WISDOM SRS High Output RTL Subwoofer
DOCUMENT CONVENTIONS
This document contains general safety, installation, and operation instructions for the Wisdom Audio High Output RTL® Subwoofer. It is important to read this document before attempting to use this product. Pay particular attention to:
WARNING: Calls attention to a procedure, practice, condition, or the like that, if not correctly performed or adhered to, could result in injury or death.
CAUTION: Calls attention to a procedure, practice, condition,n or the like that, if not correctly performed or adhered to, could result in damage to or destruction of part of or the entire product.
Note: Calls attention to information that aids in the installation or operation of the product.
Introduction
Congratulations on purchasing your Wisdom Audio High Output RTL® subwoofer. The SRS’s Regenerative Transmission LineTM technology delivers tremendous bass performance in terms of depth, dynamics, and distortion resulting in articulate bass that integrates seamlessly with high-resolution main speakers such as Wisdom Audio’s Sage and Wisdom Series.
The SRS addresses the need for a high output subwoofer with minimal size vent opening, offering improved integration, with a focus on Large Micro LED Display installations. We recognize that setting up a Wisdom Audio High Output RTL subwoofer can be a bit more involved than connecting a common sealed or ported subwoofer, which is why we recommend that our systems be engineered and calibrated by Factory Personnel While we expect your local Wisdom Audio dealer to take care of the setup and calibration of the system, we still recommend that you at least briefly review this and the other manuals (SA-DSP Series amplifiers) to understand the system’s full capabilities.
Overview
There is a class of bass enclosure that has been around since the 1950s, which can be generically described as a “low frequency tapped waveguide” or “tapped pipe.” It was an idea that was a bit ahead of its time, since fully optimizing its use required both powerful drivers and complex modeling. Your Wisdom Audio SRS subwoofer uses a modern implementation of this old idea for high-quality low-distortion bass
reproduction. Utilizing sophisticated modeling software, we’ve optimized our enclosures and drivers specifically for this application. We call our unique implementation of this relatively old idea a “Re-generative Transmission Line” subwoofer, or “RTL” sub for short.
While the roots of the Regenerative Transmission Line go back to the 1950s, it is the combination of modern computer modeling and the vastly more powerful motors of contemporary driver design that makes the RTL, not only realizable but also an incredible solution. If you are into such things, check out US Patent 2,765,864 (filed in 1955), and an AES paper published in 1959, “Analysis of a LLow-Frequency Loudspeaker System”.
For a partial and very simplified understanding of the RTL, consider that all dynamic drivers develop energy on both sides of the diaphragm, with the rear energy being 180° out of phase with the front energy. If you allow the driver to operate in free space (no enclosure), the front and rear energies cancel each other out at low frequencies, (long wavelengths).
In our Regenerative Transmission Line subwoofer, the energy from the back side of the driver is sent along a long, folded path in such a way that its lowest frequencies arrive back at the front side of the driver in phase, summing to an increase of up to 6 dB in output (4X power). Thus, energy is productively used from both sides of the woofer cone, doubling the effective surface area, thereby reducing cone motion, and
substantially reducing distortion. As an example, the two 10″ woofers in an SRS have a more effective radiating area than single 18″ woofers in more conventional enclosures. The results are quite stunning. Low frequencies are strikingly dynamic and responsive and integrate quite seamlessly with the fast and detailed Sage Series planar magnetic hybrids.
Unpacking the SRS
The Wisdom Audio SRS subwoofer is a substantial piece of equipment. Please exercise caution when unpacking your SRS to ensure that you do not strain yourself from its (perhaps unexpected) weight. The handles on the ends of the SRS can be used for lifting.
CAUTION
Do not attempt to lift your SRS by yourself. Unpacking this subwoofer is a two-person job. It is unwise for a single person to attempt to do so. Do not attempt to lift your SRS while bending or twisting from the waist. Use your legs for lifting, not your back. Always stand as straight as possible and keep the SRS close to your body to reduce strain on your back.
