You have changed the size of the horn mouth with your split design. It will not play down to the original WO lower frequencies.

Welcome to the forum! And thanks for your nice illustrations.

buzz

Ok, so ill stick to the original design, i don't want to waste time and money building something that has not been really tested before. in the long run ill probably end up building two of these baby's.

so~ first step accomplished, chose my design.

this morning i went and bought the drivers, 2x 10" umm... probably a local made sub, but it wasn't the cheapest in the shop, so i hope that it does not disappoint me. paid Rp. 250.000 for each them (thats US$ 27 each) nothing too crazy, and if everything fails (i hope not) i haven't spent a fortune on it. here are some images of the drivers;






the box didn't have any specs, but from what I've understood, the WO works with prity much any sub driver out there.

i also tried to find an appropriate amp as well this morning. i went to about 5 different electronic/music shops here and was not able to find any panel amps eg;


which is a pity, cos that would be the easiest solution... instead i think i have to build my own amp... (good thing we have an electrician here, who will be helping me a lot i think lol)

so what I've found are some mono, or stereo amps, the best one I've seen (quality wise) seems to be a 2x 400W amp. its prity much just the circuit board, one page instruction manual, and the heat sink... from there ill need to buy or build a suitable power supply,  24v(for the amp) + 12v (for the safety circuit) @ 5amp? he he... totally new to this. anyone have any advice regarding appropriate power supplies? I'm almost tempted to just buy a car amp from the car mod shop at this point. however the price will be a lot higher i would imagine, and how to power that? just a 12V something amp converter?

then there is also another little gizmo that they had that adjusts the volume and frequency. however i was told that i don't need that since ill be running the signal from my Yamaha amp that has a SUB-Woofer out plug (mono), and it should be set to the right frequency for sub usage. ill have to read that up in my amp manual exactly what the parameters are of that sub outlet.

just ordered two panels of MDF 18 mm (we don't use inches here  ;D) but thats about equivalent to 3/4" when i get it this afternoon, or tomorrow ill start cutting them down to size, if i remember i might take some pictures.

I'm thinking of using both Lamello, and screws to fasten the main structure, and then just screw the top on so its possible to remove it on a later date. by the way, what is recommended to use as sealant when placing the top on (so its possible to remove later)? i have my doubts that it will be such a perfect fit as to be air tight...


"lamello joint"

thanks about the info Gex n Buzz, and hope to hear some more from everyone  ::)

cheers!

So lamello is out then, was just thinking of extra durability/sturdiness... ill see, if we got enough biscuits lying about i might use some, otherwise just stick to screws.

i heard that wood glue doesn't stick so well too MDF, is that correct? should i maybe go all out extreme and use epoxy? he he...

i just got the price for a sheet of 3/4" MDF, 20 bucks  :( i thought everything should be cheaper here, a friend of mine told me he can get a sheet for 15$ over in the states... bah.

so now I'm waiting to find out f i can get plywood or MDF for a cheaper price than here from the neighboring island  ;)

regarding the sealant, I'm wondering what to use to seal the top on, since from what i've understood, this should not be glued and just screwed on, so its possible to open up later on for repairs/upgrades.

to keep the price down i think i will have to stick to a DIY amp, make another little box for it as well, and sit it on the floor somewhere.

if i get a Mono amp, do i just splice the output and plug em into each sub? how about a Stereo Amp? since my sub out is Mono i guess i just splice the output of my Yamaha amp, into my new amp (well "to be built amp"), then run a cable to each woofer from the amp. correct?

thanks  :D

Hey Wayan,

MDF is very good for glueing, don't worrie about it!
You could just glue the whole box without screw, it would be a challenge to line the corners up and press everything well together, but the glue is realy strong and more then sufficient.
You do have to give it some time to dry of course.

