QUESTION......the 0.1 channel of a 2.1ch setup

[3rutu5]

Guys, constantly thinking here and a little in uncharterd territory as well not ever using a 0.1 channel in a DIY project, if i was looking at a portable option again and wanting to conceal the mid/sub channel, is there anything to look out for, no no's or suggestions regarding mounting a speaker firing downwards? After doing some of these bluetooth speakers firing downwards and having the waveguide i dont see this generally being an issue, but this is a unit i want playing anything under 150hz and not sure if it needs a guide.

questions i'm a probably have are;

* is it possible to do?
* is it better to have it firing upwards?
* would you need a waveguide allowing it to fire in the same direction as the smaller drivers?

i'm sure there are more, but at least a start.

I ordered a 2.1ch bluetooth amp\board and thinking of trying something portable and battery powered again.

[billfitzmaurice]

The .1 channel is the subwoofer. Subwoofers are omnidirectional.

[3rutu5]

Yeah ok, so doesnt matter where it is pointed. Guess i'll have to provide a gap in it is downward other wise it will slide around the surface when on

[tvrgeek]

Onmi, sort of. Depends on the crossover frequency. With small portable systems, sometimes one may pick a higher crossover so they can use smaller mains. 100 would be omni, but 200 you may want forward fire. For a portable, I might mount the woofer on the back. Regardless of position, you still need to deal with the time/phase delay so as not to have a big notch in your response.

[3rutu5]

Onmi, sort of. Depends on the crossover frequency. With small portable systems, sometimes one may pick a higher crossover so they can use smaller mains. 100 would be omni, but 200 you may want forward fire. For a portable, I might mount the woofer on the back. Regardless of position, you still need to deal with the time/phase delay so as not to have a big notch in your response.

oh i thought i would over complicate this haha.....

how does one compensate so something like this? by adding a filter to the driver on the 0.1ch?

[3rutu5]

even though i ordered a BT/AMP combo board, i got bored today and started designing up a small thing with the intention of using nothing by recycled parts, i have the PE 2.1ch class d amp, BT chip, 2x Visaton BF37's and one left over DA CE65W and armed with a new 3d printer....the last image was the inspiration for today, but even though when i asked the question i had no intention of doing this, down the rabbit hole i went shortly afterwards....

as it is only going to cost me the price a filament, i thought i would prototype something, but when the other board arrives it will be bigger and a bit better thought out.

[billfitzmaurice]

200 you may want forward fire.

Only if the baffle approaches one wavelength in dimension, which at 200Hz is 5.6 feet. That would be one mighty big boom box. 200Hz is well up into the directionally locatable range, but that's of no consequence where the OP's question is concerned.

[tvrgeek]

oh i thought i would over complicate this haha.....

how does one compensate so something like this? by adding a filter to the driver on the 0.1ch?

Yea. Most plate sub amps have a "phase" adjustment.

Nothing beats prototyping. MDF is cheaper than filament.

[3rutu5]

Yea. Most plate sub amps have a "phase" adjustment.

Nothing beats prototyping. MDF is cheaper than filament.

Yeah generally, im using an old roll I stopped using a few months ago in this case and so far it is looking ok

I guess I don't have to do much apart from check in occasionally with a print, but it does take significantly longer than going down to the garage and using a couple of different saws etc

[tomzarbo]

That thing actually has me confused... it appears to have two small full rangers, and a smallish sub sharing airspace along with end cap passive radiators. Unless I'm missing a partition inside.

I wonder how that would work. It's a clever looking design. I like your opposite curves and corners to change it up a bit.

TomZ

[3rutu5]

I printed out a concept yesterday, I think its too small, I cannot fit the port there along the back.

I was thinking about having two sealed enclosures for the BF37'S, but really not sure, going back to the CAD drawing board I think.

The creative one is a bit confusing, has passives there also.

On the diyaudio forum this guy printed his own passives which looked cool, didn't have time to watch his sound test yet, but does make me think what can I do with a TPU filament can be any worse that the unknown chinese membranes

[Dukk]

The concept drawings look good. I too am playing around with a design for a tabletop with a downfiring woofer. My current hold up is not wanting to spend the $200 in drivers.

[buggers]

If those are two smaller driver sharing the same space as the bigger driver, this concept will not last very long...

[3rutu5]

The concept drawings look good. I too am playing around with a design for a tabletop with a downfiring woofer. My current hold up is not wanting to spend the $200 in drivers.

I definately need to go back to the drawing board, perhaps a little bigger and in pieces\screwed together to make it easier to work with. I keep wanting to print it as one massive piece, which can be done in a day, but trying to make it a bit easier for massive paws to navigate around in is proving to be annoying for me at current

the print had an issue with the filament getting snagged around 80% of the way, hence the glue line.

[Dukk]

Interesting. Based on the renderings, I thought it would be longer. How are you going to isolate the small drivers?