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post #1 of 86 Old 10-07-2011, 03:51 PM - Thread Starter
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Hello, my name is Jonny! Been a lurker here for a while but now I am looking for some criticisms with my latest upcoming mobile audio build. For years I've been rolling around LA with my bike crew doing mobile parties in lowkey places

We've been using mainly JBL's Eon series (510,515,518s) because they are lightweight and efficient, but they run on AC so we have to use inverters and bigger-than-necessary batteries. However they sound great outdoors and are totally rugged- almost 2 years strong so far. Battery life is about 10 hours and easy enough to pull 20-30 miles in a night.

For the new system I want to do away with the inverters and the heavy batteries and also extend the range of the audio, so I'm going to use a tripath based amp and build my own speaker enclosures.

What do you think of using these components for a DIY bicycle system build?

Build components!
Sure 4x100w Class D amp
Dayton PS180-8 6.5" Full Range Driver (2X)
Dayton NS270-44 10" Neo DVC Subwoofer

Wiring
Sub (each voicecoil hooked up to a channel at 4ohm 100W, 200W total)
2X Full range speaker (8ohm ~30W)

I am most concerned about the bass. Tuning the sub box with WinISD I am using 1.33cu/ft enclosure with two 2" ports and F3 around 30hz.

Let me know if this speaker choice is a bad idea. I am looking for extended bass and audio clarity for music in a small lightweight enclosure. I just don't know if this setup will match well because I do not have enough experience actually building speakers!
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post #2 of 86 Old 10-07-2011, 04:05 PM
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Maybe try out one of these :

http://www.parts-express.com/pe/show...number=300-380

Powered by 8 AA batteries. One woofer per channel.

I would suggest tuning quite a bit higher than your target, and I would use pro woofers instead. ( higher sensitivity ) Think ~40 hz ish tuned.

Any of these your buddies?


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post #3 of 86 Old 10-07-2011, 06:45 PM
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I can see some crazy horn designs on this. They are about as efficient as it gets. Check out some of the horn designs here and also on Bill's site.


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post #4 of 86 Old 10-07-2011, 08:45 PM - Thread Starter
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No, those are not any of my buddies... but I think you are getting the picture!

I don't think 8AA batteries are going to be enough to power the size of system I'm hoping for though

My goal is to get a nice extended bass response out of a small enclosure. The setup now sounds good at anything above 58hz with the EON 510, 40hz I'm sure would be a huuuge difference from that.

...I didn't see any 10" neodymium pro woofers that dig any deeper than 50 or so herz. Looking at the 12" selection I am still not seeing much below 45hz.

I am limited to about 1.5cu/ft of enclosure volume on this particular bike. I might be able to squeeze out a little more if I get creative.

I don't see any pro audio speakers that will even get down to 40hz without a 15" or higher... unless I am missing something?
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post #5 of 86 Old 10-07-2011, 08:57 PM
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Quote:
Originally Posted by jonnyb0y View Post

No, those are not any of my buddies... but I think you are getting the picture!

I don't think 8AA batteries are going to be enough to power the size of system I'm hoping for though

My goal is to get a nice extended bass response out of a small enclosure. The setup now sounds good at anything above 58hz with the EON 510, 40hz I'm sure would be a huuuge difference from that.

...I didn't see any 10" neodymium pro woofers that dig any deeper than 50 or so herz. Looking at the 12" selection I am still not seeing much below 45hz.

I am limited to about 1.5cu/ft of enclosure volume on this particular bike. I might be able to squeeze out a little more if I get creative.

I don't see any pro audio speakers that will even get down to 40hz without a 15" or higher... unless I am missing something?

If you use sonotube, you can achieve more volume internally with the same bulk. Fiberglass the outside, and you are good to go. You could always find a piece of green PVC pipe, and add endcaps, but beware it is HEAVY and thick compared to sonotube.

Neo woofers are nice, but pricey, especially since China raised the prices of the raw neodymium.

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post #6 of 86 Old 10-08-2011, 03:29 AM
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Hi jonnyb0y,

I've been on a few SoCal bike party rides (C.R.A.N.K. MOBs). Super fun!

I've also spent some time thinking about what it would take to make a good music bike. Your selections tell me that we think alike: it is all about sound for the pound. Sensitive speakers and efficient amps. Neodymium woofers.

I'm not a speaker designer, but I know just enough to have some (perhaps stupid ) ideas...

MAINS:

Those full range drivers have neo magnets and are pretty sensitive for dynamic drivers. And not having to include a crossover will save both weight (inductors can be pretty heavy) and complexity. That seems like a pretty good choice, IF they can play loud enough and have wide-enough dispersion.

