My Polk db 690 have no bass, WHY?

[aweir 10+ year member]

I have Polk 6X9 in little enclosures that sit on my back seats. There's NO BASS at all.

My Polk 6.5" in my front doors have about wice as much bass even though all four speakers are amped. I thought that the speaker were wired out of phase so I checked inside the enclosure and they're wired just fine.

I even hooked them up to my home stereo to see if I could get bass and no, there's almost none. It's very weak. I'm dissapointed I paid about $90 for the 6X9s and almost $40 for the carpeted enclosures.

Am I supposed to do something with these enclosures like use baffles with the speakers or something? I mean they are 100W RMS and I'm getting more bass from my 6.5" fronts. It really makes no sense. they're completely sealed enclosures, there's no air leaks to cancell out the bass so what's the problem???

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[aweir 10+ year member]

I found out that by removing the speaker's terminal plug from the back of the enclosure and letting it hang out the back, it becomes "vented" and the bass is much stronger now even though the speaker has no damping any more.

So what should I do? Stick with the sealed enclosure and loose all my bass or remove the plug and have more bass but risk damage from the high excursion?

 

[Sunfire01 10+ year member]

When I ran my polk ex693a (older model) 6x9s in free air (in the back deck of my car), they moved quite a bit also to produce the sub 80hz tones (bass). Dont worry if your not clipping the amp

 

[aweir 10+ year member]

But now sometimes I hear a rattle when a bass note hits. It worrys me; the reason (to get technical) is that the enclosure is now improperly tuned so low that there is not adequate damping below the proper tuning frequency. The speaker should really not be trying to produce a 40-50 HZ note at such a high db like it is.

I have not been able to find any vented 6X9 enclosures. I wonder if I can buy a smaller tube (like a PVC tubing) to use for the vent enclosure and raise the tuning frequency so I don't do any damage by the excessive cone movement.

I payed alot of money for these speakers and I belive they should be in vented enclosures to get the most out of the bass.

 

[darren700 10+ year member]

i have those speakers and they have decent bass, however once i put a box in my trunk, and sealed off the trunk from the cabin, thus creating a makeshift box out of the airspace in the trunk (db690s were in rear deck) then they had a very surprising amount of bass, off of my headunit power even

 

[XanderMoser 10+ year member]

The sealed enclosure is probably way too small for the speaker. And I think most 6x9 speakers are designed to be run IB in a rear deck or a door, not sealed in a box. Different Qms, Qes, and BL parameters (I think, but I could be wrong on which parameters) determine what kind of enclosure, or IB, it will work best in.

 

[Joseph K 10+ year member]

Make your own enclosure... should be VERY VERY easy to make one for 6x9's.

 

[aweir 10+ year member]

I have four 6x9" enclosures and only two 6x9 speakers. couldn't I just cut out the top and bottom of two of the enclosures and attach them together to increase the size of the enclosure. then add a port and put PVC piping for a port?

Can you help me figure out port size/lenghth.