October 31, 2011

Point source horn prototype #2 - getting the sims to work

I've had to modify the sims to get them to match the actual measured response. With some input from Mark on AVS, I have a result that is a closer match:

Black is the measured response. Red is the simulation now matched fairly closely. The blue is more like what I'm aiming for with modified ports.

October 30, 2011

Gated vs listening position measurements

Green - horn gated @ 1m
Magenta - horn in the listening position
Red - Ewave gated @ 1m
Blue - Ewave in the listening position

October 28, 2011

S2 Point Source prototype #2 - evaluation

My second point source horn prototype (S2) sounds very good, but I would like the mids to extend higher. Here is the measurement compared to the hornresp sim:

As with the previous horn (S1), the peak is bigger at 300 Hz, and extends a little lower than expected, -3 dB @ 210 Hz, not 230 Hz as predicted. Top end roll off begins at 900 Hz (-3 dB) not 1.2k. 

Hornresp input for S2 as built:

October 27, 2011

Australian Audio and AV show - part 2

See part 1 >

Kyron Audio

Previously, Kyron Audio only made custom speakers. The Gaia is their first non-custom speaker and it was one of the most talked about speakers at the show.

The Gaia is an open baffle speaker that has no baffle for the woofers. It's also a digital active speaker with sophisticated digital speaker and room correction - DEQX. 

Designer Leon Suter

 The room looked more like you see above and I really did like the music chosen. When I sat down they had a Sarah Mclachlan track playing - "In the arms of the angels." The sound was quite spectacular, flawless, airy, detailed, all that you could ask. I could not fault the sound. I didn't notice any room issues at all in this room, which could be related to the open baffle design as well as the digital correction.

 His partner Lee Gray is an industrial designer and it shows in the creation of a speaker that is both stylish and superlative in performance.

WAR audio

The War Audio room featured a speaker designed by Pat O'brien and was one of the most popular at the show. 

The speaker features Accuton ceramic drivers and a ribbon tweeter. This speaker is available as a kit or fully assembled. The sound of this speaker was beautifully detailed and magically refined. There isn't much that I can say, it was simply a great accurate speaker with nothing to complain about.

VAF audio

Phillip Vafiadis put on the best show.

Many had a take it or leave it approach, but Phillip put in a show. The room was always full. He played a reference track first on their smallest speaker seen on the left, i90, which is a compact coaxial point source driver. He described it as the smallest a lifestyle speaker can be without serious compromise. Next up we heard "Soundwall" which uses the same driver mounted on a wall - the red print you see behind Phillip. 

The sound was very similar. Then i93, their top of the range speaker. There was a nice mix of technical information and demo. All three speakers sounded very good indeed.

Martin Logan (Advance Audio Australia)

There was something very natural about these Martin Logan Electrostatic speakers. The sound was "just there." There was something "unhi-fi" about their sound. Many speakers seemed a little artifical in their sense of airiness, while these had a more realistic balance. 

Vivid audio

Beautifully made speakers with some of the best bass I heard at the show. However, on the tracks that I heard, I felt they were just a little clinical in nature. 


Genelec need no introduction in the studio world. They make very well regarded active studio monitors. The speakers shown above are active speakers with a waveguide loaded dome tweeter. The larger unit is a 3 way speaker. You can't tell from this photo, and even up close in the flesh it is hard to tell, but it features a coaxial driver where part of the waveguide is actually a midrange driver that doesn't have a surround. The Genelec speakers had very solid bass and a dynamic sound although they did also have a slightly forward nature. 

B&W + Classe

I'm a long-time admirer of the B&W 800 series and in this room they were powered by Classe electronics. It was a short demo but on the music played they were very dynamic, clean and accurate. 

PMG - Pure Music Group

Some large JBL monitors were played in the Pure Music Group room. 

When I introduced myself to Warwick Freemantle (above), he asked me about the kind of music I like. With PMG, it's all about the music. There was another room with JBL speakers, but the two rooms were worlds apart in sound. This one was far better. A very nice sound indeed. Typical complaints about horns weren't evident here. 

