I heard two of those Daytons in seals cabinets with dual bryston's in mono and EQ, I felt plenty of chest slam. I started a sealed cab for one today, 1 1/2 ply walls and baffle, oak T brace, relatively simple but effective.
Note too that the long, super high aspect ratio vent is probably acting as somewhat of an acoustic resistor, especially at higher power, like stuffing a round vent with straws, so imagine it's rolling off the bottom octave, sucking up amp power/bottoming the driver in the process.
GM
GM
Plenty of good info on here to chew on and digest.
I've heard a mention or two about port things. I built it exactly to calculation (or as close as I possibly could anyways). Is there a way I can properly calculate, or figure out, exactly what my port tuning frequency is, and what it's doing, with my REW? Perhaps stuff my mic in the port and run a sweep from 15-30Hz or something? I honestly can't think of anything else that could be wrong with my box unless the WinISD model is just completely wrong.
The 90-95dB was rms, which is what REW does with a sweep. Probably peaking around 95-100 with the kick. Granted that was with pro subs, which generally have a sensitivity closer to ~100dB, but my modeled 110dB rms should have no issue hitting "the same volume" in a small room as opposed to 2x pro subs outside, or in a large auditorium.
Today is bike day, but I'll see if I can lug my sub upstairs and get it all set up properly tonight. Especially since I realized the vinyl wrap I ordered is coming from china, which means customs. >.< Anyways, it's replacing my dual TangBand W5 subwoofer that goes down to ~28Hz and can almost thump my chest, but not quite. I fully expect it to be able to blow the doors off of that sub in all areas without breaking a sweat.
I've heard a mention or two about port things. I built it exactly to calculation (or as close as I possibly could anyways). Is there a way I can properly calculate, or figure out, exactly what my port tuning frequency is, and what it's doing, with my REW? Perhaps stuff my mic in the port and run a sweep from 15-30Hz or something? I honestly can't think of anything else that could be wrong with my box unless the WinISD model is just completely wrong.
The 90-95dB was rms, which is what REW does with a sweep. Probably peaking around 95-100 with the kick. Granted that was with pro subs, which generally have a sensitivity closer to ~100dB, but my modeled 110dB rms should have no issue hitting "the same volume" in a small room as opposed to 2x pro subs outside, or in a large auditorium.
Today is bike day, but I'll see if I can lug my sub upstairs and get it all set up properly tonight. Especially since I realized the vinyl wrap I ordered is coming from china, which means customs. >.< Anyways, it's replacing my dual TangBand W5 subwoofer that goes down to ~28Hz and can almost thump my chest, but not quite. I fully expect it to be able to blow the doors off of that sub in all areas without breaking a sweat.
An externally hosted image should be here but it was not working when we last tested it.
You mean you ran an REW test sweep through the live PA system and it was 90-95dB?
I was thinking you meant you took a reading in the venue while it was playing live music. In which case the peak of the kick drum could easily have been 20 or 30dB over the long term RMS reading of the system SPL.
You have a bike day? Lucky! Sounds like a good idea.
You were correct the first time around. I on a slow response setting, my dB meter showed low 90's and on a fast response, it would peak up to 95-100 dB at listening position in the middle of a song. Given that the bass, and other instruments/vocals, are playing continuously (usually), I consider that comparable to 'rms'. Similarly, since the kick is a very short hit, I consider that to be 'peak'. Obviously, it doesn't translate exactly like that, but it's a quick general comparison.
Heck yeah! I try to get in at least 2 good rides a week preferably on the mountain bike if I can. Otherwise, I get flabby flying a desk.
Heck yeah! I try to get in at least 2 good rides a week preferably on the mountain bike if I can. Otherwise, I get flabby flying a desk.
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You can run the REW sine wave generator at frequencies around the Fb, the excursion will be at minimum at Fb, and will increase above and below Fb.
Putting a light colored dot on the cone makes it easier to see the excursion. Be careful to not use too much voltage for too long, lest you let out the "magic smoke" ;^).
Art
You have to remember the ear doesn't work very well at very low frequencies. So the output might seem much less than it really is.
Do you know what frequency you measure those dB.
Sure you did not program the amp with a massive EQ for very low frequencies. That would explain the big cone excursion and the low audible slam that you are missing.
Sure you did not program the amp with a massive EQ for very low frequencies. That would explain the big cone excursion and the low audible slam that you are missing.
AFAIK, the only way to calculate such a high aspect ratio, especially one with the no-no of being > 9:1, is to use the complex wave equation and whatever else is required for its high resistance due to friction loss, so measuring is the most practical way to 'see' what the vent's response, tuning is.
I forgot to mention that the vent's bends are affecting its output, tuning also, so looking forward to some vent only response measurements [mic inside it ~1/4"].
I imagine AkAbak is the only freeware that might can sim it 'close enough'; for sure none of the 'simple' programs can, plus WinISD has vent calculation issues to begin with: Discrepancy between WinISD & HornResponse
GM
If the measurement on the first page is accurate then you might just be used to room modes.
In another room or with an other subwoofer you might have had +20 DB @ 30 Hz and if that's what you like then you will never be satisfied with this sub. A lot of Action scenarios (explosions and so forth) are between ~30 and ~ 50 Hz. That's where your output actually goes down.
