bigger box = lower bass???

[infinity1412 10+ year member]

is it true that the bigger the box is, the lower the bass will hit???

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[WarDrumz 10+ year member]

is it true that the bigger the box is, the lower the bass will hit???

I think it's: bigger box = more low-end output.

But I think the further you stray from the manufacturer recommended volumes, the sub will not be able to handle as much power mechanically. Bcuz of the increased excursion.

I think if you have good midbass with your incar speakers than that is what I would go after. I'm currently getting quoted for a custom box from http://www.gnomeaudio.com and the enclosure is about .3 cubic feet bigger than recommended per sub. Hey, thats less power my amp has to put out, and more low-end. I feel I win both ways. Because I have pretty good midbass with my incar speakers.

 

[WarDrumz 10+ year member]

BTW, I'm talking about sealed enclosures. Vented MIGHT be a little different, I'm not for sure.

 

[HK2k 10+ year member]

A bigger sealed box will give you lower bass than a smaller sealed box but you lose much of the tightness in the bass. IMO, if you want really low bass, a ported box would be best.

 

[infinity1412 10+ year member]

alright, thanks for the info

 

[BDIDDY 10+ year member]

A bigger sealed box will give you lower bass than a smaller sealed box but you lose much of the tightness in the bass. IMO, if you want really low bass, a ported box would be best.

I don't think you would lose that much sq because it's still sealed. Ported gives you that extra oomph.. go with it..

 

[LoudCrownVic 5,000+ posts]

Ported boxes have far far FAR tighter bass than sealed! I just switched from sealed to ported and I should know the difference. Sealed boxes do what i call "carry over" a bass note. They have equal sound output through the note because they have a sealed environment that wil either have pressure or vaccuum. It seems to fight itself to produce the sound. For a ported box, a bass note such as a quick hit in a speed metal song, is a quick hit because the pressure is dissapated from the hit and the voice coil can respond freely to the next hit. The difference, if you have two boxes sealed and ported right next to each other, will be that the sealed will respond pretty much the same except for the ported box will be in all instances louder (as they are more efficient) and in my opinion far more detailed.

Notice that this all is speculation, and i did not mention if you had more cubes you would get lower bass louder. To be honest, I built my ported box and it made little difference on how low it played, it just played quite a bit louder.

 

[Jim Boom 10+ year member]

Its all in how you tune it, I tuned my box to 28 hz with the rear port speed at 17-lower at 34hz-higher, so it has punchy low bas around 34 to 50 hz which is what most songs frequincies are, at least mine are.

 

[WarDrumz 10+ year member]

A bigger sealed box will give you lower bass than a smaller sealed box but you lose much of the tightness in the bass. IMO, if you want really low bass, a ported box would be best.

I don't fully agree with the "much" part of your post. It all depends how much larger you go over the recommended volume. If the rec. is 2 cu.ft. and you put the sub in a 3.5 cu.ft. then yes, "much" of the tightness will be lost.

"much" is appropriate if your "much" over the rec. volume. So it all depends.

 

[BDIDDY 10+ year member]

Ported boxes have far far FAR tighter bass than sealed! I just switched from sealed to ported and I should know the difference. Sealed boxes do what i call "carry over" a bass note. They have equal sound output through the note because they have a sealed environment that wil either have pressure or vaccuum. It seems to fight itself to produce the sound. For a ported box, a bass note such as a quick hit in a speed metal song, is a quick hit because the pressure is dissapated from the hit and the voice coil can respond freely to the next hit. The difference, if you have two boxes sealed and ported right next to each other, will be that the sealed will respond pretty much the same except for the ported box will be in all instances louder (as they are more efficient) and in my opinion far more detailed. Notice that this all is speculation, and i did not mention if you had more cubes you would get lower bass louder. To be honest, I built my ported box and it made little difference on how low it played, it just played quite a bit louder.

Have to disagree here too.

It probably just depends on what sub you're using but with most that's not true...

 

[helotaxi 5,000+ posts]

Ported boxes have far far FAR tighter bass than sealed! I just switched from sealed to ported and I should know the difference.

So based on your *vast* experience, this is the case?

Sealed boxes do what i call "carry over" a bass note. They have equal sound output through the note because they have a sealed environment that wil either have pressure or vaccuum. It seems to fight itself to produce the sound.

It's called damping. It actually is less for a sealed box than it is for a ported box.

For a ported box, a bass note such as a quick hit in a speed metal song, is a quick hit because the pressure is dissapated from the hit and the voice coil can respond freely to the next hit. The difference, if you have two boxes sealed and ported right next to each other, will be that the sealed will respond pretty much the same except for the ported box will be in all instances louder (as they are more efficient) and in my opinion far more detailed.