However, I do wonder if you might get better sound, more sensitivity, and more SPL from a CD (compression driver) and a neo pro midwoofer. You could use an active crossover. Perhaps even a really simple one made with a handful of electronics parts (I think), since the speaker does not need to be super accurate. You could run just one of these 2-ways pointed out the back of the bike. Or maybe point one out the back and another out the front. You could run it mono. Use one amp channel for the CD(s) and another for the midwoofer(s). Use a Sonotube for the midwoofer enclosure. You'll probably want a neo CD, too -- CDs with ferrite magnets are heavy little suckers. This setup might be kind of nice in that you could blast sound out the back and/or front without it being deafeningly loud for you, and you might even be able to hear someone on the bike next to you.

Or maybe there is some better way to do this since you probably don't need as much output as a normal CD? Here's a not-so-huge speaker design with high sensitivity, lots of SPL capability, and wide dispersion:
http://www.billfitzmaurice.com/Wedgehorn.html

Perhaps it could be useful to think of this as a 3-way, with the "sub" playing up higher than most home theater subs play -- something like 200Hz, maybe higher. And then the challenge of making a high-output, high-sensitivity "top" might be a lot easier. It does seem like the pursuit of bass extension is what causes a "top" to be relatively large.

BASS:

If you go with a ported box for the sub, a Sonotube is surely the best option for the enclosure. They are pretty light and they are strong because of the shape. A box with the same volume would almost surely weigh a lot more. You could have two and mount them like bass canons on the sides of the bike.

However, at the expense of more enclosure weight, you could get more sensitivity (= less battery, and perhaps higher SPL) from a horn-loaded sub. Here's a small-ish one, but it is still pretty big:
http://www.billfitzmaurice.com/autotuba.html

In the interest of maximum sound for the pound, I wonder if it is possible to design a horn-loaded sub that uses a Sonotube as the outer surface? Maybe there is some way to install some divider boards (and bracing) within the Sonotube to produce a bass horn. That seems like it could be an interesting design challenge.

Alternately, making a horn that divides so that it can be placed on a rack over the rear wheel of a bike could be interesting. It might look like a combined trunk bag + panniers. Or maybe the horn extends only down and out from one side (flaring as is descends), and the other side can hold batteries and electronics or something. That way it wouldn't have to "split", which seems like it would be hard to do well.

MORE TERRIBLE IDEAS:

This isn't really a performance-optimized idea, but I think it would be interesting to make a fiberglass speaker enclosure that is part of the bike frame. You could make a weird shape - extending up, down, and/or out the front, back, or sides to achieve the required volume. Paint it up to look cool. That low profile sub driver you specified could even fit in the front triangle without being too wide between your knees. You could do something like this for the "top", too, instead of or in addition to the sub.

If you are carrying some big ass batteries, I don't think it would be cheating to add a hub motor. You could also add some fancy lasers, spoke lights (it could be like a video screen!), EL-wire, etc. that actually respond to the music. Maybe even a cheesy smoke machine? Disco ball?

Maybe a thing where people can txt songs (a link to a youtube video?) and the bike will download and play it. Or maybe they can text you messages and the bike does text-to-speech on the messages between songs. Or maybe have a display screen (scrolling LED, or the spoke lights) and the texted messags would appear there, rather than messing with the sound.

Have two bikes: L and R, and have each one play a single stereo channel. One is master and the other one gets its signal wirelessly. Ride in formation to produce stereo image for those in the right place(s). Bass from one or both bikes.

-Max
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post #7 of 86 Old 10-08-2011, 03:41 AM
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I just noticed that those Sure amps want 12-30v (max 32v), which is sort of a pain to create with 12v batteries: 2 may not be enough, 3 may be too many.

This amp does 2x50w into 8 ohms and runs on 24v (or 12v, but the output will be lower) -- I've used it on a bike before with 12v :
http://www.parts-express.com/pe/show...383&FTR=dta100

I don't know which ones to pick, but some car audio amps might be a good choice, too, since they are easy to run on 12v.

-Max
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post #8 of 86 Old 10-09-2011, 01:37 AM - Thread Starter
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You guys are answering questions I didn't even know I had! Sonotube looks like the best way to go, for sure! Weight is a HUGE factor. Also I believe that sonotube will be much more aerodynamic than a big box enclosure. Win win.

Max, if you've been on C.R.A.N.K. Mob there is a good chance we have met! How rad to meet someone here that has been on rides too!

