Valutronic Revisited

[pastorola]

Well guys, I'm going for it again. The speaker building itch really hit me this summer. I'll be back with some details, but this is my rebuilt and shrinked version of the nationally famous Swedish DIY speaker "Valutronic SQ-50", built around the great-bang-for-the-buck Monacor SPH-170 6,5" woofer.



Later guys.

[S7910]

Re: Valutronic Revisited

Very cool. Am I imagining things or are the cabinets made from hardwood flooring?

[fastbike1]

Re: Valutronic Revisited

Looks more like pine. Nice job on the cabs though.

Very cool. Am I imagining things or are the cabinets made from hardwood flooring?

[pastorola]

Re: Valutronic Revisited

Here's my story.



When I built my Swope 2.1 I suddenly had an extra pair of floorstanders (, my first DIY build from like ten years ago. They fit nicely into the living room, but now my 12-year-old son wanted them and he has a really small room. What to do?

Drivers are Monacor SPH-170 6,5" woofer and DT-280 1,1" dome tweeter. 53 Liter vented with F3 of 32 Hz.

fastbike1 had been so kind as to teach me box simulation in Jeff Bagby's Woofer Box simulation software, so I thought: why not try to do my own simulation and design my own boxes to be able to give my son a nice set of speakers? After some simulation I ended up chosing a 15 liter vented enclosure with a port tuned to 38 Hz for a F3/F6/F10 of 57/47/37 Hz. No bass monster (and nowhere near the original F3 of 32 Hz) but hopefully a decent computer speaker.

Two challenges: no more money for speaker building, and no more vacation with lots of time. So it had to be cheap and easy. I spent SEK 100 (USD 14) on some lowest quality pine construction planks and started working with my simple setup of tools.



The planks are tongue and groove in a very rough quality and only 3,7 inches wide. After cutting them and gluing the together to form "sheets" of hardwood pine, I managed to build simple rough boxes with front slot ports. Only 17 mm (appr 3/4") thick walls I added internal bracing between the side walls, and glued some simple bracing to the top and back panels. Leftover polyester fibres worked as lining on three non-parallell walls inside.

[pastorola]

Re: Valutronic Revisited

I wondered what to do with the finish. As some of you know my wife has a thing for white, but I let my son decide. I have done a lot of floor work in my house, oldfashioned spruce planks treated with (I hope I get the translation right) lye and oil. We decided to try that on the speakers (but the wood is pine instead of spruce)!



Here is after the double lye treatment.



Here is after the final oil treatment and everything soldered and mounted (and actually a sanding with 240 after the oil. Rough wood, fibres rose after every treatment step). I am quite happy with the result. They are no bass monsters, the deepest bass isn't there (The Swope sub shows there is more bass to be found) but they aren't thin either.



Here is a size comparison with these (15 liter), My Swope MTM's (20 liter) and the old floorstanders (53 liter).

[pastorola]

Re: Valutronic Revisited

Looks more like pine. Nice job on the cabs though.

Thank you. And THANK YOU for tutoring me in the simulation! I went on to experiment with the Monacor woofer as you can see Yeah, it's tounge and groove pine planks glued together to form hardwood sheets.

[Blacktree]

Re: Valutronic Revisited

I have done a lot of floor work in my house, oldfashioned spruce planks treated with (I hope I get the translation right) lye and oil. We decided to try that on the speakers (but the wood is pine instead of spruce)!

In English it's called 'wood lye'. Close enough, right?

By the way, I like the finish on the speaker cabinets. It must have taken a lot of work to smooth out those rough planks. I'm sure your son will enjoy the speakers, too.

[bullittstang]

Re: Valutronic Revisited

Very nice build! That wood looks great after the finish was applied, makes them really "pop". Your son is one lucky guy and they will be a great set of speakers for him to use for a long time.

You certainly got "bit" by the DIY speaker bug and did a great job on both your builds.

[S7910]

Re: Valutronic Revisited

Looks more like pine. Nice job on the cabs though.

Ah, that makes sense. I do agree, the cabinets are beautiful.

[pastorola]

Re: Valutronic Revisited

Thanks for the kind words everybody. I guess I should be happy with the result considering I spent almost nothing and finished everything within a week



Tried them in his room today, he got tired of me auditioning them in the living room... They fill his little room quite nice and they feel more bassy in there. He gets my old Marantz PM550DC to power them. It makes a nice little setup in my opinion.

[Audio Geek]

Re: Valutronic Revisited

Looks nice.

[evilskillit]

Re: Valutronic Revisited

Setup looks nice. Lucky kid.

Thanks for the kind words everybody. I guess I should be happy with the result considering I spent almost nothing and finished everything within a week

[ATTACH=CONFIG]49924[/ATTACH]

Tried them in his room today, he got tired of me auditioning them in the living room... They fill his little room quite nice and they feel more bassy in there. He gets my old Marantz PM550DC to power them. It makes a nice little setup in my opinion.

[pastorola]

Re: Valutronic Revisited

My son hooked them up to his iPad Air tonight. He smiled. I smiled. The Marantz is 2x100 W so there is plenty of punch and the 5 band EQ allows us to extend the low end a few extra Hz by raising the 50 Hz band a few dB. Actually this was accounted for when simulating the box. This EQ setting gives us an F3 in the 47 Hz region instead of the F3 of 57 Hz that a flat EQ offers.

Now I'm thinking of building a 0,7 cf sub with the Dayton SD215A to complement these. But not for a while, I've got to do some normal living. In my head I'm already planning though

[Ithaca]

Re: Valutronic Revisited

Those look great. I don't often get to see pine look that nice.

[Uncle Bob]

Re: Valutronic Revisited

I wondered what to do with the finish. As some of you know my wife has a thing for white, but I let my son decide. I have done a lot of floor work in my house, oldfashioned spruce planks treated with (I hope I get the translation right) lye and oil. We decided to try that on the speakers (but the wood is pine instead of spruce)!

[ATTACH=CONFIG]49890[/ATTACH]

Here is after the double lye treatment.

[ATTACH=CONFIG]49891[/ATTACH]

Here is after the final oil treatment and everything soldered and mounted (and actually a sanding with 240 after the oil. Rough wood, fibres rose after every treatment step). I am quite happy with the result. They are no bass monsters, the deepest bass isn't there (The Swope sub shows there is more bass to be found) but they aren't thin either.

[ATTACH=CONFIG]49892[/ATTACH]

Here is a size comparison with these (15 liter), My Swope MTM's (20 liter) and the old floorstanders (53 liter).

Amazing...your back yard view in Sweden is identical to mine here in Mid-Michigan....your tag line at the bottom says it all.