LUH-15TA - Loudspeaker Lowell - Free user manual and instructions

Product Type	Re-entrant horn speaker
Model	LUH-15TA
Brand	Lowell
Power Rating (RMS)	15W
Frequency Response	740Hz – 704kHz ± 6dB
Sensitivity (1W/1M)	105dB
Max SPL (15W/1M)	116.8dB
Conical Dispersion	80 degrees @ 2kHz octave
Input Impedance (nominal)	5000, 2500, 1300, 666, 333, 133, 89, 45 ohms
Voltage Input	25V, 70V, 100V selectable taps, also 8 ohm direct
Transformer Power Taps	25V: .13W, .25W, .50W, 1.0W, 1.9W, 4.7W, 7.5W, 15W; 70V: 1.0W, 2.0W, 3.8W, 7.5W, 15W; 100V: 2.0W, 4.0W, 7.5W, 15W
Housing Material	Cast aluminum with gasketed rear cover
Grille Material	Perforated aluminum, press-fit with trim ring
Dimensions (Horn housing)	7.1 in (180 mm) dia. housing, 8.0 in (203 mm) dia. face x 3.72 in (94 mm) depth
Dimensions (with trim ring/grille)	7.1 in (180 mm) dia. housing with 9.6 in (244 mm) dia. trim ring/grille x 3.30 in (84 mm) depth x 0.772 in (19 mm) proj.
Mounting Bolt Circle	7.625 in (194 mm) with 4 holes for E.I.A. 8 in speaker grille
Cutout Diameter	7.25 in (184 mm)
Weight	4.9 lbs (2.22 kg)
Mounting Options	Exposed, recessed (drywall, drop tile, masonry), surface-mount with optional backboxes and brackets
Accessories Included	Press-fit mesh grille with trim ring, mounting dogs
Optional Accessories	LUH-BRKT bracket, LUH-VRG vandal-resistant grille, LUH-BOX/BOX-INT backboxes, LUH-TP trim plate, LUH-RIB rough-in bridge, LUH-TBAR tile bridge
Certifications	UL 1480A, CSA C22.2 No. 205-12 (outdoor wet use), UL 2043 (plenum)
Environmental Rating	Indoor/outdoor (when exposed without backbox; some accessories indoor only)
Wiring	Red/black pigtail for 25V/70V/100V; jumper removal for 8 ohm

Frequently Asked Questions - LUH-15TA Lowell

How do I wire the LUH-15TA for 8 ohm operation?

Remove the jumper on the upper 8-ohm terminal strip and connect input wiring to the positive (+) and negative (−) 8-ohm terminals. This bypasses the transformer and selector switch.

What is the cutout diameter required for recessed installation?

The cutout diameter is 7.25 inches (184 mm). Use the inside of the trim ring to trace the hole.

Can this horn be used outdoors?

Yes, the cast aluminum housing is suitable for outdoor applications when mounted exposed (without an accessory backbox). Some accessories like LUH-BOX are rated for outdoor use.

How do I select the correct power tap?

Use the selector switch on the transformer. Refer to the table: e.g., for 70V systems, positions 1-5 provide 1W to 15W. Avoid positions beyond the rated power to prevent damage.

What is the maximum SPL of the LUH-15TA?

The calculated maximum SPL is 116.8 dB at 15W/1M.

Does the grille need to be installed?

No, the press-fit mesh grille is optional. It provides a finished look and protects against birds and insects. The horn can operate without it.

What is the frequency response?

The frequency response is 740 Hz to 704 kHz (±6 dB), optimized for voice communications.

What are the mounting options for recessed installation in a drop tile ceiling?

Use the LUH-TBAR tile bridge. Remove the tile, cut a 7.25" hole, place the bridge on top, and mount the horn through the trim ring. Tighten the three dog ears to clamp.

What wire gauge is recommended for connection?

The manual specifies using field wiring with a round jacket diameter of 0.197" to 0.354" to maintain the UL seal at the waterproof connector. Use appropriate gauge for the distance and power.

Is the horn UL listed?

Yes, it is listed for UL 1480A (general signaling) and UL 2043 (plenum spaces). It also meets CSA C22.2 No. 205-12 for outdoor wet use.

USER MANUAL LUH-15TA Lowell

I-LUH (Rev. 9/30/19): Instructions for Unihorn™ Models LUH-15TA and LUH-15TX

The Unihorn ^® is a re-entrant horn engineered for general voice communications systems. While all Unihorn models feature cast aluminum housing suitable for indoor or outdoor applications when mounted exposed (without an accessory backbox), note that some accessories are not suitable for outdoor use.

