First diy project: Bose buster

[JonP]

Yes, cool little setup! Giving me a few ideas for a few spare parts...

I was wondering what you used for the finish? Looks like some kind of textured paint....

[augerpro]

Thanks for the kind comments guys! Jon I used Duplicolor truck bed coating from lowes. The stuff is awesome. As long as you fill and sand properly (which I didn't in a couple places) it really comes out even. Like an off the shelf product.

I actually had the little speakers two tone using the textured stuff and some black lacquer in a spray can. Just finished painting and went to peel off some painters tape and it pulled the black lacquer off in some spots :M LAcquer takes FOREVER to dry and I had to get these on the truck to my parents before Xmas so I just shot everything in the textured finish.

[gonar]

that's sweet.

can you post full plans for that set? that is something I could make for my folks that they would love (WAF _very_ important for my dad)

I would probably build 3 of the "center" for the front stage.

also, could you please clarify which posting is the "final" crossover for the MTM "bose-busters"?

Thanks!

[Mazeroth]

Awesome projects, Brandon! I just got my SoundEasy working yesterday and can't wait to get some speakers designed. :B

[Gir]

Excellent design! I may have to look into a pair of these for my parents! Also, I don't suppose you could you post detailed instructions on how you applied the duplicolor? I've seen people who have done it wonderfully (such as you!), and I've seen people that have done it... well... errrr... bad. I really don't want to waste a whole bunch of the stuff because I have no idea on how to apply it well. Thanks!

[augerpro]

Tyler> it's pretty idiot proof as long as everything is smooth. You can see a couple of my corners in the back where the router chipped them and I didn't do a good job with the bondo. But what you can't see in the pictures is all the seams that are invisible, and no other surface imperfections. The fronts obviously look pretty good. My advice is use bondo on every seam or imperfection and sand everything smooth with 220 grit or so. Then primer with automotive primer and a quick sand with 220 again just to knock down the roughness of the primer. Temperature does make difference. Try to paint in >60 degrees to keep that fine textured look. And don't spray too heavy or too close.

gonar> I suppose I could post some details. I worked up another XO that is slightly flatter, the treble isn't so pronounced. I intentionally did that for speech intelligibility knowing I could always adjust the treble on the receiver if my mom found it too annoying. anyway here is a flatter one that should do fine in most settings:


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I used Jantzen aircores, mostly 18-20 guage, you'll have to much up the DCR values to know where I used what though. The fullrange baffles are 4.5" x 4.5". I think I made them 5-6 inches deep, stuffed pretty well. The center channel I think was 4.5" x 6.5" and about 4.5" deep. I used a .5" roundover.

BTW Aurasound is still moving production to factory in China I believe so it will be awhile yet before these woofers are back in stock at madisound. You may know of other places that have them though. Here are some links to those unfamiliar with these drivers: Aurasound NS3-194 Aurasound tweeter

Oh ya gonar- Final MTM specs are in post 65.

[gonar]

1/2" or 3/4" mdf?

[augerpro]

1/2" for the speakers and 3/4" for the sub.

[JonP]

I thought that was a bed liner kind of paint. Spray can Duplicolor... what state do you live in? I've tried mightily here in CA to actually find the stuff on the shelves... I find empty shelves, or I just find the can variety. I wonder if it's "illegal" now... Nobody says this, just 4-5 stores all say "uh, guess were' out of stock, should be in soon..."

Tried the can type on some stands... it's tricky applying evenly and not having texture differences as it dries pretty fast. Kind of rougher than I wanted, using a foam roller. Oh, don't use a foam roller... it eats them slowly... ops:

[augerpro]

I live in Denver. I'm sure there are many kinds and I don't how many are any good besides this. I bought it Lowe's, pretty sure HD didn't have this exact brand though. It's just a regular spray can of Dupli-color Truck Bed Coating.

