Subwoofer Frequency Setting: How to Set the Crossover for Perfect Bass
The crossover frequency — the point where your main speakers stop playing bass and your subwoofer takes over — is one of the most important settings in your entire audio system. Set it wrong and you get a bass hump (too much bass at a certain frequency) or a gap (missing bass where neither speaker is playing). Get it right and bass becomes seamless, natural, and impactful. Here is exactly how to do it.
What the Crossover Frequency Setting Does
The crossover is essentially a frequency divider. Below the crossover point, audio is directed to the subwoofer. Above it, audio goes to your main speakers. The goal is to find the frequency at which this division happens as smoothly as possible — neither the sub nor the main speakers struggling at their respective limits.
The Standard Starting Point: 80Hz
THX (the Lucasfilm audio standard used in cinemas and home theater) specifies 80Hz as the recommended crossover point for home theater systems. This is a good starting point for most setups because:
- Below 80Hz, bass is largely non-directional — hard to localize, so the sub can be anywhere
- Above 80Hz, bass starts to have directionality — your main speakers should handle it
- 80Hz is within the comfortable range of virtually all main speakers, including small bookshelf models
Matching Crossover to Your Speakers
The crossover should be set at or slightly above where your main speakers naturally begin to roll off. Here are guidelines:
| Speaker Type | Typical -3dB Point | Recommended Crossover |
|---|---|---|
| Small bookshelf (4-5 inch woofer) | 100-120Hz | 100-120Hz |
| Medium bookshelf (6-6.5 inch woofer) | 80-100Hz | 80-100Hz |
| Large bookshelf (7-8 inch woofer) | 60-80Hz | 80Hz |
| Small floor-standing | 50-70Hz | 60-80Hz |
| Large floor-standing (10+ inch woofer) | 35-50Hz | 40-60Hz |
The speaker’s -3dB point (where output drops 3dB below the mid-frequency level) is listed in its specifications. If not available, check reviews or frequency response measurements on sites like AudioScienceReview or Stereophile.
Using Your Receiver’s Bass Management
If you have a home theater receiver with bass management (virtually all AV receivers), use it rather than the sub’s built-in crossover. Here’s the setup:
- In your receiver’s speaker configuration, set all main speakers to “Small”
- Set the crossover frequency for each speaker individually (or globally) based on the guidelines above
- Set the subwoofer output to “LFE” or “LFE + Main” (LFE + Main is better if your main speakers have limited bass capability)
- On the subwoofer itself, set the crossover knob to maximum (bypassed) or to LFE mode — let the receiver handle the crossover filtering
Using the receiver’s crossover rather than the sub’s typically produces better sound because receiver crossover filters are often higher quality and better integrated with the room correction processing.
What Happens When You Set It Wrong
Crossover Too High
If you set 150Hz crossover with large floor-standing speakers that handle bass well down to 40Hz, you create a massive bass hump between 40-150Hz. Both the speakers and the sub are playing the same frequencies, adding together and creating boom. Bass sounds bloated, slow, and muddy.
Crossover Too Low
If you set 40Hz crossover with small bookshelf speakers that roll off at 100Hz, there is a significant gap between 40-100Hz where neither the sub nor the mains is producing output. Bass sounds thin, lacking punch and body.
Fine-Tuning by Ear
After setting an initial crossover based on the specs, fine-tune by ear:
- Play music with sustained bass notes — bass guitar or bass-heavy electronic music works well
- While listening at your seat, slowly adjust the crossover frequency up or down in small increments
- Find the setting where bass sounds most even and natural — no obvious peak and no gap
- Play a variety of content to verify the setting works across different material
Using Room Correction Software
Audyssey MultEQ (Denon, Marantz), YPAO (Yamaha), AccuEQ (Onkyo), and similar room correction systems measure your speakers and room acoustically and can set the crossover automatically — and often more accurately than manual adjustment. Run the room correction setup first, then evaluate the result. You may want to adjust slightly after, but the auto-measurement is an excellent starting point.
SVS App Crossover Control
If you own an SVS SB-1000 Pro or similar SVS sub with app control, you can adjust the crossover remotely from your listening position in real time. This is a significant practical advantage — you can make adjustments and immediately hear the result without moving to the sub. Highly recommended for fine-tuning.
Final Thoughts
Start at 80Hz, match to your speakers’ rolloff point, and fine-tune by ear. Let your AV receiver’s bass management do the heavy lifting if you have one. And if in doubt — 80Hz is the THX-endorsed standard that works well in the vast majority of home theater setups. Get the crossover right and you will be amazed at how seamless and impactful bass becomes.
