I quickly ran a sim of the xover's transfer functions. Only 2 dB baffle step compensation for the 7" wide baffle design (see attached pic). You will get right tonal balance only if the cabinet depth is shallow and placed close to wall, or used as a desktop nearfield monitor.
Zaph tested this midwoofer a long time ago. Look under "Three Surface Mount Midwoofers" in his Tidbits page. FR and distortion measurements look pretty good. 3 mm xmax for this little driver is not bad.
The tweeter is a non-chambered, black dome version of the long-time favorite D25AG-35. With CAD for crossover design these days, its higher Fs due to the lack of a larger chamber, doesn't necessarily mean a higher crossover point to be required.
We can estimate how much the drivers would cost if they were available separately. Both the tweeter and the midwoofer would be $20 to $25 each, which means total $80 to $100. Still a good deal.
If anyone's interested, I can design an increased BSC and lowered xover point version. Then this will meet exactly the same design goal as Zaph's old HiVi W5/Vifa D27 2-way did: versatile little HT speakers that can be used even as a center channel speaker when placed on its side.
-jAy
Zaph tested this midwoofer a long time ago. Look under "Three Surface Mount Midwoofers" in his Tidbits page. FR and distortion measurements look pretty good. 3 mm xmax for this little driver is not bad.
The tweeter is a non-chambered, black dome version of the long-time favorite D25AG-35. With CAD for crossover design these days, its higher Fs due to the lack of a larger chamber, doesn't necessarily mean a higher crossover point to be required.
We can estimate how much the drivers would cost if they were available separately. Both the tweeter and the midwoofer would be $20 to $25 each, which means total $80 to $100. Still a good deal.
If anyone's interested, I can design an increased BSC and lowered xover point version. Then this will meet exactly the same design goal as Zaph's old HiVi W5/Vifa D27 2-way did: versatile little HT speakers that can be used even as a center channel speaker when placed on its side.
-jAy
Attachments
Moondog55 said:
Hi,
I would not recommend it as the kit comes with a crossover, you
can do it but you would need to simulate to make sure sure the
c/o phase is not messed up and optimise the treble drive.
Technically an active monitor would also use active BSC effectively
(if it indeed had proper BSC), this option would require mods (not
complicated) to the plate amplifier. Ideally also the gains would
need playing with but extra BSC boost might circumvent this.
/sreten.Jay_WJ said:
H Jay,
The XO's for the previous "Swifty" are $35 each albiet better components.
Chuck the XO components and board in, Madisounds quoted
$160 for the total parts does not seem unreasonable at all.
If you do play around with a increased BSC version I'd say
the challenge is unusual. Lower the XO point if you can but
the main challenge is reusing XO bits as much as possible.
/sreten.Anyone have reviews on this kit? Built per madisound specs. No extra mods..
I'm trying to get my brother to get a set so I can build them for him. He isn't really in to this stuff, but I gave him a stereo Onkyo amp and he has a decent HDTV setup and no tunes.
I'm tempted to get a set for myself even though I don't need them.
I'm trying to get my brother to get a set so I can build them for him. He isn't really in to this stuff, but I gave him a stereo Onkyo amp and he has a decent HDTV setup and no tunes.
I'm tempted to get a set for myself even though I don't need them.
The recession buster just got sweeter - Nik Brewer of Uber-Stealth Audio is
offering CNC cut baffles at $15! And that's for a pair.
Complete boxes are $40 a pair.
http://techtalk.parts-express.com/showthread.php?t=209396
http://www.freewebs.com/uber-stealth/diyhomeaudio.htm
offering CNC cut baffles at $15! And that's for a pair.
Complete boxes are $40 a pair.
http://techtalk.parts-express.com/showthread.php?t=209396
http://www.freewebs.com/uber-stealth/diyhomeaudio.htm
sreten said:
(possibly not bad as the top section of a budget 3-way either .....)
Hi,
Just a thought ... this is on special at the moment :
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-386
as used in : (noting bass level is adjustable by the c/o point)
http://www.quarter-wave.com/Project08/Passive_Crossover.pdf
budget 3 way OB ?
/sreten.Nice find Sreten. Thanks.
Compares very favorably to the P13 /D27 bookshelf combo we did a few years ago.
I grabbed a few kits and last night put a pair in some TL's I had previously made. This is a nice speaker. Clear, smooth and detailed-- a little more laid-back than the P13, but a fuller bass in the TL. (48Hz tuning) Doesn't cry out for a sub like the bookshelf did.
Was planning a bi-pole config. as I like that soundstage, but now thinking about getting more drivers for an MTM, as what it's missing is lower-mid detail. As you said, well worth playing with.
Compares very favorably to the P13 /D27 bookshelf combo we did a few years ago.
I grabbed a few kits and last night put a pair in some TL's I had previously made. This is a nice speaker. Clear, smooth and detailed-- a little more laid-back than the P13, but a fuller bass in the TL. (48Hz tuning) Doesn't cry out for a sub like the bookshelf did.
Was planning a bi-pole config. as I like that soundstage, but now thinking about getting more drivers for an MTM, as what it's missing is lower-mid detail. As you said, well worth playing with.
Some further information .....
Hi,
From Zaph :
So it seems the crossovers have already been "bodged up" which
means an attempt to redesign the c/o reusing the more costly
components wouild be misguided - its already been done.
Which makes this "built to original specification" misguided :
http://www.madisound.com/catalog/product_info.php?products_id=8526
$80 to upgrade non-optimally designed crossovers ....
/sreten.
Hi,
From Zaph :
So it seems the crossovers have already been "bodged up" which
means an attempt to redesign the c/o reusing the more costly
components wouild be misguided - its already been done.
