I need a formula for calculatin max spl at various frequencies and wattages, or a program that can graph this for me. I'm considering the 10" Dayton Series II in a 1.5 ft sealed box, giving an unequalized f3 of 80hz and a system Q of 0.54. I'm going to use PE's 250 watt sub amp which has a bass boost that is adjustable in both frequency and amount. If I use the sub at lower volumes in my bedroom can I equalize it flat to 20hz as long as I don't turn the overal volume up too high?
Also, how's this sub sound at very low volumes, below conversation level and at 150+ frequencies? I'll likely be crossing it over high and it will be forced to take on primary playback of much of the 150-200hz or so range, I'm pairing it with some small 5.25 inch drivers.
Thanks,
Keith
Also, how's this sub sound at very low volumes, below conversation level and at 150+ frequencies? I'll likely be crossing it over high and it will be forced to take on primary playback of much of the 150-200hz or so range, I'm pairing it with some small 5.25 inch drivers.
Thanks,
Keith
If room gain isn't considered you would need a 24 dB lift to reach 20 hz (two octaves at 12 dB each). I don't know what your amp module is capable of doing.
OTOH it might be sufficient combined with the room effects.
The rather high tuning of 80 Hz together with the low Q of 0.54 would propably make your box a suitable candidate for an ELF circuit.
Regards
Charles
OTOH it might be sufficient combined with the room effects.
The rather high tuning of 80 Hz together with the low Q of 0.54 would propably make your box a suitable candidate for an ELF circuit.
Regards
Charles
Well, let's consider your speaker's air moving abilities.
A normal 10 inch has about 56 in² of area. Your Dayton probably has about ±0.3 in of excursion. That translates into 16.8 in³ of air this speaker can move in a sealed box, no matter what the size, no matter what the power.
This chart I posted gives you the amount of air that must be moved for a certain SPL at a certain bass frequency. You might want to press F11 or full screen to see the whole chart.
http://www.diyaudio.com/forums/showthread.php?threadid=5668&highlight=spl+chart
Starting at the bottom, we follow the "20 Hz" line all the way until we are approximately at 17 in³, (we have to estimate between 12 and 32). That lands us approximately at 92 dB. This chart dies not count room gain, which might average 6 or 7 dB.
98 or 99 dB at 20 Hz is not really hearable or feelable.
Even with room gain, I don't think you are going to get much useful output from this sub at 20 Hz. Not enough air moving ability from the 10 incher. You have to move your expectations higher up the scale. That does not mean that isn't a good sub for it's size.
A normal 10 inch has about 56 in² of area. Your Dayton probably has about ±0.3 in of excursion. That translates into 16.8 in³ of air this speaker can move in a sealed box, no matter what the size, no matter what the power.
This chart I posted gives you the amount of air that must be moved for a certain SPL at a certain bass frequency. You might want to press F11 or full screen to see the whole chart.
http://www.diyaudio.com/forums/showthread.php?threadid=5668&highlight=spl+chart
Starting at the bottom, we follow the "20 Hz" line all the way until we are approximately at 17 in³, (we have to estimate between 12 and 32). That lands us approximately at 92 dB. This chart dies not count room gain, which might average 6 or 7 dB.
98 or 99 dB at 20 Hz is not really hearable or feelable.
Even with room gain, I don't think you are going to get much useful output from this sub at 20 Hz. Not enough air moving ability from the 10 incher. You have to move your expectations higher up the scale. That does not mean that isn't a good sub for it's size.
Thanks, I actually emailed PE about this and Eric there wrote back and basically said the cheaper standard Dayton 10" (295-315) would be better for my purposes, which are mostly to get good QUALITY bass at lower volumes. He provided a good analogy, when you stand by a DJ stand and feel your lungs being pushe, you think 20hz, but really it's 50-60hz, so the higher the volume the lower you think the frequency sounds/feels. And the Dayton Series II has such a high f3 that at low volumes it would not sound very low at all. He even plugged the two drivers into a sim to give me some numbers. The cheaper one that he recomended has a lower f3 of 51hz so it will go lower, and the power handling should be enough for me with my small mains, and the Series II's large power handling wouldn't be usefull to me as the xmax is about the same.
To sum it up PE has really good tech service, especially since they recomended I buy something only 1/3 of the price I was prepared to spend.
To sum it up PE has really good tech service, especially since they recomended I buy something only 1/3 of the price I was prepared to spend.
>I need a formula for calculatin max spl at various frequencies and wattages, or a program that can graph this for me.
====
I can dig up all the formulas if needed, but for quick comparisons I've been using BoxPlot 3.0 for ages, which plots the identical results as the formulas. Here's the free demo, which should be good enough for your purposes:
http://members.aol.com/dctools/boxplt3.exe
====
>Starting at the bottom, we follow the "20 Hz" line all the way until we are approximately at 17 in², (we have to estimate between 12 and 32). That lands us approximately at 92 dB.
====
I never was any good at reading nomographs, so went searching for the math behind them and had a buddy with good math skills work out a few examples for me to follow till programmable calculators came along. You nailed it though, I calculated 92.04dB, right where BoxPlot shows it.
