Product Review - Adire Audio
Rava Subwoofer - June, 2002
Drivers: One 12"
Amplifier: 250 Watts
MFR: 27 Hz - 160 Hz - 3 dB
THD: < 3% at 95 dB
Dimensions: 18" H x
18" W x 18" D
Adire Audio has fully established itself as a recommended DIY supply store that now features several factory-assembled speaker lines along with the countless DIY parts they offer. This ranges from speaker kits, drivers, components, and other types of accessories.
Less than a year ago, I had the chance to review the Adire Audio Kanada bookshelf speakers, which are part of the growing Exact series offered from Adire Audio. There are now two subwoofers available from Adire Audio in the Exact Series, including the Rava subwoofer in this review and the Dharman subwoofer. The Rava sub is lighter/smaller than the larger/heavier Dharman sub. The Dharman uses the same driver and look, but a more powerful amplifier and has twin-flared vents for higher output instead of being sealed. However, the Dharman subwoofer does carry a heftier price tag at $599. A recent subwoofer addition from Adire Audio is the Shiva SE subwoofer that uses a more feature oriented set of controls on a Hypex HS200 amplifier and 4th order Linkwitz Riley crossover. Keep in mind this is not your garden variety $399 subwoofer, because it is sold only by mail order, saving you about half of what you would expect to pay in a store.
I love to see a company double box their equipment, and that's what was thoughtfully done here. When I finally cracked open the box I was introduced to multiple goodies both on and off the Rava subwoofer. There are plenty of options on the back of this sub including line-level RCA in and out, binding posts for speaker level inputs and outputs, variable phase control (00 - 1800), detachable power cord, and auto-on power. You can even flip a little red switch to change power supplies for use outside of the US.
The first thing you will notice when taking the Rava out of the box are the rounded edges instead of the traditional squared-off corners. I remember the first time I saw rounded corners inside of a home and the soft look it gave the audio system. The impression I was left with was a more inviting, comforting feeling that made me a solid believer in this type of design. There is also a recessed step on the bottom on the sub that raises the sub off the ground just enough to protect it from an unwanted foot, while giving it a improved look over the typical run of the mill square box. These days, consumers want the speakers to look like furniture, and the Rava does just that.
The Rava sub is centered around a Shiva 12" driver (driven with a Class A/B amp pushing 250 watts RMS at 4 Ohms), a custom built driver designed by the folks at Adire Audio. Derived of a mix of paper fused with Kevlar for the cone, and backed by a heavy-duty 60-ounce magnet, this driver has become almost legendary in some circles (well maybe not legendary, but is in high regard). It boasts a linear stroke of 1.25" with a maximum excursion of 2" front to rear. That's the way to move a lot of air. For those willful DIYer's out there who are interested in such a driver, the Shiva is available for separate purchase, but at $399 it may be a wiser investment to buy the whole sub.
The Rava was built for accuracy over output with the sealed enclosure, although there is plenty of output for any small to midsize home theater or music setup. It's nice to see that they designed a sub for a specific purpose, being a small to medium theater, and stuck with that basic premise. The people at Adire Audio didn't try to fill everyone's need with one product.
Notes by Colin Miller: Although many very good subs use the sealed variety, and it's the only design route I'd dare take on as a DIY task, due to the greater complexity, and therefore difficulty in getting a bass-reflex system truly right, I would argue that it is quite possible to do a very good job with a ported design, but it just requires more work. Whether any benefits are worth that extra work, and eventually, extra cost, one must evaluate them, I feel, on an individual basis. While most of my favorite subwoofers are of the sealed variety, I've heard vented systems that did sound extremely good, and certainly fit the accurate category. However, they were all on the expensive side.
The output advantage of a ported design is primarily at the tuned
frequency, where the maximum advantage is in a relatively narrow range, and of
lessening advantage as you begin to move above that frequency, and of
detriment as you start to move below that frequency. So, while a ported design
may have an incredible advantage over a sealed design in terms of maximum SPL,
if the testing procedure uses a tone at or very near the tuned frequency of
the ported system, in applications which use a much wider frequency range,
such as listening material, the output difference capabilities are less
dramatic. In the case where information is substantially below the tuned
frequency, the sealed system will win hands down.
