How many square feet is your listening area, what sub are you using, and does it fill your room?:)

Cubic feet is a much more useful measurement. A 20x10 room with an 8 foot ceiling might be easier to drive than a 15x8 room with a 30 foot ceiling. Also, if your room opens up into another room, that next room's volume should be considered as well. As for me, my room is 11x10x8 (sealed off from other rooms), I run two co-located SVS PB10-NSD's, and yes, they fill my room :).

I said Square Feet but I meant Cubic Feet. Your supposed to know what I was thinking DUH!!!!;)

The area I was planning on was 20x10x8, but the one I ended up with is 25x23.5x9
I have one a7s-450, haven't tested it in the new room yet but will probably need to get one more at some point.

The area I was planning on was 20x10x8, but the one I ended up with is 25x23.5x9
I have one a7s-450, haven't tested it in the new room yet but will probably need to get one more at some point.

Wow, that's quite a bit larger. Yeah, I think you'll want a second a7s-450 - not because it's necessary, but because you've been on the bass forum too long :D.

OP - was the question just a "curiosity" question, or are you looking for a sub to fill your room of "xxxxx" cubic feet and want to get a feel for what subs might work well for you?

IMO an adequate average would be 5L of driver displacement(sealed cabinet) per 1000cu ft of room volume,here you have headroom aplenty and are not to restrained by the sub working too hard at any time.

With ported subs as little as 2L of displacement may do the trick in the same 1000cu ft space.





Me I have over 30L in a 800cu ft space and ~50L in a space around 3500 cu ft.
This is in no way needed or makes much sense. And I will have over 80L in the smaller space soon. Just for the kick of it.

IMO an adequate average would be 5L of driver displacement(sealed cabinet) per 1000cu ft of room volume,here you have headroom aplenty and are not to restrained by the sub working too hard at any time.

With ported subs as little as 2L of displacement may do the trick in the same 1000cu ft space.

It's likely closer to 3L per 1000ft^3, but it really all depends on a person's SPL goals. I'm soon to use 11L in about 4600ft^3 (over estimating because it's open to other rooms), but are currently dipole in a ~900ft^3 room and do alright.

So in a larg'ish sized room, two high excursion 15's would be about standard...or four mid excursion 15's (eD's A5-350). Jumping up to 18's is even better!

hmm
this is interesting. How are you calculating driver displacement? eg; I own a pair of eD A7s-450. on the website it states:

Driver Size 18"
Driver Quantity 1
Driver Excursion 21.5mm
Total Driver Linear Displacement 5872.6cm²

Room Tuning
Vented
Frequency Response (+/-3dB) 15~100Hz
Amplifier RMS Power 1300W
Cabinet Type Vented
Shipping Weight 215 lbs
Internal Size 10ft³
External Size 13.38ft³
Width 25""
Height 37""
Depth 25""
Vent Size Vented
Amplifier Voltage 115V/230V
Included Crossover Yes
Crossover Frequencies 50Hz - 100Hz
Phase Switch Variable
Line Level Input Yes
RCA Level Input Yes
Level Control Variable

do you multiple the linear displacement by the excursion? if so, the driver excursion would be = 2.15cm x 5872.6 = 12626.09 or about 12.6 liters. Is that correct?

since i own two, it would be 25 liters. The basement is large; ~9200 cubit feet (23 x 50 x 8). it does open up to more space, but the other rooms have doors and can be sealed off from the main area.

so, since they are sealed, according to the 5l / 1000 cu ft, i should have ~46Liters of sealed subs or 25 liters of ported.

plz let me know if these calculations are right. seems i may need two more subs.....

Total Driver Linear Displacement 5872.6cm²


That seems high (actually way out of wack!!) compared to all the driver specs I have seen. I havent read the specs on the Ed though.


The 12 Liters is also to high, I have never seen that displacement so I would have to wonder if your calculation is wrong. Even the $1000 LMS Drivers from TCSound had only 8.34 liters of displacement and they are definitely better drivers then what Ed has in that box.


isnt displacement = 2 * SD * Xmax ?

I have 4 18" drivers from fiCar and they have 6.53 litres each. My displacement is around 26L. They are in an array powered by 2 1000W amps. the Room they are in is probably around 40x30x12.....HUGE room and they can create true compression in the room.

