American Bass Hawk 1244 - 4th Order Bandpass

[audatrucking]

I've been trying to enter the T/S Parameters for an American Bass Hawk 1244 into WINISD according to the certain order they specify letting it auto-calculate several and failing miserably. For one I have no idea what msqM possibly stands for since there is no such measurement for Sd that I'm aware of. You would think it's a typo and really mm2 but the value makes no sense even then. I tried not entering it and using other values or even entering the basic 480 cm2 for a 12" sub in its place to get me in the ballpark. Nothing is jiving at all in WINISD and ending up in crazy off the wall auto-calculated values. I've scoured different methods to enter only the parameters and still fall flat on my face.

I think the values provided by American Bass are not exactly sufficient or maybe nowhere near precise. Anybody had this issue with American Bass parameters and entering them into WINISD? I know WINISD can be pretty picky. I'm using the latest WINISD.

I'm building a single 12" 4th order bandpass that will go in the back of a RZR 800S. When I called American Bass, they recommend 1.25 ft3 for sealed but I would much rather have everything graphed in WINISD before making decisions. Most likely going with a 2:1 tuned to around 45-46Hz from what I can halfway get to work in WINISD. The values American Bass provides is attached. It will be run in parallel at a 2 ohm load with near 1250W-1500W RMS to it.......going to require lots of AGM battery power.

Anybody have any advice or luck entering these provided values? Appreciate the guidance.

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[Buck 5,000+ posts]

Their Sd is funky, IIRC the decimal isn't in the right spot. A lot of companies do that, especially with CMS where the decimal point clearly isn't in the right spot.

I would personally do them in a ported or 6th. I'm not sure what model you have, but the older ones were right on the edge between a 4th and a 6th IMO. The problem with 4th's can be low frequency reproduction issues. Sub seems alright in that sealed airspace, with that said. Ratios don't mean anything, subs are subs and subs can only compress so much air.

Not your fault OP, it's a community struggle. I'm so tired about hearing about ratios. The size of the sealed shouldn't change the size of your ported. Sealed side to ported side ratio is largely irrelevant. The size is the size, doesn't matter what the ratio is. Doesn't really work like that, at all. When I see dudes say 4:1 fourth order, I say good luck getting that to sound good, because that's really not how it works, from designing from the ground up.

 

[audatrucking]

Their Sd is funky, IIRC the decimal isn't in the right spot. A lot of companies do that, especially with CMS where the decimal point clearly isn't in the right spot.

I would personally do them in a ported or 6th. I'm not sure what model you have, but the older ones were right on the edge between a 4th and a 6th IMO. The problem with 4th's can be low frequency reproduction issues. Sub seems alright in that sealed airspace, with that said. Ratios don't mean anything, subs are subs and subs can only compress so much air.

Not your fault OP, it's a community struggle. I'm so tired about hearing about ratios. The size of the sealed shouldn't change the size of your ported. Sealed side to ported side ratio is largely irrelevant. The size is the size, doesn't matter what the ratio is. Doesn't really work like that, at all. When I see dudes say 4:1 fourth order, I say good luck getting that to sound good, because that's really not how it works, from designing from the ground up.

Thanks for the feedback. Ported would definitely be nice and simple except I really want the sub to be somewhat hidden from the elements with the box being out in the open on the bed not under any sort of cover. The port itself will be located between the seats somewhat near shoulder height and protrude from the box several inches to get it a little bit of cover under the roof. Now a 6th order I've never done and am hesitant since it will most likely require an even larger box. Space is somewhat a constraint.

I don't really follow the ratios too much but it works out in my builds to be in the range of a 2:1 or 2.5:1. I want it to play a decent bandwidth without a massive dB differential so I usually stick to the optimal sealed volume and then adjust ported side from there. The Hawk sub is brand new from American Bass. I must have the first round of them with incorrect values printed in China with new made up measurement types.

 

[Buck 5,000+ posts]

Thanks for the feedback. Ported would definitely be nice and simple except I really want the sub to be somewhat hidden from the elements with the box being out in the open on the bed not under any sort of cover. The port itself will be located between the seats somewhat near shoulder height and protrude from the box several inches to get it a little bit of cover under the roof. Now a 6th order I've never done and am hesitant since it will most likely require an even larger box. Space is somewhat a constraint.

I don't really follow the ratios too much but it works out in my builds to be in the range of a 2:1 or 2.5:1. I want it to play a decent bandwidth without a massive dB differential so I usually stick to the optimal sealed volume and then adjust ported side from there. The Hawk sub is brand new from American Bass. I must have the first round of them with incorrect values printed in China with new made up measurement types.

It's been wrong for years on a lot of subs, it's just some sort of weird way they put it down.

 

[shredder2]

4th orders bring out the experts with a bunch of theories. I'd size your sealed side around 45-46hz and choose a ratio that won't overpower the lows then match tuning close to the sealed side. 1.5-2.5 is a good place to start. Depending on velocities and peakiness you might need to be a bit shy on port area due to length, If you are use a low port ratio to help with velocities. I took a look at that with that sub and in a 4th it don't look horrible.
In your setup in a Razor your starting from a bad position from the get anyways. Set the bar lower than normal. But a 2:1 4th tuned 47 around 40in2 of port looks OK to me.

 

[Buck 5,000+ posts]

I'd do their recommended sealed and not go over 2.5 ported, personally. I'd do 2-2.5 ported. Sorry I forgot to even answer. I don't wanna give away too much secret sauce, so I'll say follow what shredder2 said hahaha.

 

[audatrucking]

I really do appreciate the help guys. It's definitely a different sort of build being in a completely open area. There's no cabin tuning aspect to it so it's not nearly as loud as being inside a vehicle but it's plenty loud while riding on the trails or stopping for a beverage break.

 

[Buck 5,000+ posts]

Doing a 4th may help with that scenario because the sealed side will control the sub, so you don't have to rely on cabin pressure to keep control of the sub.

 

[Buck 5,000+ posts]

You know, since there is no cabin pressure, is what I mean