I impulsively bought this woofer...

lazzer408 · 2010-09-26 3:14 pm

I impulsively bought this woofer at a swap meet. Price was right and it's new. There's glue over the mounting holes. What should I do with it? I was thinking about building a home theater sub with the driver in side and ported out the front.

Sub800 Specs:

Diameter________18"
Impedance_______8ohm
Sensitivity_______99db
Response________25-1,500 Hz
RMS power_______800w
Peak power______1600w
Voice coil________4"
FS______________30hz
Qts_____________0.22
Qms____________10.0
Qes_____________0.23
Vas_____________350L
xmax____________8mm +/-

chris661 · 2010-09-26 3:49 pm

What will you be using to drive this?

Krisfr · 2010-09-26 4:00 pm

Buy some HOME earthquake insurance and some Q-tips to sop up the blood running from your ears....LOL

GOOD luck and I wish you the best with your design, please post PICs when done. THANKS

lazzer408 · 2010-09-26 4:00 pm

chris661 said:
What will you be using to drive this?

Dayton HPSA500

Dayton HPSA500 500W Subwoofer Amplifier | Parts-Express.com

Krisfr said:
Buy some HOME earthquake insurance and some Q-tips to sop up the blood running from your ears....LOL

GOOD luck and I wish you the best with your design, please post PICs when done. THANKS

Will do. The box will be braced MDF, 6 cubic feet, and ported. 6" port roughly 5" long. puts me about 36.71hz. I'm shooting for 36.71hz (D1) because it's in the middle of a musical scale. "A0" being 27.50hz and "G1" at 49hz. This "logic" has resulted in some very "musically sounding" subs for cars. I hope it works out as well for a home system. It scales higher octaves quite well. I'm going completely by ear. Meter readings don't impress me. I've heard subs that look great on paper, rumble the walls watching movies, but are worthless when it comes to music.

Rullknufs · 2010-09-26 4:05 pm

Oh dear! 99db sensitivity and 800w power handling?

richie00boy · 2010-09-26 4:05 pm

It's a PA bass speaker. It needs a big ported box and even then it will struggle to hit the real lows. It will be very loud though! The other option which is probably better for a movie sub is to make a sealed box and add loads of EQ.

A 12 inch proper sub driver will probably perform as well if not better and in a smaller box...

chris661 · 2010-09-26 4:12 pm

So, plenty of power.

I'd agree with richie that a small sealed box would be best for a HT... Unless space isn't an issue. Even so, I doubt you'd get lower than 30Hz when ported. EBS would be out of the question (again, space considerations).

The other option, of course, is to put it in your car.

lazzer408 · 2010-09-26 4:15 pm

richie00boy said:
It's a PA bass speaker. It needs a big ported box and even then it will struggle to hit the real lows. It will be very loud though! The other option which is probably better for a movie sub is to make a sealed box and add loads of EQ.

A 12 inch proper sub driver will probably perform as well if not better and in a smaller box...

Correct in both. It's all for DIY fun though right? I listen to music more then I watch movies. Deap rumble isn't very important to me. Bass guitar is and I think this sub will work great for that.

chris661 said:
The other option, of course, is to put it in your car.

Already measured. lol It's not going to happen.

tritosine · 2010-09-26 4:19 pm

richie00boy said:
A 12 inch proper sub driver will probably perform as well if not better and in a smaller box...

you mean ported 12" vs sealed 18" ?

or sealed 12" vs ported 18"?

or sealed vs sealed?

( I am particulary interested about sealed 18" with a similar driver)

lazzer408 · 2010-09-26 4:23 pm

tritosine said:
you mean ported 12" vs sealed 18" ?

or sealed 12" vs ported 18"?

or sealed vs sealed?

I'd imagine both. And are we talking volume or sound quality? A 12" with high excursion can move more air then this 18 in terms of surface area/xmax. There's so many variables involved (including amplifier specs) that size isn't the only major factor.

Sealed subs always sound best to me but lack sound volume. A large speaker could help with that. I could always cut the port last and give my opinion on it's sealed performance but a 6 cubic foot sealed box might not be ideal for this speaker. I don't have the test equipment required to plot the frequency response either.

chlorofille · 2010-09-26 4:34 pm

lazzer, do you have more specs? 6 cubic feet seems too huge for a low Qts PA woofer.

richie00boy · 2010-09-26 4:52 pm

Well for a play for fun it should be an interesting project given the requirement you just gave. But I wouldn't be interested myself as the box is just too huge - the cost to make it and the space it takes up would make it not worth it for me.

If you want to try sealed and ported you will definitely need to make two boxes though as the sealed one will be about half the size of the ported one.

lazzer408 · 2010-09-26 5:01 pm

chlorofille said:
lazzer, do you have more specs? 6 cubic feet seems too huge for a low Qts PA woofer.

Only what I got from their site.

http://www.oversound.com.br/pagina/produto/sub800-8.html

The large box helps get deaper bass without having to use a really long port. The port is 6" in diameter but now that I think about it I could probably get away with a 4". This speaker doesnt have much excursion so I probably don't have to worry about port huffing. With a 4" port it doesn't have to be as long.

A 20" cube would be about 4.5 cubic foot.

richie00boy · 2010-09-26 5:15 pm

4 inch is too small for this woofer, that's the size I use for 12 inch speakers with less excursion than yours.

lazzer408 · 2010-09-26 5:27 pm

richie00boy said:
4 inch is too small for this woofer, that's the size I use for 12 inch speakers with less excursion than yours.

You think? Consider I won't be driving it very hard. It won't get pushed anywhere near it's xmax.

richie00boy · 2010-09-26 5:30 pm

Hmmm, maybe if you keep the level down real low, but you are looking to use a 500W amp? Problem is you won't be tuning it very low so airspeed will be high. I suppose you could try.

lazzer408 · 2010-09-26 5:44 pm

richie00boy said:
Hmmm, maybe if you keep the level down real low, but you are looking to use a 500W amp? Problem is you won't be tuning it very low so airspeed will be high. I suppose you could try.

273 watts RMS

With the port, I can always go bigger but not smaller so if a 4" is huffing I'll make sure it's located where I can open up the hole. It's going to look like a big Bose sub with the port in front but towards the top. The sub will be mounted in the side. The box would be symetrical otherwise, including finish, so I can try things like front loading the driver aiming it into the wall or flip it to put the port at the floor and things like that. I wouldn't touch this woofer with a 10 foot pole if I was aiming for quality. lol

richie00boy · 2010-09-26 7:53 pm

Actually I think the driver is quite reasonable quality. Keep us informed

bjorno · 2010-09-26 9:04 pm

FYI,

b

badman · 2010-09-27 1:14 am

Driver looks like an old EV with rebadging. Should be a nice woof. I'd use a sealed box and EQ for home use.

I impulsively bought this woofer...

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