DIY Audio General - stuff you're making, tips, advice sought, etc

After 4 bottles of London Pride I can only agree.

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Nice
:smiley:

Fine work

Its heavy stuff for a school night tbh.

Life is at-least 50% end-grain…

Graham - try the Golden Pride: killer but lush AF :ok_hand:

This should replace “scroll up”.

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I’ll try to find some :+1:

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Waitrose have it :ok_hand:

Gurt lush.

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Much prefer the Golden to the original London. A nice pint, well 500 ml from a bottle !

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It’s not often a brewery takeover results in better beer :+1:

Is there some empirical way of determining how much damping material should go into a sealed box cabinet or is it just a question of taste given the drivers used & volume of the box?

I seem to remember being told that a sealed box (acoustic suspension) type needs more wadding than a similarly sized ported type.

Wadding increases the apparent volume so it’s down to taste really. (You can measure the bass roll off as you change the stuffing if you want to do it empirically)

I use very little on ported enclosures in general, I just line the walls with bitumen type stuff and acoustic foam.

In all seriousness, what is the wadding supposed to be doing in there?
Is it to some extent absorptive of energy, and if it is, presumably it’s frequency-dependent?
Or is it diffusing standing waves inside a really-reflective structure?
And how does it increase apparent volume?

Yes, yes and yes. And the sound travels slower through it, so it takes longer to get to the cabinet.

I recall a piece that Jimmy Hughes did in HiFi Answers where he tried removing the wadding from some speakers and reported a much livelier faster sound. Many of the readers did the same & agreed but the effect was also leading to a significant increase in distortion & colouration as more sound was bouncing around inside the cabinet and then passing out through the diaphragm.

I’ve been playing around with the wadding in some 2 way sealed box speakers here. They definitely can become overdamped & sleep inducing with too much in. There are a couple of other issues at play. These speakers have fairly sturdy cabinets with internal bracing and panel resonances are also controlled, to a degree, by bituminous sheets that have been stapled inside but that is addressing a separate issue to that of standing waves being set up in the enclosed air volume & then emanating through the driver.

That theoretically is what the wadding is addressing. I was wondering whether it was possible via an impedance plot or straight FR measurement to see where the optimum point is or whether it really is down to taste ie some liking a looser slower bass than others.

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The wadding has a very obvious, direct impact on the sound with the Frugelhorns I have owned.

Also the effect of wadding (lambs wool for example) is going to be very different to treating the walls (Dynamat etc) as they do different things.
I have always preffered more stuffing, generally as it gives a cleaner sound, in the midrange, especially with full-range drivers, at the expense of bass, such as in my Frugelhorn Lite, not that they have much to begin with!

I visited him once for a listen - his speakers impulse H2’s were facing rearwards.

It’s basically box tuning. There is no right answer. It’s which QTS you like.

I heard that set up. It sounded ‘spacious’ but they were actually the bigger H1’s iirc

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