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200L Barrel Subwoofer

voodooless

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The simulation for the specific driver is available on speakerboxlite if you want to check.
1636967438700.png

They also have not more than the manufacturer shows...
And it gives a neet little error box when trying to make a sim:
1636967552136.png

For some reason, if you use the wizard, it magically does make a graph... Which I would not trust, it gives a -6 dB at 10 Hz. No way that is true
 
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kiwifi

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Maybe someone measured it with a Dayton DATS then or something.
The boxlite parameters seem to be taken straight off the data sheet...
 

voodooless

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This is probably a more realistic simulation using Hornresp (with a few parameters guestimated) for a single driver:
1636968236989.png

Which at first sight looks okay. But when we factor in excursion, where I give the thing a very genourous 8mm of Xmax, maxSPL looks like this:
1636968425604.png

Which is optimistic at best, because also the 1000 Watt power handling is only peak, so I used 500W here, and even that is probably wishful thinking. In any case, below 60Hz, you are excursion limited. So at 20Hz, max SPL is about 102 dB. Which might still be respectable. If you have a second one, this will add some dBs as will room gain. So all in all might even be usable.
 

abdo123

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This is probably a more realistic simulation using Hornresp (with a few parameters guestimated) for a single driver:
View attachment 165551
Which at first sight looks okay. But when we factor in excursion, where I give the thing a very genourous 8mm of Xmax, maxSPL looks like this:
View attachment 165553
Which is optimistic at best, because also the 1000 Watt power handling is only peak, so I used 500W here, and even that is probably wishful thinking. In any case, below 60Hz, you are excursion limited. So at 20Hz, max SPL is about 102 dB. Which might still be respectable. If you have a second one, this will add some dB's ass will room gain. So all in all might even be usable.
something is wrong there is no way two 10 inch drivers in isobaric can come close to 120 max SPL yet along exceed it.
 

voodooless

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something is wrong there is no way two 10 inch drivers in isobaric can come close to 120 max SPL yet along exceed it.
It's a single driver in eighth space (so corner placement), in half-space it barely touches 110dB, which is possible with the generous 8 mm of Xmax that I specified.
 

abdo123

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I would honestly save up and buy a 18" woofer kit from parts express for 500$. (not just any 18", a Dayton Ultima)

This project is risky at best and is not worth even the time you would spend on it.


(Simulation is @ 2pi we're not savages :p)

1636969375069.png
 

voodooless

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But yes, there was something wrong: this was a closed box :facepalm:.

Doing the same with reflex yields a deeper response, but not much better power handling, except for a small peak around the tuning frequency. From where I stand, I'd say just put them in a closed box.
 

voodooless

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I would honestly save up and buy a 18" woofer kit from parts express for 500$. (not just any 18", a Dayton Ultima)
That would always be the better option, but if you already have all the stuff, and it costs you nothing... why not try!
(Simulation is @ 2pi we're not savages :p)
Because you pile up your subs in the middle of the room?
 

voodooless

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it's at least more sensible / standard than horn loading sub-bass frequencies :p
Not really. You should simulate close to the environment you use the thing in. So if you put it in a corner, you should do a corner simulation. Yes, you boost the low end, but that is at least more realistic (in reality, you'll probably get even more boost than that down low).
 

abdo123

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Not really. You should simulate close to the environment you use the thing in. So if you put it in a corner, you should do a corner simulation. Yes, you boost the low end, but that is at least more realistic (in reality, you'll probably get even more boost than that down low).
maybe if all the walls are made out of reinforced concrete, otherwise the bass will go right through the walls.

I feel 2pi would be more representative of the 'worst case scenario'. leaky walls, nulls in the response .etc
 

Chrise36

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Chrise36

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The boxlite parameters seem to be taken straight off the data sheet...
Yes they do this for every driver but since you are not building a new box from the beginning what would change? Max SPL probably impossible but you never know.
 

ta240

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This project is risky at best and is not worth even the time you would spend on it.
....

I understand what you are saying, but if they have fun with it then it could be worth their time. And in reality, is my posting this worth the time? I'm going to stop doing half what I do if I look at if it is really worth the time or not ;)
 

abdo123

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I understand what you are saying, but if they have fun with it then it could be worth their time. And in reality, is my posting this worth the time? I'm going to stop doing half what I do if I look at if it is really worth the time or not ;)

I have fun farming and gardening and it's very much worth my time, that doesn't mean that i would plant bad seeds ;)
 
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kiwifi

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I have measured the Pyle PL1090BL. I only measured one. When I measure the second, I can average the results...
PL1090BL.PNG
Some parameters are close to the spec sheet but the resonant frequency (Fs) is way off.
This is not surprising considering that the rubber cone surround is quite stiff. I was able to temporarily reduce the measured Fs by 10Hz, by simply warming the rubber with a hair dryer! Maybe it will loosen up over time, but I doubt it will ever be loose enough to match the spec sheet.

This is how it affects the response...
Meas-30HzLPF.PNG
The barrel (200L) and vents (15Hz) are the same, but I have had to reduce the LPF to 30Hz to get things flat from 20Hz to 30Hz.
Because the driver output peaks at 51Hz now (vs 27Hz on the spec), it's output falling rapidly by the time we get down to 30Hz and more power is required from the amplifier. At 400W Xmax is just under 8mm.

So is it still worth building? I think so...

i: I am interested to see if a barrel works as sub-woofer enclosure before I shell out for better drivers, and
ii: I still think that this sub will work for it's intended purpose, that is to supplement the output of my existing subs at very low frequencies. If the sub-bass peak is too much, I can control it with EQ and/or vent damping.

In the meantime I will be on the lookout for a better quality 10" sub (or two) with a lower Fs (that is real!)
 

voodooless

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With a real Qts of > 1.0 I would definitely not use bass-reflex. A closed box would suit much better here, but the high-ish FS does not really make for a good subwoofer that way.

A good quality 10" driver will most definitely not use 200 litres of volume. If you really want to go < 30 Hz, I would recommend looking at something like a tapped horn. Look at something like this or this for inspiration :) . But in the end, 10" woofers are just too small to give you any significant output below 30 Hz unless you have a serious amount of them.
 
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