James Loudspeaker

Series
AT Series Satellites	QXC/SXC Ceiling
BE Reference Series MKII	SA Small Aperture®
BE Reference Series	SLT3 Soundbars
Cube Series	SPL2 Soundbars
EMB II Subwoofers	SPL3 Soundbars
FXA/FXAQ Angled Baffle In-Wall/Ceiling	SPL5QT Soundbars
Mavericks Home Cinema	SPL6QT Quadratech/BEQ Soundbars
Omni Series	SPL8QT Quadratech/BEQ Soundbars
OT Outdoor Tower Series	ST Series Subterranean Subwoofers
OW Series - On Wall	VXQ
OW-M Marine Series - See On Wall Series	Wedge Series
PD Pendants	Custom Designs
PP Series - PowerPipe Subwoofers	Discontinued Products
QX In-Wall Series
QX In-Wall SoundBars

Application
2-Channel/Hi-Fi
Bookshelf / In-Cabinet / Under furniture
Ceiling
In-Wall
Landscape
Marine
On-Wall
Theater
Marine Grade Wedge and On Wall Speakers

Type
Amplifiers
Angled Baffle
Centergy Technology
DSP
Grille - Rectangle
Grille - Round
Grille - Square
Subwoofers
UL1480A/UL2043

AT42-70
4" 2-Way All-Terrain Speaker

Tags:

AT Series engineered landscape speakers now feature a coaxially mounted 0.75" aluminum dome tweeter design over a proprietary high-excursion 4" woofer. Constructed of aircraft aluminum dual enclosure, aluminum perforated grill, woofer features an aluminum cone and Santoprene™ surround, severe powder coat finish to withstand harsh outdoor environments. Available in 4 Ohm or 70 volts (low loss, 50W toroidal transformer) with built-in crossover network, allowing these outdoor speakers to play at higher volumes while still maintaining a smooth frequency response of 80-20kHz. Ground stakes or tree/wall mounts are available separately. The ground stake options are an 18" stake (Model# AT.STAKE.18) or a tree/wall mount (Model# AT.42/62.MOUNT).

Specifications

Frequency Response

80Hz-20kHz +/-3dB

Nominal Impedance

70V

Sensitivity

89dB 2.83V/1m

Voltage

70V Power

50W Toroidal Transformer

Woofer

(1) 4" (101mm) Aluminum

Tweeter

(1) 0.75" (19mm) Aluminum

Enclosure

Aircraft Marine Grade Aluminum

Finishes

Black Wrinkle, Bronze Wrinkle, Verde, Weathered Iron, Premium Finishes and Plating Available

Width

4.75 in (120.65 mm)

Depth

7.875 in (200.02 mm)

Height

4.75 in (120.65 mm)

Product Documents

CAD drawings
- AT42-70 CAD Drawing (PDF)
- AT42-70 CAD Drawing (DWG)
Datasheets/Cutsheets
- AT42-70 Datasheet
EASE/CLF files
- EASE GLL file for AT42-4/AT42-70
Color Samples/Finishes
- Standard Powder Coat Finishes

AT42-70 - Available downloads

Title: 42AT70 side

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AT42-70 - Available downloads

Title: AT Sleeve Demo

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AT42-70 - Available downloads

Title: AT Rear

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AT42-70 - Available downloads

Title: AT Side by Side

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AT42-70 - Available downloads

Title: 42AT in the Shade

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AT42-70 - Available downloads

Title: 42AT Provides Audio for Outdoor Kitchen Island

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AT42-70 - Available downloads

Title: 42AT Withstanding the Elements

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AT42-70 - Available downloads

Title: 42AT Golf Course

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AT42-70 - Available downloads

Title: Sat Mounted in a Tree

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James Loudspeaker Helps Expand Maverick Integration's Outdoor Audio Business

Dennis Jaques of Maverick Integration in Nashua, N.H., explains how the 70V Landscape Series line of speakers from James Loudspeaker enabled the company to expand its outdoor audio business.

Sound Waves Discusses Why They Love James Loudspeaker's Outdoor Tech

Joe DeMarco says he was so impressed by James' outdoor technology that he went out to visit the company to learn more.

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Category FAQs

Answer:

Traditional 70V speakers will have a transformer as the load. Because tranformers react differently to DC and AC signals, an ohm meter reading will measure the DC resistance (DCR) of the transformer and will not provide any info on the actual rating of the speaker when passing audio, and might even read near 4 or 8 ohms which might indicate incorrectly, it is a 4 or 8 ohm speaker. In the audio band, the impedance presented by the transformer will be much greater than the DC resistance.

Unlike traditional 70V speakers, James Landscape sats, the AT series, also feature an additional low frequency roll off via a built-in network to protect the speaker as well as allow running the sats on the same line as a subwoofer. These features block all DC signals, making an ohm-meter useless for testing as it will measure "open circuit" on both 4 ohm and 70V speakers.

So the speaker must be measured with an 70V IMPEDANCE METER which characterises the IMPEDANCE at 1kHz, not at DC RESISTANCE. Examples follow the table.

Below is a table which shows impedance and DCR reading to be expected on AT sats and ST subwoofers.

**Table1 - AT and ST loudspeaker impedance data**
MODEL	1kHz	DCR	NOTES
32AT4	9 ohms	open
32AT70	300 ohms	open
42AT4	7 ohms	open
42AT70	150 ohms	open
62AT4	11 ohms	open
62AT70	105 ohms	open
81ST4			Bi-amp only
81ST70			Bi-amp only
81ST70-X			Crossover for fullrange systems
101ST4			Bi-amp only
101ST70			Bi-amp only
101ST70-X			Crossover for fullrange systems
121ST4			Bi-amp only
121ST70			Bi-amp only
121ST70-X			Crossover for fullrange systems
151ST4			Bi-amp only
151ST70			Bi-amp only

Fig 1 shows three examples of 70V impedance measurement tools; the TOA ZM-104A, the TENMA 72-6948, and the Dayton Audio DATS2 speaker testing software. The two impedance meters test at only 1kHz which can give you readings which may appear out of spec, where as DATS2 gives you a full 20Hz to 20kHz impedance curve so you see all the data and read the frequency of interest. DATS2 is our favorite as it works with a laptop, is small and also the cheapest of the options.

**Fig 1 - 70V mesurement tools**

To show the versatility of DATS2, Fig 2 below shows a DATS2 curve run on a 32AT70 loudspeaker. To get the same reading as an impedance meter, you would read the impedance at 1kHz o the graph, but as you can see, there is a wealth of information in the curve. In this example, DATS2 is calling out about 281 ohms at 1 kHz, close to the 300 the impedance meters will read.

For those with an understanding of the math, the power at 1kHz will be 5000/281 = 18W. The lowest impedance is around 450 Hz at about 190 ohms, giving 5000/190 = 26W. So as you can see, even though the transformer is rated at 30W at 4 ohms, when used with a speaker the real power is quite different.

When this same transformer is loaded with a 4 ohm resisitive load, the reading is 140 ohms which is 5000/140 =3 5W, typical for a 30W rating. So all contant voltage transformers, regardless if they are 25V, 70V or 100V, only have a nomial power rating at a nominal load impedance - results will vary in use!