Getting loud in a trunk

[LongThrow]

Starting over again, using a 91 Honda Accord. Simple question - Would using one sub with a very large box gain more DB than 2 subs in the same box and sufficient power to both subs? I was told having 2 subs rather than 1 sub. In the same size box will be counter intuitive because of the limited trunk space for a large enough box to properly accommodate 2 subs.

Input?

Click to read more...

 

[los33 10+ year member]

Starting over again, using a 91 Honda Accord. Simple question - Would using one sub with a very large box gain more DB than 2 subs in the same box and sufficient power to both subs? I was told having 2 subs rather than 1 sub. In the same size box will be counter intuitive because of the limited trunk space for a large enough box to properly accommodate 2 subs.
Input?

Cone area + power + resonant freq will determine how loud you get.

Not to forget cancellation and stiffness to allow solid pressure.

Have 2 subs suffocating compared to one large sub that can breathe also should be looked into.

Sent from my Z970 using Tapatalk

 

[SimulatedZero 10+ year member]

Starting over again, using a 91 Honda Accord. Simple question - Would using one sub with a very large box gain more DB than 2 subs in the same box and sufficient power to both subs? I was told having 2 subs rather than 1 sub. In the same size box will be counter intuitive because of the limited trunk space for a large enough box to properly accommodate 2 subs.
Input?

Depends on the subs, the trunk, and the install. If you want to build into the trunk then two 12's would be fine, but two 15's might be a bit cramped. Depends on how much air space you can squeeze out.

Typically, one well done sub will equal or out perform two poorly installed subs of the same size. Depends on your goals though. Are you shooting for numbers or do you want a daily build for music?

 

[kr15 5,000+ posts]

1 sub in an optimal box will generally do as well or better than 2 in a shitter box. Sometimes it isn't necessary to go down to 1sub, sometimes you can downsize Subs. For example, if you can't fit 2 12s, perhaps you can fit 2 10s rather than downsizing to a single 12.

System goals will play a large role in what you can fit

 

[LongThrow]

Have 2 subs suffocating compared to one large sub that can breathe also should be looked into.

Sent from my Z970 using Tapatalk

This is my question

Depends on the subs, the trunk, and the install. If you want to build into the trunk then two 12's would be fine, but two 15's might be a bit cramped. Depends on how much air space you can squeeze out.
Typically, one well done sub will equal or out perform two poorly installed subs of the same size. Depends on your goals though. Are you shooting for numbers or do you want a daily build for music?

Just going to fit a big of a box as possible into the trunk. No building ONTOit or anything special like that. Just going to be a daily beater and just want it loud as possible.no competitions or picky on sq.

1 sub in an optimal box will generally do as well or better than 2 in a shitter box. Sometimes it isn't necessary to go down to 1sub, sometimes you can downsize Subs. For example, if you can't fit 2 12s, perhaps you can fit 2 10s rather than downsizing to a single 12.
System goals will play a large role in what you can fit

So in

So for arguments sake if I have 2 12 inch subs that require 3 cubic feet pur sub. And all I have is a 3 cubic box that is made for 2 subs instead of one and put both of them in there would it be louder than having that same subwoofer in the box by itself rather than suffocating both of them

 

[kr15 5,000+ posts]

Bandwidth will be vastly superior with the 1 sub, and will likely be louder across bandwidth. Cramming Subs in a small box will limit bandwidth and make the box very peaky. It cannot be empirically stated that 1 optimal will always be louder than 2 crammed. It can be stated to about 99% certainty that it will sound better. It will possibly be louder

 

[kr15 5,000+ posts]

Get what you believe to be your max dims and report back. Will you be using the kicker 500?

 

[SimulatedZero 10+ year member]

So here's my usual recommendation for customers with similar goals. Get one good quality sub and put your money into an awesome install. Subs that are put in an enclosure that fully utilizes them can have some pretty impressive results.