I dunno how to calculate displacement in Liters for my sub, but I have an ACI Maestro XL in my 12'x11'x9' room and have plenty of headroom. This subwoofer used to be in a 18x12x9 room and didnt have any troubles there either.

So in a larg'ish sized room, two high excursion 15's would be about standard...or four mid excursion 15's (eD's A5-350). Jumping up to 18's is even better!


lol, standard for who?

I dont know of anyone that has two high excursion 15's, I know lots of people using 12" subs or less and they are still happy (little do that know)

"Standard" is really, really subjective.

hmm
this is interesting. How are you calculating driver displacement? eg; I own a pair of eD A7s-450. on the website it states:

Driver Size 18"
Driver Quantity 1
Driver Excursion 21.5mm
Total Driver Linear Displacement 5872.6cm²

Room Tuning
Vented
Frequency Response (+/-3dB) 15~100Hz
Amplifier RMS Power 1300W
Cabinet Type Vented
Shipping Weight 215 lbs
Internal Size 10ft³
External Size 13.38ft³
Width 25""
Height 37""
Depth 25""
Vent Size Vented
Amplifier Voltage 115V/230V
Included Crossover Yes
Crossover Frequencies 50Hz - 100Hz
Phase Switch Variable
Line Level Input Yes
RCA Level Input Yes
Level Control Variable

do you multiple the linear displacement by the excursion? if so, the driver excursion would be = 2.15cm x 5872.6 = 12626.09 or about 12.6 liters. Is that correct?

since i own two, it would be 25 liters. The basement is large; ~9200 cubit feet (23 x 50 x 8). it does open up to more space, but the other rooms have doors and can be sealed off from the main area.

so, since they are sealed, according to the 5l / 1000 cu ft, i should have ~46Liters of sealed subs or 25 liters of ported.

plz let me know if these calculations are right. seems i may need two more subs.....

That's not the specs for a Sealed sub (a7s-450)..... At least not the last design I looked at..... It states vented all over your posted specs. ;)

sorry. you are right. here are the sealed specs:

Driver Size 18"
Driver Quantity 1
Driver Excursion 21.5mm
Total Driver Linear Displacement 5872.6cm²

Room Tuning
Sealed
Frequency Response (+/-3dB) 22~100Hz Un-eQ'd
Amplifier RMS Power 550W/1300W Depending on Amplifier
Cabinet Type Sealed
Shipping Weight 130 lbs
Internal Size 4.5ft³
External Size 6.37ft³
Width 22.25"
Height 22.25" - w/ Spikes 23.5"
Depth 22.25" - w/ Grill 23.5"
Vent Size Sealed
Amplifier Voltage 115V/230V
Included Crossover Yes
Crossover Frequencies 50Hz - 100Hz
Phase Switch Variable
Line Level Input Yes
RCA Level Input Yes
Level Control Variable

however, the calculation is from the driver linear displacement and since it's the same driver, the numbers are the same.

still waiting to hear from someone how to calculate driver displacement? thx

That seems high (actually way out of wack!!) compared to all the driver specs I have seen. I havent read the specs on the Ed though.


The 12 Liters is also to high, I have never seen that displacement so I would have to wonder if your calculation is wrong. Even the $1000 LMS Drivers from TCSound had only 8.34 liters of displacement and they are definitely better drivers then what Ed has in that box.


isnt displacement = 2 * SD * Xmax ?

I have 4 18" drivers from fiCar and they have 6.53 litres each. My displacement is around 26L. They are in an array powered by 2 1000W amps. the Room they are in is probably around 40x30x12.....HUGE room and they can create true compression in the room.

again, that is a direct cut/paste from eD's website.
what is SD? standard deviation? why the 2 in front?

i found a good explanation of the theil parameters here:

http://www.speakerplans.com/index.php?id=faq1

after reading this, it seems the eD specs are a misprint. the number:
Total Driver Linear Displacement 5872.6cm²
should be in cubit cm as that is the vD. so, each of my sealed subs are just under 6L of displacement, giving me a total of ~12L of displacement for a room that's ~9k cubit feet.

with TheEAR's recommendations, i am at 1.3 L / 1000 cubic feet!!!!! i would need 45Liters for that size room (5L/1000cu feet). so that would mean i would need 6 more A7S-450 in my basement? or ~2 more a7-900's.

can that be right?

frankly, i feel the two sealed are more than enough for my room, but i also said that 2 years ago with my SINGLE axiom EP500.