To seal a side that has to be removable use weatherstriping, works very well.
When the lid is screwed on, it's almost invisible because it's pressed flat.
Or just put it upside down on a carpet, seems to play at its best this way
you need a flat floor, no bumpy tiles etc.

I made a few Velleman amps before, have a look at there website, nice stuff, not the cheapest though.

If you like to use a stereo amp:
Take the mono/sub out of your Yamaha.
Go to the input of the stereo amp with a splitter and feed left and right the same signal.
Then use one output side for one driver in your WO and the other channel for the other woofer.

happy building!

Bart

Particle board is weaker, maybe you should use those biscuits now, but that's more work and glue.
If you don't plan on dropping them from the stairs, it should be ok.  ;D

edit: be sure to predrill holes for screw, specialy with paricle board.
If you use a lid, you should use those metal threaded pieces instead of just screwing directly in the wood.

Velleman dealer in India:
(maybe that's the nearest, so not a good solution for you?)
VPL Infotech & Consultants
301 Savitri Sadan II 15 Comm Centre Preet Vihar
110092, DELHI
INDIA

For someone who read almost all of the WO post, you seem to have a lot of questions that are already answered or are clearly explained in the plans.
B.

Yes, I forgot this is you're first build, sorry Wayan!

Particle board is indeed not strong on the edge, otherwise it's a good and cheap box material.
Use lots of glue to fill in those little air pockets on the sides of the board.
Consider using polyurethane based wood glue!

The boards go inside the lines, but that depends what you think of as being 'inside' of course.
If you look at those different little drawings, you can see the box itself as if it was a faint shadow, it's clear that these thick faint lines run on one side of the drawing lines.

good luck!
B.

so i went on another shopping trip to get together all (well most) of the hardware to build the amplifier. this is what i was able to get for $55.00



thats the power supply, 5A, two heat sinks (don't want noisy fans, so got em big), power cord, fuse, power switch, cable connector thingos, some electronics for the power supply (no clue what they do) and the input connector to go from my Yamaha amp to this amp.




this is the amplifier that seemed to be the best they had over there ($20 for it, out of the $55 i spent). there were some 1000 or 2000W amps, but the owner of the shop said it was just fake, probably like 2000w p.m.p.o. or something. anyhow, the components on this one looked better. i still doubt that this thing has 2x400w (800w) of output, lol... ill be happy if its able to get a bit of rumble out of the WO.

so, back to the drivers, this amp is not strong enough to power my double coil 4Ω 300w subs, so the shop owner told me to link the two connectors on each drive in series (to get 8Ω), and not parallel (to get 2Ω), since that would probably cause the amp to blow. is that correct?

i also just realized last night that i totally forgot to get a volume control for this thing, ha ha... i think its possible to adjust the volume from my Yamaha amp, however i think i am going to go and get a volume control, maybe even an equalizer (if its not too expensive) so i can even use the amp for other speakers in the future. so, for those electricians out there~ how do i hook up the equalizer/volume control? between the sub-out and this amp, or between this amp and the WO?

i still haven't finished cutting the particle board, almost done tho, just need to cut two more little pieces, and ill have all the components ready. then ill have to cut the angles.

i have decided that ill use Epoxy glue during assembly, i also want to fill in all the edges of the particle board with epoxy, since that seems to be the most likely spot to get damaged. it only needs a little bump and the edges/corners start to flake. I'm thinking of veneering the whole thing on the outside to make it look better. still need to see how much that would cost, if not ill just have it painted black with a glossy finish.

ill take some pictures of the assembly process. might have the time to get it started today.

cheers,
w

5A at how many volts? Most Mosfet amps are about 70% efficient - soooo - assuming its 32volts that gives us 160 watts of input power which will be about 112 watts of music power (approximately) 70volts@5A would be 350 in and 245 out. On discrete amplifiers you don't want to drop the load below the amplifiers rating IE if its rated for a 4 ohm load don't wire it to a 2 ohm load. Tube amplifiers are different (depending on their construction) most of the ones I've dealt with like lower loads than higher ones . Don't believe everything your read on packaging. I had a book showing some amplifier circuits. Had a stereo 70Watt amp with tone control and it required a +-35 volt transformer @ 5 amps (350 watts) not very efficient (40%). Reminds me of pyramid car amplifiers - boasted 2000+watts but when tested in the real world could barely eek out 70watts.

