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Discussion Starter #1
As the title says, this is a little different than your normal subwoofer build. It's not your ideal design/build for massive amounts of low-end bass, however, it does/did pretty well with the mid-bass region. This sub has a lot of sentimental value to me



To start, my dad and I built this back in 1995 (I was 13). Back then, I thought Bose was a decent speaker builder and saw an acrylic Acoustimass module sitting out on display. At 13, I knew I would never be able to buy a complete system from Bose due to the high prices and my $7 a week allowance (when I wasn't in trouble), so I asked my dad if we could build one.




We used 3/4" plywood and 6 1/2" woofers (vs 5 1/4 that Bose used). At the time I couldn't just get on the 1nt3rw3bz and order parts, so we were stuck with what we could find local at a reasonable price. We ended up using some Radio Shack "Subwoofers" and had to improvise on the front port... For that we used some plastic martini glasses and the top/lid to some hair spray (and lots of glue). We picked up some crossovers from Radio Shack as well. Here are some pictures from when we first built it.




I was 13 in this pic (thank God my parents got me braces!)



Finished in 1995





Although the port looked decent, it was HORRIBLE for sound and would lead to LOTS of port turbulance. This helped make the sub extreme sweet spots.... You'd have to be VERY careful on placement, or all you would get is port noise. I also found the crossovers we used vibrated as we mounted them straight to the wood. With some of the higher bass tones, I could hear these things just vibrating against the wood like crazy.


The port we made: Not ideal, but I didn't know better then.





Now, it's 2009 and I was listening to some music on my computer and though, "man, I would really like some bass to go along with these tunes" and asked my dad to send me my subwoofer from home. I thought, that I could cut out the back, add a plate amp (BASH 300S) and replace the port with a Precision Port flared port tube and it would sound a whole lot better and I wouldn't need to find a way to power the sub. Well, as lovely as Fed Ex is, they manage to drop the box from high enough to do some damage, so now I'll be sanding the entire thing down, filling and refinishing.


Damage





How the rest of it looked. When my dad refinished his Klipsch LaScala's, he didn't put the emblems back on so I took one. I'll leave it off this time around.






When I cut the back out, I knew I would have to go through a crossover, but didn't think I would get hung up as bad as I did. It did cause me to remove more material than I wanted to in that area, but not enough that the amp could not seal.... Because I am picky, I am going to build that area up and sand it so it is straight and smooth. I did end up damaging the speakers during the process, but I sort of expected to replace them anyway as I'm sure there is a much better speaker available than the Radio Shack ones we used.


So here is where I am now. My plate amp fits nicely and I'm looking to replace the busted speakers with these Vifa woofers. I am also looking to replace the port with a Precision Port 3" flared (both ends) port tube. Lastly, this time around, I'm going to use some Liquid Nails on all the corners in the inside of the box to ensure there is no air leakage anywhere.












Now here come the questions...


- Does anyone see any reason not to go with the Vifa speakers I picked out?


- Is there a better suit for this application?


- Anyone have any ideas to throw in?!
 

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wow...


father son diy. no beating that.


what you have there is called an 8th order triple reflex band pass enclosure.


bose is one of the few companies that used it.


amazingly, i was able to find a calculator for you (complete with instructions).


anybody who comments on the sound quality of this design or of bose products, clearly doesn't understand the whole point of this thread.


good luck with your build.


EDIT: this guy has a simulator for 8th order bandpass that you can download. click on "download link" on the left side. http://www.geocities.com/f4ier/newsubsim.htm

 

8obp.zip 135.41796875k . file
 

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Wow that's pretty cool. Despite your port not working, correctly, I do give an A for effort.
 

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I'm 2 years older than you and I still do those father/son projects. A lot of fun, aren't they?
 

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I was just thinking about 1995. At the time we paid $45 a month to use a gopher BBS called VA-Connect. (Blue and white on the old procomm plus) They got a conduit to the internet that you could pay $90 extra for 5 hours usage a month.




I think at the time I had a Yorx brand stereo and it was the greatest thing since sliced bread.
 

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Quote:
Originally Posted by LHD21 /forum/post/16310579


I was just thinking about 1995. At the time we paid $45 a month to use a gopher BBS called VA-Connect. (Blue and white on the old procomm plus) They got a conduit to the internet that you could pay $90 extra for 5 hours usage a month.




I think at the time I had a Yorx brand stereo and it was the greatest thing since sliced bread.

lol The good old days of 3600 baud modems and procom plus.
 

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Neat build by the way. My first DIY was a sub for my first car that I made with my dad around 1992.


Good times.
 

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Discussion Starter #9

Quote:
Originally Posted by LTD02 /forum/post/16307987


wow...


father son diy. no beating that.


what you have there is called an 8th order triple reflex band pass enclosure.


bose is one of the few companies that used it.


amazingly, i was able to find a calculator for you (complete with instructions).


anybody who comments on the sound quality of this design or of bose products, clearly doesn't understand the whole point of this thread.


good luck with your build.


EDIT: this guy has a simulator for 8th order bandpass that you can download. click on "download link" on the left side. http://www.geocities.com/f4ier/newsubsim.htm

Thanks for the additional info!! I'm glad you guys all see were I'm coming from. It's not a horrible design and it generally sounds decent for what I'm planning to use it for. I always loved how it turned out (build quality/finish), but learned a few things in the process.

Quote:
Originally Posted by LHD21 /forum/post/16310247


I'm 2 years older than you and I still do those father/son projects. A lot of fun, aren't they?

