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Discussion Starter · #1 ·
I've decided to give a DIY subwoofer a go, but since i've never made one for a home theater before, i need a lot of help.

If anyone has experience in this, any advise is appreciated, so i'll start with some following measurements and setup i have.


I have a richter odin sub(australian made)its a single enclosure ported with 2x10" subs and a active 250wrms power.

Its in my right side corner at the rear.

Room is 26f lenght x 19f width.

Its not a bad sub, but i think its more suited to music and im mostly interested in movies these days, so want a sub/s to fill out the room size and get a nice rumble/shake, so subs more suited to movies would be my choice, even tho im sure there are subs that can do both pretty good.


I also want to position them in a different place, im thinking under my screen

this time...

Here is where i want them.



I would make an enclosure under the screen and make it similar looking as now but with the driver being seen front facing, covered with grill or something similar, so making the box look pretty is not important as the enclosure will not be seen.

The biggest size available from each of the sides under that screen is w37" x h29" x d18", that enclosure is the maximum externally and for each driver/sub, so i need to consider the thickness of wood and internal bracing sub etc, if anyone know how much volume i can get out of those measurements with everything considered, that would be goo so i can look for subs for that enclosure.

Going smaller then what i have is of course ok, im just giving the max room i have


Now for a lot of questions, as id like to get a start with people in the know as im very limited in the driver knowledge or even making the right spec'd enclosure, however im ok with putting the box/enclosure together and making it.

Here we go...


1). Do i use 15" or 18" driver/s?


2). Do i go 1 or 2 drivers/subs? or a combination like 2x15" or only 1x18" If everyone thinks one 18" is enough for my room or 2 is way overkill, let me know as i dont know how to calculate the volume i need for this room size.


3). Ive been reading about some subs and seen many like rythmik, dayton, elemental designs, mfw, maelstrom(however this one i was told is out of bussiness?). So with a budget of around $1200-$1500 for 2x subs( not including extra bits like wood,amps etc) i would like to know what brand and make should i be looking/aiming for? Obviously if a very good driver can be had cheaper then even better as the extra money saved would go towards an amp.

Like some of those daytons are very cheap, under $200.


4). If the subs are positioned under the screen, is that a bad idea for screen vibration? will it cause some issue's while watching a movie where it might shake the screen way too often and become unwatchable?


5). Do i go ported or sealed?

Im not too experienced with this but was reading ported will go lower but requires a bigger box, with my dimensions i gave, could i go easily with ported or is sealed the way to go?

The other thing im worried about is the talk of tuning, when they say you have to have a port such and such lenght and width, placement etc i have no idea how to get these facts or how to go about it, so im hoping if ported is the way i end up going i have some help to figure this out.

More things like equilisers etc is also something i worry about, so a box that will need the minimum things to make it sound good out of the box without any extra equipment would be my preferred choice.


6).If i put a plate amp, will it overheat being in an enclosure under my screen enclosure? if so i will go rack type amp.


7). Any online shops that carry the good drivers that will ship overseas? Im in australia


I know this is a lot of questions, but thought if im going to try and attempt this, i may want to get a good start and get some decent input as to what to go with.


I'll add more information if required as needed but for now i think thats it (IMG:style_emoticons/default/smile.gif)

Much appreciate any help.
 

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I will be starting 2 x Dayton RSS390HF-4 15" in approx 130L sealed (4.5 cubic ft) sealed boxes for a customer in a month or so with Oaudio 500w amp for each.

Room is 4.9m x 5m x 2.7m.

With space available to you could have 2 large ported subs which would likely give you more output overall.

1 x 270L ported box tuned to 17hz will give you more output @ 20hz than the 130L sealed but the sealed will have slightly more output at 10hz.

All depend on your listening level tastes.

You are also in the DIY forum so there is no such thing as overkill.

If it was my room. 4 x 15" sealed or 4 x F-20 horns if room was available.

