The Ultra-Fi thread

Nielsio · #1 11-28-2007, 03:37 PM

Purpose of the thread
The purpose of this thread is to share information and experiences on ultra-fi systems. The essense of ultra-fi is that audio-quality is the main goal, and looks, costs, labour and so on are of lower importance. However, this does not mean that ultra-fi systems have to be ugly, expensive and labour-intensive, but it does mean that there are certain things you'll have to expect when you are looking for seriously good audio reproduction.

Not the purpose of the thread
This thread is not for discussion of home theater (televisions, projectors, surround systems, and so on); there are other threads for that.

Concepts
Room interaction and directionality
Audio means longitudinal airwaves. Unlike with headphones, speakers interact with the room and in designing a system we have to take this into account, and either try to diminish it or use it to our advantage.

Standard mistakes are: *wide-radiating tweeters in small rooms, *uneven setup and a setup that creates a lot of room interaction, *speakers who's low end measure flat in a dead room but cause insane standing waves and overall a completely unbalanced response in small to medium roomsizes.

Essential reading on room interaction (and equalizing):
http://nielsio.blogspot.com/2007/11/...akers-and.html
(posted on my blog because this text is hard to find on the net)

Coherence
The idea of an audio system is to recreate sounds. Like a piano, or a trumpet, or a voice. The frequencies that those sounds consist of are very wide. But in order to reproduce a sound and have it feel like exactly that sounds, 'right there', isn't easy. There are a lot of things you can do to mess it up. One example is breaking up the sound in many different speakers who sound different, radiate differently and then putting a big fat passive filter behind it. Our mind is able to piece the information back together to make it one sound, but it's naturality is lost, and with it a lot of detail, and it will cause listeners fatigue. This is what is called coherence. Keeping the sound natural and intact, making it blissfully easy to listen to.

One strategy of accomplishing that is by using wide-range speakers; meaning that only one speaker will produce the important frequency range, preferably unfiltered. But it's always a give and take, and you have to find a balance that fits for you.

Efficiency/power
Compare a speaker-driver with a racing car. If it's light then it can take bends more easily, and it requires less power to accomplish the same. The same philosophy applies to audio. Efficient systems are good because they can more easily give off the amplitude needed. And when a system is less stressed, the quality of sound goes up compared to a stressed system. But again, high efficiency can have its drawbacks, so again: personal preference and balance.

Less is more, but not too less
In audio systems, there is a danger of overengineering things. Wanting the system to do something perfectly according to one scale of measurements, but forgetting other aspects of sound and electro-information. In that regard, less is usually more, but the more simpler and more effective designs require higher quality components and parts. This philosophy applies to all parts: DACs, amplifiers, speakers. We can't make the systems too simple though, and almost everytime we have to make tradeoffs.

Balance
If you think about an audio-system as a whole, you want it to be in balance and overall suited/matched. When you have crappy speakers, worrying about mp3 vs flac is foolish. Buying expensive speakers but never changing your amplifier or DAC is also unsmart. And the components that you do get should be suited for each other.

System examples

BD-Design Oris

These are tractrix shaped horns with AER full-range drivers. They are insanely efficient, and because of the horns, the response balance stays good. The horns have a drop-off of around 150hz so it requires a bass-system. The bass-drivers are manufactured on BD's specifications to be suited for this system. Probably the most detailed system on the world across the whole range. Downside: not as coherent as single driver systems. Bass integration can be hard. Note: you can tune it to your needs with different drivers. I'd personally go for the lower strength magnets so that the sound is much warmer/sweeter.

http://bd-design.nl/

Open baffle

Supravox single driver or PHY-HP which has a subtle tweeter on it (simplest possible filtering). Ultra-coherent. Good radiation (directional when it needs to be). Downside: less efficient than horns. Less bass than a two-way system, but with a very large baffle and using the room to your advantage, it can be balanced. Using an equalizer is also an option, if the driver is apt for it (high linear excursion).

http://www.phy-hp.com/
http://www.supravox.fr/

Multiway open baffle

http://www.bastanis.com/

Link with a bunch of systems (some standard, some very interesting)
http://www.arduman.com/aa/Sayfalar/friends.htm

And:
http://www.sakurasystems.com/show.html
http://bd-design.nl/contents/en-us/d1_Showroom.html

My system
Soundcard: E-MU 0404 (outputs clean spdif)
Digital equalizer: Behringer 8024.
DAC: DIY non-oversampling 1543 DAC with CS8412 spdif receiver. Can also be run through a 12v battery.
Amplifier: Joe Rasmussen's JLTi ( http://www.customanalogue.com/jlti_mark_2.htm ).
Speaker: filter-less openbaffle single-driver Supravox Signature Bicone ( http://www.supravox.fr/anglais/haut_...s/215_SBIC.htm )

How it looked in my old room:
http://my.hifi.nl/index.php?user=1088

My amplifier is currently being repaired and upgraded. I'm also going to build a new baffle for the speakers. I'm looking to move soon so I can set it all up again.

My history?
I started with a simple Sony system some 8 years ago. I soon discovered that the musical experience is enhanced with a better system. I then kept upgrading and learning about audio, and also falling in love with more and more music, and I was finally happy and ultra-satisfied with my system about two years ago. The need to improve had gone because I could listen effortless and amazed to music around the clock. No listeners fatigue, completely natural and amazing. Also I felt it was balanced really well where I would have to sacrifice some things if I wanted to gain other (like sacrificing coherence, which I simply was not willing to do). In this journey I've heard almost all types of speakers, amplifiers, and so on. From the most expensive hifi brands to the illest ultra-fi DIY stuff.

Electronics
Amplifiers
The current rage is chip amps (amplifiers that use opamps). 47 Labs came out with the Gain Card some years ago based on the LM3875, and ever since the DIY community and other amp-makers have been making great amplifiers based on opamps. Before that, it was pretty well established that single ended tube-amps where the greatest (at least for mid to high efficienct speakers). I've personally heard one of the best chip amps on an Oris system, compared it to a 300B tube amp, and my conclusion was that they were in the same category of quality but that they had a slightly different 'colour'.

Ofcourse there are a bunch of different amplifier designs, but they have a hard time keeping up in terms of directness, detail, naturality, etc.

Chip amps

http://www.sakurasystems.com/products/47amp.html

http://www.sakurasystems.com/products/shigaamp.html

Single ended tube amps

http://www.ukd.co.uk/product.asp?ProductID=113

Some single ended 300B amplifier

DACs
47 Labs also introduced a 'less is more' DA convertor: non-oversampling 1543. It was a hit also and there exist a bunch of DIY and commercial variants today.

http://www.scott-nixon.com/dac.htm

http://www.sakurasystems.com/products/shigadac.html

There are also kits for the 1541 DAC I've heard. Don't know of any commercial variant of those yet.

Epilogue
Pokerplayers often have money for nice things. I know many people love music, but you can go really far in this enjoyment if you learn about and invest in a good audio-system. Maybe I can help you out in this a little. Feel free to ask anything you'd like.