Which makes this "built to original specification" misguided :
http://www.madisound.com/catalog/product_info.php?products_id=8526
$80 to upgrade non-optimally designed crossovers ....
/sreten.Say I were to buy two of these kits, but just use the woofers from one, and add to the other to build a MTM. Is that completely out of the question here? My biggest concern is what would happen to the crossover frequencies.
Along those same lines- using just the crossover out of the second kit if I do the above- what are the XO points for a 8 ohm tweeter, 4 ohm woofer.
Or- where could I determine these points on my own?
Thanks guys.
Along those same lines- using just the crossover out of the second kit if I do the above- what are the XO points for a 8 ohm tweeter, 4 ohm woofer.
Or- where could I determine these points on my own?
Thanks guys.
These are really tempting... I've been considering Zaph's ZBM4's as my first build, and my goal is cheap but accurate near-field monitors for my computer desk. I like listening to music & recording, and I would love to have something better than the average computer speakers but at a low price.
I was planning on building the ZBM4's, and the price list for drivers & crossover components was about $100, not including sound dampening, ports, or enclosures. I was planning on building enclosures out of MDF.
So the big question is... how does the RB-kit compare to the ZBM4's? I understand they're different prices, I'm just trying to get a feel for how they compare to each other in order to make my decision. It seems like I could save a bit of money by buying the RB-kit and building an enclosure myself. The FR graph on the ZBM4's looks very flat, not much low-end response, slightly higher output above 600hz. The FR for the RB-kit looks a little more lumpy, and big bass hump from 50-100 hz. I wonder if that'll be better sounding or more annoying than the ZBM4's response. Ideally I would be able to listen to both and make a decision, however I really can't afford to build both.
Any input is appreciated. I realize comparisons may be subjective, but even those may be helpful in making a decision.
I was planning on building the ZBM4's, and the price list for drivers & crossover components was about $100, not including sound dampening, ports, or enclosures. I was planning on building enclosures out of MDF.
So the big question is... how does the RB-kit compare to the ZBM4's? I understand they're different prices, I'm just trying to get a feel for how they compare to each other in order to make my decision. It seems like I could save a bit of money by buying the RB-kit and building an enclosure myself. The FR graph on the ZBM4's looks very flat, not much low-end response, slightly higher output above 600hz. The FR for the RB-kit looks a little more lumpy, and big bass hump from 50-100 hz. I wonder if that'll be better sounding or more annoying than the ZBM4's response. Ideally I would be able to listen to both and make a decision, however I really can't afford to build both.
Any input is appreciated. I realize comparisons may be subjective, but even those may be helpful in making a decision.
I'm thinking about building the ported design as a nearfield monitor. I keep reading about the advantages of using a front slot port and I see a back slot port in pictures of Nik's finished enclosures. I was wondering if there exists a worked out design featuring a front slot port?
If anyone has a design or can point me to one, I'd greatly appreciate it.
Also, I'm thinking of rounding over not only the sides of the baffle, but also the top and bottom. Will this have an adverse effect?
If anyone has a design or can point me to one, I'd greatly appreciate it.
Also, I'm thinking of rounding over not only the sides of the baffle, but also the top and bottom. Will this have an adverse effect?
There are a few builds with a front port -
http://forums.audioholics.com/forums/showthread.php?&t=52695&page=5
http://www.xtremeplace.com/yabbse/index.php?topic=60875.0
http://forums.audioholics.com/forums/showthread.php?&t=52695&page=5
http://www.xtremeplace.com/yabbse/index.php?topic=60875.0
Re: Re: Why plate?
There seems to be some confusion here between magnetic shielding and electromagnetic (RF) shielding.
RF shielding is done to prevent electromagnetic waves from going in or out of an enclosure. This is the aluminum foil, grounded metal cage, Faraday cage, and the hard to see through plate with holes on the front of a microwave oven. On a loudspeaker, this is almost never done, and arguably, almost never necessary. Unless your loudspeaker enclosure has a built-in amplifier, it is not going to pick up radio interference easily. A faraday cage will also protect from static electric fields. This is why being inside of a car can protect you from lightning.
Magnetic shielding is not really a function of blocking a magnetic field, but actually one of conducting it off into a different direction-- changing the magnetic circuit. Some expensive materials can be purchased to do this, but more often a canceling magnet is added to the back of a driver to do this. It is really only necessary when placing a loudspeaker close to a CRT based screen (or potentially other electronics like other types of vacuum tubes).
Some useful info can be found here:
http://www.lessemf.com/faq-shie.html
and here:
http://en.wikipedia.org/wiki/Magnetic_shielding
Stuey said:
sreten said:
There seems to be some confusion here between magnetic shielding and electromagnetic (RF) shielding.
RF shielding is done to prevent electromagnetic waves from going in or out of an enclosure. This is the aluminum foil, grounded metal cage, Faraday cage, and the hard to see through plate with holes on the front of a microwave oven. On a loudspeaker, this is almost never done, and arguably, almost never necessary. Unless your loudspeaker enclosure has a built-in amplifier, it is not going to pick up radio interference easily. A faraday cage will also protect from static electric fields. This is why being inside of a car can protect you from lightning.
Magnetic shielding is not really a function of blocking a magnetic field, but actually one of conducting it off into a different direction-- changing the magnetic circuit. Some expensive materials can be purchased to do this, but more often a canceling magnet is added to the back of a driver to do this. It is really only necessary when placing a loudspeaker close to a CRT based screen (or potentially other electronics like other types of vacuum tubes).
Some useful info can be found here:
http://www.lessemf.com/faq-shie.html
and here:
http://en.wikipedia.org/wiki/Magnetic_shielding
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