30 x 31 x 9 room using and Axiom EP600v2 DSP sub and 2 of the new Axiom EP350v3's.

Total Driver Linear Displacement 5872.6cm²
should be in cubit cm


Yeah, that sounds right, Great link too.

with TheEAR's recommendations, i am at 1.3 L / 1000 cubic feet!!!!! i would need 45Liters for that size room (5L/1000cu feet). so that would mean i would need 6 more A7S-450 in my basement? or ~2 more a7-900's......can that be right?

The Ear, lives in a different world then the rest of us :D so I would say no, its not right.

You should first make sure your room as acoustical treatment before blowing money on extra subs. The seal Ed sub might just be okay, try it out first before you follow someone's opinion but I would go ported if you want to fill larger rooms.

The audio world is full of more opinion then fact and even the fact is subjective ;)

The seal Ed sub might just be okay, try it out first before you follow someone's opinion but I would go ported if you want to fill larger rooms.



For it's price I'm not sure you can get a ported sub that would beat it in SPL.

lol, standard for who?

I dont know of anyone that has two high excursion 15's, I know lots of people using 12" subs or less and they are still happy (little do that know)

"Standard" is really, really subjective.

Dolby specs 115db output for the subwoofer(s) at reference. This is at listening position right? I would like to see that happen with a single or dual 12's (in that 4000ft^3+ room). Dual 15's in an EBS would be about minimum and you'd still miss out on the <15hz content.

I had a single 12 (Infinity SW-12) in a ~1800ft^3 room and it did alright, but left much to be desired.

For it's price I'm not sure you can get a ported sub that would beat it in SPL.

Probably true, unless its DIY ;)

Dolby specs 115db output for the subwoofer(s) at reference. This is at listening position right? I would like to see that happen with a single

The problem with those specs is that 115db is never a level we watch movies at. Im always confused about all the "reference" talk when in reality on average people listen to sound at a much lower SPL level (maybe 85db?). Its not normal to listen at reference level (bass heads and AV freaks not withstanding), you cant even hear anyone else unless they yell and trust me, "turn it down" would be the first sentence they yell at you ;)

The problem with those specs is that 115db is never a level we watch movies at. Im always confused about all the "reference" talk when in reality on average people listen to sound at a much lower SPL level (maybe 85db?).

While reference IS very loud, some people do like to listen that loud. I'm usually within 5dB of reference when I watch movies. Keep in mind that the numbers listed by Dolby for "reference level" (105dB for front/center/surround speakers, 115dB for LFE) are "peak" numbers, and are not indicative of constant playback levels. If I heard 105dB constantly above 1khz for any prolonged period of time, it would be excruciating. But for a quick peak, such as a glass window being shattered, it adds impact without being painful. Same thing with the LFE. A movie won't have constant bass playing at 115dB, but bass in the 110+ dB range can occur during explosions or deep shockwave-type sounds (Ironhide flip in Transformers comes to mind). Still, I do agree that practically speaking, for most people, Dolby's definition of "reference" level won't really come into play.

The problem with those specs is that 115db is never a level we watch movies at. Im always confused about all the "reference" talk when in reality on average people listen to sound at a much lower SPL level (maybe 85db?). Its not normal to listen at reference level (bass heads and AV freaks not withstanding), you cant even hear anyone else unless they yell and trust me, "turn it down" would be the first sentence they yell at you ;)

I would have to agree, though, if those individual's are not bass/AV freaks, they likely wont be in this forum :) I can only assume (uh oh) that they want more volume, and SQ than my sister, whom would be just fine with a system capable of 100-105db peaks as opposed to 115db peaks.

Oh and I believe you about the "turn it down comment". With two pairs of Cerwin Vega LS-12 towers, I can unleash quite a bit of volume on the unsuspectin ears.

