Enclosure shape on Port box, does it matter?

[Bobbytwonames 5,000+ posts]

Even "most" synthesized shit rarely goes that low and that would be rare to find outside of pipe organ concerts or that slowed crap or test tone tracks.
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In theory it shouldn't matter provided there's a port width of clearance around inlets. In practice there will be some difference unique to your vehicle and the placement of the box but you can't guess until you have tested it installed and differences should be inaudible or nearly so.



Give it a whirl, use some caulking or other non-permanent adhesive to affix the port and you can always test various lengths of port especially if you have 4" pipe left over from jobs or whatever.

Maybe on the radio. If you want to hit the lows and get windy like most people do then your box needs to be tuned fairly low. My box peaks @ 31 hz. and I can play music from the radio and rebassed music and it sounds great. 28 - 40 hz. sounds awesome. I guess that some people like the high bass notes.

 

[hispls 5,000+ posts]

I can play music from the radio

Name 5 songs you hear on the radio that contain 31hz material.

 

[Bobbytwonames 5,000+ posts]

Name 5 songs you hear on the radio that contain 31hz material.

I don't give demos off the radio, do you? I hear plenty of sounds on the radio that get low. If you strictly play the radio then rock your 45 - 60 hz. I like the bass notes between 28 hz. and 40 hz. I have mids and tweets for the other frequencies. You treble rebels can rock your stunt walls and techno music if that's what you are into. I prefer this.

 

[Bobbytwonames 5,000+ posts]

Name 5 songs you hear on the radio that contain 31hz material.

Here look it up. Why do I have to do your research?

 

[hispls 5,000+ posts]

I don't give demos off the radio, do you?

So you're conceding that pretty much nothing you'd find on a regular commercial radio station is going to have much program material at 32hz.

You treble rebels can rock your stunt walls

WTF is a treble rebel and a stunt wall?

I prefer this.

So basically just adding a 20hz sine bomb on top of real music? That shit is more of an abomination than the ones played at half speed. If that entire Black album isn't loud for you without adding 20hz sine waves into it you've done something wrong.

Why do I have to do your research?

Because I'm not the one making a claim that you're going to turn on the radio and find program material in the 32hz range, this is the claim YOU have made.

 

[Bobbytwonames 5,000+ posts]

So you're conceding that pretty much nothing you'd find on a regular commercial radio station is going to have much program material at 32hz.

WTF is a treble rebel and a stunt wall?

So basically just adding a 20hz sine bomb on top of real music? That shit is more of an abomination than the ones played at half speed. If that entire Black album isn't loud for you without adding 20hz sine waves into it you've done something wrong.

Because I'm not the one making a claim that you're going to turn on the radio and find program material in the 32hz range, this is the claim YOU have made.

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Do some research and see where people tune their boxes. Please show me all the people tuning their boxes between 40 and 50 hz.

 

[mrj858 10+ year member]

I haven’t listened to music on a radio station in like 8 years…. Can’t stand commercials

 

[Bobbytwonames 5,000+ posts]

I haven’t listened to music on a radio station in like 8 years…. Can’t stand commercials

Exactly. I'll listen to sports talk radio occasionally in the radio.

 

[Affray]

I still haven't started the sub box build yet as I'm currently rebuilding the front end (so many mistakes made ), but hopefully, that will be done by the end of this week and assuming I'm not too knackered, the plan is for this weekend.

The 28 hz playing down to comes from the fact that it's the cut of point for the piano, I listen to musicals quite often (Les Misérables, wicked, etc,) and I have always loved the piano and would like to hear every part note from it. Not sure I'll get it but that's the aim

 

[Buck 5,000+ posts]

I still haven't started the sub box build yet as I'm currently rebuilding the front end (so many mistakes made ), but hopefully, that will be done by the end of this week and assuming I'm not too knackered, the plan is for this weekend.