[PoorboyMike]

I've heard good things about THIS stuff and you can choose your color. It's durable like bed liner, but is water based and goes on easy. I'll be ordering some for my stage monitor soon and will post my impressions.

[JonP]

Yep... that's what I can't find. (haven't tried for a few months) Only thing I did find was the brush on variety.

About 4-6mo ago, there was a quiet revolution in CA, many paints and stains had to be removed from shelves, and new versions with lower volatile compound levels had to replace them. Or, some products didn't come back. Thought this might have been one of the victims, though all the other paints and finishes had gone and returned already... Maybe I'll do another search..

[bolognablake]

New work system is up and running. This system sounds much better than my old B3N/TB6.5 set up.











Still waiting to hear from ThomasW on the PE feet. I made an Ariel like base for the sub but thought it might look better with the feet.

Did you end up still going with solid oak front baffles? Also, what size is the subwoofer enclosure, and did you use the original poster's XO?

Thanks, I've been lurking for a while, and I stumbled upon this build and I think it's just what I need to uncluttered my desk and replace my KEF monitors I've been using.

[AlanH]

actual drivers?

Hi all,

Brandon, I really like the look of the your original Bosebuster set using the HiVi drivers. I have read through the thread, but I'm a little confused over which drivers were used in the center channel. Is this correct?

Tweeter: Dayton ND20
Midrange: HiVi M3N
Woofers: HiVi M4N

Thanks!

[augerpro]

Alan that is correct.

[PoorboyMike]

Did you end up still going with solid oak front baffles? Also, what size is the subwoofer enclosure, and did you use the original poster's XO?

Thanks, I've been lurking for a while, and I stumbled upon this build and I think it's just what I need to uncluttered my desk and replace my KEF monitors I've been using.

No, I didn't end up using solid oak. I bought the wood, measured once, and cut it 1/2" too narrow. :M The 1/2" oak is expensive, so I just used MDF rather than buy more and risk screwing that up too. :B

The dimensions on the sub are: 10.5w x 15.5h x 16.5d. Those are external dimensions using 3/4" material. Port is a 3" precision port at just under 14" long for an Fb of 34hz. You could get away with a 2" and get a lower tune, but I already had the 3" laying around.

If you end up building these, I think you will be very happy with them. I used Brandon's original xover, and I mean that literally.

[bolognablake]

Cool, thank you very much.

I'll be upgrading (down grading in size ) from a set of vintage KEF's so the extra desk space will be nice.

[JJones]

Anybody compared these little MTMs to Zaph's single driver speaker?

My dad (and his friend) both want a pair of small cheap (but decent sounding) speakers to use outside, mounted on the wall.

They don't need to play loud, and, since they're small, we won't expect much bass out of them. Won't be using a subwoofer. Dad says he doesn't want them ported (to prevent bugs from making a new home in there).

[Bent]

I've built a pair of Zaph's B3S's (but I used the b3N's as the S's weren't available.]
They sound very good if crossed to a sub at 150 hz, but they really need a lot of power to make them sing. (B3x's aren't very sensitive)>

[augerpro]

Well, I think they sounded pretty good, but keep in mind that this was also the first crossover I ever did. On the other hand I've found a single fullrange driver (B3N or M3N) to be so compromised that the addition of a tweeter sounds leaps and bounds better, even if it was a noob design. I would recommend these or Zaph's ZBM4.

[impulse]

Hi

How did You mount the ND20? Did you use glue?

[seanski]

New work system is up and running. This system sounds much better than my old B3N/TB6.5 set up.











Still waiting to hear from ThomasW on the PE feet. I made an Ariel like base for the sub but thought it might look better with the feet.

that looks sweet! are all of the drivers the HIVI M-series? how do they perform? i was looking at the 5" ones for an upcoming project.

[cobblepots]

Brandon, these are great looking! I'm considering creating a pair for the hang out room. Sometimes it's a bit too much to fire up the statements for playing cards...

