Cerebus Subs for my Tritrix Towers...

[lunchmoney]

I think I've I finally come up with a design I like for subs to compliment my Tritrix towers.

Since I was planning on elevating the towers a bit anyways, I decided to make two subs, and use each one as a stand... they will be run in stereo.

They use the Tang Band 6.5" sub, and are based on the Cerberus design by Roman Bednarek... many thanks to him for posting the design! They have the same internal volume and port dimensions as his original design, but the porportions of the box have been modified. Here's a link to Roman's Cerebus design:

http://www.rjbaudio.com/Cerberus/cerberus.html

They are 11" wide x 8.25" high by 16.75" deep. The ports are 1.5" x 7.5".

Each sub will have a Dayton 70 watt plate amp on the back, turned horizontally to accomodate the short height of the enclosures... I gather that since these amps have no aluminum fin heat sinks, it's ok to rotate them horizontally.

Yes, the towers will be blue, although a bit deeper than shown here. Haters go away. Blue sounds better

Thanks for everyone's help on this!

[philiparcario]

They will be very nice. post pictures!

[Wolf]

I think I've I finally come up with a design I like for subs to compliment my Tritrix towers.

Since I was planning on elevating the towers a bit anyways, I decided to make two subs, and use each one as a stand... they will be run in stereo.

They use the Tang Band 6.5" sub, and are based on the Cerberus design by Roman Bednarek... many thanks to him for posting the design! They have the same internal volume and port dimensions as his original design, but the porportions of the box have been modified. Here's a link to Roman's Cerebus design:

http://www.rjbaudio.com/Cerberus/cerberus.html

They are 11" wide x 8.25" high by 16.75" deep. The ports are 1.5" x 7.5".

Each sub will have a Dayton 70 watt plate amp on the back, turned horizontally to accomodate the short height of the enclosures... I gather that since these amps have no aluminum fin heat sinks, it's ok to rotate them horizontally.

Yes, the towers will be blue, although a bit deeper than shown here. Haters go away. Blue sounds better

Thanks for everyone's help on this!

I would personally recommend you bump up the ports to 2" diameter, and make them about 17" long. Thos 1.5" chuff when they start moving.
Later,
Wolf

[jonpike]

I would personally recommend you bump up the ports to 2" diameter, and make them about 17" long. Thos 1.5" chuff when they start moving.
Later,
Wolf

Ditto... Perhaps you could make them a bit deeper to accomodate a straight port. Though a wide radius elbow near the end woud be OK.

Another thought, play with a slightly larger volume in WinISD, for the same tuning the port length will shorten. As long as you're about half a diameter or more (Wolf, an opinion here?) of the port from the back you should be good...

Looking forward to pics... and hearing how they work out.

And hey, being different can be cool! My wife wanted her pair of work computer speakers (formerly in a nice light Baltic Birch) PURPLE!!! Found a stain, and you know... they ended up looking pretty good!

[bobblickle]

Blue makes Happy! (Loosely translated from a German VW commercial)

I like the idea. As the others mentioned, doesn't look like going deeper would cause you problems.

Personally I'd rather have a bigger port with a turn in it than a small straight one. The tubing solution from Phil A. a week or two ago would be another possibility. Maybe check your local AutoZone for a cheap radiator hose or some of the still reinforced stuff for pool pumps.

peace

bb

[Chris Roemer]

I would personally recommend you bump up the ports to 2" diameter, and make them about 17" long. Thos 1.5" chuff when they start moving.
Later,
Wolf

Sim this:

H x W x D: 8" x 13" x 20-1/4" (0.81 cf)
The SA70 and 2-1/2" (nom) vent leave you with about 0.67 cf.

The vent is 2.5" PVC "conduit" (LOWE's, Menard's, or FLEET FARM electrical dept.) It's actually only 2-3/8" ID, about 2-7/8" OD. Make it 17" long.

If you're near Appleton WI, I'll make you 2 (with roundover ends) at my cost (which will be very tiny).

If you MUST use smaller (chuffing) vents, aim them out the back. Also (as I think was already stated) rounding over the inside ends, particularly where the vent exits the box, goes a long way to minimize the port noise.

Chris

[lunchmoney]

Sim this:

H x W x D: 8" x 13" x 20-1/4" (0.81 cf)
The SA70 and 2-1/2" (nom) vent leave you with about 0.67 cf.

The vent is 2.5" PVC "conduit" (LOWE's, Menard's, or FLEET FARM electrical dept.) It's actually only 2-3/8" ID, about 2-7/8" OD. Make it 17" long.

If you're near Appleton WI, I'll make you 2 (with roundover ends) at my cost (which will be very tiny).

If you MUST use smaller (chuffing) vents, aim them out the back. Also (as I think was already stated) rounding over the inside ends, particularly where the vent exits the box, goes a long way to minimize the port noise.

Chris

Hrrmf... that's getting a tad large... thanks though.

Could I simply do as wolf suggested, whereby I keep the same box dim's I have, but do a 2" x 17" port? I'd have to put a corner bend in it of course...