This raises an interesting dilemma for those who opt for a ported design. While it makes intuitive sense to design the system for the maximum extension, a lower tuned frequency, say 20 Hz, means less advantage in maximum output at, say 40 Hz, compared to a design tuned to 30 Hz. Since most of the obvious bass information is higher than the limit of human hearing, while the bass connoisseur might opt for the extension, the average listener will be more impressed, at least initially, with the greater output capability at the expense of extension. In either scenario, the ported design would do well to cut its losses below the tuned frequency via a high-pass filter to protect the driver from excessive excursion, as the enclosure/reflex system no longer loads or restrains the movement of the driver at frequencies much below the tuned frequency, and since the output of the port and the driver becomes equal but out of phase below that frequency, that extra movement doesn't contribute to acoustic power anyway, although it might be visually impressive if you can see the driver moving.
You know you are back to basics when the owner's manual comes with a staple holding a small stack of papers together. Included in the manual are good tips and steps to help you set up your sub. Several hand-drawn (well maybe not hand-drawn, but easily understood) illustrations show various options for hookup, depending on what your existing equipment provides. The answers to the �How Do I Dial In My Sub?� heading help to make setup that less arduous. The 10-page manual is a nice change that has some character instead of the tectonic or distant language that too many audio manuals are written in.
The removable power cord that came with the Rava wasn't the thickest of cords I have seen (removable being key), but it allows you to use after market power cords or more specialized cords. However, at this price range and modest amplifier power, the supplied cord should do fine. It's listed in the Rava owner's manual that if I split the LFE I would get an extra 6 dB of input signal by doing so. Of course operating on the more is better mode I made the connection with my LFE out and split it into the low level input with a y-cable. After meddling around the room looking for the best placement I settled on a position between the speakers that was 12" further from the back wall. Not the perfect position for a working home theater, but for testing a sub it served just fine.
The recommended break-in time for the Rava is a mere hour or two. Just "give the sub one decent action movie or a ripping music CD, and it's broken in." That's the kind of go-ahead I like to hear.
My initial setting had the output level at about the 10 o'clock position, so I could adjust the dB gain of the subwoofer through my receiver's setup. If I weren't careful setting the output level, I could easily get too big (boomy) of a sound for music.
I first set the crossover at 160 Hz to see if the Rava could pair it well with a small set of satellite speakers. As a result, I found it much easier to blend to a large floor-standing speaker than the couple of bookshelf speakers I tried. However, when the proper blend was found, as in many sub/sat systems, the sound was overall very good.
When the Rava was belting out a little too much bass, I was taken back to my days in high school when all that mattered was in the trunk (or at least we thought so). What I would be left with if I didn't adjust the output down a bit was a thick bass sound that may not suit everyone. However, even after all the tweaking and blending in the world everyone still may not agree one the same sub level setting or crossover point or even placement. Setting the crossover at about 50 Hz made a huge improvement in both minimizing overlap with my choice main speakers and maximizing its ability to set a solid foundation for music. What put a little smile on my face was going back over the manual to review the recommended settings for the sub, and they coincided similarly. Once again, a very good manual for sure.
Continuing along this line, I also found it much easier to pair the Rava with the larger bookshelf speakers I tried (Mirage FRx-3's, Phase Tech 3.1's). In fact, I found that when paired with a set of Adire Audio Kanada (because I had them at the same time to review), which are above-average size bookshelf speakers, the Rava was right at home. The Rava subwoofer excelled when paired with almost any pair of quality floor-standing speakers, requiring only reproduction of the lowest octave.
Paula Cole's "Tiger" from their album This Fire features some very heavy bass passages. Each time these very low notes hit, the Rava subwoofer was up to the task filling my listening room with a burst of energy with a realistic sounding residual base.