Making a horn loaded sub using sonotube sounds like a grand challenge and I am definitely up for it. I am interested to know the proper way to shape a horn because I'm sure there is some sort of golden ratio math in there that makes everything work. Seems to me that free dB is the way to be.

So Max, it looks like you are recommending a 3 way system like this:
sonotube sub (maybe horn loaded)
sonotube midwoofer
horn loaded compression driver

That's what you meant, right? Two sonotubes?

Quote:
Originally Posted by maxcooper View Post

...If you are carrying some big ass batteries, I don't think it would be cheating to add a hub motor. You could also add some fancy lasers, spoke lights (it could be like a video screen!), EL-wire, etc. that actually respond to the music. Maybe even a cheesy smoke machine? Disco ball?

Maybe a thing where people can txt songs (a link to a youtube video?) and the bike will download and play it. Or maybe they can text you messages and the bike does text-to-speech on the messages between songs. Or maybe have a display screen (scrolling LED, or the spoke lights) and the texted messags would appear there, rather than messing with the sound.

Have two bikes: L and R, and have each one play a single stereo channel. One is master and the other one gets its signal wirelessly. Ride in formation to produce stereo image for those in the right place(s). Bass from one or both bikes.

Ok here we go...
big ass batteries = hopefully soon to be small ass batteries
hub motor = check
fancy lasers = check
spoke lights = check
spinning midi controlled LEDs = check
spinning LED POV display = in progress
sound sensitive el wire = check
wireless master/slave style stereo transmission = check!

I have a feeling that we think alike, Max!


Quote:
Originally Posted by maxcooper View Post

I just noticed that those Sure amps want 12-30v (max 32v), which is sort of a pain to create with 12v batteries: 2 may not be enough, 3 may be too many.

This amp does 2x50w into 8 ohms and runs on 24v (or 12v, but the output will be lower) -- I've used it on a bike before with 12v :

I don't know which ones to pick, but some car audio amps might be a good choice, too, since they are easy to run on 12v.

-Max

Those sure amps are totally perfect for my needs, or anyone's really. They have a super wide input voltage range. This is especially useful because one can run the amp directly off of bicycle generators or solar panels.

With most 12v systems, over-voltage protection will turn things off at around 15.5v-16v to protect the circuitry. Meaning: a solar panel at 18v or bike generator at 20v could fry normal 12v stuff if hooked up directly with no regulation.

Also you can have any number of 12v batteries and still maintain a 12v open circuit voltage, just have to connect them in parallel. The beauty of having a wide input voltage range means the amp can accomodate about any kind of battery setup- either parallel or series, 12v or 24v.

The only other tripath amps I've seen with more power are the "truepath" ta3020 based amps, which need a 48v supply to even get started. But those are 1200W+ amps! Overkill for the size of batteries I want to haul!


I have a question about the sonosub: in what direction does most of the sound travel? Out from the driver or through the port? Just wondering how it should be oriented.
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post #9 of 86 Old 10-09-2011, 06:23 AM
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I'm still leaning towards a horn design because they don't need a ton of power to put out a ton of sound. Here's an excellent example of one of Bill's designs. You don't have to go this big, but you get the idea.

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post #10 of 86 Old 10-09-2011, 07:01 PM - Thread Starter
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I had a free day today, so I decided to run over to home depot and see if I could build a sonotube enclosure using some old car audio components I had laying around. It worked!

There was some guess work involved because the crappy sub driver doesn't even have t/s specs available anywhere, and is even discontinued.

I got the 12" sonotube, .25" MDF, and some 2" black PVC tube. I wanted to try extending the low frequencies so I upped the enclosure volume by about 33% and tuned to 32hz with 2 ports.

I hooked it up with one of my smaller soundbikes, which uses fostex full range 4" drivers and a 10W tripath amp. The result is a fully extended low end, go figure right? Anyway it is much better than the crappy / too small sealed MDF enclosure it was in before. I am eager to get my hands on some real speakers and build more of these things.

Hope you like it, it's the first time I've ever built a speaker enclosure
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post #11 of 86 Old 10-09-2011, 07:37 PM
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You need to quit tinkering and build a towable DJ booth with integrated subs.

Regards,
Dan
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post #12 of 86 Old 10-09-2011, 08:08 PM - Thread Starter
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Quote:
Originally Posted by NEO Dan View Post

You need to quit tinkering and build a towable DJ booth with integrated subs.

Agree w/ the integrated subs! We've already got the DJ gear strapped and ready to go Another one of my bikes has 510 + 518 sub + DJ gear on a sidehack, with a 70Ah battery bank the life is about 10 hours full volume, and it projects a nice full range sound with long distance- but I don't take it out much anymore because the volume is so loud and it is very heavy (worth it though!).

