Here's another Thor (Small)

[greenie512]

Easter weekend .... good time to get the top/bottoms onto my version of Dave/Scot's Small Thor design. Sides went on yesterday.



For a couple more pics and "mess-up" log see ... http://www.greenie512.net/greenie512/html/wip.html

Public thanks again to Dave/Scot (Panet10/Scotmoose) for all their time, help and knowledge they share unreservedly with us all.

I'll come back to this thread and post more final pictures later.

Cheers - Phil

[planet10]

Love the swiss cheese

Will be very interested in the before & after reviews.

dave

[Scottmoose]

Yes indeed. Nice work.

[greenie512]

Dam, dam, dam – Dave and Scott you’ve lost me an extra $500 ………. I now have one redundant sub woofer, hey-ho never did like that idea.

So how does the Small Thor sound – well, can’t do an A/B test as most of A is now in B. But having living with the Original Thors for three years that’s no problem. “Small” sounds the same – well it would but and it’s a BIG BUT it now sounds like I thought the original should have from the word go – I’ve now got BASS. Quite amazing from a smaller box, how low do these things go – dunno – no measuring gear. Who needs it, I’m moving the sub woofer out of the room tomorrow – that’s how much.

Now the sub will vibrate the settee and you can feel its impact, the “Smalls” can’t do that. But acoustic bass sound true and low, low notes on a piano get there. So for me I’m very happy.

One strange result is more vocal clarity – which has thrown me a bit? And the sound stage seems more integrates and deeper?? I’ve only done a couple of hours listening so will have to work those out.

Bases are currently loosely fixed, will leave them for a little while until I’m sure I don’t need to get back in before fitting them tight and front edges need rounding over before the whole lot gets veneered.

Thanks again Dave and Scott.

[imjatse]

Nice work Phil! I bet they are rock solid with all that bracing.

[planet10]

Originally posted by greenie512
One strange result is more vocal clarity – which has thrown me a bit?

That could easily be attributable to the swiss-cheese supporting brace for the mid-basses. The intention is to tie the entire mass of the box to the driver which does 2 things -- it sinks vibrations into the rear of the box instead of leaving it on the front baffle, and it means the drivers move less in space relative to their surroundings -- both contribute to increased downward dynamic range.

dave

[Scottmoose]

That sounds the most likely thing to me. That bracing can make a real difference. Also, damping can play funny tricks on you. A large quantity can contribute to midrange purity, that's for certain, but it's also possible to go overboard & blunt the dynamics. It's subtle, but it's there, and getting the balance right is tricky.

Glad you like them! One suggestion: make the roundovers as large as you possibly can. Lynn Olson commented on this WRT his Ariels, and the wide radii do make an audible improvement.

In-room F10 should be in the low-mid 20Hz regions, with usuable response down to ~30Hz. That's SWAGed of course -depends how big the room is, positioning & the rest of the system etc.

[Pit Hinder]

re radii - B. Timmermanns (Hobby HiFi mag) once ran a series of tests on that, using standard 19mm (3/4") panels. Any radius below 19mm proved to be purely cosmetic, with hardly any effect. With thicker panels one could use larger radii with even better results, but router bits are hard to come by and/or cripplingly expensive - in this case a 45° mitre is the best solution. Works OK with 19mm too, if no router is available.

Pit

[greenie512]

Now that'll be interesting - I'll run the sqare edge box for a few weeks to get the sound. Then I'll put a 1" radius round over on the front verticals and see if I can actually hear a difference - will report back on that.

Dave, really glad your front to back bracing has an audible effect on the .drivers - all those holes took ages to drill out.

Cheers - Phil

[Pit Hinder]

Phil,
we are not talking of a difference that will make the Earth move for you, but a difference there is.
Sharp edges perform like an additional source of sound (remember school physics lessons?),repeating what you already got directly from the driver. Unfortunately this "echo" arrives within the time window your brain uses to locate real or stereo generated sources of sound and your brain has to filter it out.
Now your brain is quite clever and can do this (does it all day long in fact), but it's h*lluvalot of work. The resuls are:

a) a certain feeling of unease - your brain tries to tell you "I can't give you an exact acoustic image of what might be dangerous around us - let's get out of here"

b) loss of information. The filtering process has to be done in a hurry, so rather a lot of the finer inner dynamics of a good recording ends up in the dustbin.

Conclusion: an additional half hour in the workshed doesn't cost money (h*ll, it's a hobby!) and it removes one more curtain between you and the music.

Long waffle, but explaining things I only half understand in a language I only half speak...try to get used to it please.

Cheers mate,
Pit