OT: Subwoofer project to support your Altecs.

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Originally Posted by alancohen

I would think you'd want more power handling for a sub. 250W min. It's amazing how much power it takes to drive 25-30Hz.

Here's an interesting link about a down and dirty home made sub(s). They're made with 8" drivers in a 5 gallon paint bucket and powered by a Crown XLS1000. I'm almost tempted to try a pair.

Subwoofer Project - Transcendent Sound Message Board

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Rather than hijack Phil_Gs thread I thought I'd start another one.

There never seems to be a shortage of inquires on how to get your Altecs to play down to 25Hz or how to marry subwoofers to them to fill in the bottom.

What I have gleaned from much of this constant conversation is that Altecs have some pretty incredible mid bass down to about 50-60Hz, but trying to get them to play to 35Hz leads to sacrificing some of what Altecs do best. I prefer not to do that. So intigrating a subwoofer seems to be a worthwhile project.

I have a little KLH 10"er that does something, but it is far from a musical subwoofer. I have seen a Muse, some Rels and others, but I really don't want to spend $1000s of dollars on a sub. I also want two, so cost is a factor.

I came upon the thread cited above and at first poo-poo'd it. But the guy who designed them has been making a living designing, building and selling speakers for 30 years and even he is amazed how good they sound. And Bruce of TS just built one and measured it. It's flat to 25Hz at 106dB when XOer at 100Hz.

It's such a cheap project and about an hours work so I don't think I can resist building two. I have several spots around the LR where I can hide 2 easy. Crown XLS1500s are $357 shipped at Amazon.

Here's the direct link to the project: http://www.transcendentsound.com/Tra...Subwoofer.html

I'll put it on my bucket list to build one...:cool:

Some projects like this turn out quite well. No knowledge on this one. But would give a listen if local.

The only question is Lowe's blue or Home Depot orange.

I’ve got a pair of (300 watt rms) Alpine SWR 1040D 10 inch subs in .75 cu ft sealed boxes and am using just a 15 band EQ to boost the 31.5 and 40hz ranges 12db and cut the rest 12db for a crude active low pass filter and behind my 150 watts rms Crown DC300A at 8 ohms.

This is paired with my 8 cu ft altec 418-8H II guitar speaker/32B/806-8A w/ pascalites and one lone Piezo super tweeter.

As bad as this might seem, I like em.

(Edit:) Sorry, I thought that this was a generic thread on subs. I have deleted the junk I included on mine.

The Dayton 12" that I have does a fantastic job of creating house shaking bass. at $120.00 plug and play...meh it's pretty hard to beat.

Here's a review I came across when researching the Peerless driver:

Exceptional value subwoofer
I built a subwoofer using this Peerless driver after hearing Ed Schilling's (Horn Shoppe) simple subwoofer. Ed mounted this driver in an inverted 5 gallon pail loaded with quikrete at the lid end. There are instructions and photos on the Horn Shoppe forum for making this contraption.

Those limited efforts result in a nimble, acoustic suspended, up-firing subwoofer that should mate well with just about any speaker. It isn't just a great little inexpensive subwoofer, it's articulate and natural sound place it firmly with the most "musical" of the genre. It's ability to reveal those bass layers and nuances make the system's overall presentation more coherent and believable. It's quite an eye-opener for little cash. And two are better than one (I'm all in for another after hearing the dynamic duo). :o)

The Madisound Speaker Store

Parts ordered.
I love this part of the instructions:

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Cut hole in bottom of bucket. Test the fit. Get another bucket if you screw it up.

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Originally Posted by Alien_Shore

Parts ordered.
I love this part of the instructions:

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He's quite the character. That's part of the charm of this project for me. That, and he's not a home theater guy. This is reported to be a very musical sub. I pondered swapping out the Peerless driver for a Tang Band W8-704P which has "better" specs. But he insisted "do so at your own risk". "It works the way I designed it." I felt scolded and ordered the Peerless.

Alan,
do you think this plate amp will work for one bucket?