With the box size you mentioned, two tens would be well suited if you have the electrical for 1200+ watts. One of the big keys is port area. You can have a smaller box, which on subs nets you a more even response than a larger box, and still get full excursion with lots of port area. The issue becomes that your 30hz or 28hz port starts to take up a half cube of space.

One 12 or two 10's is where I would draw the limit. There are 15's that do well in smaller enclosures, but larger ports with low tuning tend to add a lot more size than you originally planned.

Something like the latest Sundown SA12 Rev 3, Fi SSD, IA Lethal Injection, Soundqubed HDC, etc.... All should net you pretty solid volume for a single driver setup with a good install.

 

[kr15 5,000+ posts]

Smaller boxes do not generally lend to a more even response. Larger boxes generally play flatter. Small boxes are usually peaky

 

[Jeffdachef 5,000+ posts]

Smaller boxes do not generally lend to a more even response. Larger boxes generally play flatter. Small boxes are usually peaky

Depends on the sub's parameters and the targeted response. Some subs get better response overall with a smaller box. The bigger the box the bigger the peak at tuning frequency, however it'll get flatter the lower you tune. However some people actually like some midbass response from their subs since they dont listen to decaf 24/7. Smaller enclosure helps with group delay as well. Its gonna be different for every setup.

 

[kr15 5,000+ posts]

Hence the term "generally"... Many of the subs that forum users run will fall within these parameters. I rarely see people building larger than spec and tuning high. Usually when people build larger than spec tuning is between 30-35, which gives what most people would deem an acceptably flat response.

Midbass from substage is another subject really, and up to the end user whether or not they want it.

DC Subs are one of the few forum brands in which I tell people to avoid going much larger than spec. DSS subs are also good small box Subs now

 

[Jeffdachef 5,000+ posts]

To show you what it actually looks like here's an hdc3 18 at 5 cubes vs 7 cubes at 35hz

With a lower tuning, you actually have a very flat response the the 18, output will not be anywhere near as good but if a person wanted an SQ oriented HDC3 18 box, that would be it.

 

[SimulatedZero 10+ year member]

So for arguments sake if I have 2 12 inch subs that require 3 cubic feet pur sub. And all I have is a 3 cubic box that is made for 2 subs instead of one and put both of them in there would it be louder than having that same subwoofer in the box by itself rather than suffocating both of them

Maybe, depends on the sub. Here's three examples of entry level drivers with very different sound profiles that we are trying to build a box for to match the sound profile we want.

Kicker C12 4ohm ~ 300w

Polk Dxi 1240 DVC ~ 320w

Sundown E12 DVC ~ 500w

These subs are all the same size and similar ish power specs. Itd be easy to buy an amp that rocked all three.

The goal: A daily build with even response from 60hz to 30hz or deeper that hits into the mid to upper 130's (different subs could get louder in this hypothetical). Graphing in WinISD would show an even line or one with minimal raise (less than two db peak at resonant frequency).

Results: The kicker would need around 7 cubic feet of air tuned low to bring the low end back up to due the tight suspension and low excursion combined with low power handling. Use the port on the box to extend the frequency range and control the excursion of the sub. You'll want decent port area, but a little smaller than the others.

The polk would need 3 cubic feet tuned to 28hz with a good size port. I can tell you from experience that these subs will hit 25mm of excursion in a good box if you keep the air velocity in the port down.

The Sundown would need around 1.7 cubic feet tuned to 30 hz with a large port. The lower the air velocity in the port, the less noise and pressure your sub has to fight. This allows for more displaced air and a louder build.

Now, each sub will sound different in terms of distortion, transient response, and authority in the low mid bass range. However, they will all play 60 to 30 hz with authority and at relatively even levels. It'll sound good and clean (if the sub doesn't distort).

All three are 12 inch subs, all three were with in 200 watts power consumption of each other, and all three required very different builds to get similar results.

