question about box size and power

[jsluss17 10+ year member]

does bigger box mean it requires less power and smaller box to require more power? i know i've seen that before i just need someone to confirm it because i'm not sure

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[Kangaroux 5,000+ posts]

The larger the box the more efficient the sub becomes. So yes you don't need quite the amount of power to get the sub to move as much as if the box was smaller. Another advantage to larger boxes is that they generally have more low end so you get a flatter response, whereas smaller boxes tend to lack low end and are peakier.

 

[JerryEllis 10+ year member]

yeah the larger the box the less power you have to have to sound loud.... you can take a single 15 throw it in a 4.7 cube box and put 1000 watts on it and do alot of flexin

 

[slvrado28z 10+ year member]

are you talking about sealed or ported?

 

[Moble Enclosurs 10+ year member]

does bigger box mean it requires less power and smaller box to require more power? i know i've seen that before i just need someone to confirm it because i'm not sure

Due to the fact that we are dealing with frequencies much larger in wavelength than our limited space vehicles, then in a conventional design, or simple compression design, making the enclosure larger will virtually be more efficient everytime. But consider the frequencies they become efficient. I can put an 8" in a 10 ft3 box and it be just as efficient as a 1 ft3 box, but at different frequency ranges. So, having a box too big is possible and can actually counter the effficiency. You don't want a box most efficient at 15Hz if you looking for an operating range of 30-75 for example.

Having the proper compression in any design is critical to the safe and efficienct operation of the system. So, knowing the efficiency by making a larger box may be just as important as knowing it can be more efficient. Keep that in mind as well.

 

[audioholic 5,000+ posts]

Once you understand what the box does to affect cone excursion, the answer to this thread becomes obvious.

What Im talking about is the 'air spring' the box creates. When a sub, which is mounted in an enclosure (sealed or ported), is moving, the cone motion affects the air molecules inside the box. As the cone moves in, the air molecules are compressed. When the cone moves out, the air molecules are expanded. The smaller the box, the more each air molecule must be compressed in order to achieve a given cone excursion. The bigger the box, the more molecules inside it, so the less each molecule must compress (or expand). So common sense tells us that the larger the box, the less 'air spring' is placed on the cone motion, the easier the cone is, and the more efficient the speaker/enclosure is (because the cone can move easier). This is especially true for lower freqs, because the lower the frequency, the more air that must be displaced in order to reproduce that note. This is why larger boxes exaggerate the lowest octaves.

And yes, even in ported boxes the air is compressed. The size of the port (length and port area) is small enough to restrict air flow, and it is that restriction that means the air molecules must be compressed. What changes, in regards to this discussion, with ported boxes, is that how close the note being played is to the tuning point of the enclosure affects the resistance the port places on air flow, cone excursion, and air compression inside the box.

 

[zako 10+ year member]

does bigger box mean it requires less power and smaller box to require more power? i know i've seen that before i just need someone to confirm it because i'm not sure

Based on things I have heard so far.

Small box gives you:

1. Better transient response.

2. Better low end response

3. Bigger excursion and more limited power handling.

Much larger box gives you the reverse. For sealed boxes, a lot of people have tended to aim for boxes with qtc of 0.7, which gives them the best compromise among all these things. I don't even look at subs that require >2 cu ft box to achieve a reasonable qtc, regardless of manufacturer recommendations (well, they always recommend 1cu ft, no ****).

 

[Bass Addict 10+ year member]

idk about the smaller the box=better low end response,since i have put my d6 in a bigger ported box over sealed,its like a whole new woofer and low end response has been turbo'ed so to speak.

 

[duanebro 10+ year member]

Based on things I have heard so far.
Small box gives you:

1. Better transient response.

2. Better low end response

3. Bigger excursion and more limited power handling.

Much larger box gives you the reverse. For sealed boxes, a lot of people have tended to aim for boxes with qtc of 0.7, which gives them the best compromise among all these things. I don't even look at subs that require >2 cu ft box to achieve a reasonable qtc, regardless of manufacturer recommendations (well, they always recommend 1cu ft, no ****).

I think you might have got that backwards.

 

[TheUnderFighter 10+ year member]

Based on things I have heard so far.
Small box gives you:

1. Better transient response.

2. Better low end response

3. Bigger excursion and more limited power handling.

Much larger box gives you the reverse. For sealed boxes, a lot of people have tended to aim for boxes with qtc of 0.7, which gives them the best compromise among all these things. I don't even look at subs that require >2 cu ft box to achieve a reasonable qtc, regardless of manufacturer recommendations (well, they always recommend 1cu ft, no ****).

No?

 

[THATpurpleKUSH 5,000+ posts]

Based on things I have heard so far.
Small box gives you:

1. Better transient response.

2. Better low end response

3. Bigger excursion and more limited power handling.

Much larger box gives you the reverse. For sealed boxes, a lot of people have tended to aim for boxes with qtc of 0.7, which gives them the best compromise among all these things. I don't even look at subs that require >2 cu ft box to achieve a reasonable qtc, regardless of manufacturer recommendations (well, they always recommend 1cu ft, no ****).

lots of incorrect information here

 

[audioholic 5,000+ posts]

Based on things I have heard so far.
Small box gives you:

1. Better transient response.

2. Better low end response

3. Bigger excursion and more limited power handling.

Much larger box gives you the reverse. For sealed boxes, a lot of people have tended to aim for boxes with qtc of 0.7, which gives them the best compromise among all these things. I don't even look at subs that require >2 cu ft box to achieve a reasonable qtc, regardless of manufacturer recommendations (well, they always recommend 1cu ft, no ****).

1) yes

2) no

3) no

My previous post covered both positions you got wrong here.