Basspig's Wireless Headphone Review

Basspig's Headphone Review

Bottom line....he gives the Sennheiser Momentum wireless headphones the Bass Pig Tested and Approved Seal.

The video is worth watching if you're considering purchasing wireless headphones in this class.

Carver C-9 Sonic Hologram Generator

I just installed an interesting piece of gear into the signal processing rack of my sound system, a Carver C-9 Sonic Hologram Generator. Designed by Bob Carver in the 80's, his Sonic Hologram Generator has been a feature in various Carver preamps at the time. The C-9 is a stand alone unit that some have called his finest implementation of the technology. I've wanted to tinker with Sonic Holography in my own system ever since it was demonstrated to me by a friend, Mark "Basspig" Weiss in his incredible sound system. 

The problem it attempts to solve is called acoustical crosstalk. What's that? For example the sound from your LEFT speaker is heard by your LEFT ear. Inevitably some of this sound is also heard by your RIGHT ear slightly delayed, otherwise known as acoustical crosstalk. This can cause some anomalies in our perception of the sound. Headphone aficionados don't experience this crosstalk at all as you can imagine, which is one of the reasons people love the sound of headphones.

So what does this thing do?

It's basic function is to take a 2-channel audio recording and attempt to eliminate acoustical crosstalk between the speakers and your ears. The Sonic Hologram Generator does this by sending an inverted copy of the audio signal to the opposing speaker with amplitude and delay such that it actively cancels the crosstalk at your ear. This can create a similar effect to using headphones, only instead of the sound appearing only inside your head as headphones do, the sound can appear in front of you anywhere in a 180 degree hemisphere. When implemented correctly, it sounds incredible. For a very detailed explanation you can read about it in the patent here. Simplified in the diagram below the Lr and Rl paths get nulled out by producing an inverted signal from the opposing speaker mixed in with the wanted direct sound paths Ll and Rr.

This all sounds interesting but there are a few downsides to be aware of. 

1. It's very dependent on the program material chosen. Not all music lends itself to the effect. 

2. Some rooms it just doesn't work well in. Speaker placement and listening position is critical. See the manual for more information. 

3. You must be in the "sweet spot" to hear the effect. If you move about 18" in either direction the effect goes away. This can be adjusted by a small amount with the Listening Aperture button. 

Despite these shortcomings I look forward to playing around with the C-9 with my 2-channel recordings. You can find the C-9 on EBay for $100 or less most of the time, which is where I bought mine. Upon receiving I opened its up to examine the inside and it looked really clean and in good condition. The power supply electrolytic capacitors showed no signs of distress and the rest of the caps are green polyester film types. I did clean the switches and RCA connectors with Deoxit D5 while it was apart. You can install this in series with any music source like a CD player or if your processor has an external tape loop connection you can use that. There are 2 sets of RCA connectors on the rear, in and out for the left and right. The unit itself has no power on/off button, but it does have a bypass/engage switch. I might add a power switch to the front panel in the future. There are also some other switches for varying parameters to a degree. Listening Aperture can be set to narrow or wide and Injection Ratio can be set to normal or theoretical. This is the amount of crosstalk correction applied. Also note that you may use this device to encode the Sonic Holography signals into a recording itself for playback on a system without the hardware.

While I find discrete multichannel audio greatly enjoyable to listen to, the selection is limited. There are a lot more 2-channel recordings in the world to hear. Sure we have Dolby PL2x and DTS's Neo:6 and many other processing modes that create multichannel surround from a 2-channel source but properly dialed in stereo sounds good too. Add in a Sonic Hologram Generator and if your setup is just right you will swear there are speakers in places none exist. That's magical! 

Links of Interest #002

Why CDs sounds better than vinyl - Its all in the sample rate!

Roger Rusell's Speaker Wire - A History - Busting those wire myths. The bottom line is you want lots of copper. Everything else is marketing.

Rod Elliot's Article on Passive & Active Crossovers - Why a passive crossover will never be as good as an active one.

The High Life - An audiophile rants. While I agree with a few things and not others, its a short, fun read if you have a couple minutes.

Project Free TV - Find those TV shows you love. Online. Free.

And lastly I leave you with a music video. The is the Main Title from Star Wars, played by Jelani Eddington, on a majestic 50/80 Wurlitzer pipe organ at Sanfilippo Residence.

