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That's right, if you want THE loudest iPod, Zune, whatever music player *this* is what you need... The iBump crossover lets you crank it up without distortion.
"Freshman volume" is the sound level metric introduced to college students in their first year - it's the highest sound level possible at which there is nobody screaming at you to turn the music down. When Ben Anderson made his first attempt at freshman volume, he used an iPod, several guitar amps, and a regular stereo. Although loud, the sound fidelity was surprisingly low. Even worse, Ben's neighbors were overwhelming his sound with their stereos. What was wrong?
Big speakers work best with low notes, little speakers work best with high notes. Sending both highs and lows to all speakers sounds bad, seriously limits overall volume, and can cause speaker damage. Ben needed a way to separate lows from highs before amplifying his music. This was the beginning of the iBump: "Bump" as in "Bump some tunes", and you know where the "i" comes from.
Designed by Ben's dad, Wendell, the iBump is an audiophile-quality active crossover (which separates the highs from the lows). It is inserted between the source (iPod) and the amplifiers. Routing the iBump subwoofer output to a bass amp enables clear, earthmoving low notes. The iBump left and right channels enable high, undistorted volumes because the smaller speakers aren't getting horsed around by the low notes.
Now, Ben uses an iBump with his iPod, stereo, and bass amp to make sure his neighbors understand the true concept of freshman volume. So can you. We're all about open source hardware, as much as we possibly can be, so we also include the schematic in MAKE 08, so you can build your own, or just get one from us assembled and support MAKE.
The MAKE iBump: World's loudest iPod - info & get it at the MAKE Store!
Update: Please read the FAQ about the iBump if you want to know *exactly* what it does, you'll learn tons about audio too - Link.http://www.quaketronics.com/ibump_faq.html
Yep, nothing new about a speaker crossover...ROFL
Any half-decent stereo you plug the iPod into will already take care of this.
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oracle - some powered subwoofers dont have a built in crossover output to a stereo, so if you're adding a subwoofer to your audio system, this is very handy. it's more suited for people who haven't spent $1000 on their audio system... like... ben.
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like the above comment which I would have put. A standard stereo will do this because all the stereo is acting as is an amplifier. so effectively an ipod should be able to link up to a stage with hundreds of speakers without distortion.
cheers,
ben
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ben - did you see my comment? --some powered subwoofers dont have a built in crossover output to a stereo, so if you're adding a subwoofer to your audio system, this is very handy. it's more suited for people who haven't spent $1000 on their audio system--
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Every powered subwoofer I've used (no matter how cheap) has been connected to the subwoofer output on the amp. The amp automatically runs the signal through a low-pass filter.
I haven't thought about it (since I've always wired them to the amp/receiver output), but I'm very surprised all powered subwoofers don't have a built-in low-pass filter. It seems like it should be a given.
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It's probably important to note that the iBump won't make your ipod louder on its own. You still have to amplify the signal yourself(through your guitar amps or whatever).
That said, it's kind of nifty to have your own crossover. The active filters in the iBump may be much better than a lot of the crappy passive ones out there. Plus, you can play with them to change the sound.
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Its important to note that in the situation in the article, they were using a Bass guitar amp, not a subwoofer. Bass amps asume you're plugging in a bass guitar, not an ipod so it seams perfectly natural that it wouldn't have a crossover, passive of otherwise.
But, for the average user, they will have a stereo with a sub-out (which means the stereo has a crossover) and their subwoofer will have its own crossover. So there is no need for another cross over (unless of course you don't like the one in your stereo)
I think its neat because I'd always like to have a pocket sized crossover but that's just me.
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I'm not following how adding a crossover lets you self-proclaim the "world's loudest ipod" title. An ipod is only as loud as the system you hook it up to. Any system that can go loud, already has a crossover built in.
"some powered subwoofers dont have a built in crossover output to a stereo"
The only systems i've seen having output jacks on the sub are cheapo 3 or more piece computer speakers. Almost all home audio receivers have built in crossovers and preouts TO a subwoofer, not FROM. The only reason i'd see needing a seperate crossover is if you're using equipment that's not exactly designed for home audio...like guitar amps.
