Musical Subwoofer.... ported or sealed?

[ODougbo]

Revboden,

I have an old computer on with Perfect Box installed, the Peerless woofer was one of the 1st on the list. Even Perfect Box recommended 5cf, 140liters (Iso). I'll just have to re-build the box, probably go with 100Liters.

Thanks for the advise.

I found the old specs, for the 831857.

That's a very small box for that driver. 1.5ft^3 gives a Qtc of 1.126

 

[tb46]

Post #91

Hi revboden,

A Qtc of 1.1 (or so) should lend itself well to applying a Linkwitz transform (which should be used with an additional low cut). That way you get the small box size, and control over the low end response.

Regards,

 

[ODougbo]

I did try to load/use WinISD, and had a few start up problems. It would be nice to get that up and running, lean how to use it.


The sheet is up on the saw table and marked for cuting for a 101 liter box, but maybe too big?


OR.... I could pick up a few liters (e.g. 110 liters), if I concentrate on no/less waste.


The box will be used for the shop, however it will be used quite a bit (-; (-;

 

[revboden]

Odougbo,
The exact size won't matter (100 vs 110) that much 100L should be fine.

about WinISD, i find that the help file - 'getting started' - 'entering new driver data' is very useful.

Tb46, good point. although you'd need a lot of power and very careful maths, building a bigger box is much cheaper and easier if you have the space.

later,
rev.

 

[ODougbo]

Okay back to 100liters. Thanks!!

WinISD ~ I was getting numerous error windows. I have a XPS computer w/Vista, a few years old, but works okay. The selection of configurations looks really interesting.

The help file, said it wasn't loaded. I'll keep trying.............Much better with power tools than computers.

 

[nonsuchpro]

Ok, to date I've bought 4 subwoofers and made 5. The most musical subwoofer I have is the driver out of a $100 Sony SA W2500 put in a 12"x12"x12" sealed box coupled with a Dayton SA100 plate amp. Amazing!

 

[SpinMonster]

Ok, to date I've bought 4 subwoofers and made 5. The most musical subwoofer I have is the driver out of a $100 Sony SA W2500 put in a 12"x12"x12" sealed box coupled with a Dayton SA100 plate amp. Amazing!

To date every time I've heard a ported sub that wasnt tuned to the max flat frequency, it sounded bad. Just as you wouldnt design a sealed sub with a high Q like 1.0, I fail to see why this wisdom gets thrown out the window for ported subs with guys tuning them to ring. You cant tune to some arbitrary frequency to induce ringing, say at 33hz, when the max flat tuning frequency should low to mid 20's.

Dont judge ported systems on your too-high-tuned prior builds. Build it to exactly the size and tuning frequency you get in WINisd and then see what you think. The reason all your sealed subs sound good is that none of them are rining in too small a box with the wrong tuning frequency.

Just an opinion since you are asking. Good luck with your project.

 

[ODougbo]

Odougbo's two cents:

I did experiment with Sealed vs. Ported boxes - using the same amp - same model Rockford P2- same location (Tacoma ex cab) - same music. As you can see in the pic #1, I tried both, following supplied RFFG plans.

The grays ones in particular.

Results: I know a lot the car buffs are not going to agree, but after several attempts, I went with the ported box. The bass is stronger, deeper, amazing really, no one believes it is an 8".

The sealed boxes? They were okay, just couldn't get as low.

btw, the P2 is very "musical" a wide range of bass notes.

**btw, let me know if some ones any of these boxes - Yikes!

*** I am enjoying the new build, (2nd pic) it is sealed.

 

[Brian Steele]

The bass is stronger, deeper, amazing really, no one believes it is an 8".

That's why - you used an 8" driver for your test .

What size was the box? Quite likely you can fit a larger driver in there if you seal it up.

I've been using 2x12" sealed in my car audio builds for the longest while. Goes as low as I want, and as loud as I want.

 

[ODougbo]

Oh sure, plenty of 10"s 12"s 15"s (on and on) out there that will run circles around these.

[however I thought the P2 8"was better than others 8"s, I didn't buy the JL]

The point is: pound for pound, after several attempts, following RFFG plans to the letter - the BR box did go lower and out perform the sealed box.

It wouldn't matter to me if it was ported or sealed, just passing along info/testing that I did.

The gray boxes fit perfectly behind the seat of a X cab Tacoma, one reason for the 8"s. But I do like them (-:

 

[Zero D]

WinISD Help

@ ODougbo

Hi, you might be interested in a thread i made to help people using WinISD

http://www.diyaudio.com/forums/subwoofers/148729-how-correctly-use-winisd.html

All the best with your designs etc

Regards

 

[bentoronto]

I just read an AES study using highly sophisticated testing showed people could readily tell "same" versus "different" when the bass was placed outside the main speakers. However, they were exactly as detectable at wide angles as at narrow angles. That demonstrates that moving the bass around stimulates different sounds and has nothing to do with lateral detectability. BTW, that does mean moving the bass driver changes the sound - but it does not demonstrate that having the driver inside the main speaker box(es) is the "correct" sound.

AES Convention Paper 6431 (check with Google and you can find the full reprint)

Ben

 

[ODougbo]

Back to fight another day

Retro fitted this box from 12" to 10"

Now a Dayton 10" RSS265 in 50Liter box.

btw.....What ever happened to Revvy?

Nosuchpro,

Did you build your box yet? I thought about your project when I worked on this 12” sub box yesterday; also used the large roundover bit I mentioned.

This is 1.8 cf, I’m estimating .25cf for blocking, etc.

Dimensions Inside: 13.5” wide 16.3” tall 14.3” deep.

So far, one day on this, going to sand it up to today. I could build a similar, custom box for say......$100, materials included (3/4” MDF). That quote doesn’t include any sealing/painting, however, it would be size you specify. Also, this is a no nail/screw box; extra glue and clamped (only).

Let me know if you’re interested?

 

[jplesset]

Sealed or vented?

I admit, I prefer to build sealed boxes. I like the transient response I get. Yes, I use the Siegfried Transform...

Main system: Kef 101 pair crossed over to 4 10" separate sealed boxes. Q about .5 measured. Works quite well in my pretty large living room, down to about 30... The woofer boxes are buried into the faux columns, so they're pretty much not visible at all...

 

[ODougbo]

Wow that's some place - I'm sure the long hallway helps. My dad's place has a extra large family/kitchen area; using 2 10's in iso box (Dayton amp) the bass just pours out with nice extension.
I finished the red box - which was a good deal, $50 for box - $50 for woofer (PE special page)

This is "new" or so the flyer says - looks like a nice woofer, ported or sealed:

http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-510

 

[ODougbo]

The one thing I need help with - is why don't sealed boxes look better in box design programs? What I missing?

 

[DrDyna]

I admit, I prefer to build sealed boxes. I like the transient response I get. Yes, I use the Siegfried Transform...

Main system: Kef 101 pair crossed over to 4 10" separate sealed boxes. Q about .5 measured. Works quite well in my pretty large living room, down to about 30... The woofer boxes are buried into the faux columns, so they're pretty much not visible at all...

(offtopic I know, but) I love those light fixtures, where'd you get em?

 

[jplesset]

Wall sconce lights? I forget where my wife found 'em. They're ceramic, and paint-ready. We used a metallic Ralph Lauren (from Home Depot) on them. They were on the order of $20 each. Converged from a single 100w to a pair of 6w LED lamps.

The room is pretty long, and leads into the dining room past the fireplace. More house pictures at: Dream We spent 4 years designing it, and nearly two years building it... The living room is the best sounding room I've ever put a system in.