Frequently Asked Questions


R1. What is a rack unit?
A rack unit (represented as RU or U) is a standard unit of measurement used in the trade. (1 RU = 1.75 inches).
R2. How much space is between the inside of a rack’s front door and the rail?
While many Lowell racks provide about 2.5 inches of space between the inside front door and rails, some rack designs provide much less space in this area. Check individual product specification sheets and/or CAD drawings for actual measurements before placing an order.
R3. How much does a mobile base add to rack height?
The height added to the rack depends on the model chosen. The standard mobile base (LMB Series) raises a rack 1.25 inches above the floor, while a shallow mobile base (LMSB Series) raises a rack 4.06 inches above the floor.
R4. How much width do side panels add to a rack?
When side panels are added to a rack as an optional accessory, they increase the overall rack width by 1.25 inches. Each panel is 0.625 inches (5/8 in.) wide.
R5. Can a mobile base (or casters) be used with a seismic-certified rack?
No. Requirements for seismic-certified racks do not permit casters.
R6. Are the front and back doors on a rack keyed the same?
No. Front and back doors on Lowell racks have different key locks to provide greater security.
R7. Are the side locks and door locks on wall racks keyed the same?
No. Lowell wall racks (LWR Series) have different key locks to provide greater security.
R8. How many screws are included with each rack?
Generally, taller racks (35+ RU) include 50 screws; shorter racks include 25 screws.
R9. Can side panels be removed from an enclosed rack?
No, some racks like the LER Series feature side panels that are welded in place. Read individual product spec sheets for complete information.
R10. Does Lowell offer thermal solutions for racks?
Yes. If doors are required on a rack, passive heat dissipation can be improved with fully-perforated front and rear doors. A more active method would include installing fan panels in the top, rear, and/or sides of a rack. A thermostat provides active control of fans. Magnetic vent blockers can also be used to direct air flow. Check with your project engineer for the specific cooling requirements required for the electronic equipment installed in your rack.
R11. Can I change the height of the Vari-Rack™as well as the depth?
Yes. Corner post mounting rails are marked in E.I.A. increments and can be field cut to trim the height using the triangular cut marks imprinted on them.
R12. Can slim frame racks (LXR Series) be ganged together?
Yes, just insert a bolt through matching holes in the sides of the mounting rails. If the racks will have an optional front door added, add the cable chase between them if you want to gang them together.


P1. What do the marks UL, ETL and CE mean?
Lowell uses third party testing laboratories, such as Underwriters Laboratories (UL Listed) or Intertek (ETL Listed), to assure manufactured products meet specific safety standards. The CE mark is a designation used in the European Union (EU).
P2. Is a special wire needed to connect Lowell remote power control units (RPCs) and switches?
No. Since the switch functions are handled by low-voltage, low-current DC signals, almost any type of wire will work (CAT5, mic line, intercom wire, speaker wire, phone wire). Shielding is not required but can be used. Distance is rarely an issue; 24-gauge wire (CAT5, phone wire) can be used up to one mile.
P3. Are there different ways to connect a remote power control (RPC Series) to a sequencer?
Yes. Click here.
P4. Can model ACSPR-RPC1-1509 or ACSPR-RPC1-2009 control other remotely located RPC units?
Yes. Click here.
P5. What do the terms ‘switched outlet’ and ‘un-switched outlet’ mean?
Some power strips include an on/off switch so that all of the equipment connected to the strip can be turned on and off without having to remove or insert the plug into the wall outlet. This is especially important when the outlet is not conveniently located. The switch saves wear and tear on the cord, plug and outlet. When a switch is included in a Lowell (ACS Series) power strip, it controls all outlets in the strip. Hence, all of them can be referred to as ‘switched’.

Most of Lowell's 19 in wide power panels  (ACR Series) include some outlets that can be turned on/off by a rocker or key switch and some that are ‘on’ all the time (not controlled by the switch). Hence, some outlets are ‘switched’ and some are ‘un-switched.’ Outlets are clearly marked on the unit and the associated spec sheet.