As for loudest ipod, i've hooked an ipod up to a concert system which i'm sure trumps your ibump crossover/guitar amp setup. And i'm sure someone's hooked theirs up to a louder system than that.
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I'm not following how adding a crossover lets you self-proclaim the "world's loudest ipod" title. An ipod is only as loud as the system you hook it up to. Any system that can go loud, already has a crossover built in.
"some powered subwoofers dont have a built in crossover output to a stereo"
The only systems i've seen having output jacks on the sub are cheapo 3 or more piece computer speakers. Almost all home audio receivers have built in crossovers and preouts TO a subwoofer, not FROM. The only reason i'd see needing a seperate crossover is if you're using equipment that's not exactly designed for home audio...like guitar amps.
As for loudest ipod, i've hooked an ipod up to a concert system which i'm sure trumps your ibump crossover/guitar amp setup. And i'm sure someone's hooked theirs up to a louder system than that.
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I'm not following how adding a crossover lets you self-proclaim the "world's loudest ipod" title. An ipod is only as loud as the system you hook it up to. Any system that can go loud, already has a crossover built in.
"some powered subwoofers dont have a built in crossover output to a stereo"
The only systems i've seen having output jacks on the sub are cheapo 3 or more piece computer speakers. Almost all home audio receivers have built in crossovers and preouts TO a subwoofer, not FROM. The only reason i'd see needing a seperate crossover is if you're using equipment that's not exactly designed for home audio...like guitar amps.
As for loudest ipod, i've hooked an ipod up to a concert system which i'm sure trumps your ibump crossover/guitar amp setup. And i'm sure someone's hooked theirs up to a louder system than that.
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sorry about the, uh, triple post. Internet is pretty shitty here at work.
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Yes, some stereos already have a crossover. We tried out the one built in to Wendell's new amp and compared it to ours. I like ours much better! Perhaps the amp manufacturer should look at the reference that we used for the article: Linkwitz Lab Crossovers.
If you add a subwoofer to a stereo, it may have a built in low-pass filter already. But you also need a high-pass filter to keep the bass out of your regular stereo. This lets you turn up your regular stereo much louder without distortion. Some subwoofers have both a high-pass filter to drive your stereo and a low-pass filter for the subwoofer. In you have one of these, you may not need the iBump at all, unless you want to try using a different crossover filter.
I have what was a decent stereo in 1986, but it didn't have any subwoofer features. I also have a Fender BXR 200 bass amp. I used the iBump to combine these into a properly loud system. Without the iBump, combining these two systems didn't sound good, to say the least.
Wendell has a much louder system based on a pair of Klipsch Heresy's and a JBL 18" subwoofer. That one blows your hair back!
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Recently I showed the iBump to a friend who has a huge 6.1 home theater. (His iPod is hooked up to little white plastic spearkers that sit on a table, but that's not relevant to this story!) He also happened to have a a nice guitar amp in the room (a reproduction of a vintage Fender tube amp).
We hooked up the iBump to the 6.1 system and added the guitar amp. Compared it to the 6.1 system by itself, the system with the guitar amp was not only louder, it sounded much more like a live performance. It was vocals were more intelligable and it was easier to hear the distinct notes in the bass line.
Our friend confessed that he had been looking into adding three more subwoofers to his system to get a similar sound! But there is some chance that even that won't help, because the key to the natural sound in the iBump is the LR-2 filter shape, which is not as common as the LR-4 filter used in many subwoofers. See the Linkwitz Lab web site to learn why! (Linkwitz is the 'L' in the 'LR' filter.) Part of the reason is that you really can hear the phase response of speakers at low frequencies, and the LR-2 crossover has a wonderfully linear phase and great phase matching between the channels. The iBump uses an inverter to remove the 180 degree phase inversion between the lowpass and highpass channels.
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Those look like Butterworth HPF / LPF if I'm not mistaken (studying those at the moment ) :)
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You're on the right track, LR crossovers are made from Butterworth stages. See the Linkwitz Lab web site for the details. If you are studying the these filters be sure to check out the group delay!
I used to work for Siegfried Linkwitz. He would free-hand the drawings like the ones on his site right in front of you, doing them quickly from memory!
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