[///Mangler]

Two (2) 10w3's or one 15" AE sub for IB?

T

[bmw325i]

The 15 will have more cone area and will most likely have more xmax. The 15 should play louder and lower.

[Fundguy1]

15 louder and lower. 10's tighter and puncher. Your preference. I like 10's. Plenty loud and higher sound quality.

[WilliamS]

This goes with the music you listen too. The 15's will get lower and with more cone throw a lot more volume but it wont keep up with say a fast beat of a kick drum in Rock music or the faster beat changes in some Rap music, or the wild changes in Dubstep/techno. The 10's although those are good 10's wont as low on the deep bass songs that you get from again but the category covers a large sound stage, rock with a sweet smooth bass guitar but will command when a fast beat rap song comes on. It really depends on your music. Me I have 2 sealed 12's

[bmw325i]

Originally Posted by Fundguy1

15 louder and lower. 10's tighter and puncher. Your preference. I like 10's. Plenty loud and higher sound quality.

There is some truth to that but it's not that simple. A 15" sub can have better sq than a 10". The larger sub has to move less to move the same amount of air so there is less distortion. If the 10" sub can't handle frequencies in the low 30's or 20's I wouldn't consider that good sq since you can't reproduce those frequencies.

[bmw325i]

Originally Posted by WilliamS

This goes with the music you listen too. The 15's will get lower and with more cone throw a lot more volume but it wont keep up with say a fast beat of a kick drum in Rock music or the faster beat changes in some Rap music, or the wild changes in Dubstep/techno. The 10's although those are good 10's wont as low on the deep bass songs that you get from again but the category covers a large sound stage, rock with a sweet smooth bass guitar but will command when a fast beat rap song comes on. It really depends on your music. Me I have 2 sealed 12's

This is somewhat of a myth. How a sub performs has to do with alot more than just cone size.

[WilliamS]

Originally Posted by bmw325i

This is somewhat of a myth. How a sub performs has to do with alot more than just cone size.

Which is true, but IB vs Sealed or Ported. Theres motor strenght, cone material, and so on. Ive seen very few 15's keep up with 10's in terms of speed an accuracy, and Ive seen very few 10's other than overworked not going to last long 10's hit as low and loud as 15's. Been in the car audio game a long long time. Sure there are exceptions to every rule, JLW7-8 will out perform in terms of volume a lot of 10/12's in the market based on excursion and motor. Not knowing what 10's hes looking at makes it hard to compare.

[bmw325i]

In this application especially I would reccomend the 15 over a 10 or 12. We have 8" underseat enclosures that should be used for midbass. The sub is only needed to play from around 60hz and under. There are plenty of 15" subs out there that can play up to 60hz with good sq.

[WilliamS]

Originally Posted by bmw325i

In this application especially I would reccomend the 15 over a 10 or 12. We have 8" underseat enclosures that should be used for midbass. The sub is only needed to play from around 60hz and under. There are plenty of 15" subs out there that can play up to 60hz with good sq.

This I will agree with completely.

[kaigoss69]

Smaller subs being "faster" and "tighter" than larger subs is a complete and utter myth.

[Jgio83]

Originally Posted by ///Mangler

Two (2) 10w3's or one 15" AE sub for IB?

T

I have been throwing around this thought as well. Most say go with a 15. However I still am considering two 10" or 12". I cannot make a decision. At least I have time to deside since I'm doing my upgrade in steps and I'm still on step one, 2 component sets and a JL 600/6

[bmw325i]

Originally Posted by Jgio83

I have been throwing around this thought as well. Most say go with a 15. However I still am considering two 10" or 12". I cannot make a decision. At least I have time to deside since I'm doing my upgrade in steps and I'm still on step one, 2 component sets and a JL 600/6

2 12" subs have more cone area than the 15, but the 15 will most likely have more xmax and possibly higher power handling depending on what subs you are looking at.

[kaigoss69]

I wonder if OP even read the responses in this thread...

[///Mangler]

Originally Posted by kaigoss69

I wonder if OP even read the responses in this thread...

Yep, still reading them as they come along. I didn't want to jump into the large speaker faster or slower than the smaller one comment.

I am leaning towards the AE15 in an IB setup with the sub reversed and the baffle at the back of the rear deck for sealing purposes. If the baffle is up against the seat you have to seal the rear deck which is a pain. I don't know if you have ever looked up under the F30 rear deck but BMW has some huge cutouts and openings. I bet a good portion of the road noise complaints can be solved by sealing up the rear deck.

T

[bmw325i]

Originally Posted by ///Mangler

Yep, still reading them as they come along. I didn't want to jump into the large speaker faster or slower than the smaller one comment.

I am leaning towards the AE15 in an IB setup with the sub reversed and the baffle at the back of the rear deck for sealing purposes. If the baffle is up against the seat you have to seal the rear deck which is a pain. I don't know if you have ever looked up under the F30 rear deck but BMW has some huge cutouts and openings. I bet a good portion of the road noise complaints can be solved by sealing up the rear deck.

T

You might as well use a sealed box with the sub facing forward. Using only half the trunk for "infinite baffle" is like having a somewhat large not so well sealed box.

[///Mangler]

Originally Posted by bmw325i

You might as well use a sealed box with the sub facing forward. Using only half the trunk for "infinite baffle" is like having a somewhat large not so well sealed box.

Well that's completely wrong. The idea is to separate the front wave from reflections and or back wave off the rest of the trunk. This is where the cancellations in cars comes from.

This is why the corner loaded sub sounds good to. No major reflections to cancel out sub freq's. You should look up shotgun array that we use in large venue pro av. I've thought about doing this too with a second sub to cancel out all the energy in the trunk so bleed over doesn't cancel out the cabin waves.

