Fixing ports on old sub?

[Kingnoob]

klh asw10-125c
Ports are annoying create too much noise . This annoying and unwanted noise is a pain.
Plus my line level inputs are broken .😞 I'll get a pic layer of them.
Amp and driver work fine. Except auto off which never worked .

 

[stv]

Depending on how much work you want to invest you could use the existing ports and make nice rounded flanges inside and outside, that will reduce most of the turbulence/chuffing noise. The tuning may get slightly higher, but i suppose that effect would remain way below room influence.
The next step up would be combining the two ports into one, maybe a slot. You could 3d-print a flared port, see my port geometry thread for geometry calculation and 3d models (links below).
The calculation tool provides geometry data for a round port, but the resulting lengths and surfaces can be used for any port cross section geometry.
It would also make sense to investigate the existing tuning by measuring internal enclosure volume, port lengths and diameters.
Feel free to ask if you need assistance!

Calculation tool:
https://www.diyaudio.com/community/...rbers-and-port-geometries.388264/post-7699173

Fusion360 3d model by @augerpro:
https://www.diyaudio.com/community/...rbers-and-port-geometries.388264/post-7699849

Freecad 3d model:
https://www.diyaudio.com/community/...rbers-and-port-geometries.388264/post-7705828

 

[Kingnoob]

Depending on how much work you want to invest you could use the existing ports and make nice rounded flanges inside and outside, that will reduce most of the turbulence/chuffing noise.?
Yeah how would you modify them ? In an affordable way ?
I couldn’t figure out how to quote you

 

[stv]

I couldn’t figure out how to quote you

You just mark the text you want to quote and select "quote" in the appearing context menu. You cannot quote and (unnecessarily) repeat an entire post in the subsequent message.

Yeah how would you modify them ? In an affordable way ?

you can make wooden flange "rings" and cut the roundover with a roundover routing bit and smoothen it with sanding paper.

Have a look here:
https://www.diyaudio.com/community/...rbers-and-port-geometries.388264/post-7436768

And a very nice project here:
https://www.diyaudio.com/community/...ead-with-faitalpro-6hx150.316684/post-5299297
Scroll down to see the port roundover routing images!

Or you close the existing holes and make a new slot port, maybe similar to the rectangular ports shown here:

https://www.diyaudio.com/community/...rbers-and-port-geometries.388264/post-7487981

Probably it is even simpler just making a slot port using one of the existing enclosure walls and adding a board with two "spacer" pieces that can include the roundovers.

 

[Kingnoob]

So the problem with the current port? Because it’s not flared.??
What? context menu for quotes? I’ve been off this site a while lol 😂

 

[stv]

Because it’s not flared.??

Yes!
And two smaller ports makes it slightly worse, because of even more sharp edges.

context menu for quotes?

Yes, look:

 

[Kingnoob]

sharp edges

Yeah I see and it’s too large to fit a smaller flared inside it . Idiots who build this sub cmon .. I don’t know if anything can be built to sit inside the port that lowers the turbulence? That’s not too expensive.
Wish I would’ve got the MTX

 

[stv]

if anything can be built to sit inside the port that lowers the turbulence?

That woukd be counterproductive and I would not advise to do it. You would also lower the tuning.
Instead as a first step you could just try to sand the sharp edges to make them round. It may be necessary to add some filler to get the surface smooth.

 

[Turbowatch2]

You can take some model clay and form flares outside the box. This is really not complicated. Form it into long rolls and make the flare from it. If it helps, you could do the same from a piece of wood.
There is of course the option to buy two flared vents of matching size and glue them in as an exchange. This would be a good idea if the modeled flares help.
Anyway, the port noise may not be from the air (in fact the two seem quite well sized), but from parts of the woofer suspension getting audible. Sometimes the leads to the voice coil touch the cone and make anoying noises.

 

[Kingnoob]

model clay

Where do you buy this guess .? it does not have to be the expense?
I could move it to the other side of the room, but the dumb subwoofer auto off on does not work.. plus level matching it isn’t easy no new .

That woukd be counterproductive and I would not advise to do it. You would also lower the tuning.
Instead as a first step you could just try to sand the sharp edges to make them round. It may be necessary to add some filler to get the surface smooth.

I’ll go look for sandpaper sometimes. Any specific grit?

 

[stv]

Any specific grit?

Depends on your sub enclosure material. But i guess starting with 80 or 120 and finishing with 240 might be good.

 

[Kingnoob]

Ok I’ll try it out later. I think the sub is just too loud to be close to my couch also. Weird for a low wattage model .

 

[Moondog55]

To test whether or not it is the ports why not just do the sock in the tube test first>???
If you still get the noise then it is possibly the driver

 

[Kingnoob]

sock in the tube test first??

Close a port or both of them ?

 

[Moondog55]

Both usually

 

[Kingnoob]

I moved it to the other side of my room I gotta Try and level match it to my jamo will a phone spl meter work ? Then I’ll see how bad the port noise is . I will plug it regardless to see how it sounds sealed . I might have to research a sub calibration guide. Haven’t done it in a while …

 

[Kingnoob]

Both usually

I Blocked one off now it sounds tuned lower , and less spl.

I’m trying to figure out how to level a match subs without REW. Reading a guide can’t find it… my other sub is almost identical to the klh.

 

[Collo]

I haven't been on here for sooo long but noticed your query.
There's a whole lot of options for Port Flares here: https://www.subwoofer-builder.com/port-flares.htm

 

[Kingnoob]

I moved it to a better spot but I still plan on. Smoothing out or modifying the ports eventually. I don’t know what to use as a doorstop . Using styrofoam . It’s less
Boomy
But not fixed .

 

[WhiteDragon]

Looks like the ports would be right up against the wall.
Likely more the noise and boom.
It has 2 ports, and likely enough port area
for 100 or so watts.
As a test does it chuff less in the middle
of room with unobstructed ports