A few days off with lots of family visits etc. Back on track to seal up the second subwoofer. I tried real hard to finish it up today as the next two days it will be much chillier outside. I can't get that out of the garage with my cheap small heater in there.
So on with it, stuffing the second subwoofer:
Sealing it up with wool felt:
And fully stuffed, ready to be closed:
And the measurements, compared to the first:
As can be seen, the curves from both woofers is slightly different. This day the ambient noise was a little lower which also shows in the measurements.
Final curves for both subs:
A few tiny differences within a Hz or so. Driver free air curve is what determines the outcome differences here.
I'll gladly accept that as they will each get their own DSP settings anyway. They both look good to me, nice smooth curves, quite a substantial drop of the resonance peak without a huge difference in overall curves. Ideally both woofers would have been broken in before these measurements, but that would take up valuable time I don't have. The plan still is to close them up in the coming days. I can do the crimping and soldering for the amplifier inside our home, so I do expect them to be finished very soon.
I don't look forward to crawling in my space below the floor to run the needed wires though. But if I get a moment of courage I will. Next month it will probably be impossible to do so while staying dry. The groundwater level usually is much higher in januari and februari.
So on with it, stuffing the second subwoofer:
Sealing it up with wool felt:
And fully stuffed, ready to be closed:
And the measurements, compared to the first:
As can be seen, the curves from both woofers is slightly different. This day the ambient noise was a little lower which also shows in the measurements.
Final curves for both subs:
A few tiny differences within a Hz or so. Driver free air curve is what determines the outcome differences here.
I'll gladly accept that as they will each get their own DSP settings anyway. They both look good to me, nice smooth curves, quite a substantial drop of the resonance peak without a huge difference in overall curves. Ideally both woofers would have been broken in before these measurements, but that would take up valuable time I don't have. The plan still is to close them up in the coming days. I can do the crimping and soldering for the amplifier inside our home, so I do expect them to be finished very soon.
I don't look forward to crawling in my space below the floor to run the needed wires though. But if I get a moment of courage I will. Next month it will probably be impossible to do so while staying dry. The groundwater level usually is much higher in januari and februari.
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Good news, first sub is up and running! 
No chance today to do any kind of experiment except confirm that it is working as it should. Family is in and listening to our yearly Top 2000 and Led Zeppelin - Kashmir is playing, can't interrupt that.
As said, I've worked slowly but surely to finish it, one more to go!
At least I know it has the power to rattle my ceiling, that much I do know from this very brief test (lol).
On with the next one....
No chance today to do any kind of experiment except confirm that it is working as it should. Family is in and listening to our yearly Top 2000 and Led Zeppelin - Kashmir is playing, can't interrupt that
.As said, I've worked slowly but surely to finish it, one more to go!
At least I know it has the power to rattle my ceiling, that much I do know from this very brief test (lol).
On with the next one....
Happy New Year
Your planned sub could potentially give you both
Just make it heavy enough!
I weighed this first sub out of curiosity, it weighs 32,3 Kg. Despite filling/lining it with heavy mass loaded vinyl which by itself is close to 14 Kg.
Baltic Birch is lighter than MDF. But a lot more pleasant to work with.
Just make it heavy enough!
I weighed this first sub out of curiosity, it weighs 32,3 Kg. Despite filling/lining it with heavy mass loaded vinyl which by itself is close to 14 Kg.
Baltic Birch is lighter than MDF. But a lot more pleasant to work with.
Your planned sub could potentially give you both
Just make it heavy enough!
I weighed this first sub out of curiosity, it weighs 32,3 Kg. Despite filling/lining it with heavy mass loaded vinyl which by itself is close to 14 Kg.
Baltic Birch is lighter than MDF. But a lot more pleasant to work with.
I do have a good friend
My material of choice would probably be 30 mm Valchromat which may possibly be better than MDF, HDF and Baltich birch, but more expensive and pretty heavy: Valchromat - Investwood - Range
Would easily pass 100 Kg each
Such heavy lifting is only good for one thing, kiropractor appointments...
I do have a prolapse in my lower back so I will need some lifting help from friend(s) [above]
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I had to reach my goal, still the 31st of december over here and both subs are finished!
Second one acted up a bit, my fault but was an easy fix. I heated up the RCA plug a bit too much, had to restore its slightly molten entrance, and resolder. Pfew...
Wowwww. Well done
.... maybe test out with new year concert from Vienna tomorrow
Hope everyone survived the start of the new year in good condition, 2020 is upon us, time for some action again.
