1st diy subwoofer

[robm]

I am trying to decide what subwoofer/amp setup to get. I am looking to spend between $200.00 and $275.00. I like the 12" and 15" quatro's and the dvc's. I want to use the 240 watt plate amp. I also want to keep the enclosure close to 3.0 cu ft. Can anyone give me some advise? It will be for HT and my listening room is 25' x 15'.

[AJ]

Working with winisd and 3ft^3, using the 12" quatro ported you can get a ~31hz F3. The 15" will reach down to about 35hz sealed in 3ft^3.

The 15" needs about 5-6ft^3 to go ported but in those boxes it can get down to ~20hz. If you could use a bigger box you could have a real HT sub covering the entire bass spectrum. And maybe knock some pictures off the walls as well...

Port size for the 12" would be 4" by 9-3/8" for 30hz tuning.

The 240w will work well for either of these drivers.

[dthomas]

Provided Link: http://www.gr-research.com/drivers/sub_pr.shtm


> I am trying to decide what subwoofer/amp
> setup to get. I am looking to spend between
> $200.00 and $275.00. I like the 12" and
> 15" quatro's and the dvc's. I want to
> use the 240 watt plate amp. I also want to
> keep the enclosure close to 3.0 cu ft. Can
> anyone give me some advise? It will be for
> HT and my listening room is 25' x 15'.

I have built two 15" Quatro subs and they both were very good especially for the price. I built one in a 6.2ft3 ported and another in the standard 3 ft3 sealed. Both work very well with the sealed version being superior from a musical standpoint.

I just recently began building a pair of GR-Research 12" subs with passive radiators. Very nice and definitely better than that the ported quatro. It reaches low 20s in 2.4 ft3. And the price is very reasonable. You don't need a port and you need less wood so it is probably a wash with 15" Quatro, plus it is a lot smaller. The build quality on these drivers is just gorgeous.

Highly recommend it and all you need to do is follow the GR box plans. Pretty straight forward.

Dave

[robm]

> Working with winisd and 3ft^3, using the
> 12" quatro ported you can get a ~31hz
> F3. The 15" will reach down to about
> 35hz sealed in 3ft^3.

> The 15" needs about 5-6ft^3 to go
> ported but in those boxes it can get down to
> ~20hz. If you could use a bigger box you
> could have a real HT sub covering the entire
> bass spectrum. And maybe knock some pictures
> off the walls as well...

> Port size for the 12" would be 4"
> by 9-3/8" for 30hz tuning.

> The 240w will work well for either of these
> drivers.
What about the DVC subs? Can you get good results with them using the same 240w amp?

[AJ]

I haven't used any of em' yet but the 240w is probably too much for any of the shielded dvc's. (cheap Ones).

The more expensive DVC's ould be a better match. The 12" in particular. Probably could get down to about 25hz, and louder than all the others.

[robm]

> I haven't used any of em' yet but the 240w
> is probably too much for any of the shielded
> dvc's. (cheap Ones).

> The more expensive DVC's ould be a better
> match. The 12" in particular. Probably
> could get down to about 25hz, and louder
> than all the others.
Can the 12" DVC reach 25hz in a 3cu ft box? If so are we talking ported or vented?

[robm]

> Can the 12" DVC reach 25hz in a 3cu ft
> box? If so are we talking ported or vented?
I meant ported or sealed. One more question. How do all of these subs stack up against $500.00 store bought subs like the velo dps 12 and klipsch sub 12?

[AJ]

Yes. Ported, tuned to 25hz via a 4" by 14.75" port in 3ft^3.

[AJ]

Also, i'm sure these would kill a store bought sub. I've heard the 15" Q in a ported box, and its nothing short of nuts. I bet the 12" DVC would be as good if not better.

Let us know how it comes out!

[robm]

> Yes. Ported, tuned to 25hz via a 4" by
> 14.75" port in 3ft^3.
Do you think it would be O.K. in a down firing box.

[robm]

> Also, i'm sure these would kill a store
> bought sub. I've heard the 15" Q in a
> ported box, and its nothing short of nuts. I
> bet the 12" DVC would be as good if not
> better.

> Let us know how it comes out!
Thnks for your input. Rob

[Chris Roemer]

> Do you think it would be O.K. in a down
> firing box.

A 3 cf box works great with:
SDVC 12" w/ 4"d by 11" port, 31 Hz
Quatro 12" w/ 4"d by 9" port, 31 Hz
$ DVC 12" w/ 4"d by 18" port, 25 Hz
RSHO 15" w/2x3"d by 23" ports, 25 Hz

The first 2 work well in a real cube.
The last 2 have ports so long the cube won't work.
Try something around 15" x 15" x 30" or so.

