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Two Halves (Read 30936 times)
wayan
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Posts: 42
Re: Two Halves
Reply #30 - 11/06/07 at 09:08:19
 
hi bart,

ha ha, yeah, i went back to my AMP guru today, and he looked shocked that i tried to connect the amp and driver without really knowing what i was doing... well no damage done, both are still working. i think that my amp was not powerful enough to break the drivers, and the driver was set at 4Ω (rather than 2Ω if i would have tried to series it up) so it did not suck my amp dry.

reading back over my own post i found that i was supposed to connect the dual coil in series to get the 8Ω, which should not put such a big load on my little amp.

which brings me back to wanting to get better capacitators, lol... well all in good time, for now ill just wait and see what the result will be like.

i tried reading through the instruction manual for my Yamaha amp, and so far am not able to figure out why its not working. maybe the sub out only works if i switch to speaker B (5 channels) rather than speaker A that i'm using now which has only two chanels. i didn't think of that till now and will need to test that i guess.

once everything is completed i plan to take my whole sound system to my friends house to figure it out (if i dont manage on my own by that point). ill keep you guys posted with the WO construction. again another day passed and i did not have the time to get working on it... maybe tomorrow Sad
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wayan
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Re: Two Halves
Reply #31 - 11/09/07 at 01:38:52
 
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 Sad

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.
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Bart_West-VL.
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Re: Two Halves
Reply #32 - 11/09/07 at 06:07:47
 
That sucks! I hope you're fine.
Don't worry about the WO, it can wait. Or can it?... Wink

Take care,
Bart☺
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Blotch
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Re: Two Halves
Reply #33 - 11/15/07 at 07:37:11
 
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 Smiley
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wayan
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Re: Two Halves
Reply #34 - 11/18/07 at 09:34:17
 
getting closer now!

the WO is almost complete;

i ended up just using Epoxy. no nails or screws so far. not sure if its needed at this point. looks like the box is really sturdy. i will only use screws for the lid, so its possible to still open it in case there are any problems down the road.







i glued some glides to hold the driver support (still need to router out the circles), but due to imperfections, i can not image that it will be air tight... what should i use to seal it? silicon maybe? since it would be the easiest to remove if i needed to change the drivers, id only need to cut the silicon away, and slide the drivers out. i plan to use screws to fasten the driver support into place once all is ready.

at this point i would like some advice regarding how best to load the two drivers... the drivers that i have already came with a sealing rubber, but it is on the front, and not the back (image of the driver on page one of this thread). if i were to load them normally, i would need to have the sealant on the back of the lip (i think), so i was thinking of loading them inverted, so that the coves are firing into the sealed chambers, and i can make use of the rubber seal that already comes with the drivers.

what are the pros and cons of loading the cones backwards? and do i have to invert the polarity as well?

another question... should the sealed compartment be filled with that fiber (forget the name for it)? and how about the rest, should i just leave it as it is (solid particle board) or should i glue something over the surface, like some kind of felt, etc?

any help would be greatly appreciated!

thanks
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Bart_West-VL.
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Re: Two Halves
Reply #35 - 11/18/07 at 10:06:11
 
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" Roll Eyes
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
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wayan
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Re: Two Halves
Reply #36 - 11/18/07 at 10:16:15
 
well, let me simplify what i was trying to ask above regarding the driver direction.

best would be if someone could tell me which way would be the best way to load the drivers, A or B? and if its not too complicated... let me know why Tongue


A A A A - Inverted


B B B B - Normal~

space wise the normal way seems like the better option.

the wiring ill probably lead into the central triangle, where ill fix the inputs.

cheers.

ps, that was a quick reply bart, so id best be following plan A (inverted)?

pps, we buy the epoxy in big cans Smiley not little tubes. that would have costed a lot is that was case, he he...
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« Last Edit: 11/18/07 at 10:21:58 by wayan »  
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Bart_West-VL.
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Re: Two Halves
Reply #37 - 11/18/07 at 11:03:05
 
All I do is sit in front of the computer and wait for you to post again. Grin

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?
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« Last Edit: 11/18/07 at 11:04:04 by Bart_West-VL. »  
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wayan
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Re: Two Halves
Reply #38 - 11/19/07 at 11:39:11
 
ok, so here are a lot of pictures!




front view and back view of the drivers bolted onto the support bracket









Various stages of the padding installation of the sealed volume.





Before and after installing the connector panels (or whatever they are called).



gluing some sealant. couldn't really find any proper stuff, so i got the closest thing to it... a foamy rubber material thats used in the soles of shoes, he he... biggest pro was that it costs next to nothing, however it was a little uneven. seems to have done its job however.





finally got the top screwed on! top-ish view, and a full frontal

after three hard days of continuous work i finally got it all together!! yay!

however i was disappointed to find out that i forgot to seal the driver support bracket to the rest of the WO and when i tested it, there was a fair bit of rattling where the unfixed pieces are vibrating on each other! i then also realized that i forgot to glue in the top padding of the sealed volume (on the lid side).

so tomorrow i will have to take all the screws out again, put in some sealant around the driver bracket, and on the two holes where the wires go out, glue the missing padding in, and then screw it all back together.