I want to build a DIY chip and and tube pre/amp to power them. The amp will do only about 4 watts per channel and I'm afraid it'll under power these guys a bit. What are your thoughts on this? Also, are these roughly 8 ohm speakers? I didn't see a resistance plot for your finalized cross over. Maybe I missed it. Thanks in advance!

[gorbs]

bose busters

hi all,

new guy here, i just wanted to say i look forward to being able to share my own build results here when finished. i just picked up a table saw and ordered the speakers from PE. thses are perfect as i am using an old Bose acoustimass 5 system for my HT needs. two of the 161's for the surround and that crappy center channel too. lol.

next is the wood and crossover parts then shop area prep. until then more reading and study is needed so thanks to all that have gone before to make this really an enjoyable pursuit.

[gorbs]

Bose busters

can someone point me in the right direction for the rears and sub build dimensions. is there one ? i can't seem to find it here or on the mission accomplished page. thanks.

[gorbs]

bose busters

how would this plate amp compare to the dayton that was used ? this can be had for less than 40.00 dollars. !

Foster WF-100K subwoofer plate amplifier

Foster subwoofer plate amplifier. 115W into 4ohms, 80W into 8ohms. 4th order (24dB/octave) low pass adjustable from 50-200Hz. 0-180 degree phase switch, RCA and speaker level inputs, volume control. Unit has a 3rd order (18dB/octave) high pass filter built into the subwoofer section. Can easily be modified for any Q and cutoff frequency that you want (change R615, R617, R618, C607, C608 and C609). As shipped filter has a boost of 6dB at 35Hz.

[augerpro]

cobblepots> PM sent

gorbs> we're you looking at using the HiVi M8N as the sub? I think PoorboyMike posted his sub dimensions above. If you use the TangBand W6-1139 I think I used a 15.5L net box tuned to 34hz. There are no rear speakers, you'd just have to build more MTM's. Enjoy.

[gorbs]

bose busters

Brandon,

i was looking for more of a build schematic than just the outside dimensions. i have no idea what is supposed to happen on the inside ops: once the sides are cut. complete noob here sorry.

i was also going to use the HiVi m8n as you listed and Poorboy's does look cool but if that would not be sufficient in a living room where i currently am using that Bose unit would a larger or different woofer be more applicable.?

my limited experience is replacing crappy factory speakers in my cars and installing some on my motorcycle. the living room is appr. 17 x 18 with a 20 or so ft high ceiling. yeah not the best acoustical design but impressive to a new home buyer 13 years ago coming from a small ranch style home lol.

[FritsK]

Very nice project Augerpro!

I found it so interesting that I decided to build a pair myself. I've just ordered the M3N's. But I was wondering which ND20 you've used..the ND20FB-4 or the ND20FA-6? Can someone please tell me?

Thank you very much!

FritsK

[gorbs]

the nd20 fb

[ThomasW]

the living room is appr. 17 x 18 with a 20 or so ft high ceiling.

Unless you plan on wearing them as headphones, these speakers are WAY too small for that room.

[augerpro]

I get a LOT of people asking questions about this project in PM's so I'm going to give this update. As much as I liked this project, it was my first. I can't help but think Zaph's ZBM4 is probably a better all around speaker. I've never heard them, but I trust he could better a noob's first project using the cheap yet excellent drivers he's used (MCM and Aura). Also mu understanding of electrical circuits was limited and more "brute force". If I did this XO now many of the values would change to reduce cost while only slightly changing the end response and performance. Given that, if anyone still wants to build these, go for it. But my involvement is done at this point. All of the questions are answered elsewhere in this thread if you look hard enough. Here are a couple last tips though:

the tweeter is the ND20FB-4

I posted this before realizing that exact component values were probably not needed in a budget system. So don't be afraid to use the closest you can. If it's within 0.2 or so, don't worry about it. That goes for coils, caps and resistors. Maybe even a bit more with the resistors.

I personally don't use R12 in the MTM.