The 28 hz playing down to comes from the fact that it's the cut of point for the piano, I listen to musicals quite often (Les Misérables, wicked, etc,) and I have always loved the piano and would like to hear every part note from it. Not sure I'll get it but that's the aim

If you like the piano and bass, this is a really good song, imo. This is just flat out one of my favorite songs ever. It will test the quality of your system lol:

 

[Affray]

It will test the quality of your system lol:

Not sure I’m quite ready for that test but looking forward to trying it when I am ready
Put the A pillars back in yesterday (exposed plywood is because there holding temporary speakers till cabin is done)

got to redo the midbass now and change them from closed to vent box

 

[akheathen Premium Member]

Quick update
I've been playing around with BassBox 6 Pro (very useful manual) and I have come up with the following design on it

After allowing for displacement, the box volume is 100 litres or 3.531 cubic feet.
Port is a round pipe with an internal diameter of 102mm (4-inch sh*t pipe in short as I have loads of it ) at 1109mm long x 3 (to deal with the vent velocity)

This gives me a tuning frequency of 25hz and an F3 of 23.61hz and this response.

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thaught i cleared up some guidelines for you... first, ill give you some things to visualize. with the port on the passenger side of a single cab space, there is not the 10 feet required to converge (develop, as its often referred to) the sound wave, so you shoot to converge the wave at the drivers floorboard, which diverts the rest of the way the strongest up to the driver/middle seat experience zone, where it will be fully developed, if that makes sense. this is why the port typically works best firing behind the passenger, close to below the b pillar as you can.... just a visual excersize..... when playing with bandpass, theres a trade off of range/sq and output, so look for a flat response in the range that you'll want. typically, youll set the cross-over/cuttoff frequency to not play above the 63-80hz range, so ignore any response above that, or youll be getting resonated on every commercial, or speaking bits, which i can tell you is extra annoying. sure, its not typical, but there are a LOT of songs/media that drop well below 20hz, in almost any genre. you do have the bennefit of small cabin low end db gain, but that goes to waste with a sharp cutoff in response, which will happen if you tune too low, and close, or below the fs of the driver, or use too large of port, which you certainly are not anywhere close to doing. 12-13sq/cu, is what i suggested, not per box. think about how the cabbin size effects the port. too large, and velocity is hindered. choke it down a lottle for a smaller cabin and its like a shotgun choke or spitting a loogie far. choke it too much, its like spitting through a straw... not much effect at all.... next post, simple rules of thumb

 

[akheathen Premium Member]

so, you get low frequency db gain, so below 30-45hz should net more than what the box calculations show for output.
12-16 square inches PER cubic foot NET chamber space is typical port size for good response. larger is more, but peaky output. smaller size, makes for flatter response, with less output, and safer for mechanical limits of the driver(usually the choice for prefab boxes)
single cabs should typically fire the port behind the passenger seat, at the door to develop the sound better, in the right spot.
if you are using 4"i.d. pipe, thats just under 12.5 sq inch area. 3.5 i.d. would be about 10, so get close to 12-13" x chamber volume......
however, bandpass, DOES add a whole other level of complexity. ive had small as 3-4x x-max displacement and large as 25sq/cu both provide astonishing results, but only after calculated for. it pays to do your research: you can be 1/4" between great and a whole lot of nope. its best to shy away from those cusp zones at first.

 

[Buck 5,000+ posts]

I would say enclosure shape does matter, it just doesn’t matter once you reach a certain clearance around the port. You don’t want the port in too skinny of part of the box, because that part can also become port length, if the cross sectional area isn’t a little bit bigger than the port. I really prefer the inside of the enclosure to have the flow to the port from the sub be at least the Sd surface area of the sub, to make sure the woofer isn’t loading or being restricted anywhere in the box. Sometimes that’s not possible, like with shallow mounts, but if you have high powered or high xmax subs, then you should make sure the chamber, itself, isn’t over restricting energy flow inside of the box.

I ‘tune’ the flow of energy in the enclosure; I try to aim all of the sound from the sub to enter the port at the same time, if I can.

 

[Bobbytwonames 5,000+ posts]

I would say enclosure shape does matter, it just doesn’t matter once you reach a certain clearance around the port. You don’t want the port in too skinny of part of the box, because that part can also become port length, if the cross sectional area isn’t a little bit bigger than the port. I really prefer the inside of the enclosure to have the flow to the port from the sub be at least the Sd surface area of the sub, to make sure the woofer isn’t loading or being restricted anywhere in the box. Sometimes that’s not possible, like with shallow mounts, but if you have high powered or high xmax subs, then you should make sure the chamber, itself, isn’t over restricting energy flow inside of the box.

I ‘tune’ the flow of energy in the enclosure; I try to aim all of the sound from the sub to enter the port at the same time, if I can.

Please don't listen to this *********. He jacks off to midget little boy **** in his Mom's basement.