The Active Crossover

In trying to better understand just what makes an active crossover so much better than a passive one, I came across a page all about crossovers at The Well Tempered Computer which says,

An active crossover gets its input from the pre-amp and sends the signal to multiple outputs, each connected to a power amp.
Each power amp drives only one driver.
As the passive crossover is removed out of the power circuit, the amp has now full control over the driver (damping).

In the case of the DSP in the JH-3A, though, the crossover is implemented in the digital domain and not after any amplification. This also means that we will be able to reprogram the device with updated crossover software and implement custom EQ’s if we so choose.

But I digress!

Edit: I’m being told on the forum that one of the main, new contributors to the sound quality of the JH-3A is the fact that here, the phase and time are tweaked to be perfect in each custom pair. This means that the sound from each of the drivers arrive to your eardrums at exactly the right time so as to reproduce precisely the intended waveform. This is allegedly not possible with a passive crossover. I’m led to believe that this, along with the true definition of an “active crossover” above, add up to the jaw-dropping sound I heard at CanJam.

Tuesday, June 8th, 2010 Audio 2 Comments

DACport USB DAC/amp from CEntrance

Another really device I got to hear at CanJam is the DACport from CEntrance. I was happy to hear there is no hiss or noise that I could hear through my JH13 even though computers often carry noise to the listener over USB connections with devices like this. And this is something that I’m pretty sensitive to… I like perfect silence between notes and songs.

I used my JH13’s because I usually find I can tell sonic differences between amps easier with these very sensitive and revealing monitors, and I was really quite impressed. The DACport really delivered some impressively detailed and authoritative sound. I would say it’s a very good mate with these and similar IEMs as well as for all but the most demanding of headphones.

Since its only input is USB (it even relies on the USB power) you won’t get to really go portable with it unless you use some kind of ultra-mobile PC with it. It’s probably more meant to be used stationary… We’ll call it a transportable, even though it’s portable sized.

They want $399 for it, which seems reasonable to me.

Monday, June 7th, 2010 Audio No Comments

JHAudio’s New JH-3A IEM System

The most impressive thing I heard at CanJam I think would have to be the new JH-3A system from JHAudio. It’s a system because the JH-3A consists of a chassis containing a DAC/amp and an IEM — buyer chooses either the JH13 or the JH16. What makes this such a revolutionary, first-of-its kind device is the fact that the crossovers that feed certain frequency ranges to one of the 3  (low, mid, and high) registers are no longer passive ones built into the IEM shells themselves, but are active ones that reside within the chassis. This allows the DSP to dynamically reassign certain ranges of the frequency spectrum to different drivers as the music plays, which apparently is lifting a very significant bottleneck that passive crossovers impose. Correction: While the crossover points can be tweaked in the software, they are apparently NOT changing as the music plays as I assumed from the word “active”. See The Active Crossover for a better idea.

When I put the demo pair of foam-fitted JH16’s in my ears (each of the 4-5 times I did) I was simply floored. I mean I’m already used to the superb performance of the JH13, but the sound from this system was nothing short of breathtaking. The detail was some of the most impressive I’ve ever heard; the soundstage was truly beautiful — and not just for and IEM. The sound was wonderfully clear as crystal, in a very good way. It was analytical and euphonic at the same time. The bass knob lets me choose how much bass I want to hear. (Jerry says it can be made to sound essentially just like the JH13 this way.) The DAC/amp is portable with 20 hours of battery life… It’s… exactly what I was looking for.

I got to spend some time with Jerry Harvey, chatting about the system. Since the system wasn’t quite production-ready, the demo included some sort of development box underneath the unit and a netbook that was using some emulation software to allow us to manipulate the volume and bass sliders that will ultimately be controlled via the physical controls on the front panel. They were feeding the JH-3A box with an iPad via an analog line-out dock.

The unit has a 24bit/192kbps capable DAC and a 3-channel amp. Each of the three amps is dedicated to each of the 3 registers of sound in the IEM. In the case of the JH16, we have 2 drivers for the high end, 2 drivers for the mid range, and 4 drivers for the bass. That bass control I mentioned is now able to act not as an EQ as such controls typically do, but actually manipulate the level of the bass amp discretely, entirely independent (literally and audibly) from the rest. The rear of the device will have a mini-USB input, and the front has a minijack input that will accept a digital coax signal, or an analog one. Since the device is manipulating the amp levels all in realtime to pull off the active crossover, the signal must always be digital before the amps. So consequently, even an analog input must be converted to digital inside the device before becoming analog again for your ears. So, a fancy DAC will not help us at all here — we’ll always rely on the D to A abilities of the device. Thankfully, they seem to be very good.