Dayton SA100

If only running the one bucket, it'll be 8 ohm, so I'll only get 75w out of the amp, and figured that may not be enough oomph, especially that the sensitivity on the peerless is only 80-something...

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Originally Posted by Alien_Shore

Alan,
do you think this plate amp will work for one bucket?

Dayton SA100

If only running the one bucket, it'll be 8 ohm, so I'll only get 75w out of the amp, and figured that may not be enough oomph, especially that the sensitivity on the peerless is only 80-something...

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It should. Bruce is using this one Bash 300W Digital Subwoofer Amplifier 300-750 for not much more $$$. I'm a fan of you can't have too much sub power.

Got 'em done.

http://www.hostboard.com/forums/hbmc...2013/08/13.jpg

It was quite a saga. I first tried painting them, but nothing sticks to this plastic. These had Walmart logos on them and that didn't even stick. So I guess I'll live with WM blue until I find some black ones.

The second issue was the Crown amp. I guess this is a pro level amp and not designed for home audio. My 12dB Grounded Grid preamp would not drive it. Even though Crown support says it has a 1.4V input sensitivity and my main amp is 2.2V and it drives that one just fine. Hum...

Every one else that has used this amp uses high level inputs paralleled off the main amp speaker outs with an inline resistor to knock the voltage down rather then the low level RCAs. I started with a 2.2K Ohm and ended up at only 220 Ohm to get the gain right. Here's a pic of the experimental cable I used while switching out resistors:

http://www.hostboard.com/forums/hbmc...2013/08/14.jpg

So now that I had output, I set off to trim it out. I've settled on 53Hz. The volume is about 8.5 of 10. At that level I can't 'hear' the subs when they're on, but the bottom drops out when they're off. That's the way I want it. Like adding salt to my soup. I want to bring out the flavor, but I don't want to taste the salt.

The blend is uncanny. My old KLH gave up some sub sonics, but it sounded dry and monotone. More of a vibration than a musical note. These sound sweet and smooth and very musical. I really can't tell where my Altecs end and these begin...until I turn off the Crown. Then..."oh, where'd all that nice deep bass go?" When I turn it back on, I can't really hear the bass come back...until I turn it off again. Nice.

Awesome job, Alan.
My first bucket is nearly complete - waiting for the concrete to hydrate.
While I am waiting for that, I played around with some box calcs for this Peerless 8" sub:

http://imageshack.us/a/img9/8155/y36c.png

This plot shows that sub in my sealed box (0.5 CF is about what's inside the bucket), and in a 3 CF vented box. What a difference!
What I don't know is what WinISD is doing regarding box shape and how it would differ if it could model a cylinder.
Perhaps the next experiment is to take a 40 gallon brute trashcan and try out a 12" LoL!

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Originally Posted by Alien_Shore

Perhaps the next experiment is to take a 40 gallon brute trashcan and try out a 12" LoL!

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I was thinking the same thing! Then I thought of the amount of concrete required...

There's a funky component going on with the bucket too. It certainly is not rigid. The whole thing vibrates. Ed strongly urges to resist stuffing with fill or damping it in any way. The bucket itself becomes a passive radiator of sorts. So sound waves certainly shoot out the top, but they must also radiate 360* around as well.

What was also not expected is that they can take a punch. I was cranking out some old Madonna and the whole floor was shaking. And they're sitting on 3 rubber feet!

Most programs just define the cab's air mass as having a uniform particle density in an infinitely rigid cab, i.e. has no resonant modes, so shape is irrelevant and the vent's output is in the same location as the driver. MJK's more recent MathCad software is a bit better as it adds another dimension in length to include its 1/4 WL resonances and an adjustable driver and vent location along it, but still no 3D [width x depth] modes. AFAIK, of the programs available to the DIYer only AkAbak does 3D.

In short, as long as the cab's LxWxD are all near the same and the driver , vent on the same vertical side, then the programs are pretty accurate if measured outdoors on a large flat area.