[Hackomatic]

I've put bends in 1-1/2" straight PVC before by using a heat gun (or paint stripper if you prefer) and blowing the air right down the middle. Granted, it wasn't a full 90, but it softened the PVC enough to be malleable. I've also observed electricians doing something similar with larger schedule 40 gray electrical conduit with a propane torch, It was a little scorched on the pipe exterior, but they were able to form it into an accomodating bend. ymmv

[Chris Roemer]

I've put bends in 1-1/2" straight PVC before by using a heat gun (or paint stripper if you prefer) and blowing the air right down the middle. Granted, it wasn't a full 90, but it softened the PVC enough to be malleable. I've also observed electricians doing something similar with larger schedule 40 gray electrical conduit with a propane torch, It was a little scorched on the pipe exterior, but they were able to form it into an accomodating bend. ymmv

I looked at your (lunch) alignment in WinISD, and I LIKE it. You ARE using WinISD ( www.linearteam.org ) aren't you? The beta vers. is a bit easier to use when you're starting out.

Anyway, go ahead and use a 2" port. Wolf's 17" length lowers the tuning over what your 1.5x7.5 ports were. To keep YOUR tuning, you can use a 2"d x 14" long port.

When pros bend metal tubing, they sometimes fill it with sand. If your walls aren't too thick, you could do the same, and heat the tube with a hot air gun (never tried this myself). The sand inside keeps the "bend" from kinking and collapsing on itself. I'd still aim the vent to the rear and roundover the exit hole if you can.

Chris

[Wolf]

I looked at your (lunch) alignment in WinISD, and I LIKE it. You ARE using WinISD ( www.linearteam.org ) aren't you? The beta vers. is a bit easier to use when you're starting out.

Anyway, go ahead and use a 2" port. Wolf's 17" length lowers the tuning over what your 1.5x7.5 ports were. To keep YOUR tuning, you can use a 2"d x 14" long port.

When pros bend metal tubing, they sometimes fill it with sand. If your walls aren't too thick, you could do the same, and heat the tube with a hot air gun (never tried this myself). The sand inside keeps the "bend" from kinking and collapsing on itself. I'd still aim the vent to the rear and roundover the exit hole if you can.

Chris

Yes it is, but you also get better extension.
Later,
Wolf

[Wolf]

Ditto... Perhaps you could make them a bit deeper to accomodate a straight port. Though a wide radius elbow near the end woud be OK.

Another thought, play with a slightly larger volume in WinISD, for the same tuning the port length will shorten. As long as you're about half a diameter or more (Wolf, an opinion here?) of the port from the back you should be good...

Looking forward to pics... and hearing how they work out.

And hey, being different can be cool! My wife wanted her pair of work computer speakers (formerly in a nice light Baltic Birch) PURPLE!!! Found a stain, and you know... they ended up looking pretty good!

I would wager a full diameter from the wall. Other than that, yes increasing the box shortens the port length.
Later,
Wolf

[lunchmoney]

Ok, so here it is with a 2" x 17" port... no other dims have changed, other than adding .25" to the depth to accomodate for the brace (I doubt it makes any difference).

The part shown in blue is a brace that also supports the port.

There is more than 1 port diameter of distance between the end of the port and the wall. Roundover on the exit of the port is 1/2"

Thumbs up?

[DougP]

Ok, so here it is with a 2" x 17" port... no other dims have changed, other than adding .25" to the depth to accomodate for the brace (I doubt it makes any difference).

The part shown in blue is a brace that also supports the port.

There is more than 1 port diameter of distance between the end of the port and the wall. Roundover on the exit of the port is 1/2"

Thumbs up?

No! You get a thumbs down because it would have taken me about two days to do that 3D rendering

I like it alot and I think that with one under each tower you will be a very happy camper.

Doug

[Hackomatic]

Ya hit yerself a homerun there, son!

[lunchmoney]

If I can't find a 90 degree bend for a 2" pipe, can I miter cut two pieces at 45 degrees to make a 90 degree corner? It would be a sharp corner obviously, not as smooth of an air flow... would that matter?

Something like this?



Maybe a 3-piece miter? Would this be better?



This whole port exercise is eerily familiar to when I modified the intake system on my car.

[Hackomatic]

You should have ZERO problem finding a 90 elbow at Slowe’s, Home Disappointment or any other plumbing/ electrical supply store, so I wouldn't worry about having to re-invent the wheel on this one!

Your drawing is eerily familiar to something I had to do to direct turds into my septic system.


I'd rather take a caning than have to paint or do plumbing work . . .

[lunchmoney]

Remember to round over the exit of the ports... this will help slow down the turds as they exit, and avoid a godawful mess.

Perhaps we can apply subwoofer theory to our home plumbing systems... to achieve just the right bass tuning when you fart on the can.

I think we're on to something here.

[djg]

Very nice pictures.

[johnastockman]

If I can't find a 90 degree bend for a 2" pipe, can I miter cut two pieces at 45 degrees to make a 90 degree corner? It would be a sharp corner obviously, not as smooth of an air flow... would that matter?

Something like this?



Maybe a 3-piece miter? Would this be better?



This whole port exercise is eerily familiar to when I modified the intake system on my car.

The lower pic would be better...man, nice 3D drawings! A definite winner. I've been able to find 90's, 45's and other elbows for every diameter, even at the local Ace & True Value. Lowes and HD have a huge selection...take your piece with you so you can dry fit it before you buy.

John A.