Shutdown98 System

[Shutdown98]

Here some pics of my system.

The making of the Adire Shiva MK IV sub in 2004

http://i1054.photobucket.com/albums/s487/Shutdown98/100_0220.jpg

A couple of years later i reinforced the cabinet with concrete

http://i1054.photobucket.com/albums/s487/Shutdown98/100_2322.jpg

In 2010 i made my Super Seas mini monitor from the site of Troels Gravesen http://www.troelsgravesen.dk Speaker building specs can be found here: http://www.troelsgravesen.dk/W15.htm

http://i1054.photobucket.com/albums/s487/Shutdown98/100_2519.jpg
http://i1054.photobucket.com/albums/s487/Shutdown98/100_2522.jpg

The system

http://i1054.photobucket.com/albums/s487/Shutdown98/DSC_0163.jpg

[Reid Malenfant]

Nice work Remco, all DIY I see - excellent :) Where's the concrete, on the outside of the sub wooden enclosure? If so you did a superb job of getting it smooth :stalks:

[Shutdown98]

the concrete is on the inside. On the second photo you can see it through the speaker hole.
It is done with floor repair concrete witch is thin and can be poured. It flows nice and has fibre reinforcement.
So the cabinet did shrink a few liters, but i took out the built in sub amp so the Qtc is still 0,6 - 0,65

[Reid Malenfant]

Ah, it must have been fun getting that in there - not! :eek:

Pretty sure you mean 0.6 to 0.65 Qcb which is just below a Butterworth Q of 0.7. Should be nice & clean, though not quite as clean as it being critically damped with a Qcb of 0.5...

Nice work though :)

I'll be having some fun a bit later this year with some decent subs myself, I have four of these to play with (http://www.creativesound.ca/pdf/CSS-SDX15-data-121107.pdf) :mental:

I guess it takes one to know one :D It's how come I recognised what you had there in your signature ;)

[Shutdown98]

You are correct, it should be 0,6 That is what i mean (corrected it in the post).
Four 15" woofers will let you rumble the place! Nice freq. curve too :eyebrows:

a Q of 0,5 would be ideal, but the reinforcement made the sound and definition allready so much better. At this point the effort to make a new cabinet is fairly big and the woofer is allready 8 years old. At this point i would choose to replace the Shiva with something like this: http://www.scan-speak.dk/datasheet/pdf/30w-4558t00.pdf
Makes a perfect fit in my cabinet and gets a Q of 0,6

[Reid Malenfant]

Is the sub stuffed? If it isn't get yourself a load of rockwool insulation & stuff the thing. That'll lower the Q & the driver resonance frequency in the enclosure.

I find that you can shrink an enclosure 20% & still get the same closed box resonance frequency by stuffing it. Rockwool teased out & broken up into smaller bits & then filling the enclosure would do the trick. I have tried just about everything including long haired wool (which is supposed to be the best - yeah right :rolleyes:) & rockwool wins every time.

You might need to cover the rear of the driver basket with something like tights or that plastic netting stuff you get fruit or onions in to prevent it getting pulled towards the cone though.

Just a thought if you haven't done it already :)

[Shutdown98]

Did not use rockwool :-)
But did stuff the cabinet.
Used Monacor MDM (50% wool and 50% synthetic) for stuffing.
Did use synthetic stuff before (baf it was called) but the mixed stuff sounds better. And against the walls there is egg-crate shaped foam.
Experimented with the amount and ended up with a light stuffing with lots of air. To much stuffing was no good.