Once again I used the DVD disc Sessions at West 54th: Vol. 1 that I had practically worn out for the music side of my review of the Kanada bookshelf speakers. One track in particular, Suzanne Vega's rendition of �Caramel�, featured a steady baseline that mainly stayed at and around 80 Hz, but occasionally dipped into the 40 Hz range for the lowest passages. With the crossover still set at around 50 Hz, the Rava did a great job of picking up where the main speakers left off, making them sound much bigger than they really were without consuming them in the process. Mission accomplished for Rava in this department.
I felt that the 250 watt amp was more than enough to keep the 12" driver moving for a smooth sounding upper bass, with minimal residual bass information from previous notes.
Next on to my favorite part of any review, home theater performance.
As mentioned before, the Rava is a sealed sub instead of the ported type that is more common. Funny thing is that I didn't notice the biggest presupposed disadvantage (less total output) of a sealed enclosure at all.
One DVD that has found itself in the trays of many DVD players is �The
Rock�, especially when determining the capability of a speaker to put out
Chapter 9 features a great chase scene filled with many large car crashes and collisions. The Rava made certain that the sound of an 18-wheeler obliterating an SUV didn't sound like a bicycle going head to head with a skateboard. The machine gun filled firefights in Chapter's 17 and 21 tested the resiliency of Rava, with pulse-pounding action at various levels. Scenes quickly switched back and forth from silence to all out war with the Rava responding accordingly.
Probably the biggest explosion in the movie happened in Chapter 20. The explosion was big enough to fill the room with an abundance low frequency energy. No doubt the Shiva driver used every bit of that 2" of linear drive mentioned earlier to fill the room with that kind of energy. Finally, in Chapter 21, a large structure from the ceiling falls to the ground. The structure that came crashing down not only looked big on the screen (ask the guy under it!), but also felt big when it impacted the ground. Mission accomplished here. Overall, I really liked what this sub did for home theater.
It would be best to pair this sub with a large pair of bookshelf speakers or a floor-standing pair, so that you can set the crossover to a frequency around 50 Hz, lessening the boomy effects that occur when you use a frequency up near 100 Hz. If you considering an Adire subwoofer you may be happier with the added features of the crossover design in the earlier mentioned Shiva SE subwoofer that lends itself better to a true sub/sat system.
The Rava is not magnetically shielded, so don't put it near your TV.
Like all Adire Audio products, the Rava Subwoofer is backed with a 3 year
parts and labor warranty including the onboard amplifier or any other
materials (5 years for labor defects). This is great considering the industry
norm only covers the amplifier section of their subwoofers for 12 months tops.
Comparisons are inevitable when reviewing any product and are often necessary to get a feel for most products. The trouble with this unit here is finding something to compare it to in the same price range and woofer/cabinet size. For example, the Rava sub has a much bigger rumble than my Mirage FRx-10 subwoofer at home in a similar price range. The differences between a larger woofer and more power between the two were readily evident. In fact, what I ended up getting was the kind of output you would expect from a 15" sub, not a 12" one.
I said it at the outset and I will reiterate here. I honestly had a hard time believing that this sub was only $399, I thought that was perhaps the dealer's cost or an accommodation price for a salesman, but not a retail price. Normally when you hear $399 as a price point, you think budget sub and you would be right, but get ready for more than a budget performance. The bottom line with this sub is that it performed well above the call of duty for any <$500-priced subwoofer.
Most subwoofers today could break your lease, but this sub will have you
listening with a smile . . . and some cash still in your pocket. I would find
it difficult to purchase or even build a sub of this quality for the same
Equipment Used In This Review:
Adire Audio Kanada Bookshelf Speakers
Integra DTR-6.2 Receiver
Mirage FRx-3 Bookshelf Speakers
Mirage FRx-Rear Speakers
Mirage OM-7 Floorstanding Speakers
Mirage OM-C3 Center Speaker
Phase Technology PC-3.1's
- Jared Baldwin -
� Copyright 2002 Secrets of Home Theater & High Fidelity
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