That being said, if you have a sub that is like the polk and wants three cubic feet of air and you slap two of them in 1.5 each, you'll loose your low end, over all volume (again, more pronounced the lower you go), and thermal power handling. Your subs won't be able to move as much and the coils won't be able to disapate the heat as well. Now, putting the box in your car will bring a lot of the lower bass back, how much and where depends on the car (typically around the low 40hz to upper 30hz range). A lot of people will build a box that drops the low end to let the vehicles cabin gain bring it back up for an even in car response to better blend with their mids and highs (an SQ setup). So it can be useful and sound **** good, but you'll loose volume overall doing it.

 

[SimulatedZero 10+ year member]

Type one long *** response and miss a good chunck of convo doing it....

 

[SimulatedZero 10+ year member]

Hence the term "generally"... Many of the subs that forum users run will fall within these parameters. I rarely see people building larger than spec and tuning high. Usually when people build larger than spec tuning is between 30-35, which gives what most people would deem an acceptably flat response.
Midbass from substage is another subject really, and up to the end user whether or not they want it.

DC Subs are one of the few forum brands in which I tell people to avoid going much larger than spec. DSS subs are also good small box Subs now

Maybe, a lot of the forum popular subs tend to be easy to peak in larger boxes. But they need to space to take advantage of that excursion, so it's a mix. My compromise is larger ports at any given tuning. Reduced pressure in the port can help the sub move more air

And just to clarify, I'm not against larger boxes for these subs, depends on your goals. I'm a little picky on how I like my response curves so I tend to prefer more cone area and power to less cone are and more box with a lot of these brands. Plus, most of my customers have never heard 138 db in their life, so it's easier to satisfy there needs with those builds.

 

[kr15 5,000+ posts]

WinISD is....

Informative. But the reality is that cabin acoustics will throw those plots out the window. I guess I've just seen enough of these plots fall flat in their face in an acoustic environment. It really shouldn't be viewed as the end all, be all by any means.

Most really good box designers, and by good I don't mean common forum designers, don't even bother with a plot. Ask the guys at Sonus, Pulse, Audio Innovations etc when the last time they used winisd was

 

[Jeffdachef 5,000+ posts]

They dont need anything because they also stick to recommending the woofers they know and done. Give them a woofer thats out of their jursidiction even they have to pull TS specs and build a box accordingly.

when you've built hundreds of JL, hertz, audison subwoofer boxes, they all start to become common knowledge.

 

[SimulatedZero 10+ year member]

WinISD is....Informative. But the reality is that cabin acoustics will throw those plots out the window. I guess I've just seen enough of these plots fall flat in their face in an acoustic environment. It really shouldn't be viewed as the end all, be all by any means.

Most really good box designers, and by good I don't mean common forum designers, don't even bother with a plot. Ask the guys at Sonus, Pulse, Audio Innovations etc when the last time they used winisd was

In my experience, not the case. If you know what your doing, and know to expect and compensate for cabin gain, then WinISD can be a very useful tool. One of the local car audio shops used to it for every custom build and used to it to take first place with a 160's db build using one 18.

A lot of larger companies tend to use more powerful software that can more accurately calculate power compression and cabin gain (approximates on the cabin gain, I don't think there's anyone who has compiled all the cabin measurements for every vehicle yet, I may be wrong). For general daily builds though, most subs act the same and you generally don't need to graph it.

WinISD is a tool. It can be used correctly or incorrectly. Like any tool, using it depends on your situation and application. Expecting to get exactly what you see on screen will lead to failure. Understanding how what you see interacts with other factors in real life leads to a higher success rate

 

[kr15 5,000+ posts]

So are you going to make a 7cu box for a kicker 12? No, because mechanically power handling will be reduced to about 25w. That is precisely what I mean, its informative. Further info is obviously needed.. I guess all the people with good results that didn't utilize these programs just got lucky.

As to other programs, I've seen others have really solid results with bass box pro

 

[los33 10+ year member]

Build a large box can mechanically break a sub.

Too small of a box can thermally kill a sub. Find recommended specs and adjust accordingly to power and space.

Sent from my Z970 using Tapatalk