Osborn Interlude Speakers
Max. Amplifier Power: 120W
Min. Amplifier Power: 20W
Recommended Amplifier Power: 100W
Frequency Response: 35 – 19kHz +/- 2 dB; 25 – 21kHz +- 10dB
Crossover: 3700 Hz @ 6 dB/octave
Minimum Impedance: 6 Ohms @ 200Hz
Bass/Midrange: 205mm Polykevlar cone, edge wound voice coil
Tweeter: 30mm Inverted Titanium Dome
Size: 250mm (W) x 855mm (H) x 280mm (D)
Weight: 31 Kilos ea. (68 Pounds)
MSRP: $2,850 Australia; $3,000 USA
The Australian Hi-fi industry has grown to a point where it's at the brink of exploding onto the world market, and with a range of some of the most amazingly beautiful timbers (for wood veneers) in the world, I believe that we have some of the most spectacular looking speakers in existence. Obviously, we don’t stand a chance against some of the big boys on the block if we don’t produce a product that is sonically excellent. Greg Osborn of Osborn Loudspeakers, Melbourne, Australia, has a passion for producing nothing short of the best, with his fundamental policy being "No Compromise". His heart and soul go into every speaker he produces, and with a range starting around $1,000 going up-to the piece’ de resistance, the $20,000 "Monument References", a bit of his heart can be afforded by just about everyone.
I was greeted by the delivery guy saying, "Can you give me a hand? These things weigh a ton." He opened the back of the van to reveal two large boxes. I thought I was being sent "Small Size Floorstanding Loudspeakers". As it turned out, the speakers were considerably smaller than the packing. This would ensure that nearly any mishap during transportation couldn’t damage the valuable contents. The first things that struck me about the speakers were their beautiful finish and immense weight. Greg explained the enclosures to be 1 ¼" thick, an inch of MDF and ¼ inch of timber (veneer) finish. He uses MDF as the main bulk of the box as it is nearly impossible to design consistently neutral boxes made of solid natural timbers because they all have different resonances.
The heavily braced cabinets actually isolate the driver from the box, eliminating any spurious vibration that results in a loss of definition and sonic purity. The ¼" timber finish (in this case Tasmanian Blackwood, which is actually quite light in color) is specially wrapped around the box as one solid piece and is also available in Jarrah and Bubinga. Jarrah looks like a combination of Walnut and Rosewood, and Bubinga looks like Birdseye Maple, except that it is red (see the Osborn homepage for samples of the finishes). The drivers are specially imported and individually tested to meet the exacting high standards set by Greg. The 8" driver has a 6.6-pound (3-kilo) magnet and a lightweight 205mm paper cone with a unique Nextel coating. 220 g cone, rubber roll surround and a resonant frequency (fs) of 31 Hz. These were specially selected for their speed and accuracy. The inverted titanium dome tweeter was selected because of its similarity to some of the best features of electrostatics. The crossover uses nothing short of the best components on the market. The capacitors are imported from the USA and all inductors are wound "in house" using 1.7mm "inductor wire" as no commercially available coils were able to meet the criteria. The crossover is wired using a high- quality "Datalink" high speed/bandwidth cable. The rest of the wiring uses the same Datalink cable and takes Greg approximately 2 hours for each pair of "Interludes" to terminate (connect all the parts electrically). It consists of 8 individual wires per strand that have to be individually stripped and joined, making a total of 96 terminations per speaker.
The speakers have a single 75mm port and have two pairs of gold plated speaker terminals. These are supplied with bridges that can be removed for bi-amping; a point that Greg strongly recommends.
Greg also supplies speaker spikes with all his units and these are available in short (about 1" long) and long (approx. 2" long). The speakers come with a full explanation of recommended room placements, which is also very helpful.
I hooked the Interludes up to my Sony CD player and Yamaha amp. I had a little bit of trouble and was not happy with the sound when I first set up the speakers. By moving the speakers around quite a bit (while consulting the additional information supplied), I managed to finally get them into the "sweet spot".
Wow, do these things go deep! The specifications point to a -2 dB point of 32 Hz, and the Interludes really do go all the way down there, and further. When you think of the compromises a two-way speaker system has in regards to bandwidth (this being mainly that you are trying to use two speakers to cover more than nine octaves), these "little big boys" really excel. I swept a frequency generator from 20 Hz - 20 kHz to double check that all the frequencies were there and at the same level. They passed with flying colors. All frequencies were present and the crossover point of 3.7 kHz was as far as I could tell, seamless.
(NB. This is not an accurate test of a speaker’s sonic ability, just one of the tools I use which gives me an indication of a flat response through the speakers bandwidth and crossover point. Program material is a lot more complicated, making the speaker react differently with different mixtures of frequencies and levels.)
I played a large variety of music through the speakers. They are a very attractive sounding speaker, very bold and "in your face" when required with faster passages. Transient response was handled elegantly but none-the-less, dynamically. My "Rockmelons" CD, which has become my main reference disc, was reproduced with fine midrange and high frequency detail, with deep, accurate and fast, well-rounded bass. Classical and vocal tracks were expertly handled, not too forward in the midrange with the notable switching to the extremely smooth titanium high frequency driver's response. The cymbals and bells, along with their harmonics, were reproduced accurately without any noticeable distortion. Metallica’s "Black Album" sounded exceptional with loads of bass and fast action guitar. I thought the Interlude’s best feature was how it handled the bass guitar's reproduction. It usually blends in with the music, but these made it more defined and pronounced. This is quite a distinguishing feat in my opinion.
I also used the Interludes as both main and surround speakers, in a home theatre situation. Playing "Starship Troopers" on DVD with no sub and all bass routed to the Interludes really told of the bass driver’s ability to handle all bass sent to it. For 8" drivers, they certainly move a lot of air without the sensation of a monotone drone that sometimes is heard in poorly designed and loaded speaker boxes. The voices were accurately reproduced with the fast moving action and thumping bass, while "the bugs" were (almost too accurately) massacring the humans.
Finally, as recommended by Greg Osborn, I removed the solid gold-plated bi-wire link and bi-amped the speakers using my Yamaha for the bottom end and Redgum RGi120 for the top (this configuration of amps sounded the best to me). This did improve the overall sound with an increase in bottom end definition and accuracy while quite noticeably opening up the detail in the mid and top-end. Bi-amping is undoubtedly the ideal configuration - assuming you have another couple of grand to be able to supply two good quality amps to the speakers. I suppose it's all relative. You’ve just spent a tad under $3,000 AUS for speakers and then you have to decide whether you want to get the best out of them by purchasing another quality amp. It is well worth it I must admit.
The Osborn Interludes are spectacular looking, beautiful sounding, full range speakers. They have been built with a "No Compromise" approach and will not require you to purchase a sub, unless you want to plumb subterranean depths as a lot of people seem to like. Whether it is for straight two-channel audio or using five or six of them in a home theater situation, they are a very worthy option. Hold onto your seat though, with all that bass from a roomful of these, you will shake the foundations!!!!
- David Wurtz -