RBH T-30LSE Recommendations

It can’t be all roses when it comes to any product, no matter how good it is. There are some negatives to this product. For one, the T-30LSE system is BIG and HEAVY. It is very difficult to move this system, especially up a flight of stairs. They require a lot of real estate in your room, which could be intimidating to your significant other. Speakers like this require a dedicated theater room or lots of “buttering up” to convince anyone they are a necessity. I have given guidelines in my Signature T-2P review on how to do this and I suggest you refer to that article if you are seriously considering these speakers.

Because of the multi-tweeter driver array, off axis lobing can be heard while moving from center-seated positions to standing in acoustically controlled rooms with relatively low ceilings (8ft or less). On the plus side, this can be said about any speaker system., The effects are more pronounced on this system mostly because of the incredible detail you can hear when seated at the proper height. You need to be sitting at least 10 feet away from these speakers to minimize lobing effects and to allow for proper acoustic summation of the drivers, thus requiring a large room for optimal performance. Care and patience must be extended to find optimal positioning to achieve the best possible sonic performance.

Editorial Note About Lobing
The classic argument against line arrays or speakers with multiple tweeter arrays suffering from lobing effects is something worth addressing in this review. You cannot get around lobing issues with these designs. You must work with them in a way that minimizes the effect as much as possible. Lobing occurs when two separate sources (i.e. a midrange and tweeter) are producing the same range of frequencies at different distances from the listener. The different arrival times of those same frequencies creates a filtering effect called lobing. Every multi-way (2 way and up) speaker design, unless it is acting as a point source, is going to have off axis lobing issues to one degree or another. Speaker designs which have multiple drivers reproducing the same range of frequencies (in this case multiple midrange or tweeter drivers) are certainly susceptible to lobing issues. The effects of lobing in the midrange and high frequencies are minimized in the T-30LSE due to the unique driver alignment of the speaker. The mid/woofer drivers are aligned in a curve so the top and bottom drivers are actually closer to the ear than they would be if the drivers where in a straight line. The tweeters are spaced apart from each other at a specific distance to minimize the cancellation effects of lobing at higher frequencies. That said, once the listener moves above or below the plane of the drivers, lobbing effects become more readily apparent. For critical listening, the listener’s ear should be within the plane of the mid/woofer and tweeter drivers. One of the benefits of this particular alignment is the off axis response is tailored to reduce image compromising reflections off near boundary surfaces.

In my huge room I initially was able to induce mechanical noise out of the subs at extreme output levels. At first listen, I thought I was bottoming the drivers but later discovered the leads on the woofers were slapping against the cone. I pushed the leads out on the problematic woofers and this virtually eliminated this phenomenon - reducing it to a slight buzz when I stuck my head next to the woofers while playing at insanely loud SPL levels (not recommended for health reasons). RBH informed me this is something they normally do with the bass drivers of every production unit before installing them into the cabinet.

The bass portion of the T-30LSE system is so phenomenal, that I’d hope for RBH to one day offer stand alone subwoofer version of this design. Mechanical noise at high output levels, especially with long throw drivers, is quite common with products that don’t employ any self limiting within the mating amplifier or electronics. Perhaps if RBH Sound introduces such a product (ie. 1010-SE/R) based on this design, they can integrate an amplifier best suited for the drivers that will work within their mechanical design constraints along with offering active equalization for the low frequency optimization. Many manufacturers are doing this in their subwoofer products and I believe it would be a huge value with a small price premium for customers wanting the ultimate “tweakability” from the product. I suspect the ultimate setup of a T-30LSE system in a large room like mine would be the compliment of two additional subwoofers matching the performance of these speakers. The fact that I can’t say that about too many full range loudspeakers, speaks volumes about the bass quality of these.

My biggest issue with these speakers is that they are addictive. Owning a pair of the T-30LSE system means you will spend less time with loved ones or doing actual work if your theater room happens to be located in close proximity to your office. Almost every time I sat down to write up my experience with these speakers on my laptop, I found myself engaged in extended pleasure-listening sessions with a dead laptop battery thereafter. Be warned, these speakers are intoxicating.

Recommendations

In order to achieve the best performance of this ultimate loudspeaker system I suggest the following guidelines:

• Room size be a minimum of 10ft x 15ft
• Seated position be no closer than 10ft from plane of the speakers
• Use of a high quality 200wpc (min) amplifier that is stable down to 4 ohms
• Use of quality, snake oil free speaker cable no greater than 12AWG
• Moderately controlled acoustical environment (no glass walls or tiled floors)

Depending on the SPL level you need to attain in your room, powering these speakers full range demands an amplifier rated to deliver at least 200 Watts per channel into 4-Ohms. Of course, very high SPL’s in large rooms will require even more power and the T-30LSE can safely be used with amplifiers capable of delivering up to 1000 Watts per channel. For powering the mid/woofer and tweeter section of the speaker only, an amplifier capable of delivering 100-500 Watts per channel is recommended. I do stress quality over quantity in amplification (ensuring good SNR, low output impedance and low distortion).

The debate about biamping vs running these speakers full range depends on how you plan to use them. If the speaker system is going to be used primarily for stereo listening, you may want to start with a single channel of amplification per speaker and check out the performance. When the speaker is being used in a surround sound system, biamping is going to be the way to go. Biamping certainly can be advantageous no matter what the source material. A good quality AV receiver may be used to power the midrange and tweeter section of the speaker, while a separate full-range amplifier or dedicated subwoofer amplifier may be used to power the subwoofer drivers. By utilizing the bass management features of a processor or receiver the integration between the subwoofers and midrange drivers can be tailored to better suit your room acoustics. Also, when biamping, room correction equalization can be more easily implemented just like I achieved via Audyssey in conjunction with two additional subwoofers.

With the almost limitless dynamic range this speaker system offers it can be difficult to correctly match them for multi channel applications; of course if you have the real estate and the bank account you can just use five, or even seven of them! It doesn’t have to come to that to achieve excellent system synergy and performance. Any of the Signature series SE/R freestanding or SI/R in-wall products would be a good match for the T-30LSE’s. I definitely recommend the matching T-1 SE/R center channel or the 6100-SE/R (freestanding) or SI-6100/R (in-wall). For the side channels, the 66-SE/R’s work perfectly and although the 61-SE/R or SI-740/R’s (in-wall) will do the job for the back channels, I would suggest the 661-SE/R or SI-760/R (in-wall) instead due to their greater power handling, bass extension and efficiency.