====
>Thanks, I actually emailed PE about this and Eric there wrote back and basically said the cheaper standard Dayton 10" (295-315) would be better for my purposes, which are mostly to get good QUALITY bass at lower volumes. He provided a good analogy, when you stand by a DJ stand and feel your lungs being pushe, you think 20hz, but really it's 50-60hz, so the higher the volume the lower you think the frequency sounds/feels.
====
BS. It sounds lower because it is since you're in the nearfield and 'feeling' the speaker's roll off BW more. That said, it's well known that our internal processor tends to reconstruct the missing fundamentals when the harmonics are prominent.
====
> And the Dayton Series II has such a high f3 that at low volumes it would not sound very low at all.
====
True.
====
>He even plugged the two drivers into a sim to give me some numbers. The cheaper one that he recomended has a lower f3 of 51hz so it will go lower, and the power handling should be enough for me with my small mains, and the Series II's large power handling wouldn't be usefull to me as the xmax is about the same.
====
Just looking at published specs/sims, the 295-315 can only handle ~50W linearly, or ~88dB/20Hz. The 295-412, which has the same F3 in 1.5ft^3 as the -315, can handle all 250W linearly, or ~96dB/20Hz, and though lower in efficiency, still bests it all the way up.
Whether the additional performance is enough to justify the increased cost..........
====
>To sum it up PE has really good tech service, especially since they recomended I buy something only 1/3 of the price I was prepared to spend.
====
In general, that may be, and for sure they appear to have your best interests at heart, but based solely on what you've posted, I'm underwhelmed with the tech advice you got.
GM
====
I can dig up all the formulas if needed, but for quick comparisons I've been using BoxPlot 3.0 for ages, which plots the identical results as the formulas. Here's the free demo, which should be good enough for your purposes:
http://members.aol.com/dctools/boxplt3.exe
====
>Starting at the bottom, we follow the "20 Hz" line all the way until we are approximately at 17 in², (we have to estimate between 12 and 32). That lands us approximately at 92 dB.
====
I never was any good at reading nomographs, so went searching for the math behind them and had a buddy with good math skills work out a few examples for me to follow till programmable calculators came along. You nailed it though, I calculated 92.04dB, right where BoxPlot shows it.
====
>Thanks, I actually emailed PE about this and Eric there wrote back and basically said the cheaper standard Dayton 10" (295-315) would be better for my purposes, which are mostly to get good QUALITY bass at lower volumes. He provided a good analogy, when you stand by a DJ stand and feel your lungs being pushe, you think 20hz, but really it's 50-60hz, so the higher the volume the lower you think the frequency sounds/feels.
====
BS. It sounds lower because it is since you're in the nearfield and 'feeling' the speaker's roll off BW more. That said, it's well known that our internal processor tends to reconstruct the missing fundamentals when the harmonics are prominent.
====
> And the Dayton Series II has such a high f3 that at low volumes it would not sound very low at all.
====
True.
====
>He even plugged the two drivers into a sim to give me some numbers. The cheaper one that he recomended has a lower f3 of 51hz so it will go lower, and the power handling should be enough for me with my small mains, and the Series II's large power handling wouldn't be usefull to me as the xmax is about the same.
====
Just looking at published specs/sims, the 295-315 can only handle ~50W linearly, or ~88dB/20Hz. The 295-412, which has the same F3 in 1.5ft^3 as the -315, can handle all 250W linearly, or ~96dB/20Hz, and though lower in efficiency, still bests it all the way up.
Whether the additional performance is enough to justify the increased cost..........
====
>To sum it up PE has really good tech service, especially since they recomended I buy something only 1/3 of the price I was prepared to spend.
====
In general, that may be, and for sure they appear to have your best interests at heart, but based solely on what you've posted, I'm underwhelmed with the tech advice you got.
GM
I wish I could get a titanic mk2 but I don't want to spend the money. I think the tech support guy was talking about the curve that the loudness buttons do. You know where at lower volumes you have to boost the bass and treble above the midrange so they will sound equal in volume, but when you turn up the volume you can leave the settings flat and it will sound flat. I forget the technical name of the effect but you probably know what I'm talking about.
I know for a fact that for the price I can spend, under $160, I won't be getting flat bass to 20hz. So I'll have to settle for the next best. I'll be using this thing in a dorm room in a year so won't be able to exploit all the power the mkii has anyways.
How would a 10" Quatro do in a sealed box with it's peak at 100hz, do you think that would sound too boomy?
I know for a fact that for the price I can spend, under $160, I won't be getting flat bass to 20hz. So I'll have to settle for the next best. I'll be using this thing in a dorm room in a year so won't be able to exploit all the power the mkii has anyways.
How would a 10" Quatro do in a sealed box with it's peak at 100hz, do you think that would sound too boomy?
go to www.diysubwoofers.org
Under ported boxes and "power response" you will find the formula(s) for max SPL.
Under ported boxes and "power response" you will find the formula(s) for max SPL.
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