This new build will go on the second bike pictured below, the lightweight version of the DJ bike.
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post #13 of 86 Old 10-09-2011, 09:18 PM
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Nice
Very cool re-cycle of the BMX bike rear triangle.

Too heavy maybe, but too loud... aw common you gotta be kidding???

Regards,
Dan
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post #14 of 86 Old 10-09-2011, 10:47 PM - Thread Starter
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Quote:
Originally Posted by NEO Dan View Post

Nice
Very cool re-cycle of the BMX bike rear triangle.

Too heavy maybe, but too loud... aw common you gotta be kidding???

Yep too loud! 3 citations after 4 months of use- one of which I had to pay and the other two were luckily thrown out at court. I saw a pattern and did not want to continue down that path. Also I prefer to not piss off the whole entire neighborhood and I really, really hate going to court at all- let alone for something that is supposed to be fun.

So for a while I dialed it back, saved all those dB's and built a big desert bike for burning man. Since then I have been rocking the small fairly nimble setup with wireless, dj rack, and 5 way splitter. So many people have soundbikes here now- having a HUGE system is pointless. When you hook them all together, it's pretty fun regardless.

Here is the DJ trike at burning man
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post #15 of 86 Old 10-10-2011, 06:33 AM
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Have you ever looked at a samson xp40iw?

I set one up for a band director. Removed the 6.5 + compression driver and installed a pair of faital pro m5n12-80's for some more volume, basically for paging, not for music.. In your case you could just change out the iron magnet 6.5 for an eminence alphalite 6.5.

Add a sub/class-d and you are set.. The samson has everything else you are looking for, including an ipod doc. (It even has a 12v to 24v dc-dc converter to run the TI 40watt class d amp)
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post #16 of 86 Old 10-10-2011, 02:08 PM
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Quote:
Originally Posted by jonnyb0y View Post

Hello, my name is Jonny! ...
Build components!
Sure 4x100w Class D amp
Dayton PS180-8 6.5" Full Range Driver (2X)
Dayton NS270-44 10" Neo DVC Subwoofer
...

Quote:
Originally Posted by maxcooper View Post

...Those full range drivers have neo magnets and are pretty sensitive for dynamic drivers. And not having to include a crossover will save both weight (inductors can be pretty heavy) and complexity. That seems like a pretty good choice, IF they can play loud enough and have wide-enough dispersion....

Quote:
Originally Posted by maxcooper View Post

I just noticed that those Sure amps want 12-30v (max 32v), ...

Welcome jonny!
I built a portable system using the PS180's and a 12v Lepai receiver.
http://techtalk.parts-express.com/sh...d.php?t=225559

The PS-series drivers are a great choice if you're staying with conventional drivers, but they do need a contour network to tame the on-axis highs (datasheet FR is real close) and the 180's benefit form a ported box, even with a sub, as they don't dig very low. I suggest you consider the PS220's as they are more sensitive, take more power, and dig lower (but need bigger boxes, thus my choice of 180's).

Just don't ignore the LR contour network. A 0.3mH coil doesn't weight much compared with the sonic benefit of the network.

Finally, amp input voltage is important as that's where you get the power. I run mine on a single 7 amp-hour gel cell, and it's clean at full volume for many hours. I suspect the Sure amp would be fine with two in series.

I like the sono-sub idea as it's hard to beat the stiffness of a cylinder. Perhaps something similar for the drivers, albeit with a lot of stuffing to avoid resonance in a tube. Sure would be lighter than my MFD box - 35 lb. mostly in wood.

Have fun,
Frank.
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post #17 of 86 Old 10-10-2011, 07:40 PM - Thread Starter
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Thanks for the link to your project with the PS180's, Frank!

So they are pretty harsh on axis, even with contouring? That's kind of a bummer. I also just realized that they call for a 1.34cu/ft enclosure, or roughly 21" length of 12" diameter sonotube. That's about the same as the dayton sub I've been looking at. Or I could use a really long 8" or 10" tube and make this thing look like the starship enterprise

The PS220 calls for 2.7cu/ft which is about 40" of 12" diameter sonotube. That is definitely too big, I still have to fit the DJ equipment on there somewhere too. Plus I was hoping the sub would be the biggest enclosure, along with a smaller full range speaker enclosure (or two).

What is your experience with making an enclosure for a full range driver smaller than recommended? Will it just diminish the lows? The sub I've been looking at will take me to 300hz... This also makes me think about the CD + midwoofer option.

