Sub Sound (or lack thereof)

[Jason B]

Last night I hooked up one of the new amps (Cadence FX5100) and all was good...until I hooked up the sub...I think.

The sub is a WS12 and I did not have it in the sealed box, it was sitting on the floor for my test. My issue is this--there was barely any sound or thump coming from it. It seemed to move ok. Is this normal?? Shouldn't I get SOME volume from it????? Or, is that normal given it is not a free air sub?

I could get a little volume from it if I cranked the gain way up but I didn't feel real comfortable doing that for long.

[xpjim1]

I have the same issue and i was just about to ask the same question. Same amp as Jason. Actually the old clarion sub (free air) never made much sound off the clarion amp but i could feel a thump now and then. Now slight movement but no thump.

Jason
what Head Unit do you have?

[dogbert]

Check your filter settings on your amp, perhaps you've got low-pass filtering set?

[Jason B]

I have the same issue and i was just about to ask the same question. Same amp as Jason. Actually the old clarion sub (free air) never made much sound off the clarion amp but i could feel a thump now and then. Now slight movement but no thump.

Jason
what Head Unit do you have?

Clarion CMD4

Dogbert,
On that amp the instructions say the fifth channel automatically has a low pass filter built in. I messed with every switch/knob on the fifth channel and nothing helped too much.

[philwsailz]

A woofer sitting on the ground without the benefit of a box will make no bass.

The wavelengths of the frequencies you are trying to reproduce are so long that the pressure waves from the front and the back of the woofer mix to net zero effect. You are making positive pressure on one side of the cone, and negative pressure on the other; if you think of it mathematically, what is the sum of +1 and -1 ???

[philwsailz]

This is why we at least mount woofers in walls, or better yet, boxes. Sealed boxes and infinite baffles totally prevent the mixing of the pressure waves from the two opposite sides of the woofer cone.

[philwsailz]

Those of you with woofers mounted free-air in front of the helm, try this:

Turn on the stereo and get it thumping. Now open the hatch in front of the helm to expose the back side of the woofer. Now stand in the walk-through at about the windshield. Notice the lack of bass?

This is the same thing; the sound from both sides of the woofer cone mix here, and completely cancel out.

[dogbert]

I've got an older Tige and the only door to the compartment in front of the helm is in the walkway. I installed a Kenwood free air sub and I've found that if I just unlatch the door, it sounds way better. It seems like it wants to be vented to some extent.

[da.bell]

Those of you with woofers mounted free-air in front of the helm, try this:

Turn on the stereo and get it thumping. Now open the hatch in front of the helm to expose the back side of the woofer. Now stand in the walk-through at about the windshield. Notice the lack of bass?

This is the same thing; the sound from both sides of the woofer cone mix here, and completely cancel out.

I do that on mine and it doesn't do that!!!!!

Ops, probably because mine is in a ported box.

[philwsailz]

I've got an older Tige and the only door to the compartment in front of the helm is in the walkway. I installed a Kenwood free air sub and I've found that if I just unlatch the door, it sounds way better. It seems like it wants to be vented to some extent.

you went there didn't you...


A vented enclosure takes advantage of the fact that air is compressable. When you open the door a little, you are using the door as a crude tuning device.

What you are doing basically is setting up a Helmholtz resonant device, where the air inside acts as a spring and compresses and releases more or less at or near the same frequency that the woofer is operating at. Rather than simply relieving the pressure inside the box, the air going in and out the door actually moves in phase with the woofer, i.e. when the woofer cone is going out, the air in the doorway is going out as well.. Same thing for inward travel.

Sounds crazy, but aids in the understanding... A vented woofer enclosure operating at resonance will have higher internal pressure when compared to a similar sealed box.

[Jason B]

So once we mount the sub in the box it will pound!?

Thanks Phil! I was a little worried, I don't want anymore delays--I want my stereo!!!!

[philwsailz]

So once we mount the sub in the box it will pound!?

Thanks Phil! I was a little worried, I don't want anymore delays--I want my stereo!!!!

Make sure you use a box that is sized appropriately for the woofer, but the simple answer is yes, get the woofer installed and it will pound, at least as well as a Wetsounds sub can or will J/K!!!!!

(Tim sorry, had to. )

If you have any doubts about the size of the box, let us know; Tim at Wetsounds, myself, or possibly someone else can help you out, but I bet you have it going on already....

[xpjim1]

Ok so Mine is a free air mounted in factory location, Door to compartment closed and nothing noticible. I have the cmd3 head unit set to full on the rear set of outputs. amp has low pass bult in. Adjusted the amp and almost nothing. Slight vibration in woofer. I need a thump?????

[philwsailz]

Ok so Mine is a free air mounted in factory location, Door to compartment closed and nothing noticible. I have the cmd3 head unit set to full on the rear set of outputs. amp has low pass bult in. Adjusted the amp and almost nothing. Slight vibration in woofer. I need a thump?????

What is the rest of the system? What amp? What woofer?

[philwsailz]

Clarion sub and amp huh? ( I re-read above)