Subwoofer Placement (An Introduction)
Subwoofers offer somewhat greater flexibility in placement since the frequencies they reproduce are not readily localizable by the human ear. This is because the wavelengths they reproduce are more than 10 feet (3 meters) long, but our ears are located only about 6-7 inches (17 cm) apart. Thus, these extremely long waves do not meaningfully contribute to the imaging that the main speakers create.
However, this fact does not mean that the placement of the subwoofers does not affect the sound quality in the room. Far from it. Subwoofers are the most likely to suffer from the response irregularities introduced by the room itself, operating, as they do, below approximately 80 Hz in most systems. This is not a property of subwoofers but rather a characteristic of low-frequency reproduction of any form in a closed space. In fact, in a typical room where a stereo pair of full-range speakers are used, or a single subwoofer, it is common to see a variance exceeding 20 decibels (dB) in sound pressure level (SPL) between various seating positions. Is that a lot, and can we use an EQ to fix the issue?
The short answer is, yes, that is a lot. Unfortunately, equalization simply won’t work, nor would we want to use it, even if we could. Here’s why. For reference, 20dB is a factor of 100 in power. 100X! To put that in context, suppose you had a 50-watt power demand to reproduce a bass note at one seating location, and a 2nd seating location only 1 meter away had a 20dB depression in the response of the same note. To establish the same output at the 2nd seating location would require 100X more power, (5000 watts), to bring it to the same acoustic level.
This is fully outside the capabilities of nearly all systems, and it would have driven any conventional system well beyond its limit. In addition, the EQ would affect all seating locations equally, and the first position would now have a 20dB peak. This is why equalization, in general, has limited value. But it is useful when an overall correction is needed. What, then, can be done so everyone experiences the same deep, articulate, and impactful bass? The answer lies in minimizing the acoustic “seat-to-seat” variance.
Acoustic variance is caused by the low-frequency waves (pressure and rarefaction cycles) reflecting around the room and interfering with each other. At some frequencies and locations, the reflected waves sum to higher sound pressure levels (pressure/rarefaction cycles are more in phase). At other frequencies and locations, they sum to lower sound pressure levels, (pressure/rarefaction cycles are more out of phase). The dimensions of the room primarily dictate the interaction, but the placement of the subwoofers affects the excitation of these room modes, or standing waves, as they are often called. Careful placement of subwoofers can significantly reduce and even eliminate some room modes. A single subwoofer can reduce seat-to-seat variance if it is properly placed, but it is limited in what it can achieve.
In practice, 2 should be
considered a minimum where there is a single row of seating, but more should be used to minimize the variance where multiple rows of seating are present or where uniform high-fidelity sound throughout the room is desired. Controlling variance and having the finest listening experience is one of the primary reasons to choose subwoofers over full-range speakers.
Compared to full-range speakers, subwoofers have the advantage that they can be placed at various locations and in multiples around a room to mitigate the naturally occurring standing waves. How many and where to place them is a science unto itself and beyond the scope of this introduction. It is truly the job of an expert to guide placement. There are also professional tools and computer programs available now to aid in selecting the optimal, or as it is in many cases, the best compromise in placement. We recommend contacting us directly at info@wisdomaudio.com to arrange to run a subwoofer analysis on your room and to help you find the absolute best placement for each of your subwoofers.
Room Treatment
Room Treatment for subwoofers is quite different than that for satellite speakers, (primary listening speakers). The absorbers need to dissipate an enormous amount of energy and have a broad bandwidth without introducing their resonances. This typically requires large absorbers that are placed at intersecting boundaries. It can also be done actively, but this again requires very powerful transducers to keep up with the demands of the primary subwoofers. Room treatment for subwoofers should always be considered a last resort for tweaking response irregularities, since, at best, they are only tweaks.
The best approach is to use modeling software along with multiple subwoofers to control the standing waves in the room. This approach should be conducted by an experienced professional. Please contact your Wisdom Dealer for more information. Room treatment for satellite speakers is quite different and can be very effective in changing the sound character of the room and improving detail, intelligibility, and imaging. More information on this can be found in other Wisdom publications not dedicated to subwoofer installation.