T

[bmw325i]

Originally Posted by ///Mangler

Well that's completely wrong. The idea is to separate the front wave from reflections and or back wave off the rest of the trunk. This is where the cancellations in cars comes from.

This is why the corner loaded sub sounds good to. No major reflections to cancel out sub freq's. You should look up shotgun array that we use in large venue pro av. I've thought about doing this too with a second sub to cancel out all the energy in the trunk so bleed over doesn't cancel out the cabin waves.

T

I don't see how it's wrong. If I built a sealed box the size of the trunk(I know it would be impossible to make it exactly that size unless it is made out of fiberglass) how would it be any different than what is considered infinite baffle(other than the fact that the sealed box would do a better job separating the front and rear waves). Using half the trunk you'll have about the same amount of volume as a decently sized sealed box would have.

[kaigoss69]

Infinite baffle does not mean that the air space behind the sub needs to be infinite. It just needs to be large enough that it does not affect the frequency response of the sub. If you make a sealed box large enough, at some point it will produce the same FR as IB. The trunk, which is a very leaky large enclosure, will do for close to true IB for a single 15.

The bottom end response in IB is what most people are after. It also makes the sub play with much more efficiency. A relatively small sealed enclosure, as suggested above, will sound dramatically different than IB. Less bottom end, and a more peaky response up top. Combined with cabin gain, most IB setups require very little EQ for ruler flat response from 20 to 100 Hz.

[///Mangler]

Originally Posted by kaigoss69

Infinite baffle does not mean that the air space behind the sub needs to be infinite. It just needs to be large enough that it does not affect the frequency response of the sub. If you make a sealed box large enough, at some point it will produce the same FR as IB. The trunk, which is a very leaky large enclosure, will do for close to true IB for a single 15.

The bottom end response in IB is what most people are after. It also makes the sub play with much more efficiency. A relatively small sealed enclosure, as suggested above, will sound dramatically different than IB. Less bottom end, and a more peaky response up top. Combined with cabin gain, most IB setups require very little EQ for ruler flat response from 20 to 100 Hz.

Yeah sorry I read your post wrong. Yes it would be nearly the same if you have a sealed enclosure in the trunk. The cancellation waves I am talking about still occur even with a sealed enclosure from the reflection off the back of the trunk. \

if you take a sealed enclosure and place it against the seat firing forward it will sound like X, if you turn it around and fire it backwards, it will sound like X with a different band being cancelled. If you slide it back to the back of the trunk firing forward it will sound different again with a different band being cancelled and then if you turn it around.......well you get the jist.

the corner loaded sub and the IB (or a sealed enclosure, ported enclosure, bandpass, 4th order, isobaric whatever) if you don't keep the back wave isolated (by sealing off the source from out of phase reflections) you will fight a null (standing wave) that there is nothing that can be done about it.

similarly to using a second and or third sub at differing phases and amplitude to fix audio in a small room (any room in a house is small).

anyway back to the issue at hand. The IB that I want to do will only be the depth of the sub. Imagine the baffle at the same angle as the back of the back seats and going from the back of the rear deck to the floor.

I would love to just make the entire rear deck the baffle but I don't want to cut anything.

T

[kaigoss69]

I understand what you are trying to do. I see three issues though. First, the front and rear waves will excite the same panels and you will get some cancellations as a result. This is probably not a biggie. Second, the baffle needs to be supported by angle brackets all around, and you will probably have to do a lot of drilling and screwing to give the baffle a solid hold. From what I have seen, it is a bitch to install it that way, because you have to remove all the panels in the trunk and do a lot of fitting and sealing on all sides. Also, the baffle will have to be at least 2 if not 3 inches thick in order to be stiff enough for the application. The third issue I see is the front wave being trapped in the space between the baffle and the rear seats. I think the output will be lower, and the rattles higher in this configuration.

[bmw325i]

I've made enclosures nearly the size of the trunk before both sealed and ported so I guess I look at "infinite baffle" differently because of that. I know you can/should have a box in infinite baffle as long as the volume is large enough. I'm just not convinced that the trunk is very large for a high powered 15" sub. My last box was ported and it was around 9 cubes net. Tuned to 28 hz it came out to around 7 cubes after taking the port and sub into consideration. With a 15" sub that can handle over 2500 watts rms it moved alot more air than I would ever expect from an infinite baffle setup. I'm sure you guys don't care about spl as much so not having a box makes it easier. I've tried positioning my sub(s) every way possible in this car and for me facing forward sealed off from the trunk is the most efficient with no rattling from the trunk.


My thoughts on putting your baffle behind the rear deck is you would have to have the seats down all the time or you are basically turning the trunk into a leaky bandpass box.

[///Mangler]

Originally Posted by bmw325i

I've made enclosures nearly the size of the trunk before both sealed and ported so I guess I look at "infinite baffle" differently because of that. I know you can/should have a box in infinite baffle as long as the volume is large enough. I'm just not convinced that the trunk is very large for a high powered 15" sub. My last box was ported and it was around 9 cubes net. Tuned to 28 hz it came out to around 7 cubes after taking the port and sub into consideration. With a 15" sub that can handle over 2500 watts rms it moved alot more air than I would ever expect from an infinite baffle setup. I'm sure you guys don't care about spl as much so not having a box makes it easier. I've tried positioning my sub(s) every way possible in this car and for me facing forward sealed off from the trunk is the most efficient with no rattling from the trunk.


My thoughts on putting your baffle behind the rear deck is you would have to have the seats down all the time or you are basically turning the trunk into a leaky bandpass box.

I have the huge ski pass opening (8"x15") and i also drive 4000mi a month alone in my car and having the seats down a lot is not a problem either.

T