The 'breathing' bucket lowers the speaker's effective Qtc [Qtb if vented], so can really 'tighten up' its transient response, so no need for any internal damping.

A 40 gal. trashcan has enough of a high aspect ratio to require using MJK's or similar software to more accurately sim it, though none can sim the 'breathing' cab's variable Q damping.

Even though the driver is upward firing, its BW is so large acoustically [80 Hz is a ~54" diameter 'sphere'] that it will still mirror image as a vertical 2pi [half] space radiator, though through the XO BW it may sound more 'airy' if it doesn't have a steep slope order.

GM

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Originally Posted by GM

A 40 gal. trashcan has enough of a high aspect ratio to require using MJK's or similar software to more accurately sim it, though none can sim the 'breathing' cab's variable Q damping.



GM

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That explains why when I drop one of my 40 gallon trash cans back onto the floor after emptying in I get one hell of a bass note from it, especially in the bathrooms. :D

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Originally Posted by GM

A 40 gal. trashcan has enough of a high aspect ratio to require using MJK's or similar software to more accurately sim it, though none can sim the 'breathing' cab's variable Q damping.



GM

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That explains why when I drop one of my 40 gallon trash cans back onto the floor after emptying in I get one hell of a bass note from it, especially in the bathrooms. :D

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Originally Posted by GM

A 40 gal. trashcan has enough of a high aspect ratio to require using MJK's or similar software to more accurately sim it, though none can sim the 'breathing' cab's variable Q damping.



GM

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That explains why when I drop one of my 40 gallon trash cans back onto the floor after emptying in I get one hell of a bass note from it, especially in the bathrooms. :D

And an echo. :rolleyes:

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Originally Posted by GM

Even though the driver is upward firing, its BW is so large acoustically [80 Hz is a ~54" diameter 'sphere'] that it will still mirror image as a vertical 2pi [half] space radiator, though through the XO BW it may sound more 'airy' if it doesn't have a steep slope order.

GM

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The Crown XLS1500 has selectable crossover points between 50Hz and 3kHz on 1/12 octave centers. They use 4th order Linkwitz-Riley filters.

As it turns out, my first Crown amp was a dud. I got it off ebay supposedly new, but who knows. I have a feeling someone hooked it up and blew out the inputs. My preamp that can produce a 12dB gain at RCA level couldn't get a whisper out of it. I had to run high level outs, paralleling off my main amp to get it to do anything.

The replacement came today and ...wow. Just wow. I'm bridging it mono and paralleling the two buckets subs at 4 Ohms. I'm guessing thats somewhere around 525W into each sub. Peter Tosh never sounded so good. I'm crossing over at 59Hz right now. It seems right.

Hostboard was screwing up not me. :D

Regarding low and high level inputs, the few guys that have made these and tested them extensively all say the same thing: that they sound better running high level inputs paralleled off the main amp instead of low level (RCA, XLR) inputs. It's not just a gain issue, the claim is that they blend better in that configuration.

I guess that kind of makes sense since you're taking the sub inputs right off the main outputs. Whatever characteristics that are inherant in the main are translated to the sub amp.

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Originally Posted by cradeldorf

That explains why when I drop one of my 40 gallon trash cans back onto the floor after emptying in I get one hell of a bass note from it, especially in the bathrooms. :D

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this may be a new trend
Man lives in Brooklyn dumpster - New York News

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Originally Posted by alancohen

Regarding low and high level inputs, the few guys that have made these and tested them extensively all say the same thing: that they sound better running high level inputs paralleled off the main amp instead of low level (RCA, XLR) inputs. It's not just a gain issue, the claim is that they blend better in that configuration.

I guess that kind of makes sense since you're taking the sub inputs right off the main outputs. Whatever characteristics that are inherant in the main are translated to the sub amp.

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I'm still evaluating. I'm running a fairly cheap 100w plate amp, and so far it is working better with the low-level inputs.
Here's the finished Alien_Shore redneck bucket:

http://imageshack.us/a/img687/8262/9t92.jpg

Look at you....

