DIY speaker Bake Off

I’m thinking September and it’ll be just off j12 M40 Gaydon junction

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Okay, im oxfordshire so will try to make it.

I’d like to come too if I can. I really need a deadline to get the Linkwitz dipole subs http://www.linkwitzlab.com/woofer3.htm at least tacked together. Maybe this can be it (better be the end of Sept …)

VB

A deadline is always good to get things finished!

What amps are you using for the Linkwitz?

I’ve got a couple of Quad 405-2’s waiting to be modded a la Keith Snook http://www.keith-snook.info/quad-405-mods.html. The subs have two drivers in each of them. Each driver will be driven by one channel of one amp. Since the subs have a 6dB/octave roll-off (approximately) I need a factor of 4 power increase per octave from the amp. If I cross the subs over at, say, 120Hz and the required amp power there is, say, 15W/sub, then I’ll need 60W/sub at 60Hz and 240W/sub at 30Hz. A modded 405-2 should, just about, deliver 240W into 8ohm loads.

Of course, modding the amps is yet another job. As is sourcing a crossover (almost certainly DSP) to sort out the feeds to the various amps.

VB

I have a spare minidsp if you want a lend of something to experiment with.

Sounds good, I had no idea that the 405 could be made to do 240 W !

The stock amp is actually pretty close to 240W (120W/ch, two channels) into 8ohms but that’s running at the limit

With Keith’s higher-power transistors and the protection circuitry removed it will go higher than that and still not burn out.

VB

Right, I’m thinking of doing this on Saturday 14th October which was alittle later than I wanted, however Dave Shelving from GIK acoustics is available to come and do a talk on room acoustics and treatment which should be much better than the one I did last year! I might be able to persuade the Linn engineers to come and talk about active speakers as well and should have some of thier DSP kit hooked up to some of my speakers by then.

That date fit with folk OK?

Stefan

Hi, i would like to come along please, the 14th is clear.

Sounds good.

Sorry, can’t make that one

Yes please, that date works for me too.

VB

I’m going to move this, I’ve been rather busy and think I’m going to struggle a bit to get this organised for mid October. I’ve spoken with Dave Shevyn over at GIK and November 25th works well for him so am proposing we do this then if you are all still up for it?

Stefan

At the moment the 25th is ok for me. So will aim to make it.

I would come on the 25th.

Right, I’ve added the date I mentioned above to the event calendar on my site.

Can those of you who want to come pop over there and use the RSVP function at the bottom to book in, that way I’ve got an easy way to see how many are coming and contact you all with updates etc.

There is a comments section at the bottom of the page, if you are planning on bringing some kit could you just pop it in there, I’ll curate a list or stuff and post it over to the various fora from time to time.

Stefan

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Thanks, done

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Nov 25th should work for me too.

VB

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Not sure I can make the that date, I’ll let you know.