THEN, hopefully it will work the way it is supposed to...

anyone think i should be putting more filler into the sealed chamber? all the people that were watching my progress here were telling me how i should fill it all up. but i don't think they have much experience in speaker construction...

by the way, since i installed the speakers inverted, should i be switching the polarity of the cables around? i asked that previously, but didn't get any feed back regarding that.

cheers
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60_and_up
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kids should live.

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Re: Two Halves
Reply #39 - 11/19/07 at 17:27:00
 
everything you do and dont do will effect performance. experiment.

your almost there.

its not an easy build, well done.
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Peace hath higher tests of manhood than battle ever knew. ...
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Bart_West-VL.
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Re: Two Halves
Reply #40 - 11/19/07 at 19:54:32
 
I agree with 60_and_up. Some things will have little effect, but others will have a huge effect, like your polarity...
...play it a minute or so one way, then change polarity, listen again. Of course both speaker connected the same!
You will hear some difference, maybe a lot, maybe little.
If your other speakers (satellites) give some fair amount of bass, it is very possible that there will be a big difference.
If you used a steep cross-over for the sub AND the satellites, the difference will still be there, but smaller. Listen carefully, try to get the loudest bass this way, then you have the right polarity.
But first put the sub where you want it, when moving it around it could be that the polarity should change again. Only trial can give you this answer. Even your listening position is important.

Thanks for all your posts and pictures, very clear! Cool

O yeah, the stuffing looks good, don't over do it though, this looks just right to me, but it could be you like the bass a bit softer, more 'wooly'. It's whatever YOU like that counts, there you're ears! Smiley

Bart
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Blotch
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Re: Two Halves
Reply #41 - 11/21/07 at 06:33:48
 
Grats - can hardly wait to see how you  like it after you get the bugs worked out Smiley
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wayan
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Re: Two Halves
Reply #42 - 11/21/07 at 07:13:59
 
from what i've tested~ it seems to be working alright! no more rattling parts after i opened her up and fastened everything properly.

however my testing platform at the moment is just I-tunes, where i adjusted the equalizer to maximize the bass, and minimize the 100+ hz frequencies. however that was probably not enough, since there were still higher frequencies audible, and probably messing the WO up.

for now the WO is still in the workshop, awaiting its final touch, a black coat of paint. after that is finally done i can lug it home where i will test it together with the rest of my sound system. and hopefully i will work out how to use the 'Sub out' from the Yamaha Amp that i have.

in the user manual it says that the 'sub out' has a cut off point at 90 Hz. which is why i have not added another cut off on the sub or  the home made amp. the only trouble was that last time i tested the Sub out with my home made amp the yamaha amp, and standard speakers i did not get anything out of it...

until about a minute ago i was thinking of eventually using the WO as a TV stand/base, however i just realized that the magnets on the drivers will probably totally warp the screen, he he... ah well, ill find another spot.

once i get the paint job done i will take a final picture and post it for everyone to comment on. I'm happy with the result of my first ever speaker construction (was definitely more interesting that a boring box). it was a lot of fun building it for sure! haven't worked on something this big since wood working classes in high school, lol.

speaking of big... the bloody WO turns out to be way bigger than i imagined. even after cutting the components it didn't seem like a big box. only after i finally got it all together, and especially after mounting in the drivers and tried to pick it up did it dawn on me that i might have overdone myself! its next to impossible to move on my own (unless i were to put wheels and/or handles on it)!!

i have the impression that the amp that i built is way under powered. although i probably wont need to go any louder than what the amp is able (keeping the neighbors in mind), it would be fun to see just how loud this WO could actually get...

could anyone give me a link or something where i could maybe get a MP3 file to test my sub? that is already cut off at 100~hz maybe, so i can re-test the sub here with the comp.

cheers Smiley
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60_and_up
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kids should live.

Posts: 933
Re: Two Halves
Reply #43 - 11/21/07 at 15:50:50
 
http://www.realmofexcursion.com/

link to downloads top of page
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« Last Edit: 11/21/07 at 15:51:25 by 60_and_up »  

Peace hath higher tests of manhood than battle ever knew. ...
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Bart_West-VL.
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Re: Two Halves
Reply #44 - 11/21/07 at 16:07:47
 
Great.  :)

You could test one frequency, 50hz or 60hz, wherever you take power out of the wall.
About ~20v gets you 100W in 4 ohm but it should deliver 5A!

Or 12V 3A, that's 36W, still plenty loud for a test tune.
Of course AC , not DC.

Listening to bass only is never nice, you should have the full spectrum of music.
Bass only is just rumble, nothing more.

B.
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