After what you have been building that driver will be a let down for you....
From the Seismic Audio website
Resonant Frequency (fs): 34Hz
DC Resistance (Re): 6.3 Ohm
Mechanical Q (Qms): 2.3
Electromagnetic Q (Qes): 0.65
Total Q (Qts): 0.5
Compliance Equivalent Volume (Vas): 299 Ltr
Mechanical Compliance of Suspension (Cms): 149mm/N
BL Product (BL): 17.4 Tm
Diaphragm Mass Airload (Mms): 145g
Surface Area of Cone (Sd): 1.2k cm2
From the Seismic Audio website
- Power Rating: 500 Watts RMS - 1000 Watts Peak
- Nominal Impedance: 8 Ohm
- Frequency Range: 35Hz-3KHz
- Sensitivity: 97dB
Resonant Frequency (fs): 34Hz
DC Resistance (Re): 6.3 Ohm
Mechanical Q (Qms): 2.3
Electromagnetic Q (Qes): 0.65
Total Q (Qts): 0.5
Compliance Equivalent Volume (Vas): 299 Ltr
Mechanical Compliance of Suspension (Cms): 149mm/N
BL Product (BL): 17.4 Tm
Diaphragm Mass Airload (Mms): 145g
Surface Area of Cone (Sd): 1.2k cm2
Thanks for the compliment. It is for a part set up,, house party dj, guy. I saw those parameters on the seismic site,, what is 1.2k square centimeters? Are you hose parameters complete enough to put into bass box? I feel like I was missing a couple when I tried,,,can't remember which one,,, something using mh.
sd and le are what I'm missing I see. xmax as well. Is it wise to leave these out when using a program such as bassbox?
Don't worry about Le, has no effect on figuring out sub box designs.
Sd = 1.2k cm2 translated into how most would state it - 1200 cm^2
Regarding Xmax, that's the great unknown - if it's like the other cheap 18" Pyle, probably around 10mm one way.
FYI - I would do a sealed enclosure, a little more protection for the driver
However, I wouldn't expect it to last very long in a typical house party dj setup, hopefully the guy your building it for has some limiters in what he intends to drive it with. 😉
btw - If the guy hasn't bought that Seismic 18", another driver that's on sale right now for even a lowrer price would be a far better choice is the Bravox PXW15D-2 15" DVC Subwoofer - using a pair of them in the same box would be even better.
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He already has it. I guess he had the siesmic audio aftershock powered sub,,the driver got damaged and he sent the damaged driver out for warranty,,and used a black widow in the original cabinet,,leaving him the raw driver (quake 18) needing an enclosure. I feel like a dumb american now with the 1.2k cm thing,,,,I'll let him know what i've learned here.I think he is just set on getting this driver in a box.
It's probably more like 4-5mm one way. 10mm would be in the realm of a decent budget pro sub (like PV lowrider or entry level B&C) which this is not. The original Pyles were 3.7mm xmax. The regular Black Widows in the same range, 4-5mm.
I am gonna build an enclosure as close to what the original dimensions were. Entered everything into bass box and doesn't model well at all (imo) for a subwoofer. I'll be loud though.
I just dialed in the numbers and recieved -3 dB @ 33 Hz. The TS Parameters tells you it requires a good sized box if you are aiming for a flat response. It is not unusual for manufactures to use a small box in order to get a bump at certain frequencies. Observe what the VAS says. A woofer offering a VAS of 299 litres is not going to give you a flat response in a box smaller than 299 litres.
It appeared to me that,,starting at 10.5 cubic feet and down to 7.5 cubic feet I was getting not much change,,f3 of 53 or so. I'll re enter everything and make sure I don't have something way off.
It appears you have something off for a 10 cubic foot box will give you 33 Hertz.
Dial in 10 cubic foot in the internal volume and type in 35 for the fb. That will give an f3 of 33 Hz.
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I was doing for a sealed box. When I do as suggested, i get f3 of 33. So what is recommended by whomever would like to say,,sealed, or vented?
I'm pro audio. Pro audio guys cannot rely on corners, ceilings or walls to extend the low frequency response since we are hired to play in various locations. So it is defintely a reflex.
Home audio guys rely on corners, ceilings, walls in addition to, equalisation to extend the low frequency response. This forum is plagued with more home audio guys than pro audio guys which, it is why the majority suggest a sealed box over a reflex.
Thanks for that pro audio insight. I was actually thinking about that,,where was this gonna be playing at. I came up with a newer vented plan that I think is going to work well for the guy that wants it built. His budget is pretty much nothing and after much sketch time, I will be able to do it with one sheet of mdf (bracing from some scrap I have). Maybe not the very best that can be done,, but maybe the best that I can do with what I'm working with.
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I see your chart has a cabinet gain of +3 dB from 60 – 80 Hz. A lot of commercial bins tend to offer a boost in that region to attain what many consider punchy bass. The whole idea of making your own design from scratch is attaining what you want (or in your case the client's needs) than what someone else wanted.
You have Bass Box Pro, which can give you precision measurements to get the wood cut at the lumber mill. If that box is going to be in heavy transit you definitely want to use wood and stay away from MDF.
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Thank you to everyone who chimed in and offered advice. In the end the guy just wants bare bones, cheap as possible box. I have already got it built. 23"x 28x 22" box,,,slot port,,1 sheet of mdf was all i had to work with. I'm sure it will sound great to him. oh well. Still fun to build something.
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