Professional Acoustic Design
Does this all sound too complicated? For good reason: it is complicated. The difference between the average listening room and one that is professionally designed and implemented is huge. A great listening room will disappear to an astonishing degree, letting the experiences captured in your recordings speak to you directly. A well-designed room is also quieter and more comfortable. It can easily become a favorite retreat for peace and rejuvenation.
If you decide to investigate the possibility of improving your room with the help of a professional, it is important to find someone who focuses on residential spaces. Most acousticians are trained to deal with large spaces – airports, auditoriums, lobbies in commercial buildings, etc. The problems seen in “small” rooms (residential spaces) are quite different and outside the experience of most acousticians. Find someone who specializes in and has a great deal of experience designing home studios, home theaters, and the like. Your Wisdom Audio dealer may be such a person; failing that, he/she can help you find such a professional.
References
Books on Acoustics
The Master Handbook of Acoustics, F. Alton Everest, TAB Books Sound Reproduction:
The Acoustics and Psychoacoustics of Loudspeakers and Rooms by Dr. Floyd Toole, Focal Press
Setting up the SRS
There is no escaping the fact that the SRS is a large subwoofer. It is designed to have remarkable installation flexibility for something so large. It may be used standing upright or lying down on its brbroadsidein which case it can be built into a set of risers or as part of a “stage” in front of the screen. For installation flexibility, the SRS includes output locations on 4 sides of the enclosure. As shipped from the factory, the vent is located on the short face of the SRS enclosure. However, you can easily change the exit location by swapping the grille with one of the 3 other solid aluminum vent covers. The stellar performance remains unchanged.
Additionally, a Floor/Ceiling vent kit accessory is available to further increase installation flexibility. Using the SRS F/C Kit, the subwoofer can be placed behind a wall or ceiling, generating its output through a register vent of your choice. This allows the subwoofer to be placed up to 24″ (60cm) from the room vent. More information can be found in the SRS F/C Kit manual.
Like most of the Wisdom Audio subwoofers, the SRS is a passive subwoofer, meaning that it does not come with a built-in “plate” amplifier or internal crossover. It must be driven with an external amplifier and the crossover function must be provided by the surround preamplifier in the system, or by the amplifier. We recommend using Wisdom SA-DSP Series Amplifier since they are shipped with the proper crossover filters and acoustic profiles to optimize the performance of the SR’s subwoofers.
NOTE: The sensitivity of the SRS is quite high; 96 dB/2.83V/1m (2.83V is 2 watts at 4Ω). You won’t need a huge, powerful amplifier to drive the SRS. However, while the SRS can handle up to 1600 watts of power and deliver 125 dB of output if you want to fill an unusually large space, consider a larger subwoofer or more subwoofers. While adding more power will increase output, like all other speakers and subwoofers, it will also increase distortion when pushed to its limit.
Making the SRS Connections
As with any system, make changes to the connections only when the power is turned off to avoid any chance of inadvertently causing a problem (such as a short circuit). We recommend using heavy-gauge speaker wire, the gauge will vary depending on your speaker run length. Please consult an authorized dealer to determine what gauge would be best for your application.
The SRS uses high-tension spring terminals for connection. These have the advantage that they offer a solid connection and don’t come loose with vibration over time. They will accept up to 7AWG (3.7mm diameter) wire, the equivalent of two 10AWG wires. Connect the outputs of your amplifier to the subwoofer, taking care to observe the proper polarity. Connect the positive (+) terminal on your amplifier to the positive (+) terminal on the SRS; likewise, connect the negative (–) terminal on the amplifier to the negative (–) terminal on the SRS.
North American Warranty
Standard Warranty
When purchased from and installed by an authorized Wisdom Audio dealer, Wisdom Audio loudspeakers are warranted to be free from defects in material and workmanship under normal use for 10 years from the original date of purchase.
IMPORTANT: Wisdom Audio loudspeakers are designed for installation and operation in environmentally controlled conditions, such as are found in normal residential environments. When used in harsh conditions such as outdoors or in marine applications, the warranty is three years from the original date of purchase. During the warranty period, any Wisdom Audio products exhibiting defects in materials
and/or workmanship will be repaired or replaced, at our option, without charge for either parts or labor, at our factory.
