bandpass box downsides

[Heide264 10+ year member]

I have been curious for a while, what ever happened to bandpass boxes and why? I have an old (ballpark 20yr) rockford fosgate dual 8" bandpass enclosure with an equally old 300W USA amp on it and it sounds very good normally and for 300W it is all the power I really need.

I was just wondering what most the big downsides of the bandpass enclosures are and why not many people use them anymore.

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[BassMechkanic 10+ year member]

people to cheap to have a good box built!

 

[Heide264 10+ year member]

Well, when the box was built there wasn't much better out there. The build is great and its still up and pumping 20 years later. I wish I had some form of literature on it though - not even rockford has a spec sheet or manual for it anymore.

I was honestly just curious why they aren't used much.

 

[bottlebaby 10+ year member]

i dont know but im fixing to do one in my m3 vert.

 

[TnT_Sounds 10+ year member]

My last build consisted of 6 12s in a 4th order bandpass. It was by far one of the loudest and cleanest sounding setups I have had. My current one is going to be 4 12s in a 6th order bandpass.

So I'm pretty stuck on bandpass enclosures. After doing a proper one I will never go back to generic bass reflex.

 

[KyleBechtold 5,000+ posts]

the thing about em is they have to be built right or you have shitty fq response

 

[galacticmonkey 5,000+ posts]

Somewhere along the line someone said "ZOMG IF YOU DONT BUILD IT TO WITHIN .0000000000000000000001 CUBIC FEET OF WHERE IT NEEDS TO BE IT WONT MAKE A SOUND AND IT WILL BLOW YOUR SUBWOOFAZ DONT RISK IT!!!".

They really arent that hard. A 4th order is pretty easy to design. Its just like any other box, with a bad design it wont perform well. But people make it sound like it will be the end of the world if you dont design it correctly. It wont be. Experiment with a couple boxes, wood isnt that expensive.

I just tore my box apart, was a 4th order for 24 15s. Ive designed and built a couple bandpasses for some 10s/12s/15s and they are always impressive for what they are.

 

[Heide264 10+ year member]

Thanks, was just curious.

I've heard that it is impossible to tell when you are pushing the drivers too hard with a bandpass box also, is there any truth to that?

I have no idea how much power this old box and its drivers can take. They are old punch drivers that I recently refoamed. Its being driven by a USA150 in bridged so supposedly 300W.

Think I am in the safe zone to set my amp gain to its correct level? Right now its down a bit just to be on the safe side since I don't normally push it too hard. I can't find spec sheets for it anywhere; not even R.F. has any on file.

 

[ciaonzo 5,000+ posts]

Bandpass enclosures are solely for efficiency. The group delay is horrible and the response is usually peaky. Other than that, they're good for getting loud.

 

[galacticmonkey 5,000+ posts]

Bandpass enclosures are solely for efficiency. The group delay is horrible and the response is usually peaky. Other than that, they're good for getting loud.

You should have heard mine. If you design it right they can sound amazing.

 

[TnT_Sounds 10+ year member]

Ya. Whoever decided to say, "it can't be a 16th off or it will sound like shit", is a ***. I was probably an 1/8th off on everything and it still hammered daily.

 

[ciaonzo 5,000+ posts]

You should have heard mine. If you design it right they can sound amazing.

Indeed, I thought yours sounded great. At least from what I could tell from the vids. I have designed some greats as well but they never compare to the transient perfect enclosures as far as SQ is concerned. They have their purpose, no doubt.

 

[RAM_Designs 5,000+ posts]

Transient response is lacking. Other than that they can be made to sound very well, but compared to ported, bandpass has a higher group delay, especially if doing a 6th order.

 

[Heide264 10+ year member]

Can somebody give me a quick run down on group delay? I have heard the term thrown around a bit and just curious as to what it actually is. Not a pro here by any means.

I've never used anything other than that box that I bought off my father for $20 since he was planning on junking it... Might have to try a standard sealed/ported one once I'm outta school and not eating ramen noodles.