DIY Speaker Build - Troels Gravesen's Poor Man's Stradivari

Not unless the WAF dips into divorce territory! :rofl:

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Incredible work!!
I have a set of TG Illuminators. Going on 6 years now. However, I cheated. My woodworking skills are in the toilet, so I drew them out in Autocad and loaded it into a CNC multi axis router.

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Do you have any photos of the build/finished article you’d like to share?

I’m always really interested to see other people’s projects.

Really nice to see your LX521 build - I have also been thinking about these but up till now had discounted the idea, as I also live in a flat with a balcony. Apparently that shouldn’t be a problem! Although this may also have to wait until my wife is travelling…

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Finally, I have the second speaker finished and assembled.

To enable me to make use of them and to free up space in the man-cave to make the stainless plinths, I’ve knocked together a pair of makeshift plinths laminated from 2 layers of poplar plywood:

I got my geek on and set up the back-tilt, level, toe-in and distance with a digital angle-finder, laser level and laser ā€œtapeā€ measure.

All set up and ready for listening:

Even without room equalisation, these are impressive.

Gone is the tiny sweet-spot that existed with my previous floor-standers. There’s now a huge wall-to-wall and floor-to-ceiling sound stage. Depth is impressive too.

Mid-range is detailed, yet smooth and not a hint of sibilance. Treble is light and airy, bass is fast and taught. The ambience on live recordings is amazing.

I might do some REW measurements tomorrow, though I suspect the tweaks will be minor. At the moment, I’m having too much fun.

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great thought! I’ll book a ticket for the speaker/beer experience… Will also walk Stan…

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No tickets required - open house to anyone who happens to be in the Maidenhead area at any given time. There’s always a decent beer, wine, or whisky to hand too ! :grin:

The stainless plinths are the final piece, but compared to the rest of the build, they’ll be relatively simple to construct.

For now, my hi-fi journey is complete - apart from maybe some closed-back cans for when I want to listen without disturbing the boss.

Time to kick back, relax, and enjoy the music.

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No :heart: to give for the next 13 hours Graeme but it had been a pleasure watching this project progress through the build and now to being complete

Hopefully you can relax and enjoy the music now and also hopefully the Boss starts to enjoy them as well :flushed:

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I’ve just read the thread through and I am seriously impressed, the build quality is amazing.
A considerable achievement.

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I agree 100%. Time to sit back and enjoy your amazing accomplishment. I bow to your patience and skill. Thank you for sharing this journey so we all know how much can be accomplished in the DIY world.

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These speakers are really growing on me. Mrs Mad Scientist asked me to turn the music down (she’d gone to bed earlier to watch TV) and now wanted to go to sleep.

So I turned it down from ~ 70 dB(A) to this:

For reference, normal conversation is ~60 dB(A). Where I had to crank the standmounts to bring them to an enjoyable listening level, these just seem to sing at even very low levels. Don’t know whether it’s the wide baffle, the high-efficiency, or a combination of the two (I’ll have to ask Troels), but I’m really liking it!

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Graeme – what a great pleasure it’s been to follow your progress, trials and tribulations as this complex DIY project proceeded. Thank you for sharing. I would love to buy you a beer or several someday and meet Stan as well. Though it will have to wait until I make a trip over the pond. Kudos.

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:radioactive:
You gotta be kidding - to extract their full potential, fully active is the way to go!

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Totally cliche by now, but what a project. Applause.

I just wished i could have a listen :-), i have not been able to listen to a system in a home where the soundstage & imaging is like you describe. Always a sweetspot, some pinpoint, some a bit wider but definitely not like you built! Enjoy and thanks for all your efforts - and honesty - to document, photograph and post your yourney.

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I guess the wide baffle is helping these sound more immense and giving a wider sense of depth. Wide baffle is a design Peter Comeau has commented on several times and was part of his move to reintroduce wider baffle stand mounts in the Wharfedale and Mission range. Would love to hear what a difference this makes but I dont have room for them.

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From a purely intuitive perspective, it makes sense that a wide baffle will sound very different.

Comparing my previous to current speakers and looking at the baffle-step compensation f3:

Standmount, baffle width 231 mm, f3 501 Hz

PMS, effective baffle width 600 mm, f3 193 Hz

With the PMS, there’s all that extra energy between nearly 200 Hz and 500Hz in 2pi space, whereas with the narrow baffle, half of it would be in 2pi space and the other half of it would be radiating behind the speaker.

The shift in balance between front and rear radiated energy across the critical lower midrange is enormous. Also, edge diffraction will occur at very different frequencies. I suspect this has huge implications for clarity across the lower midrange. Also with more direct sound relative to reflected sound, soundstage should be better due to stronger positioning cues.

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Yes! You’ve pushed that baffle step transition down fro 500hz where your ear is very sensitive, to 193Hz where it’s a lot less sensitive. If you look at the Fletcher Munson curve, you’ve bought yourself like 6dB of loss of ear sensitivity. So even if you have funkiness happening from the 2pi to 4pi transition and how you handle it, you padded that trouble spot with a bit of ā€œear blindnessā€.

In that regard wider is better, but from a ā€œliving with speakers in your lifeā€ standpoint, not everybody can get away with it. That said, I’m a Quad guy so I’m pretty used to wide and gawky speakers.

Get that lovely benchmark amp fired up on those things and enjoy some tunes!

Sheldon

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I can barely make things with cardboard and scissors. This is mightily impressive. Even if they sounded terrible, the mere construction and finish are beautiful. And that they sound good…wow. Graeme you are quite the inspiration!

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Not yet. REW FR measurement please :grinning: - VAR smoothing please.

Here ya go:

L & R measurements:

After correction using inversion:

I might do some further playing around with REW to try to improve things further (haven’t tinkered with rephase yet), but they’re sounding pretty good right now.

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