Hopefully today I'll get the needed cables run below the floor. Still thinking of ways to mix/match the subs with the arrays. As said, I'm not bound to a fixed crossover per sé, I could mix/match the sub with the arrays to get to the best results. It will take time to find what brings the cleanest results with the best left/right separation.
Unconventional, as usual, but due to the room's large influence in these frequencies it might actually present a benefit to have both the array and the sub run with overlap, while still largely reducing the low frequency strain on the arrays themselves. As said I expect a 6 to 9 dB advantage at low frequencies for the arrays. More if I get lucky.
A lot depends on how well the subwoofers can work within the room. only measurements will tell. I'm anxious to find out, but won't have the room to myself in the coming days.
As it is still mostly dark weather outside I can't snap a picture of the new look. I like how the Cat protector turned out. It really works visually with the rest of the sub enclosure. I count myself lucky to have this accepted by my family members, I didn't get any grief about it, but the Audio/Video wall is becoming hard to ignore with the 55" OLED and the arrays + subs. Not an average sight in today's world with ever smaller speakers being the norm.
Still I can't think of a smaller solution with the same or similar potential.
Hopefully today I'll get the needed cables run below the floor. Still thinking of ways to mix/match the subs with the arrays. As said, I'm not bound to a fixed crossover per sé, I could mix/match the sub with the arrays to get to the best results. It will take time to find what brings the cleanest results with the best left/right separation.
Unconventional, as usual, but due to the room's large influence in these frequencies it might actually present a benefit to have both the array and the sub run with overlap, while still largely reducing the low frequency strain on the arrays themselves. As said I expect a 6 to 9 dB advantage at low frequencies for the arrays. More if I get lucky.
A lot depends on how well the subwoofers can work within the room. only measurements will tell. I'm anxious to find out, but won't have the room to myself in the coming days.
As it is still mostly dark weather outside I can't snap a picture of the new look. I like how the Cat protector turned out. It really works visually with the rest of the sub enclosure. I count myself lucky to have this accepted by my family members, I didn't get any grief about it, but the Audio/Video wall is becoming hard to ignore with the 55" OLED and the arrays + subs. Not an average sight in today's world with ever smaller speakers being the norm.
Still I can't think of a smaller solution with the same or similar potential.
It took me another day to get the 'below floor' wiring done. I had to spend the afternoon yesterday making preparations. Stuff like the Impedance Equalization network had to get a new place too. I haven't even run a test today as it was taking me the whole afternoon to get things done. There aren't many routes to get the wires under the floor so it always takes up a lot of time to get things done.
Hopefully a first test and some pictures will follow soon!
Hopefully a first test and some pictures will follow soon!
Late this morning I started to work on a preliminary array/subwoofer crossover. Not a standard crossover but make them work together to save headroom on the arrays.
Lots of work of course, lots of measurements too. What I've done so far is put a few EQ PEQ's on the subwoofers, left sub and right sub separately. After that I made some phase manipulation on each one in RePhase and used that as the preliminary FIR input for the subs.
The arrays are freed from low sub duty by using a low shelf filter of -12 dB at 160 Hz on the both of them. The subwoofers are crossed at that same 160 Hz point (linear phase crossover, actually it is a 2 piece crossover first one is set at 160 Hz, first order and a second order at 700 Hz to make sure I do not still have output that might trigger the 3 KHz ringing these alu coned woofers can exhibit).
I worked on this in pairs, to see if I could clean up the left side and right side separately (s left sub with left array and right sub with right array). It worked out quite well I must say, I can certainly get this to work as I envisioned. So now the subs can cover most of the array's shortcomings instead of having the left array helping out the right one and vice versa.
Here's a distortion plot, measured at the listening seat with left + right playing (including subwoofers):
Don't mind that little peak at 50 Hz, as that truly depends on the traffic outside (changes in each plot, clean with a moment of silence outside). This was a last step measurement I made after a long, long session, so I did not have the patience to go for the best graph I could get. I'll revisit the measurements soon enough. Start fresh so to speak. I can definitely work with this material.
The wavelet belonging to the above graph:
(only looking at frequencies below 1 KHz at this time)
At about 17:00 hour I quit the measurement session (lots of traffic outside) and started listening. At first I wasn't immediately swept of my feet. A few minor tweaks further and things improved a lot. I raised the subs a further 3 dB, put on the mid/side processing again and: boom! Quite enjoyable. I had about an hour and a half to play with but enjoyed it immensely.