Thanks for all the knowledgeable replies. You guys rock, seriously thank you!
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post #18 of 86 Old 10-11-2011, 12:37 AM
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Quote:
Originally Posted by jonnyb0y View Post

Max, if you've been on C.R.A.N.K. Mob there is a good chance we have met! How rad to meet someone here that has been on rides too!

Cool. It's been a few years, but who knows.

Do you camp with RidazzCamp? I camped with RidazzCamp in 2008.

Quote:
Originally Posted by jonnyb0y View Post

Making a horn loaded sub using sonotube sounds like a grand challenge and I am definitely up for it. I am interested to know the proper way to shape a horn because I'm sure there is some sort of golden ratio math in there that makes everything work. Seems to me that free dB is the way to be.

I started to think about this a bit. You can see the folded horns that use rectangular boxes for some idea of it would be like. However, I'm not sure you can do it within a cylinder (sonotube) very easily. I was hoping you could just put some boards inside the sonotube, but then I realized that the non-square shape really presents some challenges. For instance, imagine that the horn starts using the sonotube as the upper wall and a flat board as the bottom. You would slant the board down a bit to create the increasing cross sectional area you need for the horn. So far, so good, I think. The problem comes when you need to make the first 180 turn. I think the cross sectional area will increase too abruptly as it makes the turn, since sonotube gets so much wider as you move away from the tube wall toward the center. Perhaps there is some way to make that work, by taking up some of the volume with "filler", but I'm just not sure what it would take.

I don't really know how to design a horn-loaded sub, but I suspect that having a smoothly-increasing cross section is part of it. I think there is some software called HornResp or something that you can use to design a horn. And then maybe do some crafty stuff to make it fit in a sonotube.


Quote:
Originally Posted by jonnyb0y View Post

So Max, it looks like you are recommending a 3 way system like this:
sonotube sub (maybe horn loaded)
sonotube midwoofer
horn loaded compression driver

That's what you meant, right? Two sonotubes?

Right. Two Sonotubes. Hopefully a not-very-big one for the midwoofer.

At first I was thinking along the lines of "home theater" systems, where it is common to have 2-way speakers and then crossover to a mono sub at around 80Hz.

But the 2-way speakers need to have fairly large cabinets to play down to 80Hz. Or at least I think so -- there are some small-ish bookshelf speakers that play pretty low. But I bet they aren't very sensitive/efficient, or maybe can't play very loud, or both. Anyway, I think it is true that you need a fairly large cabinet to make a high-sensitivity, high-SPL-capable speaker that plays down to 80Hz. That is a problem for your application.

People use 80Hz for the crossover frequency in home theater systems because that is about the minimum frequency that is said to be localizable (you can tell which speaker it is coming from) in a room. But you have no such concern about localizability -- all the sound is going to be coming from your bike (or bikes) anyway.

So my thinking is that you might want to use a much higher crossover frequency for the sub. I think that would allow the midwoofer enclosure to be much smaller. It might be useful to design your project as more of a 3-way rather than a 2-way+sub system.



Quote:
Originally Posted by jonnyb0y View Post

Ok here we go...
big ass batteries = hopefully soon to be small ass batteries
hub motor = check
fancy lasers = check
spoke lights = check
spinning midi controlled LEDs = check
spinning LED POV display = in progress
sound sensitive el wire = check
wireless master/slave style stereo transmission = check!

I have a feeling that we think alike, Max!

Haha, we sure do! Nice!



Quote:
Originally Posted by jonnyb0y View Post

Those sure amps are totally perfect for my needs, or anyone's really. They have a super wide input voltage range. This is especially useful because one can run the amp directly off of bicycle generators or solar panels.

The problem is that they only make full output power at their max input voltage, though.

Quote:
Originally Posted by jonnyb0y View Post

With most 12v systems, over-voltage protection will turn things off at around 15.5v-16v to protect the circuitry. Meaning: a solar panel at 18v or bike generator at 20v could fry normal 12v stuff if hooked up directly with no regulation.

As long as you have a battery in the system, the peak voltage should be less than 16v. I have a 12v DIY solar setup at home, and it never hits 16v.

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Originally Posted by jonnyb0y View Post

I have a question about the sonosub: in what direction does most of the sound travel? Out from the driver or through the port? Just wondering how it should be oriented.

Low bass is said to be fairly non-directional. If you end up making a sub that plays up to higher freqs, I think the sound primarily emanates from the speaker (or the mouth of the horn). I'm mostly just talking out my ass, though , so hopefully someone who knows more will chime in.

-Max
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post #19 of 86 Old 10-11-2011, 02:53 PM
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Originally Posted by jonnyb0y View Post

...So they are pretty harsh on axis, even with contouring?

