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User's Manual

15

There are two main methods for

adjusting the level, crossover frequency
and phase of the Sunfire Subwoofer to
match a system:

Bob Carver’s preferred method:
By listening and making the
adjustments to suit your taste.

Laboratory method:
By  measuring the output and
adjusting for a flat frequency
response.

Excellent results can be obtained if

you make the adjustments based on
simply listening. This is Sunfire’s
preferred method as it allows the system
to be voiced based on what sounds the
best, whereas laboratory-flat frequency
response can often be clinical and less
than exciting.

The following procedure is for those

who prefer a more methodical and
scientific approach. This excerpt is from
“The Audio Critic,” issue 24, page 31,
written by contributing editor David Rich,
and is reprinted here with their kind
permission.

You will need a test CD with low-

frequency warble tones, and a sound
pressure-level meter. The Radio Shack

®

SPL meter will do fine, as will the
Stereophile

®

 test CD.

“Step 1.  Disconnect the subwoofer

and run the main speaker with a tone in
its passband (80-100Hz). Measure the
level.

Step 2.  Disconnect the main speaker

and reconnect the subwoofer. Set the
subwoofer to its highest crossover
frequency. Set the level control of the
subwoofer to give the same sound
pressure level with the same tone you
used in Step 1.

Adjusting the controls

Step 3.  With both the subwoofer and

the main speaker connected, measure
the level of the tones at the available
frequencies.  Because the crossover is
set too high, you will have a peaked
response. Adjust the crossover control to
get the smoothest response.

Step 4.  Use the phase control to make

the response even smoother. It has its
biggest effect at the crossover fre-
quency. You can iterate between the
crossover and the phase controls. Keep
your hands off the level control! It was
set correctly in step 2.

Step 5.  Listen to the subwoofer.

Resist all temptations to turn up the level
control. Play something with really deep
bass to confirm that your subwoofer is
working.”

Control settings

Use this drawing to record some of

your favorite settings.

Содержание MK IV

Страница 1: ......

Страница 2: ...connected to a power supply only of the type described in these operation instructions or as marked on the Component 9 Power Cord Protection Power supply cords should be routed so that they are not likely to be walked upon or pinched by items placed upon or against them paying particular attention to cords at plugs convenience receptacles and the point where they exit the Component 10 Cleaning The...

Страница 3: ...onfigurations 11 Adjusting the controls 15 Specifications 16 Troubleshooting guide 17 Limited warranty 19 Service assistance 19 Contents To find out more about this and other Sunfire products please visit our website www sunfire com This apparatus does not exceed the Class A Class B whichever is applicable limits for radio noise emissions from digital apparatus as set out in the radio interference...

Страница 4: ...Continuously variable volume level control Soft clipping circuit allows graceful overload and prevents speaker damage due to clipping Gold plated inputs and outputs Dear Friend Thank you for purchasing my Sunfire True Subwoofer MK IV I hope you enjoy it and the music it makes as much as I have enjoyed creating it for you The big breakthrough features of the subwoofer are its uncanny tracking downc...

Страница 5: ...should position the driver with the bump towards a protected side The Amplifier The large movement range of the drivers creates greater air pressure inside the box than a conventional woofer Therefore the drive amplifier must be much more powerful than an ordinary woofer amplifier In fact it has to be so powerful that it is almost hard to believe The power amplifier within your Sunfire Subwoofer i...

Страница 6: ...p to 100 Hz With the control fully counter clockwise the subwoofer reproduces up to 35 Hz Rotate the control until the bass sounds natural If the mid bass sounds natural but you want more low bass turn the crossover frequency down a little then turn the volume control up by about the same amount This increases the low bass output while leaving the mid bass output the same 4 Phase Control This cont...

Страница 7: ...signal is present at the inputs of the subwoofer The high pass crossover is a passive network with a fixed crossover frequency of 70 Hz and a 6 dB per octave slope We recommend using this high pass function with main satellite speakers that are small and not designed to reproduce low frequencies If your main speakers are capable of operating full range then you will not need to use the high pass f...