And speaking of restrictions, because the IEMs are without crossovers themselves, they rely exclusively on the box, and the box relies exclusively on the IEMs. In fact, the box is digitally tuned specifically for the IEM shells. No two people will get the same IEM or box.

In the end, this system sounded just too damn good to pass up. I plunked down the plastic and am eagerly awaiting some quality time with Jerry’s new innovation.

More info can be found on this Head-Fi thread.

Sunday, June 6th, 2010 Audio 22 Comments

CanJam 2010

So I just got back from CanJam, the annual international Head-Fi meet, and I can say that I had a really great time. It was my first CanJam, so I don’t have much to compare it to, but there were plenty of high profile vendors and Head-Fi members represented.

I got to hear a bunch of stuff I’d heard before and a bunch of stuff I haven’t heard before. The Woo Audio room (pictured) featured a number of impressive tube and electrostatic setups… I also checked out the offerings from HeadRoom, Westone, HiFiMan, Shure, RudiStor, CEntrance, Sensaphonics, and others, but there are a couple that particularly impressed me.

After hearing from others how impressive the LCD-2 is, I headed over to the Audez’e booth. (It’s pronounced like odyssey but with a “z” sound instead of an “s” one.) The planar magnetic driver in the LCD-2 gives it an uncanny ability to react to transients faster than most headphones, so the detail is really, really impressive. Also, I didn’t find it lacking in any part of the frequency range. It’s a bit heavy (for the magnets, Alex said) and it does clamp pretty well, but I found the pads to make for pretty good comfort otherwise. They’re quite efficient, and really did sound impressive.

A funny moment was when I asked Alex Rosson, Co-Founder of the company if he was the dnb head behind the collection of drum ‘n bass I found on the iPad that was sourcing the system. When he said he was and I mentioned that I was a dnb dj myself, he mentioned that Reid Speed is his wife! Haha… I dig Reid Speed and thought her Resonance mix from 2002 was excellent. What a coincidence that I meet her husband at CanJam representing a headphone company. :)

The other company is one that I already had a special affinity for… Their new product really impressed me more than anything else at CanJam. More on that shortly…

So I’m very glad I made it out to this year’s event, and send my sincere thanks out to the coordinators, vendors, members, and of course Jude for making it a reality!

Sunday, June 6th, 2010 Audio No Comments

ATH-ESW10JPN vs JH13 Pro

Someone on Head-Fi asked me to compare the ESW10JPN to the JH13, so I decided to just share my thoughts with a wider audience.

The ESW10JPN, with its rich, wood cups, is a beautiful headphone. It is very light and has a grip on the head that is just right. The supraaural design does fatigue the ears eventually, but it takes a lot longer than I thought it would before I purchased. This is in part due to swivel of the cups and how I can position them to put the pressure on different parts of the ears and head throughout a session. I also like how they are easy to put on and off, and are comfortable to wear around the neck.

When I first tried the pair of my friend’s, I was very struck with the “energy” in the mids and highs. It is a very detailed headphone with a presentation that is very pleasing for many genres. There is great, well-textured bass, but it is not the centerpiece of this sound signature. Acoustic instruments — like the shimmer of strings — sound very vivid and enjoyable. The isolation isn’t great, so I wouldn’t want to use them some place noisy. I’m glad I got a pair of these limited edition headphones before the 1500 were gobbled up. I still really enjoy them.

The JH13, by contrast, is an IEM. They have great isolation. (Though, interestingly, it’s not quite as good as foam tips on universal fit IEMs.) They have a perfectly formed, custom fit for your ear canals, so their uniform pressure throughout your ear easily lets them “disappear”. Compared to the ease of taking the ESW10JPN on and off, a custom IEM like the JH13 is a bit more work. Once you get the hang of it, inserting and removing the JH13 is pretty fast and easy, though (only a couple seconds) but it is a bit more abrasive. And I always wipe earwax and debris from the tips before inserting. With the right fit (JHA has a great track record) and well-adjusted ears (only a few days to a week or so for new wearers) I think the JH13’s are incredibly comfortable. I can wear them for many hours without issue.