I also just realized that they call for a 1.34cu/ft enclosure, ...make this thing look like the starship enterprise

The PS220 calls for 2.7cu/ft ...

...The sub I've been looking at will take me to 300hz...

The contour network reduces/eliminates the harshness; it's a direct result of a rising FR, so once you fix that, the issues go away. I kept my network conservative in favor of better off-axis response, something you should consider if playing to more than one person. What harshness remains is very tight to the driver axis.

Where do you get 1.34 cu ft out of 11 liters? PS220 wants a big box, but I got the PS180 to dig below 100Hz at 11L, tuned to 80Hz. Look at the FR measurements I posted. If there's a sub, of course, low extension become a non-issue and the focus flips to integration of sub and speaker. That's a different animal outdoors as room boundaries that drive HT sub integration are missing.
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post #20 of 86 Old 10-12-2011, 03:50 PM - Thread Starter
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Do you camp with RidazzCamp? I camped with RidazzCamp in 2008.

Just helped to head up RidazzCamp this year! My gf did the shade structure, I did the sound system / LED beacon, and I drove a huge 20ft truck loaded with almost 40 freak bikes This was my third year, so I guess I missed you by just a year

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...The problem comes when you need to make the first 180 turn. I think the cross sectional area will increase too abruptly as it makes the turn, since sonotube gets so much wider as you move away from the tube wall toward the center. Perhaps there is some way to make that work, by taking up some of the volume with "filler", but I'm just not sure what it would take.

I don't really know how to design a horn-loaded sub, but I suspect that having a smoothly-increasing cross section is part of it. I think there is some software called HornResp or something that you can use to design a horn. And then maybe do some crafty stuff to make it fit in a sonotube.

Makes sense to me. I will do some mockups in CAD to get an idea! Then it will be easy to make printable templates to cut out the right shapes.

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So my thinking is that you might want to use a much higher crossover frequency for the sub. I think that would allow the midwoofer enclosure to be much smaller. It might be useful to design your project as more of a 3-way rather than a 2-way+sub system.

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The contour network reduces/eliminates the harshness; it's a direct result of a rising FR, so once you fix that, the issues go away. I kept my network conservative in favor of better off-axis response, something you should consider if playing to more than one person. What harshness remains is very tight to the driver axis.

Where do you get 1.34 cu ft out of 11 liters? PS220 wants a big box, but I got the PS180 to dig below 100Hz at 11L, tuned to 80Hz. Look at the FR measurements I posted. If there's a sub, of course, low extension become a non-issue and the focus flips to integration of sub and speaker. That's a different animal outdoors as room boundaries that drive HT sub integration are missing.

11L is small, I dunno where I got 1.34cu/ft. *smacks face* Seems like 0.5cu/ft is the answer. That's not hard to fit at all.

I've been scouring the internets looking for more sub driver options, looking for something with higher sensitivity than that Dayton NS270 (~84dB). Then I found the Vifa NE225W-04 8" driver on PE and got really excited.

Seems that the Vifa NE225W would be great because:
small 8" driver
4ohm 125W RMS (matched to one 100W 4ohm channel of tripath amp)
less than 5lbs (neodymium magnet)
30-1500hz frequency range
1.58cu/ft Vas
90.7dB

Anybody have any experience with these? It seems almost too good to be true. Definitely way better sensitivity AND frequency range than the Dayton NS270. Might even try to run two of these if I can fit the enclosures- I have heard that running two smaller subs is better than one sub with the same amount of wattage?

Now say I use the Vifa NE225W-04's (2 of them hopefully), which have a frequency range up to 1500hz. That covers the midrange too, right? Could I then just use a compression driver like the B&C DE38, which has frequency response 1500-20Khz and be done with it? Theoretically there would be no gap between the sub + CD?
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An option....

http://www.parts-express.com/pe/show...umber=294-3214

1cu.ft. box tuned to 60hz. (2" port 1" long) 95db at 1 watt from a cheap neo (5lb) driver.

add a monoxover
http://www.instructables.com/id/mono...dio-crossover/
cross at about 3k, and add whatever HF you want, like maybe an asd1001 driver and a selenium hc23-25horn. (and then you've about built a DIY peavey PR10 -- that happens to sound better than a PR10)
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Quote:
Originally Posted by jbelljbell View Post

An option....

http://www.parts-express.com/pe/show...umber=294-3214

1cu.ft. box tuned to 60hz. (2" port 1" long) 95db at 1 watt from a cheap neo (5lb) driver.