I'm doing another room next year. 5.6m x 4.4 x 2.7m. I can't fit the F-20's so it will have 4 x 130L sealed RSS390's with the oaudio 500w amps.
 

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Discussion Starter · #3 ·
Thanks for the reply crabra, appreciate it.


Listening levels would be average for tv shows, and cranked up enought to feel some bass on movies on blu ray etc.

The type of feel im after is that feeling of a nice rumble though your body on explosions in movie scenes.


I have no idea if a sealed design box would give me this, but if it did, i feel it would be simpler to build and easier.

If ported, i would have to find someone to help me to tell me what size port and how many i would need etc, thats the only problem im afraid of with a ported design.

You say sealed will go louder at 10hz compared to ported, i didnt think it would be even able to reach that low?!


I only have room for 2 subs, from calculating my dimensions, i get 341 liters or 12 cubic feet per driver available.

Being that im now looking at either the daytons hf or mach5 ixl in 2 x 15's as ive decided 18's would be too much for me( no need to crack the walls lol).

These two seem like a good value and decent subs from what ive read so far.


Anyone have opninions of mach5 vs daytons hf's?
 

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If you have the room do the 18's for sure!!! Don't waste your time and money on two Dayton 15's in that room you'll likely be left wanting more. When modeling the 15 HF you are down between 6-10db from 20-80hz. Since the price increase they no longer possess the same value they once did. I have a room similar size that had two 13av.2's which have greater output than the Daytons and they weren't enough output for me. I now have two 18's and will be adding more to even the room response. I modeled the eD 19ov.2 and the Fi Q18 each in 6 cu ft sealed, powered with an EP4000 bridged and you should get reference levels from 20-80hz no problem (10hz output w no room gain = 101db). If you went ported you could get increased output but at the expense of box size and a more complicated design.
 

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Discussion Starter · #5 ·
Wow,you think 2x 15's will be too small?

I was sure it would be a big difference and upgrade from my 2x 10's that i have now.

I could easily go 2x 18's just im not sure ill be using them to even close to theyre potential.


Another question.

Would 2x15's ported be similar to 2x18's sealed everything else equal?

If so i could go 18's and have same output with smaller enclosure
 

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Discussion Starter · #8 ·
So far ive known brand ive found a local distrubitor for mach5 18's(but im not getting a reply or getting in contact with them today,tried calling 10 times already) www.affordabledrivers.com.au at au$319ea


Peerless Or artisan r1500 at $289ea but they are only 12's.


Theres also a nz distrubitor for rythmik subs.

I have checked shipping from parts express at us$350 for a quick air shipping and its still worth importing as it ends up pretty much the same price but more driver options.

If kept under au$1000 theres no duty/tax,so some things i would have two order seperatly to keep it under the limit threshold
 

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Discussion Starter · #9 ·
By devestating,do you mean very bad in a bad way or as in a killer output?

Asking as i dont know how to read that graph so dont know if its good or bad.

Thanks for doing that btw,appreciate it
 

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Quote:
Originally Posted by MAZMAN808 /forum/post/20786348


So far ive known brand ive found a local distrubitor for mach5 18's(but im not getting a reply or getting in contact with them today,tried calling 10 times already) www.affordabledrivers.com.au at au$319ea

I think the Mach5 are out of stock in the USA, so it wouldn't surprise me if they're out of stock down under as well?

Soon to be replaced by an upgraded model though.
 

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Discussion Starter · #11 ·
OK,

Got in contact with Sam from Affordabledrivers and ordered 2x ixl-18 mach5.

I would of payed similar dollars for them if i shipped them from overseas due to high shipping cost's, so i thought id support the local guy.


Now i have to figure out how to make these boxes.

His website mentions 130L for sealed and 200L for ported.


