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nothin seems to work out (Read 5797 times)
Adrian D.
Ex Member



nothin seems to work out
10/30/05 at 16:06:24
 
i found a tech paper at adire.com about horizontal monting the woofers. i worked out the maths and it turns out my 12'er in my db-12 is sag. no prob, i put the box on it's side, put the db-10 on top of it and pointed them at a corner.
stupid cancellation  >:( , each db is louder by it's own rather than when they work both.
Blasted things, they seem to work best alone. what should i do ? because i've had enough mono listening (db-10 + one fullrange).
i crossed the 12 @ 160 hz (12db/oct) and the 10 @ 160 hz (24db/oct, using 2 identical x-overs cascaded). could this cascading affect the phase ? i know they're crossed too high. i've ordered an active x-over and separate sub amp and i'm waiting for them. btw, i'm using them in-home, not in-car.
please help with any ideea, no matter how weird/stupid/crazy it may seem.
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« Last Edit: 10/30/05 at 16:08:23 by adi_ro »  
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Hotsauce
Ex Member



Re: nothin seems to work out
Reply #1 - 10/30/05 at 18:10:30
 
Did you try reversing phase to one box?

John C.

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gexter
Ex Member



Re: nothin seems to work out
Reply #2 - 10/30/05 at 23:11:53
 
If you can't do it with the crossover just reverse the leads on one.

unless you have the same type in each corner you will run in problems and have to use crossovers and the like to balance it.

if you ended up winding coils you need about 8 mH to go to 80Hz @ 4 Ohms and put the 12 on the coil, and balance the wattage to each. play with the active on the 10 and cross it at 160 and down at 12 db .
your still not getting stereo and you still have to put them in the same location maybe in phase maybe not.

You specifically asked for CRAZY ideas. and those are crazy. You can also put the baffle as low as possible on the 12 and higher on the 10. the 10 will overwhelm the 12 until you balance everything out.
with the 10 a soft corner is going to be your friend. try firing it into a corner with a pillow opposite the port.
Crazy is what I am all about.
You should not try stereo bass with two differant subs.

Did I also mention to move them away from the corner and towards the center of the room on top of everything else.
Ah no I did'nt   but I did now

Gex ( you asked for crazy )

All above is expressed opinion only with no knowledge of speakers of any sort. all opinions do not reflect the good sense of knowledge of any of the people on this forum. Opinion above is considered completely useless if something blows up and in such case above writer is not held liable of any incompetency or chemical fires that may arise.
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« Last Edit: 10/31/05 at 00:58:50 by gexter »  
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Adrian D.
Ex Member



Re: nothin seems to work out
Reply #3 - 10/31/05 at 14:12:14
 
i put them today in the same position.i wired the db-10 out of phase. it seems to be ok. i've tried some music (atb, mop, rage against the machine and some club music) but i have to listen to them for a while.
they sound a little "harsh" when i play music only through them. but i guess the x-overs are to blame.
i also pushed them more against to the wall ( the wall facing the bottoms, so that they fire closer to the corner ).  
i got lucky because the dbs one on top of the other fit perfectly under the piece of furniture that i have in that corner. too bad wires are coming out of the boxes or they would have "dissapeared" since they have the same finishing as the furniture.
the bad part is that the neither k-slot nor the half-moon isn't visible anymore Sad and they are very good looking.
for the moment i'll leave them like this, for about 2 days listening. as a first thought the "feeling" is just right and i can say that it sure is good to listen again to stereo.
the x-over i've ordered has stereo input and double mono sub output. so the stereo bass is about to be solved.
Quote:
You can also put the baffle as low as possible on the 12 and higher on the 10. the 10 will overwhelm the 12

that's just what happened. i have the 12 baffle as low as possible and the 10 baffle almost at the top of the halfmoon.
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gexter
Ex Member



Re: nothin seems to work out
Reply #4 - 10/31/05 at 17:33:09
 
Super
glad it was an improvement

Gex
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Adrian D.
Ex Member



Re: nothin seems to work out
Reply #5 - 11/01/05 at 16:27:10
 
yesterday, after reading some very old posts about the db-10 i decided to round my port. so i took a piece of sandpaper and a knife and rounded the inside part of my port to a radius of about 6mm or 1/4". do you think it's enough to do the inside or should i round the outside edge ? and is the radius enough ?
i put my hand once on my woofer and pushed it slightly. to my surprise i felt air coming out of the dust cap/cone as i was pushing the cone. i really don't think this is a good thing.  what do you say about this ?
the woofer has a hardened paper cone and vented pole piece.
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serenechaos
Ex Member



Re: nothin seems to work out
Reply #6 - 11/01/05 at 18:18:22
 
[quote author=gexter  link=1130691984/0#2 date=1130713913] the 10 will overwhelm the 12 until you balance everything out... [/quote]
What does this mean?  
A 10 is louder than a 12?  
I haven't built either yet.  
I have a pair of 12" drivers and was planning to build a db12 for when I have time...  
Is the 10 "better"?  
Robert  :)
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gexter
Ex Member



Re: nothin seems to work out
Reply #7 - 11/01/05 at 22:18:39
 
When I wrote that I was refering to the midbass. By experimentation I have found that the lower the baffle the lower the sound ( bass) but the SPL suffers.
The higher the baffle the louder and high freq's are exagerated.
I do say this is not always the case, but has been for me.

