I just bought an rb kit. This will be my first speaker build.
I'm interested in what you guys "in the know" will come up with. My wife and I have a small master bedroom and she's been asking for something that will play some nice tunes. I'm thinking of pairing this with a chipamp that I'm building.
I'm interested in what you guys "in the know" will come up with. My wife and I have a small master bedroom and she's been asking for something that will play some nice tunes. I'm thinking of pairing this with a chipamp that I'm building.
I'm building the LM1875 kit from chipamp.com. I should get about 20 to 25W/channel out of it. My wife isn't looking for anything near earth shattering.
The other reason I'm here is to see if someone has ideas on a speaker enclosure that is more aesthetically pleasing.
I've got table saw, router, drill press, etc. so I can get around most any woodworking issue. But you're right, the one provided by Madisound leaves a lot to be desired.
I'm a total noob when it comes to designing enclosures, but I want to give it a shot.
The other reason I'm here is to see if someone has ideas on a speaker enclosure that is more aesthetically pleasing.
I've got table saw, router, drill press, etc. so I can get around most any woodworking issue. But you're right, the one provided by Madisound leaves a lot to be desired.
I'm a total noob when it comes to designing enclosures, but I want to give it a shot.
Oh, great! I've actually read that a long time ago, but forgot about it. I think that's exactly what I'm looking for. Buildout looks pretty simple... he leaves out the details on the enclosure, but I'm assuming the tweeter in the RB-kit has to be flush mount, right? What about the woofer? Just curious what kind of tools I'm going to need for the baffle. Thanks!sreten said:
Hi,
Rebate the tweeter, flush mount the woofer, round the sides
(and top and/or bottom) if you feel like it. Another way of
doing it is 12mm and 6mm MDF with 45 degree bevels, see :
http://www.humblehomemadehifi.com/USB.html
One way of rebating the tweeter is using a
layer of hardboard on top of the baffle proper.
/sreten.
Rebate the tweeter, flush mount the woofer, round the sides
(and top and/or bottom) if you feel like it. Another way of
doing it is 12mm and 6mm MDF with 45 degree bevels, see :
http://www.humblehomemadehifi.com/USB.html
One way of rebating the tweeter is using a
layer of hardboard on top of the baffle proper.
/sreten.Re: Re: Re: Re: Why plate?
Neither the question nor the answer specified magnetic vs. RF shielding.
Now if someone has some unobtainium that works as gravitational shield, I still need some for my hovercar design.
I figured you weren't confused. I just didn't want someone to come away from your post confused thinking that a speaker could be magnetically shielded with galvanised / tin plate.sreten said:
Neither the question nor the answer specified magnetic vs. RF shielding.
Now if someone has some unobtainium that works as gravitational shield, I still need some for my hovercar design.
sreten said:
I respect you, based on hundreds of your other posts, so it is with a bit of trepidation that I assert my disagreement. You always seem to know what you are talking about, based on either education or experience, so now you have me wondering how you may be right about this, as well.
We are talking about steel or iron, with a coating of tin or zinc. I am not sure if you are asserting that the coating does any part of this magic, but steel and iron are not well known for doing anything to a magnetic field other than conducting it very well.
Certainly, they will affect the field, and some creative arrangement may get the field moved in a convenient direction.
I just don't see how this could be done to keep all of the flux in the box. If I model this in FEMM, it appears to do just the opposite: draw the field more strongly outside of the box.
Is this being done commercially? If all it takes for for magnetic shielding is some cheap zinc or tin coated steel, then why is there a market for expensive Mu-metal and Permalloy shields?
As far as I can tell, the bucking magnet gets credit for all of the heavy lifting here.
What's an implementation I can look at where this shielding works? Or, how could I stage an experiment to see it? Just take a big magnet and hold it 5 inches from my TV screen and see what happens when I put a sheet of steel between them?
I am searching now for something that will help me understand how this may work, and am only finding data that appears to be contrary.
