WISDOM S90i High Output RTL Subwoofer Owner’s Manual

Owner’s Manual
S90i / S90 basic-port / S90-f/c
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 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 ® in-wall subwoofer. The S90’s Regenerative Transmission Line 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 Insight or Sage Series. 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.

Overview

Your Wisdom Audio S90 subwoofer uses a modern implementation of an old idea for high-quality, low distortion bass reproduction. 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 make the RTLTM so special.
There is a class of bass enclosures that has been around since the 1950’s, which can be described generically as “low frequency tapped waveguides” or “tapped pipes”. It was an idea that was a bit ahead of its time then, since fully optimizing its use required both powerful drivers and computer modeling. But, 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 Low-Frequency Loudspeaker System”.
We have utilized sophisticated modeling software to fully optimize our enclosures and have developed drivers that are specifically optimized for this application. We call our unique implementation of this relatively old idea a “Regenerative Transmission Line” subwoofer or “RTL” sub for short.
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 largely cancel each other out – especially at low frequencies.

In our Regenerative Transmission Line subwoofer, the energy from the backside 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, effectively summing to an increase of 6 dB in output. Thus, the energy from both sides of the woofer cone is used in a productive way, resulting in a substantial reduction in distortion and an effective surface area double compared to what you would otherwise expect. As an example, the effective radiating surface area of the two 5”x7” woofers in the S90 are equivalent to a 12″ – 13″ woofer 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. As an example, the S90 has an output in excess of 123 dB at 20 Hz.

Unpacking the S90

The Wisdom Audio High Output RTL ® S90 subwoofer is a substantial piece of equipment. Please exercise caution when unpacking your S90 to ensure that you do not strain yourself from its (perhaps unexpected) weight.

CAUTION
Do not attempt to lift your S90 by yourself. Unpacking this subwoofer is clearly a two-person job. It is unwise for a single person to attempt doing so.
Do not attempt to lift your S90 while bending or twisting from the waist. Use your legs for lifting, not your back.
Always stand as straight as possible and keep the S90 close to your body to reduce strain on your back.
There are three different types of the S90 Subwoofer. Below is a description of the types of installations each one is used for, and what comes with each type.
S90
This version (i) is used when you are needing the S90 to have an exposed grille:

• (1) S90 Enclosure
• (1) White Grille
• (1) Uni-grip frame
• (1) Port reduction plate

S90 basic-port
This version (basic-port) is used when installing the S90 behind the fabric and a grille is not needed:

• (1) S90 Enclosure
• (1) Port reduction plate
• S90-f/c

This version (f/c) is used when installing the S90 in a remote location up to 24″ away from the room it will be vented into:

• (1) S90 Enclosure
• (1) HVAC Grille
• (1) Extension Hose
• (1) Mounting Plate for S90
• (1) Mounting Plate for Wall
• (2) Hose clamps
• (1) Roll of heavy rubber tape

Subwoofer Placement

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 contribute meaningfully to the imaging that the main speakers create.

However, this fact does not mean that the placement of the subwoofers has no effect on the sound quality in the room. Far from it. The 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.
For the best location(s) we recommend contacting us directly at info@wisdomaudio.com and we will run a subwoofer analysis on your room to help find the absolute best placement for each of your subwoofers.

Room Treatment

Rectangular rooms have six reflecting surfaces (four walls, ceiling, and floor) that reflect sound to the listener, after various delays introduced by the indirect routes the sound take on their way to the listener. These first reflections are particularly damaging to sound quality. Looking at the simplest case of stereo reproduction, you have a minimum of twelve first reflection points in your room that deserve some attention.
Unfortunately, it is often difficult to do much about the ceiling and floor reflections, even though they are arguably the most destructive. (The minimization of these reflections is one of the strongest arguments for the tall, line source loudspeakers that Wisdom Audio builds.) This leaves you with eight “first reflections” that you should consider minimizing somehow. These points are easily found by having an assistant slide a small mirror along the four walls of the room, while you sit at the listening position. Any place on the wall where you can see a reflection of any speaker is a first reflection point. Concentrate on the first reflections for the Left and Right speakers first.
If you can, arrange to apply either absorption or diffusion at these eight points (don’t forget the wall behind you). Absorption can be as simple as heavy, insulated drapes; diffusion can be provided by a well-stocked bookcase with books of varied sizes. Alternatively, you can buy purpose-designed room treatments (some sources listed under References, below).
The important things to remember are these: a good room should have a balance of absorption and diffusion; and if you are going to treat only a few areas of the room, the first reflection points are the most important ones to treat.

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

Installing the S90 in a Wall

Your dealer has extensive knowledge of wall construction and will customize these installation instructions to suit the needs of your situation. But these notes provide an overview of the process.
Note that the Regenerative Transmission Line opening that vents the low frequencies into the room may be placed either up near the ceiling or down near the floor. In most rooms, these are largely equivalent positions in terms of acoustics. The difference will usually be aesthetic rather than performance-based.
As seen from above, a cross-sectional view of the S90 as mounted in a typical 2 x 6 stud wall looks like this:

The front board of the S90 is made from 5⁄8″ MDO plywood, which presents a smooth, paintable finish surface similar to dry wall. It can be butted up against the 5⁄8″ drywall, taped, and spackled, and painted like any other section of wall. It will also readily accept skim-coating if the construction calls for plaster walls.