add a monoxover
http://www.instructables.com/id/mono...dio-crossover/
cross at about 3k, and add whatever HF you want, like maybe an asd1001 driver and a selenium hc23-25horn. (and then you've about built a DIY peavey PR10 -- that happens to sound better than a PR10)

Hmm yeah that is a nice loud 10", do you think 60hz is good for dance music though? My eon 518s subs dig down to 42hz with range down to 37hz, and it's almost an essential part of initiating dance party mode. I'm kind of obsessed with the idea of having that amount of low frequency range or more on the fast bike, and it's definitely a huge reason for going the DIY route because the eon510 that's on there now sounds GREAT outdoors- it just lacks the low bass frequencies that makes the bodies jump up and down.

So I guess the main goal is to achieve sub 37hz frequencies in a small lightweight enclosure with the highest efficiency possible... It seems like the highs will be a bit of a no brainer. Thanks for the recommendations, I trust that way more than t/s parameters
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post #23 of 86 Old 10-12-2011, 09:34 PM
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Give this a look. Just a couple of pounds heavier

http://www.parts-express.com/pe/show...umber=248-4022
cheap and actually a good speaker.Surprising for a Pyle.



Definitely do pro audio drivers for the mids and highs. This is going to be the most efficient way to go if weight is an issue. Fiber glass as well for enclosures. 10" or 12" will offer the most output per watt per pound. I wouldn't worry about power handling or matching power to speaker.

Bass.
I love the sonotube idea that was offered up. While smaller ports save weight, they fastly get compressed. Download WinISD pro alpha and model your speakers in the software. Just put in the enclosure volume and signal and you can model about everything. What's nice is that it will show you the "open air" frequency response. Which in your case will be the end result. tuning higher gets more efficiency as the low stuff does not recieve any low end gain like it does in a car or room. Since most music has little info below 30 hertz, I would maximise above that.

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post #24 of 86 Old 10-13-2011, 06:09 AM
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Quote:
Originally Posted by jonnyb0y View Post

My eon 518s subs dig down to 42hz with range down to 37hz, and it's almost an essential part of initiating dance party mode. I'm kind of obsessed with the idea of having that amount of low frequency range or more on the fast bike,

uuhhh... an 18" sub sound on a bike? Even though that's a neo driver that's still about 65lbs... To me that sounds like big weight, big size, and big power... Not bike OR battery friendly. A 10" driver of any kind in any ported box will never match that...

If you have that much size, I have a 50lb tapped horn option that is 105db efficient, and has been built for battery operated systems, like this:
http://www.diyaudio.com/forums/subwo...ml#post2529128

I assumed that small, lightweight, low power was needed, and therefore a waves maxxbass was a foregone conclusion. http://www.waves.com/Content.aspx?id=337

The peavey 10" neo I mentioned is F3 of 50hz (tuned to 60hz) and would work REALLY well with the maxxbass. However if you want to sacrifice a couple db in efficiency, you can tune lower.

If you really want real bass, in a slightly smaller/lighter form than the 105db tapped horn mentioned above -- I also have a tapped horn based on the eminence 2512 car sub. I've installed it in dance studios with great success.

I guess what's needed is your maximum size, maximum weight, and maximum spl/extension goals. (hitting 37hz on a bike is easy, hitting it at 130db is not)
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post #25 of 86 Old 10-13-2011, 01:01 PM - Thread Starter
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Quote:
Originally Posted by cubdenno View Post

Give this a look. Just a couple of pounds heavier

http://www.parts-express.com/pe/show...umber=248-4022
cheap and actually a good speaker.Surprising for a Pyle.

Definitely do pro audio drivers for the mids and highs. This is going to be the most efficient way to go if weight is an issue. Fiber glass as well for enclosures. 10" or 12" will offer the most output per watt per pound. I wouldn't worry about power handling or matching power to speaker.

Quote:
Originally Posted by jbelljbell View Post

uuhhh... an 18" sub sound on a bike? Even though that's a neo driver that's still about 65lbs... To me that sounds like big weight, big size, and big power... Not bike OR battery friendly. A 10" driver of any kind in any ported box will never match that...

If you have that much size, I have a 50lb tapped horn option that is 105db efficient, and has been built for battery operated systems, like this:
http://www.diyaudio.com/forums/subwo...ml#post2529128

I assumed that small, lightweight, low power was needed, and therefore a waves maxxbass was a foregone conclusion. http://www.waves.com/Content.aspx?id=337

The peavey 10" neo I mentioned is F3 of 50hz (tuned to 60hz) and would work REALLY well with the maxxbass. However if you want to sacrifice a couple db in efficiency, you can tune lower.