TAG - The Audio Group

Magneplanar speakers

There were Maggies in two different rooms and both performed very well. I do know that one of them are priced around $3k and I agree with comments made by many that they are value champions. They held up very well against pricier options. My only complaint is that they sounded as if they had an exaggerated amount of treble detail.

Vienna Acoustics

These speakers were very well built but I found the sound to be harsh and clinical. 


Aktimate had the cheapest speakers I saw at the show and they had very respectable performance.

This pair had surprising bass - an ideal choice for a good quality PC setup.

Creek + Epos

Australian Audio and AV show - part 3

Part 1 >
Part 2 >

Sound Labs Group

Sound Labs crammed a great deal of gear into their room since they have such a large range. Their Audel speakers shown below were beautifully made.

The room was crowded and very popular. I didn't get a chance to have much of a listen, and arrived in the room towards the end of the show looking for photos. 

The Raysonic tube CD player is beatifully made.


Speaker bits

Do you see the Coral full range drivers below? The term "rare as hens teeth" always comes up where they are found. I have heard other Coral speakers in a horn loaded DIY speaker and they were very refined.

Scan Speak Illuminator drivers very nicely presented.

Duntech and Orpheus speakers

I heard both the Orpheus (middle) and Duntech (inner) speakers and both sounded excellent.

October 26, 2011

Point source prototype #2 complete

My second point source horn prototype is now complete! Quite a bit bigger than the previous one:

The previous has been stripped of its drivers during testing. I wanted to be sure it works before buying more drivers. Here is the crossover:

It has gone through a quick optimisation. Raw responses shown in grey. You can see the midrange has a peak as expected from the sims, easily removed with EQ to get a nice smooth response shown in green. The top end extension is less than anticipated, something which I will need to investigate further. The tweeter runs a little lower than I prefer. Just one PEQ filter was needed to get the treble response flat. So with two PEQ filters it measures very flat, most of the response is +/- 1.5 dB. The treble runs 2 dB lower than the midrange to achieve the slightly mellower voicing that I prefer.

Here you can see the ports and baffles that make this design work. You can also see wedges to fill up the corners.

Very industrial looking. It looks even more militant than the previous horn. Drivers are wired to achieve a 12 ohm load. 

This version has been made more smooth, with no sharp edges.

I have only had a chance to have a quick listen in mono (hard to judge that way). The sound is very similar to the first, but with wider coverage. I now need to finish the second to evaluate it properly. 

My polar measurement rig is now complete, so I will be taking more extensive measurements soon. 

October 23, 2011

Australian Hifi show

For the past decade, hifi shows have been something that Australian audiophiles can only read about. So it's no great surprise that the 2011 Australian Hifi Audio and AV show has been so well received. In the week leading up to the show, the last of 50 rooms at the Marriott Hotel were booked. It was a great chance to hear a great range of gear all in one location. If you are like me, you are reluctant to ask for an audition to listen to equipment you know you won't buy. 

Weston Acoustics / Von Schweikert

The show ran for three days, but I went in the day before to help set up the Weston Acoustics / Von Schweikert room. I measured the room in various listening positions to assist with speaker positioning. The results were highly variable based on position and as expected there was a fair peak around 40 Hz in the sweet spot - a primary room mode based on the length along the listening axis. We tried placing the Von Schweikert speakers as per manufacturer's recommendations - near the wall with no toe in. This turned out to be less than ideal for a show situation, although we could tell that the speaker was voiced to sound balanced tonally with no toe in. Greater toe in widened the sweet spot but also increased brightness. In the end a compromise seemed to work best. 

Above: Von Schweikert speakers driven by Weston tube amps.

Left: Geoff Doherty the distributor of Von Schweikert speakers Right: Earle Weston of Weston Acoustics

As a nice gesture, Earle provided bottled water free to guests - very welcome considering the rooms were quite warm and there were no other sources of water except in going back down to the ground floor. 

Geoff Doherty is the Australian distributor for VS speakers - Cardoh

There were no shortage of valve amplifiers at the show, but Earle's stand out in two ways. Firstly, they retain a certain hand crafted charm. Many of the amps at the show take on an aesthetic that almost suggests they are trying to be a solid state amplifier. Earle's amps have a certain charm that befits a hand made product, with a beautifully finished timber chasis.