Страница 8: ...gy allowing it to adhere solidly to the floor To move the woofer along the floor rotate it onto one edge and it will slide along easier Heat rise Allow adequate ventilation around the metal control panel of the subwoofer Do not let anything come into contact with the panel and keep at least two inches away from any walls The metal control plate serves as the amplifier heat sink and also as a condu...

Страница 9: ... be fully shielded and as short as possible for the job The longest cable in your system will likely be to the subwoofer so choose a good quality brand Some patch cords can be a very tight fit and there is usually a preferred method of getting them off Some have to be removed with a twisting action Be gentle or you may damage the jacks of the subwoofer or your other compo nents Speaker Level conne...

Страница 10: ...ur subwoofer s performance Moving the subwoofer from one corner to another can have a major effect on the bass response Remember to keep it at least two or three feet away from any TV screen computer VCR or magnetic tapes and discs This will reduce the chance of the magnetic fields upsetting the TV screen or erasing your magnetic media Also position the control panel so that it is not touching any...

Страница 11: ...Make sure this is correctly adjusted and that the Sunfire Subwoofer s crossover frequency is set to 100 Hz This is by no means an iron clad rule rather it is a good starting point See the crossover frequency control details on page 6 and adjust ments on page 15 You can set the subwoofer s Bass Level control to 0dB and then use the preamplifier s subwoofer level control for normal and routine adjus...

Страница 12: ... R bass The opening scene in Top Gun for example has loads of L R bass information If this is not preserved the bass in these scenes sounds anemic The Sunfire Subwoofer utilizes differential gain on the left and right inputs to retain both the L R and L R information Therefore systems which do not have a dedicated sub LFE output should use both the left and the right inputs as shown for the greate...

Страница 13: ... amplifier and front speakers will play the frequency range above the subwoofer s fixed high pass crossover point The signals coming out of the subwoofer s high pass outputs are not affected by any of the controls They are just a copy of the signals going in except that the low bass is filtered out This uses the subwoofer s passive crossover network rather than the active network and controls PREA...

Страница 14: ...action of your receiver s power is transferred to the subwoofer There is no need to use the Speaker Level inputs if you are using a separate amplifier and preamplifier Such systems are best connected using the Line Level inputs as shown in the previous diagrams If you are using the Line Level inputs and there is a excessive amount of noise or hum present using the Speaker Level inputs may yield a ...

Страница 15: ...will do fine as will the Stereophile test CD Step 1 Disconnect the subwoofer and run the main speaker with a tone in its passband 80 100Hz Measure the level Step 2 Disconnect the main speaker and reconnect the subwoofer Set the subwoofer to its highest crossover frequency Set the level control of the subwoofer to give the same sound pressure level with the same tone you used in Step 1 Adjusting th...

Страница 16: ...or full output 250mVrms from left input with volume control at 0dB 60mVrms with volume control fully clockwise 0 75Vrms from right input with volume control at 0dB 200mVrms with volume control fully clockwise Input impedance 12 kΩ for Line Level inputs 15 kΩ for Hi Level inputs Driver Extra large magnet and long throw mechanical design yield very high back emf The result is extraordinarily high op...

Страница 17: ...tween the driver and the wall Home theater preamplifiers usually have a way of adjusting the level of the subwoofer LFE output either using a remote control or with a small volume knob on the back panel Make sure that this is adjusted correctly If the preamplifier s subwoofer LFE output has an adjustable crossover frequency make sure that the subwoofer s own crossover point is set higher or part o...

Страница 18: ...that they are disconnected where they first enter the room so they are making no connection to your preampli fier TV or any other component If the hum is caused by the cable TV line then you will need a ground loop isolator This is an inexpensive device fitted in line with the coaxial cable feed If the hum persists disconnect all the source components one at a time from the back of the preamplifie...

Страница 19: ...fective product and shall not in any event include property or any other incidental or consequential damages which may result from the failure of this product Some states do not allow limitations on how long an implied warranty lasts and or do not allow the exclusion or limitation of incidental or consequential damages so the above limitations or exclusions may not apply to you This Warranty gives...

Страница 20: ...Manual part number 913 016 00 Rev D ...

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