Bandpass SQ shortcomings

[IamDeMan 5,000+ posts]

I am an SQL guy. I like it to be acceptably accurate while being able to give some output.

Many say the all bandpass enclosures have bad transient response. What exactly is it that causes this negative impact? Can it be remedied or lessened?

Basically, I have never built or owned a BP before. I have heard some. they were mostly pre-made garbage though. So my reference in this area is limited. I am thinking of making a 6th order for my 12" mag. I would like to know all the things to look out for when building and tuning this type of enclosure, so I can make it sound as good as possible.

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[Warbleed 10+ year member]

Any particular reason you want a bandpass box? Worst possible transient performance of any alignment (the higher the order of an alignment, the worse the transient response).

This is not to say you cant make a bandpass sound decent, but they require a lot of work, and honestly, if SQ is your goal, it's not a very wise choice.

If you want more SPL over sealed, I'd recommend just using a vented box. If you are just concerned about SQ, go sealed or IB.

 

[Volenti 10+ year member]

Basically if you are after SQL from a BP you should go with 4th order and tune the vented section very high, 70-80hz or so (BP tuning is different to vented tuning), you are looking for a response curve that resembles the curve of the sub in sealed (only it's louder of course) a smallish (relative) front chamber tuned high has a pretty low GD, typically only 2-3x that of sealed.

Just keep in mind that some subs simply won't work well in bandpass and will want to "one note" no matter what you do.

 

[xclusiv3 10+ year member]

Any particular reason you want a bandpass box? Worst possible transient performance of any alignment (the higher the order of an alignment, the worse the transient response).
This is not to say you cant make a bandpass sound decent, but they require a lot of work, and honestly, if SQ is your goal, it's not a very wise choice.

when you say worse transiet response....

does that mean like all of the notes whether 35 or 55hz will pretty much sound the same????

b/c im looking to do a 6th order in my car so i can get rid of the trunk rattle.

 

[Vipervenom18 10+ year member]

when you say worse transiet response....does that mean like all of the notes whether 35 or 55hz will pretty much sound the same????

b/c im looking to do a 6th order in my car so i can get rid of the trunk rattle.

No.

He means that it will sound "sloppy" or "slow" or "muddy" if you want to use those terms (generally).

Aka it cannot change frequencies fast enough, or well enough. Aka double kick bass from a metal song would sound terrible on a system with bad transient response, for example.

However if it is just hitting a single bass line from a rap song, it could wang, lol

 

[bk12321 10+ year member]

I wouldnt do BP if you want "quick" response

third order (ported) is as high as I would go. BP's CAN have decent sq/relatively low group delay, but you have to know what you are doing and each chamber has to be exact, and frankly its a lot of work. depending on your system, it can still be pretty loud in a sealed application, but a properly done ported box I think you would be happy with.

 

[80INCHES 5,000+ posts]

if u going for sq dont do a bandpass. even though a 4th order bandpass can dsplay sealed box characteristics itd hard to design one to perform as such. 6th order bandpasses r harder to design and use in any ride due to the transent response and the steeper slope (18db slope on the low and high end of the bandwidth..4th orders have 12db slopes on low and high part of the bandwidth which will be more forgiving in blendin in with the mid bass. as far as tuning u tune the 4th order in te middle of the bandwidth. and tuning a bandpass between 70-80hz is not good for wat he wants to do. i would tune lower more like between 40-55hz but that also depends on the sealed chambers and port chmaber as well 80

 

[xclusiv3 10+ year member]

However if it is just hitting a single bass line from a rap song, it could wang, lol

then it should be okay for me lol.

all i listen to is rap, so really there is no need for me to worry about SQ as much....

hopefully blends with the midbass well even though its a 6th order.

 

[Igno 10+ year member]

Any particular reason you want a bandpass box? Worst possible transient performance of any alignment (the higher the order of an alignment, the worse the transient response).
This is not to say you cant make a bandpass sound decent, but they require a lot of work, and honestly, if SQ is your goal, it's not a very wise choice.

If you want more SPL over sealed, I'd recommend just using a vented box. If you are just concerned about SQ, go sealed or IB.

sorry what's IB? please

 

[Max_Power 10+ year member]

sorry what's IB? please

Infinite Baffle - like putting you sub in the rear deck and using the trunk for a box.

Type infinite baffle in the search window

 

[wenn_du_weinst 10+ year member]

infinite baffle

beat me to it

 

[Igno 10+ year member]

thank you both, did not get much with my ib google lol, and I am sorry there are plenty of sealed subs that get plenty loud for SQ, my 1 tc sounds 10 inch in a sealed .53 enclosure is pretty loud for SQ needs

 

[nauc 10+ year member]

fq response dictates a lot of the systems sq. the flatter the fq response, usually the better the transients/sq. thats why most recommend and use sealed setups if youre going for sq because sealed setups usually have the flattest response of all the box types.

 

[IamDeMan 5,000+ posts]

To answer some question.

Why BP? Just out of curiosity. Never heard a proper BP. Plain and simple. Mopre research and experimentation than anything.

I am not looking for straight SQ, but SQL. I can forgive some sloppines for output.

Does group delay = sloppyness factor?, because according to Winisd(yada, yada, yada it isnt accurate I know, but we all need some kind of base) A mag in 6th order would have an acceptable group delay compared to its optimum ported.

Is sloppyness really a concern if the sub is used for absolutely sub bass(low pass of 60 with a slope of 24) and coupled with an 8" midbass in the front stage?

I am more than likely going to build one like I said just to get reference. What I am looking for out of this thread is advice on how to make it the best it can be and avoid mistakes. I'll never be able to intelligently speak on the subject until I finally get my feet wet in it //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[nauc 10+ year member]

for sql, id run ported and tune low, youll get some sick lows

as far as your GD ?, not sure