Surround Sound Speaker Systems
- Written by Chris Eberle
- Published on 28 October 2010
- Axiom Epic 80-800 Speaker System: M80v3 Tower, VP180 Center, QS8v3 Surround, and EP800v3 Subwoofer
- Page 2: Design of the Axiom Epic 80-800 Speaker System
- Page 3: Setup of the Axiom Epic 80-800 Speaker System
- Page 4: The Axiom Epic 80-800 Speaker System In Use
- Page 5: Conclusions About the Axiom Epic 80-800 Speaker System
- All Pages
Beginning with the M80 – this tower model is fairly tall at just under 40 inches but not the biggest tower out there. It uses six drivers, all active, in a three-way ported design. Crossovers are set at 160 Hz and 2.3 kHz. The woofer and midrange are aluminum with a silver dust cap. The tweeter is a newly designed titanium dome and in an unusual touch, there are two of them. Impedance is 4 Ohms with a high sensitivity of 95 dB. Three ports (one front, two rear) take care of air management. The ports utilize a contoured lining to prevent chuffing. The cabinet is a familiar wedge shape which serves to reduce interior standing waves. My sample came with a single pair of binding posts but you can order duals for an extra $40 if you want to bi-wire or bi-amp. Thick rubber feet are included and you can specify spikes for an additional $18. There are also a huge number of finish choices available. The basic choices are Black or Boston Cherry vinyl which is of very high quality. For an extra $75 you can pick from 15 custom vinyl choices. If you want to go high-end, Axiom offers real wood veneers (six) with six stain choices. You can also specify piano black or gloss white. All of these options add anywhere from $245 or more to the final tally.
The VP180 center is quite unusual. For starters, it's the largest center I've ever laid eyes on. At over 39 inches it is as wide as the M80 is tall. In fact the VP180 is pretty much an M80 turned sideways. The cabinet is angled differently to maintain a 90-degree angle between the bottom and the front baffle. The driver arrangement is also different being W-T-M-M-T-W. The three ports are all on the rear and different crossover points are used (170 Hz and 2.7 kHz). The same foot options are available as are the different finishes. Axiom markets a stand for this behemoth which runs $243. If you want to bi-amp or bi-wire the VP180, just specify dual binding posts when ordering. Impedance is 4 Ohms with 95 dB sensitivity. Like the M80, the -3dB point is 34 Hz.
The QS8 surrounds are also unusual in that they are a quad-pole design. Two midrange drivers fire up and down and the two tweeters are on the angled faces of the quadrant. Impedance is 6 Ohms with 95 dB sensitivity. The drivers are wired in phase with a 2.5 kHz crossover. For wall-mounting, a bracket and rubber bumpers are included. There is also a threaded hole in the rear for Axiom's swivel mount, available separately. You can also buy a tall stand from Axiom if you wish. If you must place these speakers on a shelf, you'll need to elevate them at least an inch to clear the bottom-mounted driver. Axiom's stand has a cutout in its mounting plate to accommodate this. Obviously it's best to hang them on the wall. They're quite compact as surround speakers go; and will blend into most rooms well. Since all the same finish options are available, it's easy to match them to your décor and wall color.
The EP800 is physically the largest sub I've ever seen. At over 45 inches tall, it dwarfs even the M80 tower. It is a sealed design with two 12-inch woofers and an 800-watt DSP-controlled amplifier. The anechoic response is 12 – 150 Hz (+/-3 dB). I suspect the in-room response is a couple Hertz lower based on my experience. The amplifier is unique to Axiom products. It has a max output of 800 watts RMS to drive the twin 3-inch voice coils in each transducer. The DSP controller, called XLF, uses custom code to increase extension and output without increasing distortion. Let me tell you, this thing can really shake the furniture! Maximum claimed SPL is 120 dB which is entirely believable. I can't even imagine the possibilities if you were to use two of them! For this review I had only one EP800 but it was well north of plenty for my small room. When buying this sub, you can choose either a vertical or horizontal orientation. You can hide it much more easily when it's lying down and its sealed design makes it more forgiving of placement than a ported cabinet. I chose vertical and installed it next to and slightly back of my right front speaker.
All the speakers and sub include Axiom's new magnetic grills. This is my first experience with these and I must say it's a luxury. Not having to fiddle with easy-to-break pins is a real plus. The grill cloth is also new boasting greater acoustic transparency than the old. Fit and finish on all the speakers is excellent with a nice deep wood-grain texture to the vinyl covering and precise joints on the cabinets. The drivers are all secured with stout screws or bolts in the case of the EP800. The rap test reveals a well-braced box with only minimal resonance. Overall quality is well above the system's modest price point.
