Drastically diminished subwoofer performance, cant figure out why, please help


New Member
Thread Starter
Sep 8, 2021
Preamp, Processor or Receiver
Denon 4700H
Main Amp
Emotiva 5Ch 250 wpc
Front Speakers
Def Tech bp9060
Center Channel Speaker
Def Tech cs9060
Surround Speakers
Def Tech sr9080
Surround Back Speakers
Def Tech sr9040
Front Height Speakers
Def Tech Di8
Rear Height Speakers
Def Tech bp9060
HSU VTF-3 MK5 x2
Video Display Device
LG C8 77"
Streaming Equipment
Apple TV 4K

I recently upgrade my HT setup and moved my old equipment into a computer / game room.
After setting everything up I am getting very low amts of bass output from the sub that use to be my main sub for 3 years (and was very happy how it performed)

My subwoofer (monoprice monolith 10") + marantz sr5013 AVR
-connected via RCA, tried both sub output 1 and 2 on AVR and tried both line input 1 and 2 on sub
-speakers set to small
-crossover at 80Hz both on AVR and Sub
-bass set to LFE on AVR
-subwoofer level titrated up to +2 and subwoofer needs to be cracked up to 1-2 o'clock to get any type of bass output (but still very low overall)
-tried phase from 0 to 180
-tried different RCA and power cables

I've conducted a sub crawl (while sub placed in my MLP)
Tried 4 different spot and still could not get good bass

Room is fully closed, 15' x 10' x 8' 1200 cubic feet, walls are drywall, floor is carpet-->floor board-->concrete
Sitting distance to sub is on average 6' (from all positions tried)

What's strange is:
-I tried my HSU VTF-3 MK5 sub in there and also same poor results
-I tried a Jamo J10 sub and its producing TONS of base with the same AVR / placement setup with the same RCA cable
-I know the monoprice sub works bc its works very well when connected to my BlueSound node 2i (vol at 10 o'clock)

Completely out of ideas as how to fix this issue.
Any ideas on what the underlying problem is and how to fix it?


Senior AV Addict
Dec 5, 2017
Central FL
crossover at 80Hz both on AVR and Sub

This setting is incorrect. The crossover on the sub should be bypassed when using the crossover on the Marantz.

bass set to LFE on AVR

This is correct and also recommended setting of the LPF for LFE is 120HZ.

How and what signal is being sent to the sub?
Is the test signal being sent to the same channel for all tests?
Are all the subs in EXACTLY the same place for your comparisons?
Audyssey off for all comparisons would be recommended.
Does the Bluesound node 2i use a crossover for the sub channel?
Top Bottom