Nice job. I'm still amazed how great these sound for how little investment, both in time and $$$.

100W will get you in the game. Overall sound and blend will depend on the crossover in the amp. I'm already invested in the crown(24dB L-R), so the cost to add more buckets is almost nothing. Two sound exponentially better than one. I'm heading for four.

I'd strongly recommend removing the handle. These things have quickly uncovered everything in my living room that can rattle.

Just need to slap a lamp shade over them to spruce them up. :)

If there is a Firehouse subs in your area they sell Fire engine red buckets with their logo for a couple bucks...used pickle buckets

http://arewecrazyorwhat.net/wp-conte...4/P1090358.jpg

Going to bed, outta here at 4 AM. SOMEBODY wants to be on the beach tomorrow afternoon.

I was thinking that in order to get the subs past my wife, I'd build a pair of simple veneered open ended rectangular boxes, 1" larger all around than the subs, put a few rubber feet on the bottom and a drop in cloth grill on the top. Just put the sub where you want it and drop the box over it. This may also add some insight as to whether just the speaker or the entire bucket was contributing to the sound - drop the cover on, and if the sound degrades, throw the cover out.

Ed

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Originally Posted by edharbur

I was thinking that in order to get the subs past my wife, I'd build a pair of simple veneered open ended rectangular boxes

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if you're going to build something using that particular driver, you may want to go 3CF vented, tuned to 30Hz.

Oh, and OG, those are some hot looking buckets!

My thinking was that I"d build, wire, and amplify the subs exactly as designed, and just put the decorative covers over them, which, hopefully, will not effect the sound in any way. This puts me in the subwoofer game without too much time or or money, and establishes a benchmark for future projects.

Mike - how do you like your bucket subs? Do you think that the 3 cf box would outperform the bucket?

Ed

Seems like it would restrict the bucket's ability to 'breathe' [flex], which is part of its 'charm'.

GM

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Originally Posted by edharbur

Mike - how do you like your bucket subs? Do you think that the 3 cf box would outperform the bucket?

Ed

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I really like it so far - we threw a birthday party this weekend at an outdoor venue, and I used the bucket there - it did pretty well under the pavillion.
As far as the 3CF box, it's really hard to say, since as GM indicates, the thin flexible bucket is definitely doing some "reinforcement" of the sound, but it's hard to argue with the WinISD plot of the 3CF box tuned to 30 Hz using a single round vent 2.68" diameter 3.63" long; it's worth a try!

Glad you like it Mike. My A5s sound anemic without them now.

As Ed would tell you, it works great "as is". The design is complete. It just works. Any changes or modifications will not yield the same result. It might yield a good result, but not the same. I even asked him what brand deck screws he used.

The real beauty of them is just how easy they are to make. It literally took me an hour to build 2. Talk about form follows function! They sure don't get any style points, but big, big function points. They don't just sound good for buckets subs. In a home audio environment, they sound good for any subs at any price.

I agree with you GM - I'll make a quick and dirty prototype out of MDF and staples. 20 minutes; done.

This just in, source for premium buckets in designer colors!!

http://www.youtube.com/watch?v=e9dkDwXBsMY

Green! LOL.

The Walmart blue is growing on me. Once you hear what they sound like, appearence is irrelevant.

I've been listening to my 604s a lot lately with my new vintage TT and Scott amp. They sound great and there is bottom to spare. I'm working my way through my entire album collection.

Just when I think that I couldn't ask for more, I fire up the A5s and bucket subs and am instantly transported back to the reality of BIG-BIG sound. The 604s sound great. The A5s with a little help from 30-50Hz ARE great. I couldn't ask for anything more, except maybe a larger room to really let them breathe.

I'm actually a little sad about this. I guess it's like post pardom depression. After all the effort to put this system together, it's done and it's everything I could ask for. I'm done. My audio system is complete. Now I get to just listen to it.

http://www.youtube.com/watch?v=XdroQF4ORsE