Potential box design for an XFL 15"

[SounDrive Pro Seller]

You are correct, I just thought it would be a pain to cut more wood on angles lol, but after this discussion I don't think I'll be going with that design.


That is an awesome idea, just need to figure out where to get some and if I can get the same colour as the rest of the cars carpet (kindof a light brown)

I'm really looking forward to further suggestions on 4th or 6th order designs though because this thread has seriously got me started looking at those type of designs... I wouldn't mind having a box with 2 wooden holes facing up...

Problem with that is both space and port breathing space, I don't have a lot of room to work with.

Thanks to suggestions I'm keen on both the bandpass designs and the acoustically transparent material as a last resort or maybe as an addition to it to even maybe hide the ports lol. I really like the hidden + security factor of the bandpass design. I only show a few good mates what I have in my boot //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif even though currently it's only 3 soundstream 12"s which aren't worth much lol.

What do you mean by not having space or port breathing space? A ported enclosure would be much smaller than a 4th order in most cases. And your port ideally should be around 4-6 inches from a surface in your car to load off of it.

 

[Buck 5,000+ posts]

Meh, horns in cars are cool, but not really that great in my opinion. I would do a ported or 4th/6th depending on t/s parameters. Ported is going to be the best option most of the time, just regardless.

 

---------- Post added at 04:18 PM ---------- Previous post was at 04:17 PM ----------

 

You don't have to give up ridiculous space and test and cut all those crazy angles and pay 50+ for a design like that.

 

[SounDrive Pro Seller]

Meh, horns in cars are cool, but not really that great in my opinion. I would do a ported or 4th/6th depending on t/s parameters. Ported is going to be the best option most of the time, just regardless. 

---------- Post added at 04:18 PM ---------- Previous post was at 04:17 PM ----------

 

You don't have to give up ridiculous space and test and cut all those crazy angles and pay 50+ for a design like that.

This man knows what he's talking about

 

[Buck 5,000+ posts]

I don't design horns, rear loaded horns, etc. (at the moment, working on it), but I know the space they require and their drawbacks. PWK and I talked about that a long time ago, ported boxes are just usually the way to go. You can customize them to do anything you want mostly, so that's what I "specialize" in. It's what performs.

I do like my occasional 4th and 6th order bandpass, don't get me wrong.

 

[RSDXzec 10+ year member]

What do you mean by not having space or port breathing space? A ported enclosure would be much smaller than a 4th order in most cases. And your port ideally should be around 4-6 inches from a surface in your car to load off of it.

The port firing back wouldn't have enough breathing space, if I made the bandpass I'd have one or both ports facing up. (depending on 4th or 6th)

Meh, horns in cars are cool, but not really that great in my opinion. I would do a ported or 4th/6th depending on t/s parameters. Ported is going to be the best option most of the time, just regardless. 

---------- Post added at 04:18 PM ---------- Previous post was at 04:17 PM ----------

 

You don't have to give up ridiculous space and test and cut all those crazy angles and pay 50+ for a design like that.

My goal for this sub would be:

good response between 25-50hz

I enjoy bass most between 30-40hz (realistically I like the lows a lot too but due to roll off I like the loudness which tends to be a little higher)

So probably a peak near 37.5hz or between 35-40hz

Following are the ALL the T/S Parameters that came in the box with the XFL1522 that I got in the mail today.

Imp: 2x2ohms

Rdc: 0.8ohms

Levc: 1.247mH

Fo: 30.3Hz

Sd: 81.43 msqM (

BL: 11.203 TM

QMS: 4.216

QES: 0.559

QTS: 0.494

n: 0.494% (judging by the symbol I assume this is efficiency)

SPL: 90.2 dB

VAS: 63.3 L

Cms: 67 uM/N

Mms: 394.5 g

VC: 3"

Magnet: 220oz

Xmax: 19mm

RMS Power: 1000W

MAX Power: 2000W

F. Range:

So would you recommend a 4th or 6th order bandpass box?

I know it would be a little bigger than a ported box but this way I can have both ports facing the roof so it's louder, ported both would be facing the driver which I know would reduce output. I also like bandpass because it makes it pretty much stealproof lol, getting the sub out of the box would be so difficult, specially when the box takes up the whole boot and weighs a fair amount.

 

[Buck 5,000+ posts]

I would still run an XFL in a 6th order.

 

[RSDXzec 10+ year member]

I would still run an XFL in a 6th order.

glad to see we agree

programs like winisd and bassbox pro tend to recommend sealed or bp 4th for some reason...

but I know the manufacturer recommends ported and my responses graphed for 6th order look amazing.

My current design is

rear chamber: 2.8cf @ 48hz

front chamber: 4cf @ 28hz

Each with I'm hoping near 16"^2 of port per cube

I haven't finished calculations yet to see how much I can actually fit but the response I get in winisd is great

The blue line is the XFL and the green line are my current 12"s, this is without even accounting for differences in port area, my 12"s only have about 9.8"^2 of port per cube lol.