Adrian has a excellant understanding of the DB and I was pretty sure he could figure out my rantings.
I know its not all that clear.
Sorry!
does the explaination help? there may be differant opinions out there

Gex
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DirtDawg
Ex Member



Re: nothin seems to work out
Reply #8 - 11/01/05 at 22:42:43
 
Quote:
When I wrote that I was refering to the midbass. By experimentation I have found that the lower the baffle the lower the sound ( bass) but the SPL suffers.
The higher the baffle the louder and high freq's are exagerated.
I do say this is not always the case, but has been for me.


Hey, Gex,

You're safe from persecution with that statement, since that's the way it works. I think you explained it quite well, too.

Grin
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serenechaos
Ex Member



Re: nothin seems to work out
Reply #9 - 11/01/05 at 23:08:48
 
I get it.  
With the baffle as low as possible on the 12 and higher on the 10,
the 10 will be tuned higner & louder than the 12.  
Thanx!
Robert  :)
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gexter
Ex Member



Re: nothin seems to work out
Reply #10 - 11/02/05 at 00:13:36
 
it's nice something works out for all the foot in mouth trouble I seem to get into at times.
I am glad I have moments of lucid behavior Wink
I have not made any DB's for a long time and I don't even have one anymore. It was my first Decware build. It's very unlikely I will ever build one again.
They are'nt for me, maybe because I learned of there characteristics right off and it did not work for me.

Gex
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Adrian D.
Ex Member



Re: nothin seems to work out
Reply #11 - 11/02/05 at 12:59:14
 
i have the insert on my 10 just at the top of the port and the insert on my 12 as low as possible. i managed to get a freq response from the 10 as low as 37 hz (the woofer's freq response is 35-1500 and the 37 hz note was'n very loud ) and i guess this is something good. above 40 hz to about 80 hz it's a dream. the 12 is very diffrent below about 40 hz is really comes alive and it is a LOT louder than the 10. but above 50 hz it looses a lot of output. i wanted to get this kind of response and it seems i got it.
the 10 is definetly louder than the 12 on regular music (i listen to LOTS of house/club and rap) the way i tuned it and with the woofers is used. the 12 has more "feeling" . i'd definetly go for the db-12 if i'd have 2 12s. the kslot looks brilliant.
the bad thing i noticed about the dbs is that they go wild above 100 hz. i mean my 10 had lots of upper bass crossed @ 160 with 12db/oct. 24 db/oct helps, but it would help if i'd have it crossed at 80 or so.
robert, i read in an arhived post (made by steve himself) that it's wiser to choose an iso loaded db-12 than a hwk with 2 12s because the spl is higher and the sq is better. steve also said that the lower the baffle the lower the freq response and the spl.
to get an idea about the db-10/db-12 combo all i can say is that with a 50w/channel amp (turned at about 60%) i can shake the life out of my closet in a 12/12 ft room.
Quote:
Adrian has a excellant understanding of the DB and I was pretty sure he could figure out my rantings.
i do ? i'd wish i only knew how to find out the tuning freq.
i'll guess i'll go with one of ziggy's early posts regarding the rounding radius. he said 1/4" is minimum. i'll stick to that
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serenechaos
Ex Member



Re: nothin seems to work out
Reply #12 - 11/02/05 at 16:02:10
 
[quote author=gexter  link=1130691984/0#10 date=1130890416] It's very unlikely I will ever build one again.They are'nt for me, maybe because I learned of there characteristics right off and it did not work for me.
Gex [/quote]
Hey Gex,
What didn't work for you?  

I'm considering building an iso loaded DB12 to use in a small room with a pair of FT1600mkIIs, crossed around 50-60 Hz.  

Or using it in  a car...
Robert  :)
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Adrian D.
Ex Member



Re: nothin seems to work out
Reply #13 - 11/02/05 at 16:58:09
 
Quote:
I'm considering building an iso loaded DB12 to use in a small room with a pair of FT1600mkIIs, crossed around 50-60 Hz.  

Or using it in  a car...  


it's gonna be a killer either way you use it. one more thing : i found that correct placing is essential. it took me almost 2 months to place both of mine the way i like it.
don't consider it, DO it. it was my 2nd serious build and it took me a whole day after i had all the panels cut. as a bonus, all the mdf you'll need is about 20$. G'luck
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gexter
Ex Member



Re: nothin seems to work out
Reply #14 - 11/03/05 at 05:09:36
 
[quote author=serenechaos  link=1130691984/0#12 date=1130947330]
Hey Gex,
What didn't work for you?  

I'm considering building an iso loaded DB12 to use in a small room with a pair of FT1600mkIIs, crossed around 50-60 Hz.  

Or using it in  a car...
Robert  :)   [/quote]

I still have not tried one with "quality" subwoofer so the verdict is not out really. My sons DB10 I built rattles his escort pretty good.
I would like to play more with the DB 10 and 12 but the money that I free up will go to other projects.

The only thing that keeps me from a clamshell 12 is the drivers I have right now. I have no specs but I believe they will not perform in the DB.
I have been playing with them free air and IB to get feel for them.

I would still build a DB 12 or 10 if I came acoss the right driver/s.
and I do think a small room is favourable to a DB so I would try it!

I like to say [" MDF is cheap " if you got the time build em all!.]
you can find a home for any 10 or even a 12 pretty easy

Gex

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« Last Edit: 11/03/05 at 05:10:34 by gexter »  
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