R3 and R8 in the MTM's are just to show the resistance of the inductor. They are not real, separate resistors. Same with R4, R8, R12, and R19 in the center channel. R22 is the total resistance for the LCR circuit. So if you picked L21 with a DCR of say, 1.0 ohm, then you would use an R22 of 28 ohm so the total series resistance would be the 29 ohms listed.

Don't forget to adjust the tweeter level!!!

[gorbs]

thanks for your help along the way. nice 1st project and it was what i was looking for 1st time out. i went to the InDIYana event and have my next project picked out.

[bobhowell]

I read your comment about updating this with Fountek 88 full rangers.

How are you progressing. My wife is always challenging me to make small speakers like Bose.

[augerpro]

I have the drivers on hand and have been modeling the MTM variant for baffle diffraction, on-wall use, and filter orders and lobing. Very satisfied with where all that is so far, so I'm pretty much done with the pre-build design work. What I do with the MTM will drive all the other variants as this is the lynchpin of the series so to speak.

That said, I have some woofer and horn testing going on for the next few weeks so no wood is being cut yet. I do hope to have the measurement mockups built and crossover design to begin July. By the end of August I should have stuff nailed down and ready to post. I have some subwoofer options and integration methods that aren't real common but pretty exciting I think, and it will take some time to nail down those things. But I'll post the design before then as I don't really need to wait on that.

There is quite a bit of interest over these already so I may just post the enclosure designs early and let people build them while I do the actual crossover and listening work.

[augerpro]

BTW if anyone is thinking they may build the new BB, the Foster WF-100k amp here: http://home.comcast.net/~jhidley/ is absolutely perfect for the subwoofers. Better than the Dayton ones in every way that is important for this design. And it's only $35. The "kickass" version (which is what I'll be building for myself) is using three small subs. I'll be buying three of these amps when I get home, so glad I ran across this today!

[bobhowell]

What sub woofer would you envision pairing with it? One of his units?

[augerpro]

Well ultimately as long as the woofer meets a couple of requirements, it's really up to the builder. But I do have two woofers in mind to meet two different price points have have different tradeoffs, but overall should integrate into this system very well. Main attributes are smooth response out to 400hz, with no crazy subwoofer cone breakups, Lowish Fs, small box size, good nonlinear distortion in the bass.

For the cheaper woofer I think the Silverflute 8" is very promising. Price is right, especially going for multiples, efficient, box size is decent, low Fs, smooth response obviously, and these Silverflutes have surprisingly good motors with low distortion. Someone looking for the econo route or for music only should consider these. Can't remember what the modeling showed for power, but I *think* the small Dayton amp may be enough for each. The 6" version is also promising if the low cost/small box thing is critical.

The more HT capable subwoofer is the TangBand W6-1139 I used these for the system I built for my mom and with the little time I had with them was impressed. Tiny box, big excursion, good distortion behavior, can get low extension for such a small driver, and it's built like a tank so the occasional overpowering low frequency effects won't hurt it. Although a sub amp with a HP of some kind may be a good idea. The 8" version may work well too, I've just never had a chance to look at its response. I want any trouble well away from the passband.

So main options are which woofer, how many, and how to power them. Plate amps for each is the design, but there is no reason on can't use a single big amp for all of them. This does impact the flexibilty of integration though, so I'll go into that in more detail when teh time comes.

The enrty level is to use the standard one subwoofer. Move it around and play with gain, and polarity until it sounds decent. ARTA and mic can definitely be helpful here but not required.

The next step up is three subs with more rigorous room/speaker integration. I'm investigating Geddes method and a couple others, but what I can say is this will require a person to download ARTA and get a microphone. We won't be doing all the advanced stuff for ARTA so it's pretty much plug and play, and I'll post a walkthrough for the technically inclined. Use pink noise in the spectrum generator and start tweaking sub levels, phase, and LP to get the smoothest and most evenly summing response you can. That's just the broad strokes, but I really do expect it to turn out quite impressive.