Standard Topaz

At the show Earle ran the system on his Tempest monoblocks, shown above. 

Above: Troubadour - this is Earl's budget amp which is intended to tempt buyers away from cheap Chinese imports. While not too much cheaper, the imports have vastly inferior performance and reliability. 

Above: Topaz. According to Earle, this is one of the better sounding and better value amps in the range, at only $1495 for the standard EL34 version, although the one shown here is KT120 priced at $1995. 

The Von Schweikert speakers are a 3 way design with decent sensitivity and very deep bass, due to the low tuned port and rear firing woofer. In the demo room the bass extended lower than I measured. At 15 Hz there was no roll off! The combination with Earle's amps worked well and gave a clear indication that valve amps can do bass well. Bass control and output were no problem at all. Many reported that this was one of the better sounding rooms and it was always full. 

SGR audio

SGR audio is a family-owned business with an impressive range of products. 

Above: Stuart Ralston standing next to the first Illuminator ever made.

You probably can't tell in this photo, but in person you might have noticed bloodshot eyes after a week of 3 hour sleeps. It was a huge challenge getting ready for the show. SGR are extremely busy! When you see their products, it's not hard to see why. Where possible they use Australian suppliers and the attention to detail is clearly evident in everything they do. Look on the back of their speakers and you see custom made in-house amplifiers - yes all their speakers are active with analogue crossovers that have been designed in-house. They even make their own heatsinks!

The Illuminator you see here is beautifully made, with a pristine finish over an exotic veneer, the front baffle wrapped in leather. The drivers are the very well regarded (and expensive) Scan Speak Illuminators. The subwoofers (8 in total) were supplied by Lorantz Audio, the only remaining Australian speaker driver manufacturer that I'm aware of. 

SGR power amps
SGR CX4 speakers 
I only had a brief listen to the Illuminators and they certainly did impress. Very neutral and transparent.

Most of the time the SGR room was crowded, but I managed to grab a shot when it wasn't busy.

As it turns out, I'm lucky enough to know the owner of the Illuminators and hope to get a chance to listen to them soon. SGR are located in Melbourne and sell direct. You can hear there speakers in the Melbourne showroom. For interstate auditions, check the website.

Equinox Audio

Equinox Audio is another family owned business and it was a good chance to meet Rick Stadelmaier, their designer. 

Walking into their room it was immediately apparent that they went to more effort than other rooms to get the room itself to behave. 

Just that little bit of extra effort taken to treat the room certainly did pay off. I was able to sit down and appreciate the speakers without having my impressions tainted by a poor room. 

Primare components
I sat down with one of my reference CDs for a good listen. The sound was clean, neutral, detailed. Bass wasn't out of control like many of the other rooms. The combination of a high end soft dome tweeter with metal cone drivers worked very well. I have an interview coming up with Rick that will reveal more details about his speakers, including their relatively new statement speaker. 

Osborn speakers

Greg Osborn

Osborn make big speakers! You might have heard of them via StereoNET where the designer, Greg Osborn was interviewed

DIYers will recognise the drivers used, they were well regarded units and the prices are very attractive. I didn't get a chance to have a good listen, but I did notice that unfortunately the bass was quite boomy - a room effect and not a speaker fault. Excellent value speakers considering their size and the parts used.


Ask just about anyone which rooms they preferred, and this one is almost certain to come up.


What you see here is a 4 way digital active speaker based around a coaxial point source driver arrangement. You can see a dome tweeter with a midrange and lower midrange driver. There is also a 15" woofer behind (not visible).

Designer Chris Cabasse

I do regret not spending more time in this room, it was one of the best sounding rooms at the show. Ask just about anyone which rooms they liked best and you are likely to hear this one mentioned.

Coming up ...

Two of the most popular rooms:
Kyron Audio - a very novel digital active speaker almost without a baffle
WAR audio - ribbon and accuton drivers driven by valve amps
VAF - the best presentation at the show