A1. What is sound masking?
Sound masking is an extensive topic; textbooks provide in-depth information on the subject. In brief, a sound masking system is most commonly used in an open office environment (an area with low partitions or cubicles) to provide a degree of conversational privacy by adding background noise and shaping the signal to mask speech. Masking conversational noise can also contribute to improved productivity. In a sound masking system, the audio signal is fed from a noise generator to an amplifier and then to the sound-masking speakers that are positioned out of view, usually above ceiling tiles in what is commonly called the plenum area.
A2. Why should I use a backbox?
The local building code may require a backbox, especially when installed in a return air plenum space. A backbox can also protect the speaker from falling debris and dust.
A3. Does Lowell have a fire-rated speaker system?
Lowell does not offer fire-rated speaker systems at the present time.
A4. Does Lowell have a speaker that can be used with a fire alarm system?
Yes. See speakers in the ULD Series, ULS Series or ULT Series or UNIHORN® Model LUH-15T.
A5. Does Lowell have a speaker and/or backbox that is plenum rated?
A component (speaker or backbox) cannot be plenum rated. A speaker system can be plenum rated if it has been evaluated by a third party laboratory — such as Underwriters Laboratories (UL Listed) or Intertek (ETL Listed) — and meets the standards for the UL 2043 test for visible smoke release. The enclosure would have a sticker stating that it meets the UL 2043 standard. The sticker would also list the components (speaker, transformer, grille) that would be required to make the speaker system complete and therefore the classification valid.
A6. Is a safety cable recommended when suspending iMount® or iMount cylindrical speakers?
Lowell recommends that a safety cable be used anytime speakers are installed in an open space above an area where people could be present. The safety cable should be able to suspend the entire weight of the speaker system in the event the primary rigging system fails.
A7. Does Lowell provide speaker rigging design assistance?
No. Lowell is not able to provide engineering assistance in rigging system design which is the responsibility of the installing contractor. Lowell strongly recommends that any rigging system for loudspeakers be reviewed and approved by a certified structural engineer before the speakers are installed.
A8. Does Lowell provide speaker system design assistance?
No. Lowell engineers are able to offer recommendations on the suitability of Lowell products for specific applications; however, the speaker system design is solely the responsibility of the installing contractor or consultant.
A9. Does Lowell make custom audio products?
Yes. Lowell can provide a quotation for a custom product configured with our standard components. Contact sales@lowellmfg.com.
A10. Are Lowell speakers available in custom colors?
Yes. A variety of custom colors are available. Additional charges and extended delivery times would apply.
A11. Can the iMount cylindrical speakers be flown from a single hanging cable?
Yes. The installing contractor would need a 3-to-1 cable adapter (manufactured by others).
A12. Do LT Series speakers (1x2 or 2x2) require an earthquake support cable to structure or hardware to attach the speaker to the ceiling tile grid?
Earthquake codes vary by geographic location. Contact your local building inspector for information.
A13. Can Lowell's  indoor/outdoor speakers be installed with hardware other than the included U-bracket?
Yes. The 50W and 100W models in the OS Series will accept an omni-directional bracket (see OS-BRKT Series, order separately). In addition, the speakers have threaded mounting points so they can be mounted with Adaptive Technologies' wall-mount bracket model MM-008-BT (by others).
A14. Does Lowell have a paging horn that can be installed in a return air plenum space?
Yes. UNIHORN Model LUH-15T is UL Listed and has passed UL 2043, making it suitable for use in a plenum space.
A15. Are attenuators continuous rotation?
No. Although Lowell attenuators were originally designed to provide continuous rotation, changing preferences over the years fostered a design that does not turn all the way around.
A16. What kind of speaker wire should I use?
Sound system speaker cable choice depends heavily on the electronic design of the sound systemʼs amplifier equipment and not just the speaker itself. More.


G1. How do I buy Lowell products?
Lowell products are sold through distributors or directly to contractors, systems integrators and those who qualify for account status. To locate a distributor or sales representative click here.
G2. Who do I call for technical information about a product?
Customer service can answer questions about Lowell products or direct you to an engineer for more detailed information. Ph. (800) 325-9660, 8:00 am to 4:30 pm Central Time.
G3. Are Lowell products compliant with the BAA (Buy American Act), TAA (Trade Agreements Act) and ARRA (American Recovery and Reinvestment Act) initiatives?
As a US manufacturer Lowell remains committed to using raw materials and components from domestic suppliers whenever possible. In an ongoing effort to support the initiatives driven by these acts, most racks and metal components are made with 100% certified US steel. See product specification sheets or call customer service for information about a particular product.
G4. Are Lowell products RoHs Compliant?
The Restriction of Hazardous Substances directive (RoHs) adopted by the European Union (EU) serves to restrict the use of certain hazardous substances — such as lead, cadmium, and mercury — typically used in the process of manufacturing electronic equipment. Lowell strives to use RoHs compliant components without sacrificing product performance or price. Check with customer service for in-depth information about a particular product.