Anyway I don't want to give up too many secrets. This will really be a highly refined system, where small formfactor and very high quality sound will not be mutually exclusive.

[bobhowell]

Sounds interesting. I will keep watching for progress.

[peter_m]

Augerpo,
have you considered the Likwitz pluto sub? I've built mine but I still have t work on the equalization filter. It's a 10" peerlees woofer in a 14L sealed enclosure. Only down side is it's not very sensitive and require about 100w.

Any how, I can't wait for your new BB to be finished.

Peter

[augerpro]

Like I said you can use anything you want as long as the criteria is met. The Pluto sub does that and could be used if one wanted a small sealed box with an LT circuit. You wouldn't use the 100hz LP of course.

For me I'll stick with either the Silverflute or TangBand since both will fit in small ported boxes so I don't need the additional expense of making an LT circuit. The Dayton RS or even RSS are usable options too. I just didn't consider them due to the large boxes they require.

[bobhowell]

BTW if anyone is thinking they may build the new BB, the Foster WF-100k amp here: http://home.comcast.net/~jhidley/ is absolutely perfect for the subwoofers. Better than the Dayton ones in every way that is important for this design. And it's only $35. The "kickass" version (which is what I'll be building for myself) is using three small subs. I'll be buying three of these amps when I get home, so glad I ran across this today!

I have been looking at these amps for 6-8 months but could not understand the electronics included. Since you like them and I am building something similar, I just got two. I can't make out if there a way to cross over from the Bose Busters to the sub at 150-200hz, or will I still need a av receiver with its xo. Anyway, I know many fetchers are included to facilitate sub integration with mains and look forward to your writeup.

Thanks

Bob

[augerpro]

A HT receiver is mandatory for this design, but how the receiver and sub amp implement their low passes can vary and will determine how you set it up. LR4 for both high pass and low pass are the targets for my system. The nice thing about the NHT amp is it uses an LR4 low pass, and it maxes at 200hz, which is exactly my intended starting point for the BB2. Some receivers only have 2nd order low passes for some reason, so using only the sub amp to low pass you know you'll be getting LR4. In the case of the NHT and BB2 you would not use the receiver's bass management to low pass the sub (let the NHT amp do it), but you would use it to high pass the mains. The 2nd order electronic filter of the receiver combined with the 2nd order rolloff of the sealed mains will yield roughly LR4. Now you have LR4 on both HP and LP.

With another amp you may bypass the subs LP (if possible) and just use the reciever's low pass. Or you may be forced to use both. In that case you probably won't end up with LR4, unless you happen to have one of the few receivers that only use 2nd order and you have something like the Dayton amps which also are 2nd order, so you would use both for an effective 4th order low pass. Otherwise you would have no choice but to use some wierd combination that would yield LR6 or LR8 low pass, it would just take more finessing with a mic and spectrum analyzer is all. At lower frequencies you just won't get perfect integration because of the room even with perfect LR4 filters on both sub and mains. You just have to measure and tweak. Using high order slopes won't be perfect but at least the problem area will be small since the sub would roll off so fast. But as frequencies get higher than the rooms Shroeder frequency having the slopes match relatively well will be important. This will probably be the case for the BB2 and most any small sub/sat system.

Simply put the mains will almost always be high passed through the receiver, but the sub may or may not be depending on what slope the sub amp and receiver low pass is, and whether they can be turned off or if you are forced to use them. Hope that all made sense.

[bobhowell]

I am starting to understand the problem and the solution.

Thanks

Bob

[augerpro]

I realize that was probably a long confusing answer to your simple question. What order slopes does your receiver use? Where do you plan on crossing them to the mains?

PS-There are some tweaks you can do with these amps and I probably would. Foe example the high pass to protect the sub is a little high (29hz) for my taste, and you may or may not need all that boost. Although it could come in handy if a person used the Silverflutes...hmmmm