MODEL SELECTION

Exterior view of a white ceiling lamp with exposed circuitry and a circular cover (no text or symbols visible)

LUH-15TA includes:
• 15W driver with transformer and tap selector
• Cast aluminum housing with mounting dogs
- Press-fit mesh grille with trim ring

Model LUH-15TA offers the greatest flexibility for 25V, 70V, 100V, or 8 ohm applications, as it includes a press-fit mesh grille and trim ring that can be mounted or not, according to the needs of the project. The grille adds a finished look, while protecting the front of horn from nesting birds and insects. The housing features mounting dogs for quick installation.

Location	Application	Accessories (required)	Accessories (optional)
Indoor	Exposed		LUH-BRKT (bracket) or custom rigging hardware
	Recessed (existing drywall)		---- LUH-VRG (grille)
	Recessed (before drywall is installed)		LUH-RIB (rough-in bridge)
	Recessed (drop tile ceiling)		LUH-TBAR (t-bridge)
	Recessed (masonry)		LUH-BOX-INT (backbox) & LUH-TP (trim plate)
	Surface-mount		LUH-BOX-INT (backbox)
Outdoor	Exposed		LUH-BRKT (U-bracket) or custom rigging hardware
	Recessed (masonry)		LUH-BOX (backbox) & LUH-TP (trim plate)
	Surface-mount		LUH-BOX (backbox)

LUH-15TX includes:
• 15W driver with transformer and tap selector
- Cast aluminum housing

Model LUH-15TX is the economical choice for 25V, 70V, or 100V applications that do not require a press-fit grille, trim ring, or mounting dogs.

Location	Application	Accessories (required)	Accessories (optional)
Indoor	• Exposed		• LUH-BRKT (U-bracket) or custom rigging hardware	• LUH-VRG (grille)
	• Recessed (existing drywall)		• SQLK-8L (grille) & P875X-4 or P875X-6 (backbox)	• SS Series (support rails)
	• Recessed (before drywall is installed)		• SQLK-8L (grille) & P875X-4 or P875X-6 (backbox)	• SS Series (support rails)
	• Recessed (masonry)		• SQLK-8L (grille) & P875X-4 or P875X-6 (backbox)	----
	• Surface-mount		• SQLK-8L (grille) & CB84 or CB86-6 (backbox)	----
Outdoor	• Exposed		• LUH-BRKT (bracket) or custom rigging hardware	• LUH-VRG (grille)

NOTE: Unihorn Models LUH-15TA and LUH-15TX may be mounted to most industry standard 8" speaker grilles. That will not void the UL Listing.

ACCESSORIES

More information and spec sheets can be found online at www.lowellmfg.com

LUH-VRG vandal-resistant grille cast aluminum indoor / outdoor

LUH-BOX recessed or surface box stainless steel indoor / outdoor

LUH-BOX-INT recessed or surface box cold rolled steel indoor only

SQLK-8L vandal-resistant security grille cast aluminum indoor only

P875X-4 4"D recessed box cold rolled steel indoor only

P875X-6 6"D recessed box cold rolled steel indoor only

LUH-BRKT aluminum U-bracket & stainless steel hardware indoor / outdoor

LUH-TP trim plate aluminum indoor / outdoor

LUH-RIB rough-in bridge steel indoor only

LUH-TBAR tile bridge galvanized steel indoor only

CB84 4"D surface box cold rolled steel indoor only

CB86-6 6"D surface box cold rolled steel indoor only

INSTALLATION

WARNING! Speaker installation should only be performed by qualified professionals with experience and knowledge of load-rated hardware, and safe installation mounting and rigging techniques. Improperly installed equipment can result in property damage, personal injury or death, and/or liability to the installing contractor. The speaker system must be mounted in accordance with all local, state, and federal codes and regulations, and the installation must conform to industry standard practices. It is the responsibility of the installer to properly select all hardware for rigging and installation, safety and restraint cables, and to consult a licensed mechanical or structural engineer to evaluate and certify the structural integrity and safety of any mounting method and its suitability for the building structure. Lowell Manufacturing Company, its affiliates, employees, and/or independent sales representatives, are not responsible for the use, misuse, misapplication, or unsafe installation of any horn or speaker system.

NOTE: To determine speaker spacing, see the technical paper “Distributed System Speaker Spacing for the Integrator” at LowellMfg.com. An online spacing calculator is also available.