happy birthday . Don't forget pictures of your finished projects.

for those that wanna see how far I've come with the actual box construction.

its been in that state since about a week, been too busy with work to get it finished. which is quite annoying... so close yet so far, he he.

still need to cut the angles, and hopefully it will all fit together without too much trouble. i noticed that our table saw isn't cutting quite as straight as it should be. so i think ill be getting some slight gaps (0.5~1 mm). I've found a rubber like material that i will glue to the top edge of the walls to create an airtight seal when i screw on the top. the rubber is like 2-3 mm thick (thats less than 1/8th of an inch i think).

Yeah....what bart said

oooo~ if this WO that im building works as good as i hope, and i find the free time and $$ to buy more parts, id be very tempted to try out the half WO! in the meantime if anyone beats me to it, let us know how it sounds. just one half, and then, two halves. i would imagine placing two halves in the room to watch movies and listen to music could work out nice.



so back to the capacitors, i redrew it, i assume this is correct? I'm just doubling the buckets right?

how much would the equivalent of this sub be worth if it was ready made? i was looking around and didn't find many options for active subs (that were sold without the 5.1 tweeters) best one i could find (excluding the Bose shop which is just overpriced) was from Yamaha, it was a single drive, down firing sub at 10" or 12", and it was selling for over $500 i think (compared to the WO I'm making now which is so far costing me like $110) saving a lot, and hoping that it will sound better than the Yamaha! he he.

hope everyone had a good week end!
cheers.

Have a look at Klipsch, they have a few subs, but you might have to look around to find out the price.
There are others that build subs only, I read a review a few days ago, can't find it anymore, sorry.
http://www.klipsch.com/products/lists/subwoofer.aspx

wow, how time flies!

well its been over two months since i last posted, and i still haven't managed to finish the sub

however i have at least completed the amp! it took me almost all of last Saturday to assemble it. i was lucky enough to know someone who's hobbie is to build his own audio hardware. he managed to give me some basic welding advice, and supervised me during the assembly.

he told me that the best way to upgrade this amp now would be to change the capacitors completely to 4 or eight better quality ones, since the four that i bought are like the lowest of low quality capacitors that are out there, he he...

i tested the amp yesterday with two Sony speakers that are around 80~100 watt each. it was not so bad. about as loud as my Yamaha amp which has 80W per channel. i would assume that once i change the capacitors it could be even louder. i hope that it is currently powerful enough to get the subs booming a bit once i get around to completing them.

once the amp is dry from the finishing room (giving it the final touches), i will take a couple pictures and post them. i meant to take some pictures during the assembly, but i forgot the camera.

i plan to get the WO sub done ASAP now to test it out with the completed amp.

cheers.

First of all, congratulations!!
It must have felt good to finish this baby.

I was just a little confused when I read:
"i did try and connect both left and right outputs to one driver, and that resulted in a more impressive kick."
I agree that it has more 'kick' because of the doubling in power, but be careful with that, if not fot the SQ, then for the life expectation of you're amp and driver.

That LFE output may only work with DVD's? I'm only guessing here because it is the .1 channel of a 5.1 setup.

bah, i had an accident on Wednesday... a car drove me right off the road! i was driving next to it (overtaking) and the car decided to overtake the car in front without looking and took me and my bike right off the road... and as usual (for this country) the car ran. i would have chased him down but my bike was in a ditch, and i was rather shaken up, lol

i was lucky and came of with just a couple scratches and bruises. my 3 month old bike came out a bit worse. but luckily its relatively cheap to fix stuff here, and will cost about $150 to fix her up again.

however that fiasco has cost me two days, and i'm doubtful that ill get the chance to complete the WO casing this week

cheers all, and take care on the road, however careful you might drive, there are always the others that end up messing everything up, he he...

w.