As I wasn't entirely alone while making these measurements this afternoon, there still is way more to gain/adjust/experiment etc. I wanted a result, that's what I got! I'm pleased.
I'll play the heck out of them in the coming days to let the subs break in some. I'll probably can't withhold myself from making tweaks but really should give them some time. Oh, more listening to do, the horror!
Lots of work of course, lots of measurements too. What I've done so far is put a few EQ PEQ's on the subwoofers, left sub and right sub separately. After that I made some phase manipulation on each one in RePhase and used that as the preliminary FIR input for the subs.
The arrays are freed from low sub duty by using a low shelf filter of -12 dB at 160 Hz on the both of them. The subwoofers are crossed at that same 160 Hz point (linear phase crossover, actually it is a 2 piece crossover first one is set at 160 Hz, first order and a second order at 700 Hz to make sure I do not still have output that might trigger the 3 KHz ringing these alu coned woofers can exhibit).
I worked on this in pairs, to see if I could clean up the left side and right side separately (s left sub with left array and right sub with right array). It worked out quite well I must say, I can certainly get this to work as I envisioned. So now the subs can cover most of the array's shortcomings instead of having the left array helping out the right one and vice versa.
Here's a distortion plot, measured at the listening seat with left + right playing (including subwoofers):
Don't mind that little peak at 50 Hz, as that truly depends on the traffic outside (changes in each plot, clean with a moment of silence outside). This was a last step measurement I made after a long, long session, so I did not have the patience to go for the best graph I could get. I'll revisit the measurements soon enough. Start fresh so to speak. I can definitely work with this material.
The wavelet belonging to the above graph:
(only looking at frequencies below 1 KHz at this time)
At about 17:00 hour I quit the measurement session (lots of traffic outside) and started listening. At first I wasn't immediately swept of my feet. A few minor tweaks further and things improved a lot. I raised the subs a further 3 dB, put on the mid/side processing again and: boom! Quite enjoyable. I had about an hour and a half to play with but enjoyed it immensely.
As I wasn't entirely alone while making these measurements this afternoon, there still is way more to gain/adjust/experiment etc. I wanted a result, that's what I got! I'm pleased.
I'll play the heck out of them in the coming days to let the subs break in some. I'll probably can't withhold myself from making tweaks but really should give them some time. Oh, more listening to do, the horror!
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Here's a distortion plot, measured at the listening seat with left + right playing (including subwoofers):
That are very nice distortion figures!
Its hard to get <1% at 20Hz...
Can you also do them at 90/95/100dB?
Further more you said that first impression was kind of disappointing.
Can imagine that with a fully flat curve down to 20Hz...
Try a room curve: starting at 80Hz and +8dB at 20Hz..
This is what I use, and I like it very much
At first I expected to have a hard time to line up the subs and arrays acoustically. It was way more easy than I could imagine. In my rush getting things to work I made a FIR file without looking at the number of tabs. It defaults at 16384, instead of the 65536 tabs I use on the arrays. While playing both a sub (without crossover) and one array (full range) at once (sweep limited to run from 10 Hz to 1 KHz) I got two pulses separated by about ~560 ms. So delaying the sub by that number immediately resulted in a pure 6 dB sum. The sweep sounds funny though .
I've got to remember that little trick, it made it quite easy to align both together to an exact sum.
Aligning both was as simple as reading the exact distance between these two peaks.
.I've got to remember that little trick, it made it quite easy to align both together to an exact sum.
Aligning both was as simple as reading the exact distance between these two peaks.
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Not without upsetting a lot of stuff in my room! I can hear my metal ceiling complaining when I run any higher.
90 dB might still work and I might try that in a next run. The walls/floor, in other words, the room helps me get these numbers. If I were to pull out the sub into the room I doubt it would look this clean reaching the same SPL. I'm not taxing the subs just yet, plenty of room to play with. [/quote]Further more you said that first impression was kind of disappointing.
Can imagine that with a fully flat curve down to 20Hz...
Try a room curve: starting at 80Hz and +8dB at 20Hz..
This is what I use, and I like it very much
I do have a raised output at lower frequencies, but not as much as you suggest. I largely follow the curve Toole published (The dashed Trained Listeners curve):
Now that I have subs, I might actually play with these numbers again to see what I like. The Trained Listeners curve was quite close to what I had evolved towards over a long period of time of adjusting. Nowadays I choose it as the curve to start with. As I've already dialed up the subs somewhat I might like more bass. I do think a lot has to do with average listening SPL.
I stay at about 85 to 87 dB on average but with bass heavy songs it's easy to have my SPL meter go higher
.