Ive searched and read through quite a few threads but I need a more specific awnser for my use. I want to build new subs using 2 dayton quatro 15s, I have a BGW professional 750D amp ( about 300 rms x2 at 4 ohm, stable to 2ohm ) amp that Im going to use. My room is about a little odd shaped, its about 25ft long and 20 ft wide at the front but after about 15 from the front it goes down to say 15 ft wide ( i guess looking down on the room it looks like a boot ). and 8ft celings, its got couch, some chairs 2 window but its not open to any other room.
I mainly use it for movies, like to be blown away but I also what them to be musical. Now ive always that the flatest responce was that you wanted as low as u could go but reading here im thinking maybe with room gain might be to much? also I was thinking of building a ported box tuned to 20hz ( 2 spereate boxes unless theres any advantage for 2 woofers in 1 box )
But what about tuning lower? higher? sealed? Im not sure how to build it for what I want to achevie so I thought Id ask the people here.
I mainly use it for movies, like to be blown away but I also what them to be musical. Now ive always that the flatest responce was that you wanted as low as u could go but reading here im thinking maybe with room gain might be to much? also I was thinking of building a ported box tuned to 20hz ( 2 spereate boxes unless theres any advantage for 2 woofers in 1 box )
But what about tuning lower? higher? sealed? Im not sure how to build it for what I want to achevie so I thought Id ask the people here.
if you DO tune to 20hz, i think you will have a large housecurve, and im mean large. you want to tune a box so that it "matches" room gain. In other words, tune it so that the slope of the box matches how much gain the room gives you, thus providing the flattest response. Tuning lower also lowers Groud delay, which increases the entire systems transient response(from what I've heard). Now some people also like a large house curve, and thats fine, but you need to find out what you want before everything is finalised.
Im not sure what teh formula for room gain is, i think room gain starts at the wavelength that matches the rooms longest dimension, but i could be wrong.
Also the man who tuned his box to 11hz is aaron gilbert, or "aaroncgi"(not sure on that one) on diy audio. He has some in room measurements for his one quatro in 9 cu ft tuned to 11hz, they were impressive to say the least.
Im not sure what teh formula for room gain is, i think room gain starts at the wavelength that matches the rooms longest dimension, but i could be wrong.
Also the man who tuned his box to 11hz is aaron gilbert, or "aaroncgi"(not sure on that one) on diy audio. He has some in room measurements for his one quatro in 9 cu ft tuned to 11hz, they were impressive to say the least.
ok, ill see if i can find the formula for room gain and see about building a box to match and tune low.
Ive got another question since I noticed the thread about the elemental designs 16kv.2, since right now its 10% off for 2 PLUS free shippinhg its comes to 63 dollers more for both than the quatro, now I know theres more to subs than xmax but its a 16.1 vs 10 for the quatro and it got compared to the tempest which I know is a good sub for the house, so would this be a better way to go?
for those that didnt read the thread heres the specs on the subs
SPECS:
Qts .32
Qms 3.60
Qes .35
Re 3.7
Vas (Liter) 329.00
Sd (cm^2) 840
Fs (Hz) 19.9
Bl 16.00
MMd 179.00
MMs 193.00
Xmax 16.1mm
Ive got another question since I noticed the thread about the elemental designs 16kv.2, since right now its 10% off for 2 PLUS free shippinhg its comes to 63 dollers more for both than the quatro, now I know theres more to subs than xmax but its a 16.1 vs 10 for the quatro and it got compared to the tempest which I know is a good sub for the house, so would this be a better way to go?
for those that didnt read the thread heres the specs on the subs
SPECS:
Qts .32
Qms 3.60
Qes .35
Re 3.7
Vas (Liter) 329.00
Sd (cm^2) 840
Fs (Hz) 19.9
Bl 16.00
MMd 179.00
MMs 193.00
Xmax 16.1mm
ive seen the specs, and IN WIN ISD** they model very close to a tempest, but in a smaller box. Unfortunately winisd and real life are two very different places. But if i were you, i would go for the elemental designs woofers. Im a fan of infrasound which requires displacement, and given eDs reputation, they must have relatively good SQ as well as some serious SPL capabilities. Im just sad i didn't read about them before i ordered my (broken) tempest.
try modeling an EBS alignment for the eD.
try modeling an EBS alignment for the eD.
Plenty of options.
I'm the one with the 9 cubic foot box tuned to 11 Hz.
Two Quatros with 300W each will definitely get into the 'blow you away' range, though granted, that depends how you define it. I feel pretty blown away myself with just one, but some real bass heads won't settle for less than several Adire Tumults or a Parthenon, etc..