Metallic cylindrical device with a metal bracket and mounting holes (no visible text or symbols)

Exposed (with U-bracket)

Diagram of a mechanical or electrical component with layered circular components and a small cylindrical component above (no text or symbols)

Recessed in drywall

Interior ceiling view with circular lighting fixtures and a central circular component (no visible text or symbols)

Recessed in drop tile ceiling (with t-bridge)

Simple diagram of a ceiling light fixture with vertical bars, no text or symbols present

Recessed before drywall installed (with rough-in bridge)

3D mechanical assembly diagram showing components like gears and housing (no text or labels)

Recessed in masonry (with backbox & trim plate)

Surface-mount (with backbox)

Model LUH-15TA

EXPOSED:

• Open Architecture (with installer-furnished hardware): Use the two threaded 1/4–20 mounting posts (on back of horn) to mount the horn with 1/4-20 threaded rods or bolts, or custom rigging hardware. Tighten the three dog ears to clamp the horn to the trim ring. Press the mesh grille into the ring to fit securely in place.
• Ceiling or Wall (with LUH-BRKT bracket): Mount the bracket to the surface. Then place the back of the horn through the trim ring and use the two threaded 1/4–20 mounting posts (on back of horn) to mount the horn to the bracket. Tighten the three dog ears to clamp the horn to the trim ring. Press the mesh grille into the ring to fit securely in place.

RECESSED: Before mounting the horn in recessed applications, be sure to check for obstructions behind the ceiling or wall. For more information, see the technical paper online at https://www.lowellmfg.com/wp-content/uploads/Checking_above_the_ceiling_before_you_cut.pdf

• Existing Drywall: Use the inside of the trim ring to trace a 7.25" diameter mounting hole in the ceiling (or wall). Cut the hole. Place the back of the horn through the trim ring and into the mounting hole, aligning tapped holes on the ring with those in the lip of the horn. Holding the horn flush against the ceiling (or wall), tighten the three mounting dogs to clamp the horn to the ring. Press the mesh grille into the ring to fit securely in place.
• Drop Tile Ceiling (with LUH-TBAR tile bridge): The tile-bridge distributes the weight of the speaker to the ceiling grid, which will help prevent sagging. Begin by removing the ceiling tile and placing the bridge on the back of the tile to mark where the mounting hole should be cut. Cut the 7.25" mounting hole, then replace the tile in the ceiling grid with the bridge sitting on top of it. Place the back of the horn through the trim ring and into the mounting hole. Holding the horn flush against ceiling tile, tighten the three dog ears on the back of the horn to clamp it to the trim ring, tile and bridge. Press the mesh grille into the ring to fit securely in place.

- New Construction

— Before Drywall is Installed (with LUH-RIB rough-in bridge): Reserve space for the horn by mounting a rough-in bridge to the framing, positioning the bridge so the return lip protrudes into the room. The drywaller uses the lip as a guide to trace the mounting hole. Be sure to install wiring so it can be accessed when drywall is in place. After drywall is installed and painted, mount the horn by placing the back of it through the trim ring and into the mounting hole. Holding the horn flush to the ceiling (or wall), tighten the horn's three dog ears to clamp it to the bridge and trim ring. Then press the mesh grille into the ring so it fits securely in place.
— Exterior Masonry (with LUH-BOX backbox and LUH-TP trim plate): Run speaker wire into the backbox, then mount the box in the wall using mortar to hold it in place. After the mortar dries, mount the trim plate to the front of the backbox using four 8-32 screws (provided). The trim plate is larger than the backbox so it will cover rough mortar edges. Place the back of horn through the trim ring and into the box. Tighten the three dog ears to clamp the horn to the backbox and ring. Press the mesh grille into the ring to fit securely in place.
— Interior Masonry (with LUH-BOX-INT backbox): Run speaker wire into the backbox, then mount the box in the wall using mortar to hold it in place. After the mortar dries, mount the trim plate to the front of the backbox using four 8-32 screws (provided). The trim plate is larger than the backbox so it will cover rough mortar edges. Place the back of horn through the trim ring and into the box. Tighten the three dog ears to clamp the horn to the backbox and ring. Press the mesh grille into the ring to fit securely in place.

SURFACE-MOUNT:

• Exterior Surface (with LUH-BOX backbox): Run speaker wire into backbox, then mount backbox to surface. Place back of horn through trim ring and into backbox. Tighten three dog ears to clamp horn to backbox and trim ring. Press the fine mesh grille into the trim ring so it fits securely in place.
• Interior Surface (with LUH-BOX-INT backbox): Run speaker wire into backbox, then mount backbox to surface. Place back of horn through trim ring and into backbox. Tighten three dog ears to clamp horn to backbox and trim ring. Press the fine mesh grille into the trim ring so it fits securely in place.

Model LUH-15TX

EXPOSED

• Open Architecture (with installer-furnished hardware): Use the two threaded 1/4–20 mounting posts on back of horn to mount horn using 1/4-20 threaded rods or bolts, or custom rigging hardware.
• Ceiling or Wall (with LUH-BRKT bracket): Mount bracket to surface. Use the two threaded 1/4–20 mounting posts on back of horn to mount the horn to bracket.