The process of installing the S90 in a standard stud wall is quite straightforward.

1. Open the 2 x 6 stud bay to be used
   a) The existing drywall (if any) should be cut back so it covers about half of the 2 x 6 on each side of the bay. The flange of the front board of the S90 will cover the other half. Obviously, there cannot be any plumbing or wiring in this stud bay, nor firebreaks. The S90 will use virtually all the available space in a standard 8′ 2 x 6 stud bay.

2. Stand the S90 in front of the bay in which it will reside; make the electrical connections
   a) There are two methods commonly used for making these connections.
   b) If you have access to the adjacent stud bay, drill a hole through the 2 x 6 stud between where the S90’s feet will be when it is in
   place, and feed the wires through the hole. You can then make the connection in the adjacent stud bay, where you will have plenty of room to work. You can even put the connections inside a J-box for future serviceability if you so desire.
   c) Alternatively, sometimes it works out easier to bring the connecting wire through the top plate or soleplate of the same stud bay in which the S90 is located. If so, the connection can be made in the space between the feet at the end of the S90 with the wires. If the signal is coming through the attic and the top plate, the S90 will need to be “upside-down” with its feet at the top of the bay. This places the grille high on the wall, which may be preferred aesthetically (since it can be mistaken as a surround speaker).
   d) The preferred method for making the electrical connection is to solder the wires together and then insulate the connection with shrink tubing. If this is impractical, use appropriately sized wire nuts and wrap the wire nut connections in black electrical tape to prevent any chance of the connection vibrating loose.

3. Stand the S90 in the stud bay, dress the wires so that they cannot rattle, and screw the front board to the studs with drywall screws
   a) The S90 has predrilled, countersunk screw holes so standard #8 drywall screws will sit with their heads below the surface, so they can be taped and spackled without any trace. A total of eighteen (18) drywall screws are used.
   b) The S90 should be supported or suspended in a manner that does not subject it to twisting or torsional forces that would stress the enclosure. No wooden or metal enclosure should be forced against an irregular surface. If the studs are curved or warped in an installation the installer must insert shims between the S90 front panel and the stud surfaces to avoid such stresses, as would be the case for any in-wall loudspeaker.

4. Tape and spackle the seams

5. After everything has been painted, slice the paint along the edge of the foam plug in the bass vent. Remove and discard the foam.
   a) The foam plug is there simply to protect the inside of the S90, and particularly the woofers themselves, from being splattered with paint. Once that purpose has been served, it needs to be removed. A sharp utility knife can be used to
   break any paint that may have leaked into the area.

Making the S90 Connections

As with any system, you should 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 dependent on your speaker run length. Please consult an authorized dealer to determine what gauge would be best for your application.
For the purposes of this manual, we will assume that you have already connected an approved signal processor or amplifier with the necessary signal processing for the S90. The S90 (like all RTL subwoofers) requires a very specific non-standard EQ slope to ensure good performance. The use of a non- approved EQ or amplifier without the correct signal processing will cause poor performance from the S90. For an approved list of amplifiers and surround processors to use please email us at info@wisdomaudio.com

• A “quick connect” clamping connection is provided at one end of the theS90 terminated in a WAGO compact splicing connector.
• Strip back the connector 0.4″ (11mm)
• Lift the lever to open the clamping unit and insert a stripped conductor.
• Then, lower the lever to close the clamp.

Since the S90 fills a standard 2 x 6 stud bay, the simplest thing is to drill a hole in one of the 2 x 6 studs and thread the wires through to the adjacent bay, where you have ample room to make connections and run the wires.
Alternatively, the incoming signal can be routed directly into the small space provided by the “feet” of the S90, and the connection to the WAGO connector can be made just prior to installing the S90 in the wall.
Connect the outputs of your Wisdom Audio SA-series amplifier to the subwoofer, taking care to get the polarity correct. Connect the positive (+) terminals on the SA-Series amplifier to the red/white WAGO connector; likewise, connect the negative (–) terminals on the amplifier to the black/gray WAGO connector.
We recommend wrapping the resulting connection in electrical tape to preclude any chance of the wire nut working loose over time.
VERY IMPORTANT! You MUST use an SW-1 or SA-DSP amplifier. If using another brand of the amplifier, you must make sure you use a specific type of surround processor as the SCS2 requires a special 48dB Butterworth bandpass filter and PEQ settings for the RTL to work properly.

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 a period of 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 has 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 prior to shipping the component. The factory will pay for return shipping charges only if the component is found to be defective as mentioned above. There are other stipulations that 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 S90 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, or 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.
It is extremely important that information about a problem be explicit and complete. A specific, comprehensive description of the problem helps your dealer and the Wisdom Audio Service Department locate and repair the 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.
WARNING : 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 unit someday.
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 in order to improve the product.

• Number of required amplifier channels: 1
• Frequency response: 20Hz – 80 Hz ± 2dB relative to the target curve
• Impedance: 4Ω
• Sensitivity: 93 dB/2.83V/1m
• Power handling, peak: 1000w
• Maximum SPL: 123dB / 20 Hz /1m
• Dimensions: See appropriate dimensions drawings on next page
• Shipping weight, each: 65 lbs. (30 kg)

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

S90 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
S90i/S90 basic-port/S90-f/c OM-7.0 © 11//2021 Wisdom Audio, Inc. All rights reserved. Printed in the U.S.A.

References

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