This will dominate the lows, it's great for me since I don't like bass over 60hz and 50hz+ isn't that great for me, once it starts getting down to 40 is where it gets good imo

edit, just going over specs now I had around 9cf external to play with but after wood and ports etc looks like i only have around 5cf to play with (net internal volume taking out wood thickness, wooden wall in the middle and port displacement) so I'll have to see how i do this lol (this is if I used 16cf of port per cube...)

I'm considering going down to 14 if I can get away with it which seems to give me 5.5cf

12 per cube gives me 5.9cf to play with

how much port area can i sacrifice here?

Cheers.

 

[Buck 5,000+ posts]

I would go up to 4 cubes rear as well. 4 cubes and 4+ cubes up to 7 or 8 if you wanted, depending on goals.

 

[RSDXzec 10+ year member]

I would go up to 4 cubes rear as well. 4 cubes and 4+ cubes up to 7 or 8 if you wanted, depending on goals.

But isn't one chamber supposed to be significantly larger than the other?

And currently I'm having to downsize... if you read the bottom of my last post I have serious space bottlenecks here

 

[Buck 5,000+ posts]

But isn't one chamber supposed to be significantly larger than the other?And currently I'm having to downsize... if you read the bottom of my last post I have serious space bottlenecks here

Well, I was talking about a series 6th, not a parallel. If you were talking about a parallel 6th, I can see what you are saying more or less. I would do a series 6th though.

 

[RSDXzec 10+ year member]

Well, I was talking about a series 6th, not a parallel. If you were talking about a parallel 6th, I can see what you are saying more or less. I would do a series 6th though.

oh ok, I'll see what kind of a response I get with a series 6th, I'll have to do it in bassbox pro since winisd doesn't model that.

Would a series 6th bp help with my space bottlenecks?

And wouldn't it technically reduce output since there's less surface area coming out?

Cheers.

 

[Buck 5,000+ posts]

oh ok, I'll see what kind of a response I get with a series 6th, I'll have to do it in bassbox pro since winisd doesn't model that.Would a series 6th bp help with my space bottlenecks?

And wouldn't it technically reduce output since there's less surface area coming out?

Cheers.

What do you mean here?

No, your output won't be affected as far as overall output. With a series 6th, your front chamber port needs to be about the SD of the woofer. So you will still have air movement man.

 

[RSDXzec 10+ year member]

What do you mean here?
No, your output won't be affected as far as overall output. With a series 6th, your front chamber port needs to be about the SD of the woofer. So you will still have air movement man.

what I meant was does a series 6th order use less volume than a parallel 6th, apparently it seems to and with a larger bandwidth according to bassboxpro

For port area should I just make it so both ports wind speed is 20-25m/s at 1500watts? (I'll probably only use around 1k anyway) I still haven't worked out port areas and I'll be getting onto that soon

edit:

alright after a fair amount of work/calculations I have a 6th order series design let me know what you think

This will be built with 17mm structural birch plywood

Box specs

Front Chamber

1.642cf @ 33.32hz

29.39"^2 of port area

29.39/1.642cf = 17.9"^2/cf of port area

Rear

3.735 @ 46.6hz

83.27^2 of port area

83.27/(1.642+3.735) = 15.486"/cf of port area

My port area seems pretty huge specially for the 1.64cf chamber, should I decrease these a bit and get more volume out of it?

Problem is with bassbox pro 6 it tells me I get peak port velocities of"

front (1.642cf):

18m/s @ ~ 24hz

rear (3.735cf):

10m/s @ ~ 41hz

This is when pushing a 1000watt signal through it.

I think it's good to keep port velocity under 18m/s I think so a smaller port on the smaller chamber seems like it would be pushing it even though it has a huge port area per cubic foot. What's your opinion?

Here's some BBP6 response curves

White line is the standard ported box

Red line is the BP6th Series box

Cheers.

 

[Buck 5,000+ posts]

Man, that may graph up well, but I don't think it's going to sound that well. You have front and rear chambers backwards from what I can see.

You should try to get the rear and front about an octave or so apart (rule of thumb). Your rear chamber is way too small as well. 6th orders in general are not known for saving space. I think you may be applying the rules of a parallel 6th to a series.

 

[RSDXzec 10+ year member]

Man, that may graph up well, but I don't think it's going to sound that well. You have front and rear chambers backwards from what I can see.
You should try to get the rear and front about an octave or so apart (rule of thumb). Your rear chamber is way too small as well. 6th orders in general are not known for saving space. I think you may be applying the rules of a parallel 6th to a series.

are you saying the low tuned port should be facing the outside world and the higher tuned port inside?

otherwise whats front and back is subjective... the motor of the sub will be in the large chamber because as you can see it wouldn't fit in the smaller one.

I figured having the higher tuned port facing out would be better because it allows me to have more external port area

Are you saying a good tune would be like 30hz and 60hz? possibly a little more/less? Not sure what's acceptable here.

I haven't gone off many rules other than how the response looks when I model it in bassboxpro

trying out the tuning and size recommendations I get this response, problem is it seems the 30hz-50hz region lacks a bit, which is the region i care most about. Although i don't know how the car envorinment would change this response.

white is the first design, red is the current box with recommendations