March 12, 2012

Bathurst 2011 - the audio event of the year

There is an audio event that happens every year in Bathurst that I call the audio event of the year. I call it an audio event but in many ways it's more about a group of mates getting together who just happen to also be audio enthusiasts who love music. This year we even had some live music (shown above). 

The host:


If you ever get the chance to meet him, "Jerry Tones" as he is sometimes called, is quite a character. The kind of person you don't meet every day. 

The event takes place near the Bathurst race event, although most don't actually go to see the races on this extended weekend. 

Le Chateau Jones:


Audio has a way of attracting people who are also into photography. One photographic enthusiast shared some tips with me in a tutorial. This gave me a little inspiration to take a few more shots.




Jerry Tones is in the process of renovating, a very ambitious project. Here is one room that is complete:


Weston Room


Earle Weston of Weston acoustics is a regular and set up a room with some Tannoy Cheviot speakers and some of his amps, including one given away very generously as a door prize. 


Sources include a Marantz player and a Zune media player.


These are beautifully crafted amps and my shots don't come close to doing justice to them.



Earle demonstrated one particular amp with the ported boxes. It was quite a lesson. The amp in question had an ultra low damping factor and as a result, the woofer had massive excursion and you could see it flop around as if playing heavy 5 Hz bass content. I was sitting there with John Reiki (HifiZine editor and owner) and we were pondering the issue when I decided to try an experiment. It occured to me that the lack of amplifier damping meant that the driver had (almost) nothing to stop it moving, especially below tuning. So we blocked the port with a thick Harry Potter book (useful for port blocking and other magic tricks). Immediately the problem was gone, the box now providing the needed damping. The bass was a little more than we might have expected, probably due to the amp lending a slightly bloated quality to the bass. So what we had was a mis-match with the ported box. The other valve amps did not have this issue. 

Andrew Ward of Aslan acoustics also had a speaker there although we didn't end up hearing this one.


The Franks


Originally the Franks lived in this box:

This explains the name, Frank being short for Frankenstein. The box now houses a sealed Maelstrom 18" sub driver.


The Franks are high sensitivity speakers with a 4 way digital active crossover (DEQX) with dual subwoofers. 

1" Morel Supreme dome tweeter
6.5"  + 10" PHL mids
18" PHL woofer

PHL make high end pro drivers that are used in Genelec studio monitors. They are expensive but very good and among the best available.

You may notice the room has a lot of fibreglass insulation. Terry has commented that he found the imaging and sound stage to improve dramatically as a result. Early side wall reflections are damped and absorption has been placed on all walls. There is also a bass trap at the rear of the room. Terry is a big believer in acoustic treatment.


2D QRD diffuser:

There are a number of these around the room. Terry has also made 1D versions which aren't in use. 


The Franks have unusual construction. The enclosure consists of an MDF skeletal frame which forms the basis for a concrete like mix made up of a fine aggregate with plasterboard base coat. The box is then wrapped in vinyl.


So how do they sound?

Many who hear this system describe it as the best that they have heard. It certainly deserves the acclaim. What is particularly unique about the sound is the sound stage and imaging. The sound stage is very wide and deep, probably the biggest I have heard. Ordinarily this requires some kind of unusual speaker like an omni or dipole, however these speakers lack image focus. By contrast, Terry's system also has pinpoint imaging. To achieve both at the same time is an impressive feat. 

DEQX demo

A highlight this year was a demo of the capabilities of DEQX. This came about from discussions of my active crossover listening comparisons, in which a small group could not hear any improvement with DEQX. Terry argued that we had dumbed down the DEQX and prevented it from showing what it can do. This is certainly true, we wanted to test sound quality only and in that regard found no reason to spend the extra compared to cheaper options. However, Terry set up a demo in which two profiles were created on DEQX. One was limited to the processing power of MiniDSP and DCX. The other allowed DEQX to strut its stuff. In particular, it was allowed to correct for phase and group delay. We then blind tested this with instant switching, not knowing what was being heard. I was the first to sit in the chair and do the demo and quite soon I didn't need to be told which was which, because the difference was obvious. 

Changes noticed with DEQX:

  • much tighter bass
  • wider and deeper sound stage (quite dramatic)
Both had a basic level of time alignment with digital delays. Both were matched in level and in response closely. These differences were related to the group delay correction. Without it, the sound was flat and almost lifeless in comparison. 

I then watched as others sat through the demo, each person noticing the same differences, differing only in the amount of time taken before declaring what they heard. 


Terry and I have discussed about another demo down the track. He has expressed concern that people don't simply buy the DEQX as a result of these comments. It isn't a trivial matter to design an speaker and there is always the risk after spending a considerable amount, that the result is quite poor. So I put this here as a warning. Don't simply dive in. Remember you take on projects at your own risk. 

More about the Franks

Their sound is clean and neutral. Clearly the system is well sorted and well balanced. They are capable of very high output and it surprises me that dome tweeters were able to keep up. This is easily one of the best systems that I have heard. 










11 comments:

  1. Good write up Paul and I am glad the DEQX performs as it should and I am sure those PHL's would sounds very nice.

    Yes, DEQX is a lot of money but wow it is a powerful box. It is very funny so many 'audiophiles' will spend thousands on some gimmicky cable for a (real or percieved) 0.01% improvement when the DEQX will completely transform a system.

    Now for the world's first DEQX powered Synergy Horns.

    Cheers,
    Mike

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  2. DEQX + Synergy horn ... that would be something special.

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  3. Notice too that the Franks are positioned off-room-axis; firing sort of obliquely/diagonally down the room. I'm thinking that each speaker would energise different room modes and the SBIR effects would be quite different to 'normally' positioned speakers. All very interesting.

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  4. What you can't see in the pictures is the huge SPL that literally pins you to the seat. As a listener you are sort of emulsified into the sound field - envelopment in spades.

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  5. I'm glad you were emulsified! lol

    SBIR is a pain in the butt because it seems to resist efforts to treat it. I have never asked Terry what is behind the unusual speaker placement, but a lot of absorption is part of it.

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  6. TJ told me the idea came from here http://www.decware.com/paper14.htm

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  7. The Franks look great.

    Question: There are 4 distinct drivers, and I would presume it was run in a 4-way configuration, but DEQX only accommodates a 3 way active crossover. Were there series DEQX units, maybe a miniDSP splitting the woofer/subwoofer after the DEQX, a passive somewhere between two drivers, or were two drivers covering the same freq range? (Tony Gee actually did that last one in a 4 way design for his Galactica speaker using a 3-way passive XO with similar drivers)

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  8. Nice summary Paul. This is truly the audio event of the year.

    Can't wait for Bathurst 2013.

    Graham

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  9. Hi Anonymous,

    TJ has 2 DEQX boxes in series.

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  10. Interesting report.

    FYI, the Bodzio "Ultimate Equaliser" is a software DSP solution that also corrects phase and group delay like the DEQX. Costs $150 so is a cheaper alternative. Downside is that needs to be run through a PC and soundcard. I'm not affiliated.

    Cheers

    Matt

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  11. Hi Matt,

    The designer of Bodzio lives not far from me. Good things come from Australia! There's a good chance that I'll be running UE in the near future. It's not quite as cheap as it sounds by the time you allow for sound cards and a fast quiet PC, but still cheaper and you can do an entire 7 channel active system with it.

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