The best match for the 240w amp is probably the Quatro. I've built that as well as the SDVC (cheap one) with the 100w amp. Very happy with either one.

Downfiring doesn't do ANY driver any favors. The bigger it is, the worse the effect of gravity has on the suspension over time.

[trevorg]

> I have built two 15" Quatro subs and
> they both were very good especially for the
> price. I built one in a 6.2ft3 ported and
> another in the standard 3 ft3 sealed. Both
> work very well with the sealed version being
> superior from a musical standpoint.

> I just recently began building a pair of
> GR-Research 12" subs with passive
> radiators. Very nice and definitely better
> than that the ported quatro. It reaches low
> 20s in 2.4 ft3. And the price is very
> reasonable. You don't need a port and you
> need less wood so it is probably a wash with
> 15" Quatro, plus it is a lot smaller.
> The build quality on these drivers is just
> gorgeous.

> Highly recommend it and all you need to do
> is follow the GR box plans. Pretty straight
> forward.

> Dave

I have had my eye on that set for a while

[unknownuser]

> A 3 cf box works great with:
> SDVC 12" w/ 4"d by 11" port,
> 31 Hz
> Quatro 12" w/ 4"d by 9" port,
> 31 Hz
> $ DVC 12" w/ 4"d by 18" port,
> 25 Hz
> RSHO 15" w/2x3"d by 23"
> ports, 25 Hz

> The first 2 work well in a real cube.
> The last 2 have ports so long the cube won't
> work.
> Try something around 15" x 15" x
> 30" or so.

> The best match for the 240w amp is probably
> the Quatro. I've built that as well as the
> SDVC (cheap one) with the 100w amp. Very
> happy with either one.

> Downfiring doesn't do ANY driver any favors.
> The bigger it is, the worse the effect of
> gravity has on the suspension over time.
I got some previous info that the Q 12" would go down to 28hz in a 2.75cu ft box with a 3" x 7" port. Does this sound right?


(Originally posted by: RobM)

[Chris Roemer]

> I got some previous info that the Q 12"
> would go down to 28hz in a 2.75cu ft box
> with a 3" x 7" port. Does this
> sound right?

You can check all this out yourself by downloading WinISD (beta vers.) from <A HREF="http://www.linearteam.org">www.linearteam.org</A> .

It shows the Q12 in 2.75 cf with a 3"d x 7" port (which tunes it to 27 Hz) as being able to reach 33 Hz (F3) with an air speed in the port of Mach 0.22. It DOES reach 28 Hz at 5dB down, but -3dB is basically the universal point for quoting "bass extension". I've heard the Dayton 8" "Classic" chuff through a 3" port in a 2 cf box, so, naturally I can't recommend using a port that small (unless you double them up). Mach 0.22 is approx. (750 mph x .22 = ) 165 mph!

I wouldn't get hung up on 27 Hz vs 30 Hz. If you've got a system that can reach below 35 Hz "robustly", I don't think you'll be taking second seat to any other "sub" system. I use my 3cf Q12 w/240w amp for music and HT. I've got the sub's xpt as low as the amp will go (50 Hz I believe) with the gain around half. My mains are some Dayton -070/-310 (8") 2-ways that can reach 30 Hz by themselves, but when I really cranked them (100w rms/ch) or some large dynamic range "effect" hit them on a DVD, they'd "snap" (bottom out against the back plate). No more!

[johnastockman]

> I meant ported or sealed. One more question.
> How do all of these subs stack up against
> $500.00 store bought subs like the velo dps
> 12 and klipsch sub 12?

Rob, here's a pic of my sub that I built a couple years ago using the shielded 10" DVC sub driver, part #295-485, in about 2.3 cu.ft. It has been compared with the 12" velodyne and a 10" version of the Klipsch...no comparison! Even though my 10" uses a smaller amp, it sounds better, more defined bass, less boomy, and is better for music. One guy has one I built for his HT which replaced the velodyne he USED to have. Another couple has the same one in their music system, and they say it is a definite improvement over the Klipsch 10. Now, this is pretty subjective, of course, so YMMV, but I've had excellent results with this enclosure/driver/amp combo. Since I've built mine, I've made 5 more for other folks after lugging mine over to their homes. They heard it here at my house, but didn't think something that I made would be an improvement over the retail unit they already had...until we compared them in their house with their set-up. For your room, I'd go with the 12" Quatro and 240W amp, like the other suggestions...it's a killer combo, especially for HT use. It will work great in 3 cu. ft. The Quatro will be able to handle that amp, where the shielded DVC series aren't rated for that much power. Good luck, and keep us posted on your progress!

John A.