Subwoofers are a constant source of conversation. So what the hell is the truth? If comes down to sealed, ported, driver displacement, moving mass and amplification – to name a few. So this illustrates some of the issues a designer has to face. And many decisions are compromised to meet a price point and profit margin.
So when EVOKE set out to build Toby there were many things to consider. First off, internal amplifiers are often inadequate regardless of power. The reason is that the designer builds a small cabinet and then EQ’s to compensate. So if the bass is down 10 dB at 25 Hz, a lot more power is directed to the lows.
Sealed, ported and passive radiator cabinet design. Typically, sealed enclosures don’t perform deeply unless there is equalization. And to remain flat and accurate a total Qts of .707 or .5 is required. If you build with a Qts of 1 or above, you can go deeper but with a fast rolloff and a hump causing a boomy sound.
That leaves ported and passive radiators. Ported is fine for mid-bass or very large cabinets where HUGE ports are possible. Correctly designed they won’t “huff” from the air flow. In a subwoofer, however, a lot of air is moving. So in a reasonably sized cabinet a passive radiator is a great solution – IF it is properly engineered. Regardless of a design – all can sound good or terrible. We chose to use a passive radiator design for Toby as a no compromise solution.
The goal is for the active driver to have a low moving mass yet displace a lot of air. If it does that it will be faster than traditional designs and match the mid-bass drivers of EVOKE speakers. Why? A 10″ driver was chosen. It weighs half of a 12″ driver and less than a quarter of an 15″ driver.
Now we have the beginning of a good subwoofer. You can see that it will match Ruby, the Eddie series and Alex. But we want to move more air. The deeper the frequency – the more air you want to move. That’s where the passive radiator comes into play.
A 12″ down-firing passive radiator, designed to match the 10″ extends response to 18 Hz! Not only that both drivers combined move more air than a single 18″ subwoofer. That’s saying something.
So how can it be accurate and musical while still extending to 18 Hz? Good question. The passive radiator is tuned and engineered to come into play at only the lower frequencies. So while the active 10″ has the musicality [as evidenced by the 1000 Hz limit], the passive radiator begins to reinforce the bass gradually from about 60 Hz all the way down to 18 Hz.
To amp or not to amp. We chose not to. We did not find anything of sufficient power or quality to drive Toby. We explored a custom-build but the price was prohibitive. And that didn’t mesh with our mission of creating audiophile products for a reasonable price. So we leave the amp to you. You have no doubt carefully matched a quality amplified to your main speakers. There’s no reason not to be able to do that with your sub. And unlike other subs, Toby is flat without equalization with a nominal impedance of 4 Ohms!
So what makes a good sub amp? An amp will drive a lot of current. The RMS rating isn’t the only measurement where we derive quality. The amp should also be linear in power delivery. For example, if it is rated at 250 watts at 8 ohms, it should deliver close to double that at 4 ohms. Our experience is the better Class D amps fill the bill.
So how much power do you need for Toby? Well Toby will perform well with 200 watts BUT you will get more control, improved damping and much more dynamic headroom with a larger amp. There are options from many quality companies including Bryston, NuPrime and Crown. We find the NuPrime STA-9 to be an exception value with Class A input and Class D output stage. Bryston is pricey but spectacular. For brute force Crown makes several bridged mono solutions – perfect for LFE use.
The risers with IsoAcoustics GAIA II Speaker Isolation feet keeps Toby planted on the floor while isolating him for superior bass. All of this delivers an overall organic result – whether classical, jazz, rock or movies.
Toby was designed to complement our EVOKE speakers and other companies’ high performance speakers. For example, a single Toby with Ruby is an excellent match. A single or dual Toby performs ideally with Eddie. A minimum of 2 Toby subwoofer are required with Alex. In the largest of rooms, 4 Toby subwoofers with Alex may be appropriate.
Toby also makes for an excellent LFE subwoofer. Depending on your room and goals, you may use 1 or 2 in the front, and another on the side toward the rear if you choose.
10″ Active Driver
12″ Passive Driver
Silver Coated Copper Custom Audiophile Wire
IsoAcoustics GAIA II Speaker Isolation
High Gloss Painted Finish – Black
+/- 3 dB 18 Hz – 1000 kHz
88 dB 1W/1M
WBT 5-Way Binding Post, Insulated
Impedance 4 Ohms Nominal
Suggested Amp Power @ 8 Ohms, 200 – 400+ Watts*
Weight – Approximately 120 Pounds
Price and Availability
Available Late Summer
Final Price TBD
Prototype Image in Final Development
Any Standard Paint Color of Your Choice – No Charge
Any Standard Color Grille Cloth – No Charge
Custom Colors with Paint Test – Market Price
Wood Veneers with Sample [Not Endangered Species] – Market Price
Designer Grille Cloth** with Test Swatch – Market Price
* Contact Us for More Information on Amplifier Recommendations
** Fabric Weight Must be Similar to Standard Speaker Fabric