bassl0va
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Posts posted by bassl0va
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hahaha i know i meant for 2
Clean power, you will be fine.
woops, far beaten to it.
Nice box though
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This part of driver tech i'm a little weak on. My two basic questions are what would happen if the pole piece was removed from the structure (not questioning cooling) and what effect do different coil placements have? IE: If the coil was completely out of the gap at rest, completely centered in the gap at rest, or 1/2 entered into the gap at rest?
I can pretty much easily assume that if the coil is too far from the gap it will produce very little magnetic force.. but how far is too far?
OK, I'll try my best at explaining.
The magnet on a speaker is magnetized vertically, so that the top is the north (I think) pole, and the bottom is the south. The top plate is attached to the top of the magnet, causing it to act as an extension of the northern pole. And the pole piece, because it is attached to the back plate, will act as an extension of the southern pole. So I assume that removing the pole piece would either cause the speaker to sound like crap, or maybe barely function.
The coil question is linked to the pole piece question in someway. In a very good speaker (lets say DD) the coil will have exactly the same amount of coil on either side of the gap. Now, lets say the coil is 2.5"s long, and the gap (the thickness of the top plate, pretty much) is 0.5"s. This means the the speaker can move linearly 1" in each direction, it can do more (maybe even double!) but it won't be as linear. To stay perfectly (or as perfect as we can make a speaker, which is pretty damn shocking) linear, the gap must have its full length, 0.5"in our example, full with coil.
Now, take the coil just out of the gap, not only will it sound shocking, the closest to linear it will get is at the bottom of its down stroke. With this placement, our example DD would have to be moving a total of 1" just for the gap to be full at the bottom of the stroke, up this to 2"s of excursion and the bottom 0.5"s will be the only part that is linear.
So unless the coil is completely centered (1" either side of the gap with our example DD) it will behave very badly and have very bad sounding and quiet output. If the spider has sagged 0.25" you will probably not ,realistically, notice a difference, but if it is as bad as your first or third examples, it will suck.
As for how far is too far. I'm sure you could get some vibration with the coil 12"s away from the gap. The magnets are quite strong, go round to grannies and sit your DD lvl5 on the table and I'm sure she will be asking WTF is happening with the picture on her 20 year old tv (which is 6-10ft away from the table).
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Type R.
Honestly though, is this the only choice you have?
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Definitely the DC, it's a better investment.
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yeah i remember someone told me hatchbacks get 3db louder which to the ear is 2 times as loud
Just to correct you here, 3dbs is twice the acoustical energy. 10dbs sounds twice as loud.
I would say the hatch would be louder. Sub and port up.
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It will squeak, or fart, or various other strange noises.
Depending on how bad the leak is depends on how it affects the box, a very small one will have little affect, it will only annoy you, a 2" hole and you got a problem though.
IIRC a sealed box is meant to have a very slight leak, not enough to squeak, but enough so that if you make it at sea level and then travel up to Tibet the sub doesn't get forced out (or in if you built it in Tibet then went to sea level) and affect the linearity.
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between half and 3/4 i think. but its usually not visible when i set it up ( bc its facing down) but i realized that my amp is technically not rated for bridged at 2ohm. so wtf.
Holy fawk! Dude, I bet your clipping the heck out of it! Set your gains with a o-scope. I'd just recone it and tune the gains properly, or get a more powerful amp (and set the gains on that properly
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Generally, big subs like this are crap for SPL.
BUT, it doesn't take much power to do a hairtrick, and they hit really super low with a good box.
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haha what i win???? a nice box making
sorry for mess understand
thanks for you help
You win a...um...um...cupcake? lol.
Nah it's fine, don't be sorry.
No problem
don't forget about all the other helpful people though and don't forget to post a few videos when it's done
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if you mean the drawing no it not to scale but the numbers are. the drawing is to give an idea what i am putting the port.
DING DING DING DING DING! We have a winner! I new it
. Yeah, I couldn't be bothered with the math, so I just went by the picture, but questioned whether it was to scale or not so I didn't get moaned at . Like I said though 17 per cube is great! -
I think that box would be around 5.6cubes after displacement, with 100 square inches of port, which equals about 17 square inches of port per cub, which is fine. Someone correct me if I am wrong.
How come the ports it´s too small?? it´s 100SQ, i think this box it´s ok, but the tuning it´s way too high, if i´m correct, you are getting 45 hz tuning on that box with 18SQof port per cubic feet, 5.5 c/f after displacement.
If you are looking for a lower tuning, then you don´t need a port that big, unless BTL really likes giant ports (haven´t use one before) , i would get a port 5x15x17 giving me 39 hz of tuning, 13.5 SQ of port per cubic feet and 5.8 c/f after displacement...
I said if the drawing is too scale, it's too small. The calculations work out fine, I couldn't be bothered doing them so I said it looks too small in the drawing. O/P says it's to scale though so WTF?!? 17 per cube is great though so stick with that box then
Haha this guy HATES port noise =P
Heck yeah
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If that drawing is to scale, then the port is too small. But thats only if it's not to scale.
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Epic high tuning fail FTW! Hmmmm, how long are they? (lol, thats what she said) you could lengthen then, but I would say remove 1 or 2 depending on how close you can get to the port area limit.
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Oh, I don't see whats wrong with it. Seems fine to me. Whats the tuning?
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Is there enough port area per cubic foot? should be between 14-16 square "s per cubic foot. Also what subs you putting in there?
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But then you have port noise, and it will be tuned to 25hz or so.
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If they will all fit in you might as well do it. If they don't your screwed
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Yep, and it doesn't matter if you have 100 1" ports, they still have to be 32". I guess you might have to go back to the drawing board?
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If that 32"s was worked out for the combined port area, then each one is 32".
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They combine. Imagine getting all those ports and squishing them into one. The area adds up, but the length stays the same. So work out the area, then divide by 6, then work out the diameter of each one, and cut all 6 to the length you worked out.
BTW. Aero ports are flared, meaning the ones in the pic aren't aero ports. Also, aero ports change tuning a bit.
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shoulda got Funky Pupz so you'd hit a million dee beez
As alway, there is always one
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oh god, another one of these
hard to tell, but I'll play along and say 145 -
alright, if i saved up for some alpine type r 12's, what amp would you recommend for them?
FYI My friend just gave me a sealed box for 2 12's... (lol i would love to go ported for the type r's but free is the best option!)
If you build a great ported box for the kenwoods, they would probably be better than the type R's in that pre-fab sealed. I'm sure you could save up a little more and make a nice box for the type R's
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don't forget about all the other helpful people though 
hard to tell, but I'll play along and say 145
dc level 4 15"
in DC Sound Lab - Big Bass on ANOTHER LEVEL!
Posted
Someone already commented on how that power will be fine for two of them, so I complimented your box