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 depends on the model chosen. The mobile base (LMB-series) raises a rack 1.25 inches above the floor. The 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". Each panel is .625” (5/8") wide.

R5. Can a mobile base (or casters) be used with a seismic-certified rack?

No. The 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. Racks in the LER, LER-F, LSER, and LSER-F series feature side panels that are welded into position.

R10. Does Lowell offer thermal solutions for racks?

Yes. If doors are required on the 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 fan noise and energy use. 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 EIA increments and can be field cut to trim the height using the triangular cut marks imprinted on them.

R12. Can slim frame (LXR Series) racks 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 the ACSPR-RPC1-1509 (or ACSPR-RPC1-2009) control other remotely located RPC units?

Yes Click here.

P5. What do the terms ‘switched receptacle’ and ‘un-switched receptacle’ 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 to 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 of the receptacles in the strip. Hence, all of them can be referred to as ‘switched’.

Most of Lowell's ACR-series rackmount power distribution products include some receptacles that can be switched on/off by the front panel switch and some that are ‘on’ or ‘hot’ all the time. Hence, some receptacles are ‘switched’ and some are ‘un-switched’, that is, not controlled by the switch. Receptacles are clearly marked ‘switched’ or ‘un-switched’ on the unit as well as on 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 a fire-rated speaker system 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, ULS, or ULT-series or UNIHORN® Model No. 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 IMC-series 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.

A10. Are Lowell speakers available in custom colors?

Yes. A variety of colors are available as a custom order. Additional charges and extended delivery times would apply.

A11. Can the IMC-series cylinder 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 the 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 OS-50 or OS-100 indoor/outdoor speakers be installed with hardware other than the (included) U-bracket?

Yes. Lowell Model No's. OS-BRKT-B (black) and OS-BRKT-W (white) are "omni-directional" brackets that are available as options for the speakers (order separately). In addition, OS-series speakers have threaded mounting points so they can be mounted with Omnimount® series 20.5 brackets.

A14. Does Lowell have a paging horn that can be installed in a return air plenum space?

Yes. UNIHORN® Model No. 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?

It depends. 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 the right engineer for more detailed information.

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.