Does More Box Volume = Louder?

[Blackout67]

So today I traded some extra subwoofers a box, 2 channel amp and some cheap Alpine speakers for a new subwoofer I've never heard of. When he send me the pictures of it in the box I was skeptical because I'd never heard anything about the brand and he didn't tell me the model just pictures of it in the box. So after he gave me the model (Definitive Audio Designs MAK15) and sent pictures of it out of the box and doing some research, I was immediately interested. Massive motor, thick sewn tinsel leads, etc. So he brought it over and we got it in my Mustang and it is ******* loud. Never had a sub move my hair but it did and I was very happy.

However, the box he gave me is quite small he said it's 3 cu ft tuned to 32 hz after displacement. After removing the subwoofer, I could see the box is definitely not built for a sub this big (62 pounds). Its a well constructed box but there is no bracing and only 1 inch baffle. Luckily, I had bought a box for an Avatar STU1546, but I never got the money to do it. This box is 4.19 tuned to 32. 1.5 inch baffle and internally braced. So I was expecting to be louder and be able to house the subwoofer better. But when I got it wired up in my mustang, I was disappointed. It's not much louder than my Deaf Bonce MF15 I had in the same box, and it's only a $150 subwoofer. I have it on an SIA3500, 320 amp, big 4, only one AGM tho but it's not clipping. Any suggestions?

Video is of the small box

Click to read more...

 

[winkychevelle 10+ year member]

So today I traded some extra subwoofers a box, 2 channel amp and some cheap Alpine speakers for a new subwoofer I've never heard of. When he send me the pictures of it in the box I was skeptical because I'd never heard anything about the brand and he didn't tell me the model just pictures of it in the box. So after he gave me the model (Definitive Audio Designs MAK15) and sent pictures of it out of the box and doing some research, I was immediately interested. Massive motor, thick sewn tinsel leads, etc. So he brought it over and we got it in my Mustang and it is ******* loud. Never had a sub move my hair but it did and I was very happy.

However, the box he gave me is quite small he said it's 3 cu ft tuned to 32 hz after displacement. After removing the subwoofer, I could see the box is definitely not built for a sub this big (62 pounds). Its a well constructed box but there is no bracing and only 1 inch baffle. Luckily, I had bought a box for an Avatar STU1546, but I never got the money to do it. This box is 4.19 tuned to 32. 1.5 inch baffle and internally braced. So I was expecting to be louder and be able to house the subwoofer better. But when I got it wired up in my mustang, I was disappointed. It's not much louder than my Deaf Bonce MF15 I had in the same box, and it's only a $150 subwoofer. I have it on an SIA3500, 320 amp, big 4, only one AGM tho but it's not clipping. Any suggestions?

Video is of the small box

It's all dependant on the sub

In most cases you go with a small box when you want a high/narrow peak and have plenty of power on tap. You will often run into thermal limits before mechanical burp box

In a bigger box the peak is shallower and wider making it more musical but you lose the box spring effect meaning the mechanical suspension of the sub does more work and thus you reach mechanical limits before thermal limits.

Port area and tuning also affects the choice as well as cabin gain. Personal preference for me is I like a larger box because it allows me to play lower and higher with less power at the loss of a little output. Playing 30-80hz flat is near impossible but the general goal is something along that line for a starting point for a musical box.

 

[Blackout67]

It's all dependant on the sub

In most cases you go with a small box when you want a high/narrow peak and have plenty of power on tap. You will often run into thermal limits before mechanical burp box

In a bigger box the peak is shallower and wider making it more musical but you lose the box spring effect meaning the mechanical suspension of the sub does more work and thus you reach mechanical limits before thermal limits.

Port area and tuning also affects the choice as well as cabin gain. Personal preference for me is I like a larger box because it allows me to play lower and higher with less power at the loss of a little output. Playing 30-80hz flat is near impossible but the general goal is something along that line for a starting point for a musical box.

Could it have been because of port velocity? Because the air space in the box is on the low side, the pressure from the subwoofer is pushing the air with more force?

 

[winkychevelle 10+ year member]

Could it have been because of port velocity? Because the air space in the box is on the low side, the pressure from the subwoofer is pushing the air with more force?

Port air velocity doesn't have much do do with mechanical power handling as the volume of air that is moving though the port same and it has the same resistive value that's how you tune the box the resistive value of the port. We use larger ports to cut port noise and in some cases we use such large ports to become more efficient albeit in a very narrow frequency range since once you go too large on the port it becomes a huge leak at most frequencies other than near tuning.

But with the different dead air inside the box you get different air spring effects just like a sealed box. And just like a sealed box more airspace means less mechanical power handling and the ability to play lower on the same amount of power. But as with anything their are limits. Too big and the speaker is near infinite baffle and relies solely on mechanical suspension.

 

[winkychevelle 10+ year member]

Ideally you want to build an enclosure specifically for that sub based around the specific vehicles cabin gain and your personally listening preference.

 

[Bobbytwonames 5,000+ posts]

It's all dependant on the sub

In most cases you go with a small box when you want a high/narrow peak and have plenty of power on tap. You will often run into thermal limits before mechanical burp box

In a bigger box the peak is shallower and wider making it more musical but you lose the box spring effect meaning the mechanical suspension of the sub does more work and thus you reach mechanical limits before thermal limits.

Port area and tuning also affects the choice as well as cabin gain. Personal preference for me is I like a larger box because it allows me to play lower and higher with less power at the loss of a little output. Playing 30-80hz flat is near impossible but the general goal is something along that line for a starting point for a musical box.

Is this why my subs that are in a big box unload before I ever smell them? I've only smelled them once in over two years.

 

[winkychevelle 10+ year member]

Is this why my subs that are in a big box unload before I ever smell them? I've only smelled them once in over two years.

Potentially. You can model them and see how much power is needed to reach full xmax.

Problem is good companies measure xmax at 70% of bl but don't always say that. We also quickly forget that box rise cuts power significantly, but box rise is often a good thing as it indicates box efficiency.

I still think you have a minor unloading issue due to the location of the internal port termination

 

[Bobbytwonames 5,000+ posts]

Potentially. You can model them and see how much power is needed to reach full xmax.

Problem is good companies measure xmax at 70% of bl but don't always say that. We also quickly forget that box rise cuts power significantly, but box rise is often a good thing as it indicates box efficiency.

I still think you have a minor unloading issue due to the location of the internal port termination

My subs unload at full tilt @ 28 hz, They are in 3.69 cubes net tuned to 34 hz. 4 - 8's. Big box and big power.