Been awhile since I've been on. Gratz on completing the amp. I tried making a little amp using some leftover stuff i got but couldnt fix a noise problem and gave up - lol. Hope you get the sub done soon

That's looking good! Isn't epoxy a bit expensive to use like this?

How to mount the driver is really up to you, various ways will have various impact on the sound but you can mount them facing the magnet to the throat with the rubber against the baffle board. This is in fact the way I would do it, like this you have the largest possible volume of the chamber. You probably won't need stuffing with wool but it's possible that it's a bit 'boomy' sounding. You could line the inside of the chamber with carpet to reduce reflection and "boomyness"
As for the boards to get fixed, it will work with silicone if you use a kind that gets quite hard and if you put a thick broad line in the corners, on both sides of the baffles.

Have fun!
Bart

All I do is sit in front of the computer and wait for you to post again.

That's what I would do, like picture 'A'.
The sealed volume is highest and towards the throat the smallest.
I think you get a good compression at the throat this way and not the big mass of air that acts like a spring. I think this gives better sound quality, if that's what you want.
Look at your drivers specs and see if the volume is about the same as the sealed volume of the sub.

On the other hand, this is all theory and what I think about it, so don't take my word for it.

B.

ps, is that 2-components epoxy glue? what make is it?

everything you do and dont do will effect performance. experiment.

your almost there.

its not an easy build, well done.

Grats - can hardly wait to see how you  like it after you get the bugs worked out

http://www.realmofexcursion.com/

link to downloads top of page

im not sure i understand your last post bart, do you mean that i can just power the speakers directly with a 12~20V AC power adapter, and get the 50~60 hz (which is the alternating frequency)?

thats pretty nifty, wouldn't have thought of that one...

however i went to the webpage that 60_and_up mentioned, there they have a lot of audio files with different frequencies. i think ill try that out when the WO is done getting painted. not in the mood to drag that thing back into the office again from the workshop, its such a mission to move it! lol

the biggest problem with testing it around here is that there is a lot of glass windows that were rattling like hell last time i was testing the WO, and it doesn't let me listen to a clean sound.

hopefully the paint job is done soon. now that its finally finished, its annoying that i cant test it out properly at home my girlfriend wont let me take it home without first painting it, cos she says it looks too ugly at the moment, he he

thanks for the info guys.

yep, already did the "head in WO" rattle test, and it seemed to be quite clean. the additional sealant and twelve screws stopped the driver mounts from moving, for now!

i just finished with the base coat for the WO, and have started with several coats of black paint. just gave it a sanding down again. another layer or two of black to go, and then a finishing coat to protect the paint should do the job.

i was browsing through the Hafele catalog and came by some furniture feet. i was thinking of using some maybe like this one:



that way i was thinking of facing the mouth of the WO downwards, so that it wouldn't collect so much dust, and also maybe not look like a star-trek space ship... would that affect the sound?

but then i would have the cable inputs on the top, also not a pleasant site... maybe ill have it sitting horizontal, and then i can use the WO as a table... sounds like a better plan i think. maybe ill cover the top with a 6~8mm glass sheet to protect it from scratches~

any thoughts regarding the feet / table thing?

About the legs. Could be retro add a little red in there maybe some white and you have designer retro furniture!
because of the design of the legs use all the holes and some good sized screws and anything else that would make them stronger. the legs would spread out if there was too much weight on them.
The ideal height IMHO is about 4 inches off its face. If you use it as a sofa table behind. bolt it to back of the sofa if you can.

I like the WO on its face whenever I can. I even place the wo32 on its face although its not as big as difference as the WO on its face.

Enjoy building while you can, life can change.