The ported enclosure actually exerts more control on the cone than a seled box does. This may seem counterintuitive but here's how that is so. A sealed box has a fixed quantity of air in it. As the sub moves out it creates a low pressure area inside the box that wants to "****" the cone back in. As the sub travels in, it creates a high pressure area in the box that wants to push the sub back out. Compare that to a ported box. As the sub moves out it creates a low pressure area inside the box, but since it is ported it ***** air in through the port to equalize the pressure. Now when the sub tries to move back in, it has to work against the "extra" air that just came in as well as the inertia of the air still trying to move in. As it moves back, it compresses the air in the box and the pressure again starts to equalize through the port, pushing the "extra" air as well as some of the air volume that normally fills the box. Thus as the cone moves in and out, the air moving in and out of the port creates a larger vacuum and high pressure area and exerts more control over the cone. This control is maximized at the resonant frequency of the box. At that frequency, the pressure in the box from the inward movement of the cone is just beginning to vent through the port as the cone reverses direction so the air moving out from the port adds to the pressure wave created by the sub's movement and gives a boost in output and the inertia of the air exiting the port combines with the sub moving out to create an even larger pressure gradient in the box and exert greater force on the cone limiting its movement. Because the box is basically combining the front and rear pressure wave of the sub, the port output is half a cycle behind the sub outout and this slurs the respnse a bit. Basically that loss in pure fidelity is one of the sacrifices that you make to get that 3dB more output that a ported enclosure enjoys over a sealed sub. As the frequency moves away from resonance getting higher, the box has less and less time to equalize and begins to act more like a sealed enclosure. As you begin to go below resonance, the box has too much time to equalize its pressure and the momentum of the air rushing into the box actually pushes the cone out more rather that controling its movement. This is why you get less usable output from a ported sub below tuning. Excursion goes way up and mechanical power handling goes way down. Also look at the response plots for the same sub in both a ported and sealed enclosure. As you start getting into the really low notes, the sealed generally remains linear, and will actually give you more output. The slow and gentle rolloff of a sealed system matches up well with the transfer function of the typical vehicle. The interaction between the sub and the air in the vehicle begins to amplify the bass at about 12 dB per octave starting around 100 hz. Since a sealed sub system with a Qtc of .7 rolls off at about 12dB per octave the tranfer fucntion works to keep the response of a sealed system flat down to really really low frequencies. With a ported system the response is typically flat until right around resonance at which point it begins to roll off quickly. Combine that with the transfer function of the vehicle and you get a large hump in the response of the system from around 60 hz to just below the tuning freq. Below tuning the respone rolls of quicker than the transfer function can make up for it resulting in the in-car response falling off as well.

Notice that this all is speculation, and i did not mention if you had more cubes you would get lower bass louder. To be honest, I built my ported box and it made little difference on how low it played, it just played quite a bit louder.

With some tradeoffs, you can get lower bass louder by using a larger enclosure. The tradeoffs are sloppier response and a decrease in power handling from the decreased damping provided by the enclosure. The only real time that this would be of benefit is if you are trying to get really low bass from a small amp, otherwise you can usually get about the same volume at low frequencies with tighter response by just making use of the increased power handling of the smaller enclosure and giving the sub more power. Thanks to that transfer function of the car you can usually optimize the enclosure for transient response and power handling and still get really good low frequency output from a sealed system.

 

[WarDrumz 10+ year member]

Dammmmmm......that was thorough. LOL!

You should write a book,lol.

Hey helotaxi, if I tell you the T/S specs on my sub do you think that you could tell me the optimum size sealed box for my sub? The little sheet that came with it says recommended is 1.8-2.2 so I guess 2 would be good, but can you find out for sure? I don't have a computer I have webtv so I don't have good software to find this info.

Thanx.

 

[helotaxi 5,000+ posts]

There is an enclosure calulator online at www.bcae1.com.

 

[WarDrumz 10+ year member]

There is an enclosure calulator online at www.bcae1.com.

Hey, thanx man. I'll try it out.

 

[WarDrumz 10+ year member]

LOL!!

Mannnn.. I tried that site, and it told me I need a 4.9 cubic feet sealed enclosure, and get this, a 9 cubic feet ported enclosure. lol. The sub's VAS is only 4.2 cubic feet. I think that site needs some repairs. The other calculators I tried were right on though.

Thanx again for the link, there was some helpful stuff on there.