Yup! I don't get to do them much anymore. I haven't lived in the same state as my dad since 2001. He felt horrible for the damage happening during shipping, so he wants to come out and help me finish the wood once everything is fitted and ready to go.

Quote:
Originally Posted by k_t /forum/post/16310626


Neat build by the way. My first DIY was a sub for my first car that I made with my dad around 1992.


Good times.

This was my first sub build
My dad and I later build (1999) a sub for my car at the time using two Cerwin Vega, Vega Series 12" subs (400w rms per sub) in a 5 cubic ft box and two 4" (x12" IIRC) Precision Ports flared on both ends. It definitely produced enough bass (I'll have to scan a photo in later) to make my eyes, head, and throat hurt. I eventually traded them for an engine.

Quote:
Originally Posted by dhgilmer /forum/post/16310637


This looks like a great project. I'm sure you and your dad will both love seeing it upgraded a little.

Thanks, I hope I can do it justice!


Can I assume the Vifa woofer choice I made is a good one? Any other suitable woofers out there?
 

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Thats a pretty cool build! I remember seeing the same acrylic sub at Dayton's sitting right next to the 901's. My dad ended up buying a set of AM5's, the first day that he wasnt home, I took the sub apart. At the time it sounded really good. He just liked it because the sub was "Unobtrusive"
 

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Discussion Starter #12
 http://www.parts-express.com/pe/show...number=297-305



Power handling: 70 watts RMS/100 watts max * Voice coil diameter: 1-1/4" * Voice coil inductance: .55 mH * Nominal impedance: 8 ohms * DC resistance: 5.8 ohms * Frequency response: 37-5,000 Hz * Fs: 37 Hz * SPL: 88 dB 1W/1m * Vas: 1.23 cu. ft. * Qms: 1.55 * Qes: .45 * Qts: .35 * Xmax: 4.0mm * Net weight: 2-3/4 lbs. * Dimensions: Overall Diameter: 6-5/8", Cutout Diameter: 5-3/4", Mounting Depth: 3", Magnet Diameter: 3-9/16", Magnet Height: 1-1/8".
 

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Quote:
Originally Posted by yamahaSHO /forum/post/16312504

http://www.parts-express.com/pe/show...number=297-305



Power handling: 70 watts RMS/100 watts max * Voice coil diameter: 1-1/4" * Voice coil inductance: .55 mH * Nominal impedance: 8 ohms * DC resistance: 5.8 ohms * Frequency response: 37-5,000 Hz * Fs: 37 Hz * SPL: 88 dB 1W/1m * Vas: 1.23 cu. ft. * Qms: 1.55 * Qes: .45 * Qts: .35 * Xmax: 4.0mm * Net weight: 2-3/4 lbs. * Dimensions: Overall Diameter: 6-5/8", Cutout Diameter: 5-3/4", Mounting Depth: 3", Magnet Diameter: 3-9/16", Magnet Height: 1-1/8".

Just be careful with the gain knob. 300 watts is quite a bit more than the vifas need



But that box may affect their power handling, someone smarter than meed needs to weigh in on that.
 

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Discussion Starter #14
The old Radio Shack subs handled 40rms/80w peak and they did okay, but I could definitely pop those suckers if I had wanted to (I tested the amp out with them). This definitely won't be an ear shattering sub, but I think it will have decent output. I was aiming at a sub amp that not only fit the back, but would give me some "headroom"
 

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This looks like a fun sub to build, lots of chambers and pretty go frequence response out of 6.5 speakers. Not a HT sub but fun even with out the DIY/Father-son side to it.
 

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Discussion Starter #16
I just placed an order for the speakers last night along with some foam to seal the woofer chamber. I've been trying to order the flared port for about two weeks now and the site keeps messing up. I sent them another e-mail... I'm ordering the Precision Port from the link given on the site as I want one without mounting holes.


I think I may try the sub out somewhere else now... If it sounds decent, I may get a receiver for the living room and add it to my RSX-3's I have for a hidden surround sound. I don't know if I can get the wife to approve though since she's letting me do theater in the basement. We'll see...
 

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Quote:
Originally Posted by yamahaSHO /forum/post/16351343


I just placed an order for the speakers last night along with some foam to seal the woofer chamber. I've been trying to order the flared port for about two weeks now and the site keeps messing up. I sent them another e-mail... I'm ordering the Precision Port from the link given on the site as I want one without mounting holes.


I think I may try the sub out somewhere else now... If it sounds decent, I may get a receiver for the living room and add it to my RSX-3's I have for a hidden surround sound. I don't know if I can get the wife to approve though since she's letting me do theater in the basement. We'll see...

Play the sentimental card. It was something you and your dad did. Surely she can't say no to that? Maybe pull a leg hair or something to tear up a little
 

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Discussion Starter #19

Quote:
Originally Posted by filtor1 /forum/post/16352104


For some odd reason, I cannot view any of the pictures past the first one.

Hmmm... That's odd as they're all hosted from the same place. Have you tried right-clicking and "show picture"?


Quote:
Originally Posted by dhgilmer /forum/post/16352135


Play the sentimental card. It was something you and your dad did. Surely she can't say no to that? Maybe pull a leg hair or something to tear up a little

Haha... I'm trying to figure out something. I wish I could find a good 5 channel amp (don't need much power) that I can hook up to my HTPC and have it on auto-sense turn on. She doesn't want to mess with a receiver for sound.
 

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Yeah, I tried to show picture. Yours aren't the only ones that are random. I need to figure out what has changed so I can get back into the swing of things.
I wonder if it is an issue with IE. I will keep trying.
 
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