Also it is just a 10" driver with 12 mm Xmax. The only thing that counts for low output volume is volume displacement. And that driver is physically restricted by is diameter/membrane surface and its linear excursion.
In my opinion your expectations regarding the subwoofers output power where to high (especially for your large room). I would recommend at least 12" if not 15". And when designing your subwoofer keep the room gain/room influence (modes) in mind. Those two can ruin the best designed subwoofers.
In another room or with an other subwoofer you might have had +20 DB @ 30 Hz and if that's what you like then you will never be satisfied with this sub. A lot of Action scenarios (explosions and so forth) are between ~30 and ~ 50 Hz. That's where your output actually goes down.
Also it is just a 10" driver with 12 mm Xmax. The only thing that counts for low output volume is volume displacement. And that driver is physically restricted by is diameter/membrane surface and its linear excursion.
In my opinion your expectations regarding the subwoofers output power where to high (especially for your large room). I would recommend at least 12" if not 15". And when designing your subwoofer keep the room gain/room influence (modes) in mind. Those two can ruin the best designed subwoofers.
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What happens when you move the subwoofer and place it in a corner.
That should excite all the room modes.
Then walk around in the room, there must be a lot of bas at least somewhere in that room. It can not just disappear.
That should excite all the room modes.
Then walk around in the room, there must be a lot of bas at least somewhere in that room. It can not just disappear.
I am not sure if you responded to Brian Steele. I had the same problem with my sub trying to drive it with a Crown XLS1000. The amp was expecting a 1.4v signal and I was pushing .775. I had to get a little direct box that converts the signal and now I can make it punch me in the chest (slight exaggeration).
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I'm thinking we need impedance measurements of this so we can see exactly what the port is doing. Ie what is it tuned to and is it being lossy or not.
If all you're doing is testing, or listening, to the sub on its own then amp gain, etc, has very little to do with anything.
As has been said before, the tuning frequency of the port corresponds to the frequency that the driver will move the least. At this point the air velocity through the port will be high. For the kind of SPLs we're talking about here the port should be blowing a small gale.
If all you're doing is testing, or listening, to the sub on its own then amp gain, etc, has very little to do with anything.
As has been said before, the tuning frequency of the port corresponds to the frequency that the driver will move the least. At this point the air velocity through the port will be high. For the kind of SPLs we're talking about here the port should be blowing a small gale.
IF you want to measure tuning frequency, just do a low level sweep with the mic nearly touching the woofer. Unless the port is very lossy, you will get a notch at the tuning frequency. This is actually preferred to impedance measurements.
Not necessarily.
Photobucket has eaten the pictures, but I found the near-field cone measurement could give results anywhere from 28Hz up to 36Hz.
Nearfield cone measurement doesn't appear to reveal system tuning
To the OP, check the following:
- NU1000 output wiring
- That the cabinet is actually sealed properly (impedance measurement will reveal this, and more)
Chris
I lugged it upstairs, got it hooked up to my computer, and fiddled with the DSP a bit (using the software). It sounds a HECK of a lot better in my computer room than it did downstairs. I must've literally had it in the worst possible place downstairs because it's night and day difference.
To my ears, playing sine waves and such, it plays 25Hz with ease. 23Hz is very strong too. It's rolling off a decent bit around 20Hz and drops fairly steep after that (to be expected). It makes my house's floorboards and deck rumble quite easily as well. It's not quite as punchy as I would hope, but it's not in its final position, nor is it eq-ed at all, but it is pretty close in the 'stock' configuration.
I haven't had enough time to get a port sweep or impedance graph just yet, but I do still plan to upload those just for fun. I'm curious about learning how to read impedance graphs and such on a sub. More to come in the next couple days!
To my ears, playing sine waves and such, it plays 25Hz with ease. 23Hz is very strong too. It's rolling off a decent bit around 20Hz and drops fairly steep after that (to be expected). It makes my house's floorboards and deck rumble quite easily as well. It's not quite as punchy as I would hope, but it's not in its final position, nor is it eq-ed at all, but it is pretty close in the 'stock' configuration.
I haven't had enough time to get a port sweep or impedance graph just yet, but I do still plan to upload those just for fun. I'm curious about learning how to read impedance graphs and such on a sub. More to come in the next couple days!
Or the amp! The amp could have been broken and started working properly again.
Or the box. Maybe it wasn't sealed properly but gremlins came in the night and sealed it with gremlin wax.
The remaining possibility we certainly shouldn't rule out is the problem was with the port design, but a freak localised termite infestation has made the necessary adjustments and now everything is fine.
Or the box. Maybe it wasn't sealed properly but gremlins came in the night and sealed it with gremlin wax.
The remaining possibility we certainly shouldn't rule out is the problem was with the port design, but a freak localised termite infestation has made the necessary adjustments and now everything is fine.
Lol. I love it! I'll have to stick that one in my back pocket for future use. 😀
The fact is, there are tons of things that affect my subs output. Everything from placement to phase to dsp setup, to having my amp now plugged into a power conditioner could all have a noteable affect on the output, so it's rather silly to point to one item (in this case a guess that had some truth to it) and say 'I told you so'. I'm still very interested in seeing what the port is doing and how to read the impedance chart. I'll be taking some more measurements and throwing those up hopefully by the weekend.
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