The warranty will not apply to any Wisdom Audio products that have been misused, abused, altered, or installed and calibrated by anyone other than an authorized Wisdom Audio dealer. Any Wisdom Audio product not performing satisfactorily may be returned to the factory for evaluation. Return authorization must first be obtained by either calling or writing the factory before shipping the component. The factory will pay for return shipping charges only if the component is found to be defective as mentioned above. Other stipulations may apply to shipping charges.
There is no other express warranty on Wisdom Audio products. Neither this warranty nor any other warranty, express or implied, including any implied warranties of merchantability or fitness, shall extend beyond the warranty period. No responsibility is assumed for any incidental or consequential damages. Some states do not allow limitations on how long an implied warranty lasts, and other states do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you.
This warranty gives you specific legal rights, and you may also have other rights, which vary from state to state. This warranty is applicable in the United States and Canada only. Outside of the U.S. and Canada, please contact your local, authorized Wisdom Audio distributor for warranty and service information.
Obtaining Service
We take great pride in our dealers. Experience, dedication, and integrity make these professionals ideally suited to assist with our customers’ service needs. If your Wisdom Audio loudspeaker must be serviced, please contact your dealer. Your dealer will then decide whether the problem can be remedied locally, whether to contact Wisdom Audio for further service information or parts or to obtain a Return Authorization. The Wisdom Audio Service Department works closely with your dealer to solve your service needs expediently.
IMPORTANT: Return authorization must be obtained from Wisdom Audio’s Service Department BEFORE a unit is shipped for service. Information about a problem must be explicit and complete. AA
specific, comprehensive description of the problem helps your dealer and the WisdomThe Audio Service Department locate aand repairedthe difficulty as quickly as possible. A copy of the original bill of sale will serve to verify warranty status. Please include it with the unit when it is brought in for warranty service.
CAUTION: All returned units must be packaged in their original packaging, and the proper return authorization numbers must be marked on the outer carton for identification. Shipping the unit in improper packaging may void the warranty, as Wisdom Audio cannot be responsible for the resulting shipping damage. Your dealer can order a new set of shipping materials for you if you need to ship your loudspeaker and no longer have the original materials. There will be a charge for this service. We strongly recommend saving all packing materials in case you need to ship your product.
If the packaging to protect the unit is, in our opinion or that of our dealer, inadequate to protect the unit, we reserve the right to repackage it for return shipment at the owner’s expense. Neither Wisdom Audio nor your dealer can be responsible for shipping damage due to improper (that is, non-original) packaging.
Specifications
All specifications are subject to change at any time to improve the product.
- Number of required amplifier channels: 1
- Frequency response: 18Hz – 125 Hz ± 3dB / -10dB at 15Hz
- Impedance: 4Ω
- Sensitivity: 96 dB / 2.83V / 1m
- Power handling, peak: 1600W
- Maximum SPL: 125dB / 1m
- Dimensions: 29.5″ x 43.9″ x 11.9″ (74.9cm x 111.5cm x 30.2cm)
- Dimensioned drawings on the next page.
- Product weight, each: 147 (66.7 kg)
- Shipping weight, each: ~158 (71.8 kg) w/o pallet
For more information, see your Wisdom Audio dealer or contact:
Wisdom Audio
1572 College Parkway, Suite 164
Carson City, NV 89706
wisdomaudio.com
information@wisdomaudio.com
775-887-8850
SRS Dimensions
WISDOM and the stylized W are registered trademarks of Wisdom Audio.
Wisdom Audio 1572 College Parkway, Suite 164
Carson City, Nevada 89706 USA
TEL 775-887-8850
FAX 775-887-8820
wisdomaudio.com
SRS OM © 12/5/2024 Wisdom Audio, Inc. All rights reserved. Printed in U.S.A.
Documents / Resources
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WISDOM SRS High Output RTL Subwoofer [pdf] Owner's Manual SRS High Output RTL Subwoofer, High Output RTL Subwoofer, Output RTL Subwoofer, RTL Subwoofer, Subwoofer |