As for most musical, sealed or infinite baffle are great ways to go. Sealed still gets you pretty good low extension, and a considerably smaller box, but power handling and maximum output is not as high. However, it is possible to make a vented box yet maintain very close to all of the sound quality of a sealed box. I have tried my box sealed, and other than the better low end extension of the vented box, I can't tell the difference between them. Note that tuning to 11 Hz does make the power handling very very similar to a sealed box, but the woofer is much less likely to 'unload' because there's so little information below 11 Hz. Power handling is still higher than it would be sealed, though.
Anyhow, not to get too in depth, it's all just a matter of compromises, so pick your poison. I like vented because by altering the tuning frequency, you can match the rolloff slope (above the tuning point, that is) to better complement the inherent gain in your room. With sealed, you are more or less stuck with the F3 and rolloff point the driver gives you.
As was mentioned, tuning to 20 Hz may give you some extra boost that you might not want, due to the room gain. My sub is down 6 dB at 20 Hz (simulated anyhow), and even this sounds like a bit too much low end output at times.
Aaron Gilbert
I'm the one with the 9 cubic foot box tuned to 11 Hz.
Two Quatros with 300W each will definitely get into the 'blow you away' range, though granted, that depends how you define it. I feel pretty blown away myself with just one, but some real bass heads won't settle for less than several Adire Tumults or a Parthenon, etc.. As for most musical, sealed or infinite baffle are great ways to go. Sealed still gets you pretty good low extension, and a considerably smaller box, but power handling and maximum output is not as high. However, it is possible to make a vented box yet maintain very close to all of the sound quality of a sealed box. I have tried my box sealed, and other than the better low end extension of the vented box, I can't tell the difference between them. Note that tuning to 11 Hz does make the power handling very very similar to a sealed box, but the woofer is much less likely to 'unload' because there's so little information below 11 Hz. Power handling is still higher than it would be sealed, though.
Anyhow, not to get too in depth, it's all just a matter of compromises, so pick your poison. I like vented because by altering the tuning frequency, you can match the rolloff slope (above the tuning point, that is) to better complement the inherent gain in your room. With sealed, you are more or less stuck with the F3 and rolloff point the driver gives you.
As was mentioned, tuning to 20 Hz may give you some extra boost that you might not want, due to the room gain. My sub is down 6 dB at 20 Hz (simulated anyhow), and even this sounds like a bit too much low end output at times.
Aaron Gilbert
Well, technically speaking...
Everyone has a house curve. I presume you are meaning that coupled with my house curve, the rolloff off my subwoofer will lead to a response that has an elevated lower end, say 10-40 Hz. You may be right. At times, it does seem like there is too much bass at certain frequencies. I do run all speakers except the center as large however, and the other speakers don't have the extension of the subwoofer, so the problem, if there, is mitigated somewhat. That said, a LOT of people tend to design for an F3 point of 20 Hz or even below, so they must have a far more boosted low end than I do (given similar rooms)!
Aaron Gilbert
Everyone has a house curve.
I presume you are meaning that coupled with my house curve, the rolloff off my subwoofer will lead to a response that has an elevated lower end, say 10-40 Hz. You may be right. At times, it does seem like there is too much bass at certain frequencies. I do run all speakers except the center as large however, and the other speakers don't have the extension of the subwoofer, so the problem, if there, is mitigated somewhat. That said, a LOT of people tend to design for an F3 point of 20 Hz or even below, so they must have a far more boosted low end than I do (given similar rooms)!Aaron Gilbert
I was playing around with winISD a lil, although im not great with it as it took me forever to get the elemental designs specs in since i needed it to auto calc half of them so it would let me save.
any i modeled a QB3 box as it sounded like the simplest vented encloures because i dont know what a EB stuff is. any way I modled a box that was 14cf tuned to 14 that looks like it would work well factoring in room gain but i dunno.
any i modeled a QB3 box as it sounded like the simplest vented encloures because i dont know what a EB stuff is. any way I modled a box that was 14cf tuned to 14 that looks like it would work well factoring in room gain but i dunno.
No to losing high end extension.
weikertball,
No, tuning lower does not sacrifice higher frequency output. The lower you tune, the more the response curve resembles that of a sealed box of the same internal volume. I don't consider 21 Hz tuning for this driver low however, as that is the Fs. The only reason I'd ever tune above the Fs of a driver would be for winning SPL competions (ie tune to the resonant frequency of your car - often 50-60 Hz). The upper bass will be far more affected by the inherent response of your car than the tuning of your box (or even vented vs sealed, at the tuning we are discussing). I personally would go sealed in a car with this driver, unless you have some precise equalization, in which case you could go either way. A vented box tuned to 21 Hz with this driver is asking for a huge boost in response below about 60 Hz all the way down to below 20 Hz. If you like that, more power to ya!