Audio & Video System Expectations

It's been quite some time since I've written to the blog. This year summer & fall had a way of running amok due to household projects, yard work, working overtime at my job, ect. While I may not had had time to spend working or enjoying my entertainment system as much as I'd like, my mind is still abuzz with where it's going with respects to future upgrades and it's direction. Having said that today I'll write a little about my system expectations.

Most audio enthusiasts are typically in one of two camps. The 2-channel music lover and the multichannel channel movie lover. A lot of folks aim for the best of both worlds, which is sometimes a compromise and sometimes very successful. Myself, I am a music fan. I have somewhat different goals than a movie fan might have. I always hesitate to call my room a "Home Theater". Actually I think the moniker is a complete misnomer. "Home Cinema" is a much more accurate description. Still I prefer to think of my room as a media room or entertainment center. Most movies I'll watch once or twice, but a good concert is enjoyed over and over again. Bluray delivers that experience with a high quality lossless multichannel sound track and 1080p picture, so it's suited for both movies and music playback. Bluray is my format of choice - but times are changing!

My video system was built with a 2.05:1 constant image area screen utilizing the maximum height I felt comfortable with. This means 16:9 video is shown as large as practically possible in my room, yet I also get to horizontally expand the picture to a wider CinemaScope 2.35:1 in order to maximize a movie if desired. Since most concert footage is 16:9 format, I've got the biggest picture for that application and still a really wide screen for the occasional movie flick. The traditional downside to a constant image area screen is that you have black bars on the horizontal or vertical image edges depending on which ratio video you are projecting. I've thought about implementing  some manual masking in the future, but the superb black levels of the JVC D-ILA technology in the RS40 projector make for black bars that are very undestracting. For now I'm pretty happy the way it is. I'm already thinking about the next generation DIY screen, so this might be it for the time being.

Now let's talk about the audio side. I've come to the conclusion that my ideal audio system must be capable of two different modes of operation. 

First and most important is the exact reproduction of what is recorded on the source material. This is typically everyone's goal. Flat frequency response, low distortion, good behavior in the time domain, ect. While these are respectable goals, they can fall short in the entertainment factor. Let me explain. Not all recordings are high quality and when faithfully reproduced can sound quite hideous. Such recordings that come to mind are mass produced rock music from the 80's and 90's, most streaming services, poorly digitized lossy MP3s and other bandwidth limited distribution methods such as Sirus/XM. Satellite radio music is so poor and compressed they it is often unlistenable even in my car! Fact is there are more recordings I'm interested in that cannot be sourced in high fidelity or high definition.  I won't NOT watch or listen to something I'm interested in, so what can I do about this?

The second goal of my ideal audio system is to modify the signal in an attempt to add back some of the lost pizzaz. One can alter the frequency response via equalization, add back in lost fundamentals with a subharmonic synthesizer, restore dynamics with range expanders, ect. The purist audiophile will poo-poo at this but if it's not enjoyable, what's the point? I'd much rather be absorbed into an enhanced performance than being distracted by a lousy faithful reproduction. The problem lies in the fact that it's not the media type that defines audio quality, but the work that goes into putting it there isn't always done with the best efforts. Even modern media can be poorly mixed or mastered. Streaming however is slowly catching up in quality and has an exciting future, with services like Netflix, Quello and YouTube. Yes I said YouTube! There are more and more high quality 1080p videos with well recorded sound out there. There are even a few 4K videos posted for those of us with capable displays. There are also products from companies like Darbee Visual Presence that are able to enhance video in ways that don't subtract details or add artifacts to the picture while increasing the viewing pleasure. 

My next few posts will be about my next level of system upgrades which support these ideas.

I'll end this post with a 720p YouTube video that has well recorded sound. This is Tool's 46 and 2 performed by the students of Aaron Okeefe's Music Instruction at The Tracking Room studio in Nashville, TN. It gives me goosebumps to see these talented young kids nail down this song!

Ethan Winer's Basic Music Theory Videos

Ethan Winer put together a new set of videos explaining basic music theory. These are geared towards the musician and audiophile. This video packs a college-level course into about 2-1/2 hours using detailed explanations and familiar musical examples. However, it includes more than just music theory, such as showing playing techniques for musical instruments, plus a segment about orchestra conductors. Because of the length the video is divided into five segments. Full information is in the description for the first video in the list. Below is the first video, and a link to all 5 videos. Excellent material as usual. Check out all of Ethan's videos for interesting and educational subjects.

See All Parts Here (1-5)