentioned this sooner! I too had not been aware of this product, but the manufacturer does seem to know what they are doing. However, somewhat moderated by the fact that they also do ported designs? For the Financial budget required, it is perhaps just beyond what I might consider for one sub. But perhaps more importantly, having completed the construction of my media room, the reconstruction required to integrate two of these (because it would need to be two) is just too much to ask.

Thank you for mentioning this company and this specific product. Maybe other forum members will see your contribution (and this reply) and take a look for themselves for something that might suit their home listening environment?

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At 1.8m square face, and 0.6m depth, I suspect few domestic rooms could physically accommodate one, let alone a pair! And at 400kg you’d need to get placement right first time, or before the forklift truck leaves the building!

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