No Sound 0 Threshold of hearing…essentially no sound
10 Breathing
15 A soft whisper in someone’s ear.
Very Quiet 20 Whisper, rustling leaves
25 Recording Studio
30 Quiet rural area, Very quiet library.
40 Very Quiet Residence
45 Typical neighborhood.
Quiet 50 Quiet suburb, conversation at home, Private office
60 Normal conversation (3-5 feet), sewing machine, typewriter.
Annoying 70 Freeway Traffic at 50 feet, vacuum cleaner
75 Typical car interior on highway
Loud 80 Garbage disposal, dishwasher, average factory, Telephone dial
tone,Noisy office
16 hours 85 City Traffic (inside car).
8 Hours 90 Power drill, shop tools, Busy urban street, diesel truck, food
blender
6 Hours 92 Clarinet, Oboe at 10 feet
4 Hours 95 Subway train at 200 feet
3 Hours 97 French Horn at 10 feet
2 Hours
Very Loud 100 Jet takeoff 1000 feet, Outboard motor, farm tractor, garbage
truck, Very heavy Traffic
1.5 Hours 102 Motorcycle
1 Hour 105 Power mower
108 Home Theater (loud peaks)
0.5 Hours 110 Chainsaw, pneumatic drill, typical rock concert, Steel Mill,
riveting, auto horn at 3 feet
0.25 Hours 115 Jackhammer
0 Hours
Pain
threshold 120 Loud thunderclap, typical live rock music

Hearing damage
occurring 125 Pneumatic riveter at 4 feet

Ear drum
distortion 130 Jet takeoff (300 feet), Noise level during a stock car race.

Permanent
hearing damage 132 Very loud rock concert, 50 feet in front of speakers
140 Gun muzzle blast
140 Prop aircraft on takeoff, gun muzzle blast, aircraft carrier deck, jet engine
at 100 feet

Eardrum rupture 150 Jet takeoff 75 feet
155 Shot from a handgun (.38 or .44) at 1 foot
160 Jet aircraft on Takeoff at 30 feet

Immediate death
of tissue 180 Jet engine at 1 foot
194 Loudest sound in air, air particle distortion (sonic boom)

that was copied and sorry for the poor formatting from an osha pdf file.

so as we all may want reference level systems, just remember not to listen to it at those levels for too long.

Another boringly tangential thread.

There is no formula for cu'/liters.

My theater is 1600cu' and I have 26L (4 18" drivers). I've read peaks upwards of 126db and it was never "too loud". Peaks are short and the ear is much less sensitive in the 10-25hz range. 100db at 1khz is ear-piercing, 100db at 10hz is almost inaudible.

It's better to have 100L of displacement and never use even half of it than to punish some little sub that displaces 2L and then an assload of distortion.

One factor to also keep in mind is whether the room is closed or open. A room that is open to other areas will need significantly more displacement.

The original question was just out of curiosity, but I was trying to get a feel for what sub or how many I would need for my room 15x21x10.5 which is open to the kitchen and a hall.

Another boringly tangential thread.

There is no formula for cu'/liters.

My theater is 1600cu' and I have 26L (4 18" drivers). I've read peaks upwards of 126db and it was never "too loud". Peaks are short and the ear is much less sensitive in the 10-25hz range. 100db at 1khz is ear-piercing, 100db at 10hz is almost inaudible.

It's better to have 100L of displacement and never use even half of it than to punish some little sub that displaces 2L and then an assload of distortion.


Is 'assload' a technical term? :) :)

FWIW I have two 15" sealed subs each powered by a 500W amp as well as a 12" Outlaw audio LFM-1 in my 2100 cf. theater room. No issues with too little bass in my room...though I don't think I listen as loudly as others.

Is 'assload' a technical term?


It's a quantity value.

Alright, back to the OP's question. I have:

1) Epik Conquest in a 4500 ft^3 room (though it is somewhat open to another 1200 ft^3 room). Does a great job filling the room, and puts me in fear of cracking the plaster on the walls...

2) SVS 16-46PC+ in a 1300 ft^3 enclosed room. In this size room, the sub can really kick some a$$ and go very low.

Will be getting 2 MFW-15's for a 2300 ft^3 room (which is fairly open to 2 other rooms) soon. I think this will do some serious damage. :D

In terms of what you will 'need' for your 3200 ft^3 room -- depends. ;) Dual 15's or a single 18 would give most people more bass CAPABILITY than they'd ever need in that space (even if it's open to other rooms). For a lot of people, one 15-inch high-quality sub would be more than enough.

But a lot of us like to FEEL our movies and music. If you're one of those, you need some firepower beyond the average home theater...