Just for reference, my sealed Adire Shiva has been measured in my car. Alone, it's F3 is roughly 42 Hz, rolling off at 12 dB/octave below that. The combined response of the woofer and car is flat down to 15 Hz, with a 8 dB peak at 50 Hz.
Aaron Gilbert
weikertball,
No, tuning lower does not sacrifice higher frequency output. The lower you tune, the more the response curve resembles that of a sealed box of the same internal volume. I don't consider 21 Hz tuning for this driver low however, as that is the Fs. The only reason I'd ever tune above the Fs of a driver would be for winning SPL competions (ie tune to the resonant frequency of your car - often 50-60 Hz). The upper bass will be far more affected by the inherent response of your car than the tuning of your box (or even vented vs sealed, at the tuning we are discussing). I personally would go sealed in a car with this driver, unless you have some precise equalization, in which case you could go either way. A vented box tuned to 21 Hz with this driver is asking for a huge boost in response below about 60 Hz all the way down to below 20 Hz. If you like that, more power to ya!
Just for reference, my sealed Adire Shiva has been measured in my car. Alone, it's F3 is roughly 42 Hz, rolling off at 12 dB/octave below that. The combined response of the woofer and car is flat down to 15 Hz, with a 8 dB peak at 50 Hz.
Aaron Gilbert
Man, you HT guys give better responces than car guys with the same question!! The reason I asked was becuase someone from another board said he tuned his Tempests to 19 hz and it played low all day but it had no upper bass. SO, he recommended me to tune to 30 but blah, I hate high tuned enclosures and I just loooooove low powerful bass into the infrasound region. And on another note, IF I would happen to go sealed, what do you recommend for a sealed enclosure. Thanks again for that wonderful responce. That helped a lot!
Agree with simon5.
Three cubic feet sealed per driver will sound great. Two drivers sealed in eleven cubic feet will be capable of more output, have less distortion, and sound _slightly_ more accurate (even discounting the distortion), but honestly I think the sound quality difference inside a car will be very small.
I suspect the guy with a Tempest tuned to 19 Hz claiming it had no midbass was just not used to having so much real low bass, so as a result he though the midbass was depressed. If you are used to 'car stereo' specific woofers, many times you will find that the Fs of the driver is very high, resulting in an F3 of 60, 70, or even 80 Hz. Yes, the car will make up for some missing frequencies below this point, but nevertheless the overall output will have much more emphasis on the midbass frequencies. To get a given sound pressure with music, the Tempest needs far less midbass output. This is because it's already getting tremendous boost below about 50 Hz due to the fact that a 19 Hz tune doesn't let it really start to roll off until about 20 Hz! Granted, this is all speculation, but the bottom line is that the tuning frequency does not affect the amount of midbass output, assuming one is designing for a smooth response. If you are specifically designing for a giant peak in your response (woofer by itself), then all bets are off, and you probably don't really care about sound quality. I would not go ported in a car unless the woofer had a very high Fs (say 40 Hz or above), unless you have a means of equalizing the response, at least from a sound quality standpoint.
Aaron Gilbert
Three cubic feet sealed per driver will sound great. Two drivers sealed in eleven cubic feet will be capable of more output, have less distortion, and sound _slightly_ more accurate (even discounting the distortion), but honestly I think the sound quality difference inside a car will be very small.
I suspect the guy with a Tempest tuned to 19 Hz claiming it had no midbass was just not used to having so much real low bass, so as a result he though the midbass was depressed. If you are used to 'car stereo' specific woofers, many times you will find that the Fs of the driver is very high, resulting in an F3 of 60, 70, or even 80 Hz. Yes, the car will make up for some missing frequencies below this point, but nevertheless the overall output will have much more emphasis on the midbass frequencies. To get a given sound pressure with music, the Tempest needs far less midbass output. This is because it's already getting tremendous boost below about 50 Hz due to the fact that a 19 Hz tune doesn't let it really start to roll off until about 20 Hz! Granted, this is all speculation, but the bottom line is that the tuning frequency does not affect the amount of midbass output, assuming one is designing for a smooth response. If you are specifically designing for a giant peak in your response (woofer by itself), then all bets are off, and you probably don't really care about sound quality. I would not go ported in a car unless the woofer had a very high Fs (say 40 Hz or above), unless you have a means of equalizing the response, at least from a sound quality standpoint.
Aaron Gilbert
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