RECESSED

Before mounting the horn in recessed applications, be sure to check for obstructions behind the ceiling or wall. For more information, see the technical paper online at https://www.lowellmfg.com/wp-content/uploads/Checking_above_the_ceiling_before_you_cut.pdf

- Existing Drywall (with SQLK-8L grille and P875X-4 or P875X-6 backbox): Cut hole in ceiling or wall according to instructions on backbox. Run speaker wire into box and recess-mount box into wall. Mount SQLK-8L grille to horn and attach assembly to backbox.

SURFACE-MOUNT

- Interior Surface (with SQLK-8L grille and CB84 or CB86 backbox): Run speaker wire into backbox and mount to surface. Mount SQLK-8L grille to horn and attach assembly to backbox.

WIRING & SCHEMATICS

Model LUH-15TA & LUH-15TX: Horn ships with pigtail exiting a waterproof connector. The red wire is the positive (+) conductor and the black wire is the negative (−) conductor. The pigtail has been factory-connected to the 25V/70V/100V input terminals inside of the termination compartment. A splice can be made to the pigtail, using UL-approved splice connectors, if the splice is made inside a UL recognized junction box (ex. Lowell LUH-BOX). If a UL-approved junction box is not used, the waterproof fitting should be loosened, the pigtail should be disconnected and removed, the field wiring should be fed through the waterproof connector, and the termination should be made directly to the input terminals in the termination compartment. The waterproof fitting should then be tightened. Note that to maintain a UL-required seal at the waterproof fitting, the field wiring used must have a round jacket with a diameter of 0.197" to 0.354".

For 8-ohm connection, remove the jumper on the upper 8-ohm terminal strip, and terminate the input wiring on the positive (+) and negative (−) 8-ohm terminals. This bypasses the transformer and selector switch as shown on the schematic below.

HORN SPECIFICATIONS

Model No. LUH-15TA and LUH-15TX
Power Rating (per EIA standard RS 426-B) 15W RMS
Frequency Response 740Hz–704kHz ± 6dB
Sensitivity (using 70V inputs) 105dB 1W/1M
Calculated Max. SPL (based on power rating & measured sensitivity) 116.8dB 15W/1M
Conical Dispersion 80 degrees @ 2kHz octave
Input Impedance (nominal) 5000, 2500, 1300, 666, 333, 133, 89, 45 ohms
Transformer Power Taps 25V@ .13W, .25W, .50W, 1.0W,1.9W, 4.7W, 7.5W, 15W70V@ 1.0W, 2.0W, 3.8W, 7.5W, 15W100V@ 2.0W, 4.0W, 7.5W, 15W
Voltage Input	25V, 70V, or 100V selectable taps

*Measured in Lowell audio lab.
**UL measured A weighted reverberant room sound power output.
***3dB increment rating with a sweep sine-wave signal source flat weight SPL meter.

PHYSICAL ATTRIBUTES

Outside Dimensions

Horn housing....7.1 in. (180 mm) dia. housing with 8.0 in. (203 mm) dia. face x 3.72 in. (94 mm) depth

Horn, trim ring, grille.....7.1 in. (180 mm) dia. housing with 9.6 in. (244 mm) dia. trim ring/grille x 3.30 in. (84 mm) depth x 0.772 in. (19 mm) proj.

Material Cast aluminum housing with gasketed rear cover; cast aluminum trim ring; perforated aluminum grille

Mounting Bolt Circle ......7.625 in. (194 mm) with 4 holes spaced to mount an E.I.A. 8 in. speaker grille

Cutout Diameter .....7.25 in. (184 mm)

Weight ...... Model LUH-15TA = 4.9 lbs. (2.22 kg)

...... Model LUH-15TX = 4.1 lbs. (1.86 kg)

SELECTOR SWITCH VALUES

Switch Position	Nominal Impedance	Watts @25V	Watts @70V	Watts @100V
1	5000	.13	1.0	2.0
2	2500	.25	2.0	4.0
3	1300	.50	3.8	7.5
4	666	1.0	7.5	15
5	333	1.9	15	X
6	133	4.7	X	X
7	89	7.5	X	X
8	45	15	X	X
X=DO NOT USE. Switch positions 6, 7, 8 (for 70V applications) and 5, 6, 7, 8 (for 100V applications) will exceed the power handing capacity of the driver and transformer and could destroy the driver, transformer and/or amplifier.

Listed for UL1480A, CSA C22.2 No. 205-

12 General Signaling for outdoor wet use.

UL2043 for use in return air plenum space.