Are there any programs out there where you give them your dimensions of space that you have available and with the 200L ported box specification, it gives you the size of the box required to make?


cheers to all for the help so far, cant wait
 

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Quote:
Originally Posted by MAZMAN808 /forum/post/20787654


OK,

Got in contact with Sam from Affordabledrivers and ordered 2x ixl-18 mach5.

I would of payed similar dollars for them if i shipped them from overseas due to high shipping cost's, so i thought id support the local guy.


Now i have to figure out how to make these boxes.

His website mentions 130L for sealed and 200L for ported.


Are there any programs out there where you give them your dimensions of space that you have available and with the 200L ported box specification, it gives you the size of the box required to make?


cheers to all for the help so far, cant wait

Notice the simulation i linked to you above. Your dimensions indicate a net internal volume of 8.75 cuft allowing for bracing and standard cabinet construction. The simulation i did was for 8.5 cuft which allows for two 4" ports and the resulting displacement. The port dimension is inside diameter of a round port of 23.5" long each. Work with the space you have to get the greatest internal volume possible. Use at least 3/4" material construction and a double walled baffle. Brace diagonally on all sided with hardwoods. No need for lining or stuffing in a ported enclosure BUT you will have to use some pipe elbows for the ports as your spec'd dimensions indicate an 18" enclosure depth. Elbows are ok. You could also do a slot ports which will aid in bracing but good ol 4" PVC drain pipe is really cheap and easy to work with so.
 

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Discussion Starter · #13 ·
Awesome...

Thats a good starting point for me with that information



Ive been reading stuffing it internally makes the woofer think the box is bigger! So you dont think it helps with quality of sound or help sound quality/boominess etc?


Youve been a great help,thank you
 

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Quote:
Originally Posted by MAZMAN808 /forum/post/20789395


Awesome...



Ive been reading stuffing it internally makes the woofer think the box is bigger! So you dont think it helps with quality of sound or help sound quality/boominess etc?

Not in the case of a ported alignment. Just brace it very well.
 

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Discussion Starter · #15 ·
cheers.


What amp should i get for these?

Im looking at the partsexpress site and they have the bash 500 which is a plate amp and a dayton sa1000 which is a rack mount amp.


With the bash 500, i would have to get one for each sub, yes? or can i get that plate amp to do both(250w each)?

If i get the plate amp, id like to mount it in a seperate place, somewhere i can reach it as the subs will be recessed inside a frame.


Id get a rack mount amp but im hearing they are noisey, and i dont want that.
 

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Quote:
Originally Posted by mayhem13 /forum/post/20788342


Notice the simulation i linked to you above. Your dimensions indicate a net internal volume of 8.75 cuft allowing for bracing and standard cabinet construction. The simulation i did was for 8.5 cuft which allows for two 4" ports and the resulting displacement. The port dimension is inside diameter of a round port of 23.5" long each. Work with the space you have to get the greatest internal volume possible. Use at least 3/4" material construction and a double walled baffle. Brace diagonally on all sided with hardwoods. No need for lining or stuffing in a ported enclosure BUT you will have to use some pipe elbows for the ports as your spec'd dimensions indicate an 18" enclosure depth. Elbows are ok. You could also do a slot ports which will aid in bracing but good ol 4" PVC drain pipe is really cheap and easy to work with so.

There was great thread a couple of years showing that lining atleast around the port inside the box reduces resonance. Secondly, if the box is too long in any dimension standing waves can start happening at lower frequences which can be too close to the operating frequency range of the subwoofer, thick lining can help with absorption. The OP dimensions are short though so there isnt an issue with his box still I would line the box.


My own subjective conclusion, I have never heard a quality ported subwofer that didnt have any lining. I definitely tried it both ways over the years.
 

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What are you using for mains? What would be the point of 2 - 18" IXL's if they overpower your mains even at moderate gain.


Not trying to say they aren't a good choice because they are a popular driver for sure. Just saying that it might be overkill if you have to keep them turned way down just so your mains can compete.


Or perhaps you might want to upgrade your mains at Xmas
 
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