Driver recommendations for 3.89Ft3 sealed sub (1 Viewer)

[Gary.Blevins]

Greetings,
I have new JBL S38's, S26's, and an S-Center on the way, and I am now looking at my old sub for upgrading.
A few years back, I converted my old 15 BSR passive sub to powered version, via a PartsExpress 150W amp. It works great, but I was thinking a new driver may improve the sound over the old dual voice coil driver.(Sorry, don't recall the brand).
The sealed enclosure is rather small for a 15" driver, at 3.89 Ft3, but the Spousal Unit is rather adamant that it not get any larger.
Before I start plugging drivers into WinISD Pro, I was wondering if anyone had suggestions for a reasonably priced unit that would work well in such a small sealed enclosure with a relatively small amp.

Thanks,

Gary

 

[Matt Dolejsi]

wait you're saying that close to 4 cubic feet sealed, is small for a sealed driver, you sure about that. I could see that being small for some vented apps, but sealed?

 

[Cam S]

You could turn that into a ported Shiva sub, or maybe squeek by with a sealed Temptest in there. A sealed Shiva would work well, but the ported version would be much better.

 

[Gary.Blevins]

Hey Matt,
I am by no means an expert, and I simply searched the web for ideas. Two sites said recommended enclosures for sealed 15" subs was 4-9 Ft3 and 5-10Ft3. If 3.89Ft3 is an adequate size for a 15" sub, Great!
Do you have any recommendations for drivers, or a site to visit?

Thanks,

Gary

 

[Pete Mazz]

Stuff with polyfill and use a Tempest for ~.7Q or an AV15 for a ~.6Q. With only 150 Watts, the Tempest will have a slight edge in output (1-2 dB). If you ever get a better amp, the AV15 will outpace the Tempest....

Pete

 

[TimForman]

Say Pete, have you done this before?

Gary,
Pete's right on. A sealed Tempest or AV15 would be right at home in that enclosure. Nice tight accurate bass for $150 plus an amp. Hard to go wrong.

 

[Jack Gilvey]

You could also try plugging in the numbers for the Dayton 15" DVC from Parts Express. As I recall, it requires a slightly smaller box than a Tempest for a given Qtc.

http://www.partsexpress.com/pdf/295-190s.pdf

 

[Gary.Blevins]

Thanks for the advice guys!

After plugging the tempest into WinISD, I found out a few things:

1. I don't know much about all of the various specs!

2. What good is a low Fs of 21Hz, say, if when you put it into a sealed enclosure, the F3 is 37 Hz?

3. If you want an F3 around 25Hz, you almost have to go with a ported box.

Do you think it would be worthwhile to port my current enclosure in addition to upgrading the driver?

Thanks,

Gary

 

[Gary.Blevins]

By the way Jack, the DVC gives almost identical WinISD results as the Tempest in my box.

Gary

 

[TimForman]

I don't think a vented 15" application would be the best choice. Perhaps you'll want to consider using a Shiva and venting the cabinet. Are you using this more for movies than music? If so, you may be happier with the vented Shiva (or equivalent) application.

 

[Gary.Blevins]

Hey Tim,
You are correct, in that I will be using this mainly for HT (70%).

I am confused (as is often the case!) by your saying that a 15" vented application might not be the best, but recommend a Shiva vented application for HT.

Were you saying that, while you would not recommend a vented application, if I had to go with one, the Shiva would be the best alternative?

Thanks,

Gary

 

[Jack Gilvey]

By the way Jack, the DVC gives almost identical WinISD results as the Tempest in my box.

The response shape is extremely similar. As I stated, in that box (or any given box) the Qtc of the Dayton DVC is slightly lower.

 

[Jack Gilvey]

That box is really too small to vent a 15". A 12" would be fine vented. See what WinISD gives you for that size vented Tempest.

 

[TimForman]

I'm making some assumptions based on the type of equipment you have and your indicated desire for bass extension (70% movies). With that in mind I'm willing to wager that you'll be very pleased with the vented Shiva. A vented 15" application in that small of an enclosure would not be very accurate and not be worth the extra money for the larger driver. A sealed enclosure with a 15" in small volume is great for music but leaves you wanting with movies.

 

[Gary.Blevins]

Thanks guys!

I think, that I will be going with a vented 12" application, probably a Shiva.

2 last questions:

1. Will the difference between a vented Shiva and a lower quality 15" sealed be readily apparent in an HT application?

2. Tim, when you state that a vented 15" in the small box will not be very accurate, is this something that can be visualized in WinISD? Or is this simply a known speaker axiom?

Thanks again for all your help guys,

Gary

 

[TimForman]

1. Depends on the 15" driver. The Shiva's got good Xmax, probably more than lower quality 15's. I built a sealed Tempest which is great for music but when I watch movies I run the Tempest along with a Shiva sonosub which delivers that WOW impact you want from today's movies.

2. Yes, it shows up in WinISD. Not very flat and a sharp roll-off. I modeled the Shiva and the Tempest in the same enclosure (110L). The Shiva looked better.

 

[Jonathan_D]

Well, I have the 122l sealed Tempest. As you'll notice from my sig, I have it equalized with a BFD. For music I run a flat curve. For movies I use a curve with more of a "hump" in the 35hz range (for my room that meant simply not attenuating a dip as much as in the music filters).

Though I probably watch more movies and TV than listen to music, my main concern was with the sound quality for music and being easier to integrate with ported main speakers. To my ears its just about impossible to tell on music where the mains leave off and the Tempest takes over.

 

[Gary.Blevins]

Wow! Now I know what a baby must feel like taking its first steps...I have so much left to learn!

Again, Thanks for all the help and great advice!

Gary

 

[Geoff L]

Hi Gary

Given your box size and current plate amp power, a Shiva ported will more than likely make you much happier than a sealed DVC-Dayton or Tempest. No question when talking movies, deeper extension with decent output.

Not to mention the cash outlay for the driver would be a little less. There was a used Shiva in the FS area for 60.00 shipped a week or so ago. You also might look for an original SVS driver. That should work quite well also ported.

Dose your 150-watt plate amp have any boosting in it????

Regards
Geoff

 

[Gary.Blevins]

Hey Geoff,
I will have to plead ignorance. What do you mean by "boost" in my plate amp?

As an aside, as I looked at the WinISD for a ported Shiva in my box, I am going to lose quite a bit of displacement in the long port required. Oh well, life is full of trade offs!

Gary