The sound is simply incredible. The JH13 is still the best headphone I have and at least among the best I’ve ever heard. It must be those 6 custom spec drivers working side-by-side that give me such a detailed, immersive view into the recording with soundstage that is simply astonishing for an IEM. Historically, it seems that a full-size headphone is needed for this type soundstage, but the detail of the JH13 seems to compensate for their “shortcoming” that they bypass the outer ear and send the sound directly into your eardrums. The first thing a new JH13 owner seems to notice is how HUGE the sound seems to be. The JH13 has some of the best extension on the top and bottom ends of any headphone. The sound signature sides on ruthlessly neutral, but with a bit of a bump in the sub-bass for low end impact that I really enjoy. The bass is massive and detailed, but it never oversteps its bounds like it does when I switch to the UE11.

When I compare the sound of the two head-to-head, there is simply no doubt that the JH13 is the clear winner. Not only does this IEM have a very neutral response curve that doesn’t really favor any genre over another, but it maintains a euphonic sound with anything I throw at it! The isolation assures that you’re starting with a quiet background, and the music is just so clear and beautiful. At the end of the day, I’m apt to say that while the ESW10JPN excels at its strong points and can be a very enjoyable can for many things (particularly jazz and acoustic music) the JH13 just seems to perform perfectly in so many ways.

Both headphones sound great right from an MP3 player’s headphone output, but they also improve with a good amp. The JH13 scales extremely well with better equipment as it seems to sap up and really deliver on exactly what it is fed.

I love my ESW10 very much… I just love my JH13 more. :)

I also started a thread on Head-Fi with this review.

Sunday, March 21st, 2010 Audio, Reviews 2 Comments

Fix Found for Weird Noise from Mac OSX Audio

Mac Audio FixAs I was just researching unrelated stuff pertaining to Android, I came across this post from a guy who was having an issue on his Mac that sounded exactly the same as one that’s been bugging me for months now! He never followed up on his post, but it was from about 7 months ago, so I thought it was worth shooting him a line to see if he ever solved it. He had!

For him, it was the Android emulator, but for me, I believe it was caused by VirtualBox. The internal speakers were fine, but when I used a USB DAC or even the in-built headphone output, I would get a subtle fuzz noise in the background when the music was playing. (The noise was missing when all audio was silent.) This forced me to rely on the optical output to get sound from the MacBook Pro to my headphones.

The fix is to open up OSX’s “Audio MIDI Setup” tool in the Utilities folder. Select your output device under the “Properties For” drop-down and make sure that it is selected to be “2ch-16bit” on the right. For some reason, these apps seem to want to switch to “2ch-8bit” and that is what causes the problem. It does appear the fix will need to be performed again after each use of these applications.

Don’t really know who to blame for that one… But thank you, Duncan, for the tip!

I hope this helps someone else. I had no luck searching for a fix, myself.

Friday, October 30th, 2009 Audio, Computers 2 Comments

Shure Announces New DJ Headphones

Shure SRH750DJIn the way of headphones, Shure have historically only built in-ear monitors. But they have since launched a line of full-sized studio headphones, too. Well, they’ve just announced a DJ headphone to add to the mix, with planned availability sometime in November. And I certainly approve of the look.

Shure Press Release

Shure Product Page

Thursday, October 15th, 2009 Audio No Comments

CanJam at RMAF 2009!

RMAF 2009Just last weekend, the annual Rocky Mountain Audio Fest happened in Denver, Colorado. RMAF is a massive audio show. Several floors of rooms in a huge hotel are cleaned out and turned into listening areas for vendors of all kinds. They set up their gear and show it off to audiophiles.

This is the first RMAF that CanJam has participated in. CanJam, of course, is an official (read: huge) meet. Up until now it was an annual event, but CanJam@RMAF is set to become the CanJam.5 each year.

Wish I could have been there, but I do have my sights on CanJam 2010 in Chicago!

Check out the RMAF thread, Jude’s pics, or Dave & Carol’s pics.

