down firing port: less dust than horizontal port? (( No acoustic discussion! ))

[skyfly]

Please do not discuss the acoustic properties of down-firing ports here!

Please discuss only dust entering the loudspeaker enclosure. Thanks in advance.

Does a down-firing port result in less dust inside the enclosure than a horizontally mounted port?

 

[wwenze]

This is even better, this goes U shaped

 

[restorer-john]

Dust isn't a problem with ports. Just clean them every 12 months with a sponge if they are plastic, or with a dry rag if they are cardboard/fibre.

I'd be more worried about spiders getting inside.

Front ports are also fantastic places for small children to "post" stuff. You know, carrots, peanuts, small Hot-Wheels cars, marbles, lego and random stuff they find that will fit in.

 

[skyfly]

Just like you, I do not care about the virus in the micro-size water droplets during shower or swimming, dust inside speaker enclosure, etc.

However, there are people far more sensitive about dust and water droplets, for example, those having NTM (non-tuberculous mycobacterial pulmonary disease).

 

[JSmith]

those having NTM (non-tuberculous mycobacterial pulmonary disease).

Sure, but wouldn't those people be fastidious about keeping their home dust free to start with, using air filters and such?


JSmith

 

[skyfly]

Sure, but wouldn't those people be fastidious about keeping their home dust free to start with, using air filters and such?


JSmith

Not all of them are living in 4nm CPU chip factory level hygiene.

They leave home regularly, not always with N95 mask.

At home, they have domestic air cleaners. However, the windows have to be opened for some moments every day to address CO2, mold, radon accumulation. They even cook (plenty of micro-dust) at home, and have ported loudspeakers (the absolute mainstream type of loudspeakers) at home.

Even with domestic air cleaner running 24/7 at home, dust accumulation on horizontal surfaces is present. Just wait for a week, you will notice dust accumulation. Not much different from my home.

 

[JSmith]

Not all of them are living in 4nm CPU chip factory level hygiene.

I see...

ported loudspeakers

If this is an issue, why not get sealed, non-ported speakers then?

Logically the down firing port will have less dust that a front or rear port, based on ol' gravity. I'd be quite inclined to not have carpet and ensure the floor is free of dust/dirt as much as possible.


JSmith

 

[restorer-john]

If this is an issue, why not get sealed, non-ported speakers then?

Actually, you're right.

Sealed speakers are better in this situation as the OP hasn't considered formaldehyde egress from MDF... It's a serious health issue, especially with board out of Asia.

 

[Roland68]

Please do not discuss the acoustic properties of down-firing ports here!

Please discuss only dust entering the loudspeaker enclosure. Thanks in advance.

Does a down-firing port result in less dust inside the enclosure than a horizontally mounted port?


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View attachment 379114

The air only moves back and forth a little in the bass reflex tube, and always at the same rate.
If you do the math, then the outside air does not reach far enough into the bass reflex channel during operation. With a 10" chassis, the bass reflex tube would have to be significantly shorter than 6cm when the chassis is fully deflected. And even then, the dust would not have time to settle, except minimally in the tube. During normal operation, the air only moves back and forth a few millimeters to maybe 1-3 cm.

If you observe dust in a closed living room in sunlight, you will notice that dust tends to fly up rather than sideways when it is stirred up. This means that the vertical bass reflex tube near the floor, where most of the dust is, is much more susceptible, as most of the dust settles on the floor and is stirred up. It could also suck up or stir up a lot more dust from the floor during operation.
Just look at PC cases that stand on the floor and whose intake openings are near the floor - they are the ultimate dust collectors.

I have opened and restored/modified 20-40 year old speakers many times and dust inside has never been a problem. Regardless of whether there are large bass reflex tubes on the front or back. There was always a layer of dust on the bass reflex tubes, even on vertical ones.

Passive membranes would prevent dust completely.