I don't usually write about the packaging a product comes in but in this case it is relevant. The only way to buy these speakers is through the mail so it's important to know your purchase will arrive safe and sound. Axiom uses FedEx ground service to ship all their products right up to the massive EP800 sub. I have purchased from them before and I must say they have improved their packing over the past few years. All the boxes arrived in nearly perfect condition. Upon opening them I found dense foam protecting the cabinets from top to bottom at all four corners. The base and top were fully covered with the same material. This foam looks like it can absorb considerable energy. I think it would take seriously abusive handling to damage one of these boxes. The speakers themselves are wrapped in thick plastic. In the unlikely event of damage, Axiom will replace the product after you provide photos to them. And they won't wait to receive the damaged speaker before sending a replacement.
Rather than paraphrase Axiom's extensive literature on speaker design, I asked founder Ian Colquhoun to answer a few questions for me. He's a 30-year veteran of the business and knows more about audio engineering than I ever will. His interview follows.
Chris Eberle: A lot of what sets speaker makers apart today is their different approaches to the development process. Can you tell me about your R & D and what makes it unique?
Ian Colquhoun: I'd say our biggest emphasis is on the outcome of our blind listening tests. We are constantly looking to improve drive unit performance, crossover optimization, and DSP performance in subwoofers, but only in the name of demonstrably better performance. R&D at Axiom is integrated within day to day product development rather than being in the form of strictly pie in the sky ideas. That's not to say that we don't have pure research projects, only that they are usually tied into a specific aspect of our product performance and every new design is looked at as a test bed for furthering our overall understanding of loudspeaker design and measurement. We are also one of the few loudspeaker manufacturers who have in-house electronics R&D, rather than farming out amplifier or DSP design.
CE: Please tell me what role your anechoic chamber plays in the R & D process.
IC: The anechoic chamber is absolutely essential for loudspeaker design. It's our firm belief that you can't do the job without one. Consistency is one of the most important benefits of having a chamber, as you can go back to a measurement from 3, 4 or 5 years ago and have confidence that that reference curve has not changed. All of our driver and system acoustic measurements take place in our chamber and it's likely the most utilized piece of equipment in R&D.
CE: Do you use any other instruments to measure speaker component performance?
IC: This depends on the component. For drive units both simulation software and loudspeaker measurement software (LMS, SpectraLAB) are used. For crossover network validation and DSP work the Audio Precision System is used regularly.
CE: Once you've moved to listening tests, what kind of room/environment do you use and how are the tests structured?
IC: Our main listening room is of standard drywall/stud construction and is of a typical family room size. All design validation and comparison tests are performed as a blind A/B where the listener is given full control over switching, program material, and listening level. A score sheet based loosely around the original NRC performance sheet is used. Listeners are able to rank overall performance, bass, midrange and treble quality on a numbered scale, in addition to free-form comments.
CE: Regarding your cabinet design – how has it evolved to its present form?
IC: Prior to 1991 we utilized the same rectangular shaped cabinets that are commonplace in the industry. In 1991 we began experimenting with non-parallel sides to assist with breaking up the standing waves inside the cabinet. Today's cabinets are the result of a number of refinements to the original design of 19 years ago.
CE: Can you give me a few details about the development of your drivers and crossovers?
IC: Having the luxury to manufacture all of our drivers in house means that each new design is a ground-up design. All motor system geometry is optimized using finite element analysis modeling software. New drivers are evaluated for not only acoustic performance, both measured and subjective, but extreme importance is also placed on driver distortion, power handling and compression. Crossover design takes place in the chamber lab and optimization is performed in real-time. We're not fans of crossover simulation software. Once the measured performance is getting close to our target, which is based on a suite of measurements, the new design is setup for double-blind listening.
CE: Please tell me about the changes to the v3 products with regards to drivers and crossovers.
IC: v3 is the culmination of many changes over the past four years. The biggest changes were in the tweeters and the crossovers. We developed an entirely new dome for our tweeters which was completed in July 2009. Many changes were made to the crossovers which were mainly focused on refining the family of amplitude response curves for each of our models.
CE: The VP180 is a fairly radical design for a center channel; essentially a tower speaker in horizontal form. Besides the obvious physical differences, are there changes to the crossover or internal cabinet design?
IC: Of course! The cabinet design is basically taken from our M80 floor-standing model with appropriate changes to the form factor, bracing and port location. The crossover is likely the most important contributor to the performance of the VP180. There is a general misunderstanding among many consumers that a loudspeaker placed vertically or horizontally will sound the same. This is completely false! A crossover that has been optimized for a vertically placed loudspeaker will likely have excellent horizontal off-axis performance but the vertical dispersion will be far less uniform. Placed in a horizontal position, that same loudspeaker will now have excellent vertical off-axis performance but compromised horizontal dispersion. This is the main reason that many center channel designs have widely varying performance depending on where the listener is sitting. The VP180 crossover was totally redesigned to meet the dispersion requirements of a dedicated center channel in addition to creating a seamless match to the rest of our product line-up.