I know, but as it is only the second sub I'm building I don't have a 100 and 200 liter sealed box with 10,12,15 and 18" baffles just lying around
I also wanted to measure the TS parameters with both drivers inside the plenum to see if the Fs changes much (I read about it lowering a few Hz) but I'm not really sure how to input the values.
2 drivers in series, so RE and Sd will be double. I attach the same weight to both cones at once for the second measurement but do I enter the value for a single weight?
That is nice thing with putty weight - it is semi sticky and attaches to cone and duatccap interface nicely. I am surprised 10g was enough mass for a big woofer like that. On my 5in in I used 23g. Actually REW will tell you to use a certain amount if it detects not enough change in Mms. I am lucky enough to have received Dayton DATS v2 for Xmas. It is so easy to use. Love it.
The design is almost finished:
It's 538x521x1900 mm, NET internal volume 370 liters, 160 (152) mm diameter vent tuned to 22Hz. Max air velocity <15m/s at Xmax. The sub will be 8cm of the ground due to the wheels (~100kg), I assume that is enough to put the exit of the vents on the bottom.
I'll drive it with an inuke1000dsp (maybe 3000) so i have a DSP to play with
All:
4th order highpass at 20
4th order lowpass at 80
Power adjusted till Xmax (7.5mm seems reasonable)
Red trace: as above
Blue trace: par EQ +3db @ 20Hz Q2
Green trace: par EQ +5db @21Hz Q2 and par EQ -1db @60Hz Q2
An externally hosted image should be here but it was not working when we last tested it.
It's 538x521x1900 mm, NET internal volume 370 liters, 160 (152) mm diameter vent tuned to 22Hz. Max air velocity <15m/s at Xmax. The sub will be 8cm of the ground due to the wheels (~100kg), I assume that is enough to put the exit of the vents on the bottom.
An externally hosted image should be here but it was not working when we last tested it.
I'll drive it with an inuke1000dsp (maybe 3000) so i have a DSP to play with
All:
4th order highpass at 20
4th order lowpass at 80
Power adjusted till Xmax (7.5mm seems reasonable)
Red trace: as above
Blue trace: par EQ +3db @ 20Hz Q2
Green trace: par EQ +5db @21Hz Q2 and par EQ -1db @60Hz Q2
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So I finished building the box and measured the sub using REW and a UMIK-1
4th order butterworth highpass at 20Hz and LR4 lowpass at 80Hz, 4db PEQ Q4 boost at 20Hz as per the sim.
I measured 1cm from the opening of the plenum and 1cm from the opening of 1 of the vents and this is what I got:
It looks quite okay but I'm not to happy about the sharp rise and fall around 52Hz. It's apparent in the output of the plenum but horrible in the vent. Can anyone recommend something to fix it? I can add some pillows or move the vent opening in the box (now it is parallel to the side walls so maybe there is some strong reflection there). Also the vent isn't braced in the box, it's only glued to the bottom, the rest is freestanding, it is 3mm thick 160mm diameter PVC so I didn't think it would start vibrating or something.
4th order butterworth highpass at 20Hz and LR4 lowpass at 80Hz, 4db PEQ Q4 boost at 20Hz as per the sim.
I measured 1cm from the opening of the plenum and 1cm from the opening of 1 of the vents and this is what I got:
An externally hosted image should be here but it was not working when we last tested it.
It looks quite okay but I'm not to happy about the sharp rise and fall around 52Hz. It's apparent in the output of the plenum but horrible in the vent. Can anyone recommend something to fix it? I can add some pillows or move the vent opening in the box (now it is parallel to the side walls so maybe there is some strong reflection there). Also the vent isn't braced in the box, it's only glued to the bottom, the rest is freestanding, it is 3mm thick 160mm diameter PVC so I didn't think it would start vibrating or something.
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The sharp rise and fall was due to the room, if I moved the sub it mostly went away.
So I finished the sub and it's a beast, it really is difficult to explain how clean it sounds.
Thanks for all the help and especially to DJK and Les Hudson for making this design available for DIY.
Pic:
So I finished the sub and it's a beast, it really is difficult to explain how clean it sounds.
Thanks for all the help and especially to DJK and Les Hudson for making this design available for DIY.
Pic:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
In room respons before (purple) and after (Red) messing with the DSP. Both plots are averages from the 3 seating positions. I mostly used the DSP simulation of REW.
Anyone have any ideas for making it better? The room is pretty horrible though. I live in a concrete house, have no carpets or drapes and there is a huge glass wall behind the seating area...
Fun story:
I had a Behringer truth studio sub when I still lived in the attic of my moms house. I built a dual opposed 12" shiva sub 2 years ago to replace it. So my mom (56) has heard some low bass before. When I invited her to listen to this one (at a moderate level) her mouth literally fell open, after 10 minutes of listening she asked me how long it would take me to build her one and how much it would cost. :-D
She wants it to be a bit smaller though but I still have 150l to play with. Any good 12" for about 100-150€ a piece? A driver with low third harmonic distortion seems perfect, Beyma publishes harmonic distortion charts, but are they accurate and do any other manufacturers?
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I have rebuilt the dual opposed shiva sub to a PPSL and gave that to my mom . As far as sound goes I really like the ppsl version better it's hard to explain the sound.
Low efficiency long stroke vs high efficiency pro drivers if you have the room go for the pro drivers they have a way of making it all sound so effortless.
. As far as sound goes I really like the ppsl version better it's hard to explain the sound.Low efficiency long stroke vs high efficiency pro drivers if you have the room go for the pro drivers they have a way of making it all sound so effortless.
What do you mean by schematic? I have some sketchup files (if I can still find them)
Hi, im reviving this because im about to embark on a similar build.
I have a pair of drivers ready to go. Im wondering whether in the last few years you have found anything youd do differently, or have had any more experience or things you would advise. I like the look of this design but im not particularly knowledgeable on technical audio things, im a woodworker primarily and have always played with speakers, rebuilt cabinets etc...
so any advice much appreciated, thanks!
I have a pair of drivers ready to go. Im wondering whether in the last few years you have found anything youd do differently, or have had any more experience or things you would advise. I like the look of this design but im not particularly knowledgeable on technical audio things, im a woodworker primarily and have always played with speakers, rebuilt cabinets etc...
so any advice much appreciated, thanks!
This sub is still playing wonderfully . If I would build it again I'd use a more elaborate construction for bracing then the point to point bracing I did here. Troels has some nice examples of serious bracing 26W-4558T00-II
. If I would build it again I'd use a more elaborate construction for bracing then the point to point bracing I did here. Troels has some nice examples of serious bracing 26W-4558T00-II- Status
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