pros and cons of bandpass vs. sealed boxes

[dutchmaster_420]

hi

i would just like to get some opinions on the pros and cons of bandpass and sealed boxes for 15" subs

Click to read more...

 

[W8 a minute 10+ year member]

Size. Most 15's require a huge bandpass box.

As far as one being better than the other I'd take a well designed bandpass over a sealed any day in a trunk car. Hatchback I could go either way, space would be my main concern.

Most people on this forum will tell you to forget both and build a ported enclosure. A huge ported enclosure. But those same people will probably say you need a MINIMUM of a 1000watts to power it. But for most sane people that's just overkill. LOL

 

[helotaxi 5,000+ posts]

I'm mostly with him ^^^.

But musical tastes, power available, space available, goals for the system and such will dictate which makes the most sense. If space is an issue, go ahead and forget about a bandpass. If you are planning on trying to build it yourself and aren't really good with wood (so to speak) forget about bandpass until you are a better woodworker.

 

[rpfuror 10+ year member]

Not all drivers are designed to work well in a BP box. If you find the right driver (based on Vb and Qts, Ts parameters) you will get great results.

Here is the options, if you select the correct driver.

Sealed = accurate freq responce.

Ported = freq responce can be lower with a couple db increase in output.

Bandpass = within the passband you will have a accurate freq responce and a couple db increase... basically best of both worlds.

 

[helotaxi 5,000+ posts]

Not all drivers are designed to work well in a BP box. If you find the right driver (based on Vb and Qts, Ts parameters) you will get great results.
Here is the options, if you select the correct driver.

Sealed = accurate freq responce.

Ported = freq responce can be lower with a couple db increase in output.

Bandpass = within the passband you will have a accurate freq responce and a couple db increase... basically best of both worlds.

The problem with a bandpass is that you have to make a tradeoff. You can either have a reasonably wide pass band or you can have efficiency. Not both. A really efficient BP is going to be a one note wonder box. It will get pretty loud but will be garbage for music because it can only do one note.

Also a ported box is no more efficient than a sealed if it is made for flat response. It is when you tune the box higer than optimal or make the box bigger than optimal that you get the extra output at the cost of low end extension.

 

[dvrmstrng 5,000+ posts]

not to thread jack but i have a question...

80 gave me a box that would be a 4th order i think for my 18"....how do you think it would compare to 6.5 cubes ported which i currently have...he said it was geared more towards having go output at low frequencies more than it was geared to be a one note wonder

 

[rpfuror 10+ year member]

The problem with a bandpass is that you have to make a tradeoff. You can either have a reasonably wide pass band or you can have efficiency. Not both. A really efficient BP is going to be a one note wonder box. It will get pretty loud but will be garbage for music because it can only do one note.
Also a ported box is no more efficient than a sealed if it is made for flat response. It is when you tune the box higer than optimal or make the box bigger than optimal that you get the extra output at the cost of low end extension.

Your right on, that is why I stated that you have to select the correct dirver.

I have built 4th order boxes that have a "tested" better output with in a 28-80hz passband, but this is not typical again driver dependant.