If you really want real bass, in a slightly smaller/lighter form than the 105db tapped horn mentioned above -- I also have a tapped horn based on the eminence 2512 car sub. I've installed it in dance studios with great success.

I guess what's needed is your maximum size, maximum weight, and maximum spl/extension goals. (hitting 37hz on a bike is easy, hitting it at 130db is not)

Definitely makes sense now to use pro audio drivers for the whole thing, seeing the drivers that you guys have posted is eye opening when comparing in WinISD to the less efficient drivers. A huge thank you for the recommendations! I did some simulations and I am getting F3's down to 42hz and below with ported which makes me very happy!

I've been reading up on folded / tapped horns and thinking about how one might fit on the bike. I LOVE the idea and form factor of a tapped horn for this bike. Although, I've also read a few things that say a sub horn isn't even useful unless its a 5' x 5' x 5' area because the wavelengths of those low frequencies are so large. Is this true? I feel like regardless the size of the horn it must help at least a little, or maybe I'm way off?

Anyway here are the goals you asked about
maximum size 25" x 13" x 20" (3.76 cu ft)
max weight 25lbs
max SPL 121dB with 100W 4ohm or 40W 8ohm for sub
max f3 @ 42hz
-10dB @ 37hz max

Really want to see your tapped horn w/ eminence 2512! Would love to hear about the details / specs To me it looks like a tapped horn would fit perfectly in the ~3.76 cu ft area I have noted in the first pic! What do you think?
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post #26 of 86 Old 10-13-2011, 03:49 PM
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My eminence TH is 17" wide, or it'd fit...

A pair of these at 4ohm/100watt ported almost gets you there.

http://www.parts-express.com/pe/show...number=294-694

What you are looking for is a tall ask.... I'll keep looking.
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post #27 of 86 Old 10-13-2011, 07:07 PM - Thread Starter
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Quote:
Originally Posted by jbelljbell View Post

My eminence TH is 17" wide, or it'd fit...

A pair of these at 4ohm/100watt ported almost gets you there.

http://www.parts-express.com/pe/show...number=294-694

What you are looking for is a tall ask.... I'll keep looking.

Jbell- thanks so much for your insights. I found a little bit of info about the size of your eminence eminator TH from a thread on diyaudio, the original box dimensions 17x20x22 are a little unwieldy for carrying behind me but the 4.33cu ft of overall dimension is quite manageable if elongated with overall dimensions 20W x 13H x 29D. That would fit well enough.

I know you can't just elongate a TH because all the S & L values change, but I've got high hopes to design one that fits using hornresp if I can get a grip on it.

My other question is about the kind of driver to use. That eminator is a bit on the heavy side, but reading up on TH's suggests that this is probably the reason it's a good choice for TH because of the heavy magnet?

If you have any neodymium woofer recommendations for trapped horn enclosures I'd be stoked to know. Going to download hornresp tonight and plug in some options.

Also it looks like my "Ang" position of the horn would be 4 Pi open space, because the horn will end up being elevated ~2.5' off the ground.
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post #28 of 86 Old 10-13-2011, 07:17 PM
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Ok, did some digging, this is the cheapest/easiest way to fit your bike.
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post #29 of 86 Old 10-14-2011, 01:09 AM - Thread Starter
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Ok, did some digging, this is the cheapest/easiest way to fit your bike.



JBELL you have COMPLETELY outdone yourself. SPL graph and everything, you are too kind, TOO KIND sir! You matched the specs perfectly, thank you!!

I did a quick 3D model to show an initial speaker alignment for those quad 10s. Also how many ports? 4? Do you think using a horn like the one on top is best with that sub?

I am not sure if this is the best way to align speakers and I don't want it to look SO boxy (open to sleek speaker box designs as long as it's flat on top)- it's just to get an idea of how much space is available for what...

The horn on top could be on a swivel so it could be faced sideways while DJing. Then it could be rotated backward for riding and projecting to the rear. Or, I could just aim it wherever I needs it most. The thing I wonder is: if all the 10s are facing sideways, will the mids/lows be nonexistent while riding behind the bike? That would definitely not be ideal. I'm just having a hard time fitting all those 10s to face backwards, and I really don't mind the asymmetry anyway. I just want it to sound great while riding behind it as well.

How thin of baltic birch can I get away with?

Also I'm not closed off to the idea of a sonotube!! I just don't know how it could possibly fit on there and have space for DJ stuff
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post #30 of 86 Old 10-14-2011, 02:59 AM - Thread Starter
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Another option I was thinking about...
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