First loudspeaker stealth grow box design


New Member

I am planning to build a loudspeaker grow box and I could really use your advice.
I'm totally new to growing, but I figure I can learn about it as I go, I've done a lot of research into this kind of grow box, and I've come up with a few ideas, I'd love to hear what you think.

I've got a pair of speakers that measure (on the outside) 80x30x38 cm.
I am planning to make as few external modifications as possible, simply removing the back panel and making it easily opened/closed.
The speakers have a bass reflex port (and a grill to cover the front), so I was thinking of using the bass reflex port as the exhaust outlet for a carbon-filtered fan, and drilling some holes in the back for air intake.

I am going to coat the inside with aluminium foil or something (is this a good idea?) to reflect the light and stop damp from getting in to the wood.

The power will be supplied via the speaker cable, there will be times when the fan needs to be on but not the lights, but I figure I can do this with only the 2-wire speaker cable, using some electronics (diodes to differentiate between two different polarity signals supplied, one will turn on lights and fan, the other will only turn on the fan)

The part I'm not really sure about is the lights, according to what I've found there are various types; sodium, metal halide, CFL, LED, and each one has different spectrum (ideally) required for different stages of the growing process.
Because it is going to be in a small space heat might be a problem so that points towards LED.
Moreover LEDs give the most light for their size (I think?).

I was thinking of using something like this as it says it is full spectrum so I presume that this negates the need to use many different lights? MarsHydro 300W LED Grow Light Full Spectrum It measures 7x33x20 so it would fit into the top of the cabinet...

What sort of yield do you think I should expect for such a setup? (I know that this is a common question that depends upon a lot of factors...).
I mean, I've read that it can be 1gram/Watt... But I think it would be unlikely to get 300g so there must be something I am missing.

I was also thinking of fitting some sort of heater inside the cabinet for the drying stage, so that it too can be done with carbon filtration to get rid of the smell.

Thanks in advance, and glad to have made my first post :D

The Stranger.
1 of those lights is a true 132w so at 50w per plant .. that means 2 plants under 1 light as for yeild that depends on many factors.

If grown right with proper nutes and depends on medium used, you may get UP TO 50g per plant so thats not bad.

2 lights would be nice to use 1 per plant.

But if you scrog and use 2 lights and grow say 4 plants under the 2 lights you could get UP TO 100g per plant.. so all depends on how you want to grow and what nutes and medium and so forth.
With that short space, be sure to do research on how far above the canopy the lights need to be. Don't forget to consider how tall your pot is. There are some micro grow journals around here~ I would check those out~ good luck!
(I've read that it can be 1gram/Watt... But I think it would be unlikely to get 300g so there must be something I am missing.)

What you are missing is that is 1g for 1watt pulled from the wall and not the rating on the light.

That 300w led your showing pulls about 135w from the wall.
Use a piano hinge for the back panel, don't use aluminum foil u can get Mylar blanket at Walmart for a few dollars much better. Stay away from any hid lamps cause ur space is really small an heat will be a major issue. I'd reccomed 4-2' floressents standing on end in the corners an floresssnt or cfl's hanging up top. U shouldn't need a heater an I wouldn't put one in that box. It will get to hot to fast. A small 4" fan to blow over the top of ur plants. Not sure how small of a filter u can actually buy but u will need a small one. Remember ur not working with a lot of space so the more u put inside the box the less room ur Gona have to grow with. U could look into a small scrog set up an would probably work quite nicely in such a small space plus it would give u ur best yield I would think. But I love the idea of using a speaker cabinet that's Gona be cool as hell :) I don't know anything about LED so u might wana ask around about how much heat it's Gona cause in a small space like that. Good luck an I'll be lurking ;)
My smallest box is close to that size (one I bought pre-made) and the bigger boxes are in my Anti Journal Journal link. Smell is still an issue to a point as the carbon filter stuff will get a lot of it but it can't take out all of it as they get pretty stinky last couple weeks (and you have to take them out to water them or least open up to do so). My Purple Kush Journal you can see the one I flowered in that box, height is tight as you need space above light and space to plant from light and size of the pot takes away from that too (that one was about 12-13 inches tall when done). In mine I have a "150W LED" (actual wattage is lower), I have "300W" lights in my bigger boxes but that would be too much in the little one and you need to make sure dimensions of light would fit into your box as it needs to be smaller than footprint of box as they vent on the sides. Foil can get hot spots and is a pain to deal with trying to get it smooth w/o ripping (same goes for those emergency blankets, they do work but a pain and can cause burning due to light being refracted like a magnifying glass), those Sunshields for your car work pretty good and those aren't all that much. There are quite a few folks Journals growing in tight spaces, you can look for those and see what was working and what doesn't to a point. Also if you talking about the wires that go to the speaker part they made for low voltage so would work on a computer fan (most are 12V like voltage in car components) but they would have a melt down/start a fire connecting it to a light as higher voltage going thru them.
So far we had the best luck in our little veg cab (48" tall) was our perfect sun mini but the mars 300 worked in there too but you need 24-30" for a seedling. When we switched the mars out and put the ps mini in the temps went from 82+ to 77 degrees consistently. Smell has been an issue for us as well DM, haven't figured out how to combat that as we use AV case fans to cool our cabs. We love growing in cabs but would love an entire room lol
Hi Guys,

Thank you for all your replies.
I'll definitely look into using mylar instead of aluminium foil.
Yes I was thinking of using one of those 4" fan and filters.
It's going to take up quite a lot of space inside the cabinet but hopefully it'll leave enough room. Lol.

Dwight I've started reading some of your journals but I'll read them again. Really interesting.

I'm still slightly confused by the lights.
I've read that most people use CFLs in small cabinets because they emit less intense light so they can be put closer to the leaves without bleaching them.
The part I don't understand is, CFLs are less efficient than LEDs and presumably they don't emit so much light, but they emit more heat, so wouldn't it still be better to use LEDs, just lower power ones?
Of course CFLs are cheaper and maybe more flexible with where they can be positioned, so maybe better to start with?

About the smell, do you think I could get away with using one of those Ona odor neutraliser gels next to the cabinet on the outside to get rid of whatever the filter doesn't?

Thanks again for all your help.

The Stranger
Depends on the strain the one gel covered up the smell of our northern light but it doesn't cover the smell of the gold leaf. At all. Might be able to use coconut stuff on a screen and pull the exhaust through it but you are going to have to try and be innovative and solve the problem with your exact setup. Still haven't come up with a good method without using a carbon filter bc we aren't willing to sacrifice the space for it. Maybe if you are able to position it so the exhaust flows right over the gel and have good results. Good luck, happy growing!
Almost forgot... and this is opinion mixed with our own experience, LED is better for light intensity and heat. Downside is you need space.
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