From: http://www.acornnmr.com/appnotes/shielding.htm
"The first approach many groups make to addressing the logical and illogical issues that the stray magnetic field can cause is to put a steel plate between the magnet and the area where they do not want any stray magnetic field. This can often make the stray magnetic field in the target area stronger. "
I did find this page, with a nice animation: http://www.jitterbox.com/mitigation_shielding.php4
This is on the website of a company that makes (or at least used to make) a device called a "Jitterbox" which was basically a steel box that covered 5 sides of a CRT monitor to protect the screen from stray magnetic fields.
From the animation, I can see that shunting with high permeability materials may work. Possibly, making a whole thick steel box inside of a loudspeaker cabinet would work for this.
Is this being done commercially anywhere? (or is mag shielding for speakers becoming a bit of a non-issue as CRTs become less prevalent?)
This is on the website of a company that makes (or at least used to make) a device called a "Jitterbox" which was basically a steel box that covered 5 sides of a CRT monitor to protect the screen from stray magnetic fields.
From the animation, I can see that shunting with high permeability materials may work. Possibly, making a whole thick steel box inside of a loudspeaker cabinet would work for this.
Is this being done commercially anywhere? (or is mag shielding for speakers becoming a bit of a non-issue as CRTs become less prevalent?)
neededandwanted said:
I really don't know much about magnetic shielding (which is sad, since I'm sure I learned about it in college), but the second part of your comment...
http://www.zaphaudio.com/ZMV5.html
From john/zaph:
So at least john thinks that with the popularity of LCD's, shielded speakers are somewhat obsolete by now. I have to agree... I don't know when I last used a CRT computer monitor, and the main tv I use is an LCD as well. There may be other reasons to shield, but definitely the biggest one (CRT TV's) is becoming less an issue.
neededandwanted said:
Hi,
So your saying that by inserting a steel sheet into a field it links
that field and is magnetised, this then causes a larger field than
without the steel sheet being there in the first place.
This may be true but I am referring to a cage arrangement that
should reduce the leakage flux by conducting the internal field.
Whilst bucking magnets do do the "heavy lifting", for fully shielded
drivers there is an addition steel cage or can, due to the proximity
to the magnet they would not be able to conduct the unbucked
field, hence the bucking magnet is required, and the bucking
magnet does reduce the stray flux used without the "can".
It is an assertion on my part steel plate (magnetic, surface
treated not to rust) can be used to magneticaly shield stuff,
I've never actually tried it with speakers, but it does work
with steel cases for circuitry and magnetic hum.
/sreten.OK, thanks.
In my head, adding a bucking magnet makes a sort of "cardioid" magnet assembly, so would be cancelling most strongly in one direction.
A complete cage could provide a controlled flux path, but it will still have some redirected, strong hot spots. A careful design could, for example, make a Left loudspeaker redirect its stray field to the left, and away from the TV.
While it is becoming a moot point (decline of CRT), I would also caution that adding magnets and ferromagnetic material will also affect the original, intended field at the voice coil location as well.
The reason I brought up the "confusion" bit was that people were starting to mention Faraday cages and using Aluminum foil.
With these "Recession Buster" loudspeakers, I would probably just use the least expensive method - space. Just move them away from the screen a bit.
[/HIJACK]
In my head, adding a bucking magnet makes a sort of "cardioid" magnet assembly, so would be cancelling most strongly in one direction.
A complete cage could provide a controlled flux path, but it will still have some redirected, strong hot spots. A careful design could, for example, make a Left loudspeaker redirect its stray field to the left, and away from the TV.
While it is becoming a moot point (decline of CRT), I would also caution that adding magnets and ferromagnetic material will also affect the original, intended field at the voice coil location as well.
The reason I brought up the "confusion" bit was that people were starting to mention Faraday cages and using Aluminum foil.
With these "Recession Buster" loudspeakers, I would probably just use the least expensive method - space. Just move them away from the screen a bit.
[/HIJACK]
Hi
after seeing the post from sreten i decided to build the http://undefinition.googlepages.com/diy-orientexpress for the rb-kit.
my question is since the speakers are not the same as the orient express, do i leave the port lenght to 3 inches or does it need to be adjusted?
after seeing the post from sreten i decided to build the http://undefinition.googlepages.com/diy-orientexpress for the rb-kit.
my question is since the speakers are not the same as the orient express, do i leave the port lenght to 3 inches or does it need to be adjusted?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.