HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

They are inside the cabinet no one can here them, they are just used as load.

Wadding out of the cabinets this afternoon and......WAP BAM BOOGIE!
These speakers have moved on from from 'excellent for the type' to supersonic music machines!

For me it is THE most stooooooooooooooooooooooooooooooooooooopid speaker design convention out of all of them, people put it in automatically. Pull the feckin' stuff out.

Well it took me long enough, but the wadding came out in the end.
I like going out on a limb with things but wadding was a sticking point. It's a difficult thing to break free of because tradition is strong. But just thinking 'sod tradition' and going for it is of course the way to go. Once you do it, as they say, you won’t go back.
Daft thing is, these drivers are pro drivers and you never see pro drivers in stuffed up cabs, so why stuff the bloody cabs for the drivers in a domestic situation?

The big 15" brothers.
I finally got around to making them look presentable. i was going to veneer the top, but the black is growing on me

Fane 15" sealed box speakers by anthony cresswell, on Flickr

Fane 15" sealed box speakers by anthony cresswell, on Flickr

covered in some faux suede material

Soooo simple - soooo music.

I’ve been doing a lot of thinking about the sound of these speakers, since I had them at Owston in June.

That they have a rising response is not in dispute and it normally doesn’t bother me, as my small room enables me to sit in the near field at around 30 deg off axis. Large rooms where you can’t get far enough off axis in the far field, give a piercing presentation to say the least, which is exactly what happens at Owston and in any large room such as Steve S’s. This is a bit crap really, as it limits their application in the domestic environment, to the smaller room, which is a pity, because the driver is one of the best widebanders I’ve ever heard.

Much measuring later I have traced the source of the on-axis peakiness to the larger of the two whizzers and I have found a nice way to reduce the large whizzer’s output relative to the small, central treble whizzer and thus even out the upper mid to treble transition to convert the driver from PA to domestic hi-fi use. The method does not involve doping, sticking things to the whizzers or otherwise adulterating the driver.

I just added a second grille behind the first. This secondary grille is of a much closer weave than the front, Fender tweed style cloth, and has a small, vertical slit cut into its centre, so that the hole resembles the pupil of a cat’s eye. This arrangement attenuates acoustically, the larger whizzer, whilst allowing the HF coming from the small, central whizzer to pass unimpeded.

The net result is a rebalancing of the driver’s frequency response, from ‘cut through’ PA towards a more benign domestic audio presentation and it works beautifully. I’m well pleased with the results. The nice thing also is that the cat’s eye lens is completely invisible.

Listening impressions are that the imaging has improved dramatically. Central vocal positioning is precise and free of vagueness, and overall positioning of instruments across the stereo stage is much more tightly defined. Midband detail is astonishingly good, with subtle details easier to hear than before. Because the upper mid frequency balance has been pulled flatter, bass is now better balanced relative to the rest of the audible range and so we get a better idea of what bass instruments are doing. The same increase in clarity applies to the treble range too, as the upper mids are no longer swamping HF details.

What we have here, is a significant improvement in the quality of the music coming out of these drivers, and it has been achieved without eq or DSP. Not that eq or DSP are bad things, but this cat’s eye secondary grille method is both cheaper and quite effective.

This is a simple representation of the secondary grille I placed behind the front Fender cloth.
The white area represents the secondary grille fabric, which is a dark brown, commercially available speaker cloth.
The cat’s pupil aperture is simply the hole I cut in the centre of the cloth. Nothing new in this method. It’s all been done before.

Interestingly, though not a totally unexpected effect of the muting of the large whizzer, is an increase in dynamic contrasts and leading edge speed. As I alluded to in the last post; the central HF whizzer gets to contribute more to the presentation because it is not being shouted down by the big whizzer to the same degree as it was, without the secondary fabric in place. So we get a commensurate increase in leading edge speed, due to less upper mid muddle, mucking up the higher registers.

Also there will have been an alteration to the horizontal vs vertical dispersion characteristics of the driver system itself, caused by the cat’s eye aperture. There are a couple of mechanisms at work here and the effect of these is simply more of the music being revealed, which of course is what this hobby is all about.

Very interesting
Very cunning
Like it
Any update pics?