Adding a sub?

Im adding a little sub to my system and my adcom preamp doesn't have a sub-out line, so Im wondering which is the best way to do it.
I can use the speaker cable deal or split the rca's on the output of the preamp, is one way better than the other?
Thanx in advance


  • rooftop59rooftop59 Posts: 4,752
    What speakers, what model amp, what subwoofer, and do you want to use te subs high pass filter (if it has one) to block some low frequencies from going to the speakers, or run the speakers full range?
    HT Rig:
    Denon AVR-X4200w; Peachtree Audio Nova Integrated; Bryson BPD-1; Mains: Dynaudio Emit 10 + MartinLogan Dynamo (original) sub; Center - Polk cs400i; Heights, Center Surround - Klipsch KHC - 6 In-Ceiling; Surrounds - Monoprice in-ceiling; Sub - SVS PB10-ISD; LG UP870 4K BDP

    Master Bedroom
    Marantz SR-5007; Peachtree Audio NovaPre; Audiosource Amp Two, PSB Imagine B, Boston VR-10 center, NHT Super One CI surrounds, ACI Titan subwoofer, Squeezebox Touch
  • Rich502Rich502 Posts: 97
    Does your adcom preamp have dual preamp outputs? Some have normal and bypass outputs. That could be an option to use the bypass set for the sub.
  • Yes it does and thats what I used, but ended up getting rid of the sub because I changed my amp to a GFA555 and it really woke up my SDA 1's
  • PSOVLSKPSOVLSK Posts: 3,780
    This could possibly be a record for amount of time between posts, but I'll glad you followed up on this thread. From my limited experience with SDA's I'd say a sub in unnecessary. Glad you're getting great sound now. Enjoy!
    Things work out best for those who make the best of the way things work out.-John Wooden
  • nooshinjohnnooshinjohn Posts: 18,550
    edited October 2017
    Look at REL Subs. They use a high level signal to run the sub, drawing signal from the left and right positive leads from your amp, and become nearly invisible...
    The Gear... Carver "Statement" Mono-blocks, TriangleArt Reference SE with PS Audio NuWave Phono converter, Walker Precision Motor Drive, ClearAudio Stradivari v2 cartridge and Origin Conquerer Mk3c tonearm, Polk Audio "Signature" Reference Series 1.2TL with complete mods, Pass Labs X1 two channel preamplifier Signed by Poppa himself, PS Audio PerfectWave DAC MkII, Krell Evolution 525a CD Player, Pioneer Elite SC-65, Oppo UDP-205 Blu-ray , Sony XBR70x850B 4k, Polk audio AB700/800 "in-wall" surrounds

  • F1nutF1nut Posts: 40,618
    There are a number of sub companies such as Velodyne that recommend using high level inputs for the best musical integration. In fact, I can remember Polk recommending that method 15 years ago.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

  • BlueBirdMusicBlueBirdMusic Registered User Posts: 311
    I received this in Paul's daily email a few days ago:

    The best way to connect a sub

    We touched briefly on subwoofers and speaker setup in yesterday’s post. What I didn’t cover is how best to connect a subwoofer if you choose to go the extra mile and complete your system.

    Years ago, there were mostly passive subs, but over time this changed. Modern subwoofers are internally amplified. So it might seem intuitive to connect them as you would any power amplifier, with an interconnect to the preamp or DAC. This works, but would not be my first choice.

    The problem with cables and subwoofers is two-fold: double-long interconnects and a missed opportunity and synergy.

    Preamplifiers aren’t especially appreciative of the cables that connect them to amplifiers. Shorter is better if you can manage. Worse is when you double up the cables: one to the loudspeaker amplifier, the other to the subwoofer amp. A much cleaner, better sounding way of doing this is with the use of a Y connector at the amp. In this scenario, you have one cable between the preamp and amplifier (with a Y connector at the amp’s input). A short interconnect from the Y connector to the subwoofer completes the circuit. This relaxes the load on the preamp relative to running two parallel interconnect feeds.

    My favorite method is to tap the output of the loudspeaker power amplifier instead. Some subwoofers have a high-level input that can accept the main power amp’s speaker outputs. (Check to make sure this feature is available before purchasing a subwoofer) In this configuration, the amp’s power is not being used by the subwoofer, just its signal. Internal to the subwoofer are high-value resistors that neck-down the amp’s big output to something usable to the sub’s internal amplifier.

    The advantage of using the second method is maintaining the sound quality of the power amplifier. As we know, each power amplifier has its own sonic signature. If you use the amp’s output to feed the sub amp, you maintain sonic consistency and improve system synergy.

    Remember, the goal of a subwoofer is to extend the low-frequency response of the main loudspeakers. We don’t want to hear the subwoofer. We only want to make believe our main speakers have low-frequency extension (which most do not).

    If you’d like to learn more on this subject, WATCH THIS VIDEO I prepared for you.
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