Caspar's Home Cinema

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Speakers

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The front main speakers are based on the tried and true Scan Audio Vifa SA-100 design published in Electronics Australia in July 1988. My new versions, pictured above, have been upgraded with what are considered by some to be the best Vifa drivers in their category: the D27TG-45-06  silk dome ferrofluid filled tweeter and P21WO-20-08 polycone 8" woofer. They have also been upgraded with high quality cabinets from John Woodhead at Acoustic Concepts in Mentone, VIC. The boxes are 25mm MDF with beautiful (I think so anyway!) Quilted Bubinga  veneer (a type of African Jarrah), bevelled edges and burgundy grills (photo didn't come out ... next time). The boxes came ready to plug in the drivers and crossover, being ported, double shelf braced and foam-lined. These are the sort of cabinets that you would normally only expect to find on exotic high priced speakers but John is happy to make custom one offs for those of you with your own designs (or from books, magazines etc.) My boxes were in the order of $600+GST. The above speakers sound amazingly detailed in the top end and much tighter in the mid ranges than they ever did with the standard cabinets although a spectrum analysis showed a 2-3dB dip in the crossover region and some minor tweaking of the tweeter level to be in order. The bass is also tight (and quite deep and strong for an 8" driver) a result of the port matching, the driver characteristics and the fairly large box. In fact a lot of music sound good without the sub but I personally like that extra oomph so usually leave it on. I am going to be doing some crossover tweaking soon when my microphone arrives ... see section on speaker workshop at the end.

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The subwoofer is an active unit based on a Shiva driver from Adire Audio and a locally made Redgum panel mount amplifier. These parts plus the custom cabinet were also sourced from John at Acoustic Concepts. The design is ported and downward firing, based on the Adire audio site (click here for plans). It is a bit of a monster in size and made from whopping 33mm MDF but sounds excellent and is truly worth its weight (and given the thickness and considerable shelf bracing is trully saying something!). Sounds extremely tight for music (never heard a kick drum sound so good on Something for Kate) and thunderous for home theatre. Make sure you get an amp with a high pass filter (A.K.A rumble filter), or else you might have problems with the driver bottoming out at high SPL. This is explained further in the Adire whitepaper. John sent the amp to Redgum for me and had the filtering circuitry added especially. Some people say they like the sound with port plugged but I find the ported design just as tight and more pleasing with extension below 20Hz at -3dB which IS audible ... I burned some 20Hz sine waves on to CD-RW to prove it.

The centre and rear speakers are modest Vifa JV-20 shielded bookshelf units from Jaycar in standard form apart from monster cable internal wiring. I am planning on designing  a centre speaker to match the mains and the sub but I haven't decided on a design yet and am waiting for a microphone on order so I can do some more accurate frequency response testing.

Source Components and Display

The rest of the system consists of stuff I have picked up over the years. Some of it like the Onkyo TXSV-828THX A/V receiver is getting a bit long in the tooth but it is still a good quality THX certified receiver and its 5.1 inputs allow me to use the DTS and DD decoders from my Panasonic A360 DVD player.

Visuals consists of a 50" Panasonic widescreen rear projection TV which has also been around a while and is actually pretty good after I extensively tweaked it based on the detailed factory workshop manual available from Pioneer Australia. Certainly the best example of these units which honestly do look pretty ordinary straight from the factory! DVD player is a Panasonic A360 with built in DTS/DD 5.1 decoder. I also have a couple of hi-fi VCR's (an Akai and a Panasonic that does NTSC record) from the pre-dvd days. I uised to watch a fair bit of VHS with prologic, since Laserdic never really seemed like a viable option to me given the cost of the media. Incidentally, VHS/prologic is one technology I don't think people will get nostalgic about ...

Speaker Workshop

Technically oriented HT enthusiasts interested in speaker design may be interested in a low cost speaker design program called Speaker Workshop. It is currently available free in beta form (I am not sure if it will become commercial when finished) but so far seems pretty usable and I was able to do some initial tests with it that generally matched frequency response plots done with the commercial LMS package. Note that the rigor of the comparison was limited by the cheap general purpose electret mic I was using. Also note that some hardware has to be built to use Speaker Workshop as described on the product's web site and in further detail on the excellent audio DIY page of Eric Wallin. Note that I actually built the older  jig 1 before I discovered he had updated the design ... oh well the old one still works. Below is a plot of the Panasonic WM-60A Microphone Cartridge that is recommended for accurate measurements, although I can't help feeling that response is optimistically flat. Anyway, the application of the software package is probably not for the technically feint hearted but I am looking forward to playing with it more and reporting the results on this page when my mic arrives.

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P.S Thanks to Tim O'Connor (toc) for the photos, although he may have been heard to complain of film grain, lens flare and other gremlins but that is a whole 'nother web page.  ...  toc can sometimes be seen in heated debate on the rec.audio.highend newsgroups or discussing the merits of his VAF speakers on aus.hi-fi etc.

P.P.S I am not affiliated with Acoustic Concepts, Redgum or any of the other companies listed on this web page but I have been very happy with their service and help, as well as the results, and am all for supporting our local product ... "I'm excited!"