SWR Sound SM-1500 - Manual (Page 12)

12
• DO NOT connect a speaker load with a total imped-
ance below the minimum rating of your amplifier to
prevent damage to your equipment.
• DO NOT connect speaker(s) with a total power han-
dling capacity that is less than the power output
rating of your amplifier to prevent damage to your
equipment.
• ALWAYS switch your system power OFF before con-
necting or disconnecting speakers.
• ONLY use unshielded speaker cable of 18 gauge or
heavier (16 or 14 gauge) for speaker connections.
Shielded instrument cable WILL NOT work and may
damage your equipment.
• ONLY connect one amplifier to each speaker load.
Two amplifiers connected to a single load WILL NOT
work and may damage your equipment.
Use the impedance and power ratings on your amplifier and
speakers to determine if a particular combination of speakers
is appropriate for your amplifier. NOTE: All SWR® bass speaker
enclosures, as well as most others, will be connected in parallel
(NOT series) when linked (daisy-chained) together. Therefore,
these guidelines apply only to parallel speaker configurations.
The speaker illustration gives you the total imped-
ance load calculations for various speaker impedance
combinations (Ω=ohms). The ideal speaker load (total
impedance) is equal to the minimum impedance
rating of your amplifier. Operating below the
amp's minimum impedance rating can overheat
your amplifier and cause damage. Operating above
the amp's minimum impedance rating, while safe,
reduces the amplifier’s maximum power output.
Something else to consider: You can obtain the
same group total impedance load from different
combinations of speaker impedances (see illustra-
tion). If each speaker in a group has the same imped-
ance, each speaker will receive the same amount of
power from your amplifier. However, if impedances
are not all equal, the lowest impedance speakers will
get the most power. For example, if you connect an 8Ω
and a 16Ω speaker to an amp output of 30 watts, the 8–ohm
speaker will receive about 20 of those watts (and be twice as
loud as the 16-ohm speaker). Take this into consideration when
calculating power handling capacities and when positioning your
bass speaker enclosures.
For an in-depth discussion of setup tips for amplifiers and speakers
(including a look at impedance and power rating issues), visit the
Support area of the SWR website at www.swrsound.com.
Speaker Guidelines
Compatible Speakers
1,500 watts is far more power than most bass speaker systems are
equipped to handle, so use caution when using the bridged mode
of this amplifier. It is recommended that you engage the compres-
sor when using the bridged mode and, if you have any doubts
about your speakers’ power-handling capabilities, check the owner’s
manual and product specifications before operation.
Each side of the amplifier is capable of 750 watts @ 2 ohms, 450 watts
@ 4 ohms and 250 watts @ 8 ohms. Ensure that your speaker system
has power-handling capabilities that match or exceed these power-
handling specifications. Using two or more cabinets per side will
optimize the amplifier's headroom and power, but remember that
each additional speaker also reduces the total impedance (ohms)
connected to the amp. For example, one 8-ohm Goliath III cabinet is
rated to handle 700 watts; if you combine two of these cabinets, the
combined power handling would be 1,400 watts, but the impedance
would be lowered to 4 ohms (please see the “Speaker Guidelines”
section of this manual for further information).
Minimum Speaker Ratings
The combined speaker impedance and wattage ratings at each out-
put should be no lower than the following.
In Stereo, Dual-Mono, or Bi-Amp modes (per side):
•2 ohm 750W •4 ohm 450W; •8 ohm 250W
In Bridged mode:
•4 ohm 1500W •8 ohm 900W