Tuesday, October 6th, 2009 Audio No Comments

Microphone Made of Frickin’ Lasers

Just imagine the types of recordings that could become possible once this technology is fully realized! I bet this is where microphone technology will be heading.

The press release on this one is full of superlatives, but somehow most of them seem justified. Schwartz Engineering & Design just announced its Laser-Accurate microphone technology, which promises to provide “pure sound” from a microphone for the “first time ever.” It works by detecting the impact of sound on the motion of particles in a stream of air by running a laser across them, and was created by David Schwartz, who holds several digital audio patents, including one that is foundational to the MP3 format (which is, ironically, not a traditional friend to the audiophile). The idea is to avoid the inherent “coloring” of sound due to a regular microphone’s physical diaphragm, since the moving particles are virtually weightless. Of course, it seems that a Laser-Accurate mic would have plenty of variables of its own to deal with in regards to the stream of air, but we suppose we’ll find out just how tight Schwartz has this thing when it’s shown off for the first time in NY next month. PR is after the break.

Laser-Accurate microphone proves once and for all that everything is better with lasers via Engadget

Monday, September 21st, 2009 Audio, Technology No Comments

Ultrasone Edition 9 vs Edition 8 Headphones

I’ve owned Ultrasone’s Edition 9 headphones for nearly two years now. While I do like their sound, the insides of the cups are not quite deep enough for my ears. The sensation of them resting on the tops of my ears starts out annoying and becomes downright irritating before very long at all. Well, I finally decided to give them up. They’re now sold and gone. During the transaction, though, I happened upon an opportunity to pick up the new Edition 8’s second hand for a reasonable price. So, since I’ve been wanting to try them for some time now, I decided to jump in and give them a go. I even had a few days with both headphones as I waited for the buyer’s payment to clear.

The Edition 9’s make no attempt to “disappear” due to their clamping force and weight. They have a long cable, terminated with a 1/4″ plug. They are obviously designed for stationary listening, though many have found use for them as a portable headphone. To me, I hear a bit of a bass exaggeration all through the low frequencies. I feel that the Edition 9’s are better suited to a rocker who wants their basslines slamming. Genres like pop, metal, or hip hop seem like they do well since bass is so important there, and detail is not the most important aspect. I always felt the Edition 9’s were really great headphones for me until I tried the JH13 and Edition 8.

The Edition 8‘s are quite a different animal. They are much lighter on my head and the enclosures almost don’t touch my ears at all. This time, it’s the bottoms of my ears that touch the insides of the cups a little. It’s far less annoying, though, and I seem to be able to wear these for much longer without issue. They are terminated with a 1/8″ plug after only 1.2 meters. This, and their weight, make them a much better choice for a portable rig. They also come with a 4 meter extension cable that I have found useful since all my headphones now have short cables.

I have the impression that the sound from the Edition 8 is more polite and balanced. While there is no doubt the sub bass has a somewhat generous boost, everything else seems quite balanced. I find this low bass occasionally annoying, but I think that it is helped with a good amp; my RPX-33 seems to take better control of the bass than my RSA portables. They also have great transients. The speed increase of these drivers mean noticeably improved detail retrieval! Ultrasone’s “S-Logic Plus” on the Edition 8 does seem to increase upon the effect of the “S-Logic” in the Edition 9. The drivers are aimed at the listener’s pinna (the outer ear) so the sound must bounce around the ear before finding the eardrum. This leads to a more “3-D” sound that seems more like a projection. I think the Edition 8 would be better suited to instrumental music like classical or jazz, where neutrality and detail are more important.

It’s interesting to note, though, that I still greatly prefer my JH13 for just about everything. They have much better detail than even the Edition 8. They are more intimate and definite in their view into the recording. The bass, while not lacking at all, is very well integrated and doesn’t stick out as much as the Ultrasones. I’d even go as far as to say that they’re more comfortable. Why do I bother then? Well, I like different perspectives on my music. Sometimes I don’t want to stick my IEMs in my ears, but would prefer to have big, warm pads enclosing my ears and have big bass and a different soundstage.

Thankfully, given that I was already in the process of letting go of the Edition 9, I found that I overall prefer the Edition 8. I really appreciate the increased clarity and more neutral presentation. And the better comfort is icing on the cake.

Saturday, September 19th, 2009 Audio, Reviews 2 Comments

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