404 Sub - Trouble ahead?

vdoguy

Just bought the 404 with 6700 sats recently and they sound awesome. However, on the Circuit City website, reviews from people who bought the 404 reveal a lot of people blowing the driver very quickly. One guy blew three in the first month! And then I found ALL the Polk subs in a showroom were blown! I use mine primarily for movies and keep the subs volume at about half, but a good action flick really needs more kick. Since I don't crank it much, I'm afrid of losing the driver shortly after warranty expiration. Has anyone heard about or experienced this problem?

Also, the upper bass seems to get lost. Like when I'm watching Drumline, most of the bass drum sound is missing. After years in drum corps I know what bass drums should sound like and that ain't it! But my Sony 57WS500 tv plays back the sound perfectly. I've adjusted the crossover frequency and that's helped very little. The Sony 685 receiver doesn't allow me to change crossover frequency (or if it does, it doesn't tell you how) and I've also wired left and right channels with the sub setting off and speakers set to large on the receiver without any improvement. The e.q. only consists of bass and treble. Could there be a hidden adjustment on the receiver or are these satellites weak on the lower end? This receiver is the most user unfriendly piece of equipment I've ever used and the manual is of little help in most areas. I use Sony high-end professional equipment on a daily basis and used to design and build speaker systems nearly twenty years ago, so I know a little more than the average joe, But I'm stuck on this one! Anyone have any suggestions?

fireshoes

I wouldn't worry too much about blowing it if you are keeping it at 12. I managed to blow one where I work but someone had turned it up to 3 and I was playing the nuclear explosion scene in the Sum of All Fears at obscene levels over and over.

I would try using a good quality subwoofer cable instead of speaker wire, then set your speakers to small and sub to yes, and use the sub's LFE input. Also you might need to experiment with placement some. There could be a null knocking out the upper bass frequencies. Try placing the sub in a corner and changing the angle of it if problems persist.

apcdog

Do you notice a low level hum coming from the amplifier section of the PSW404 when the power is off? I've had two with this problem and still not sure if it's normal.

The PSW404 floor model at my local CC was blown too! Made me wonder the same thing.

TonyPTX

Man, this one fell off the radar screen for me. If it's not too late, I still recomend you use the "Polk Way" to run the sat/sub combo. Set your AVR subwoofer to "OFF or NO" and set the mains to LARGE. Run the line level to the sub, and then wire to the front sats. Flip the 80Hz/Full Range switch to 80Hz and crank the low pass filter knob on the sub all the way up to 150Hz (that's the internal x-over of the rm6700's). Then adjust the subwoofer volume control to 12 or 1 o'clock MAX. Run a calibration dVd to get the volumes adjusted properly.

Good Luck!!

Tony (a previous RM6700/404 Combo owner who saw the light)

Dr. Spec

Tony:

Setting the mains to large and the sub to no/off will terminate the output to the receiver sub pre-out. Unless I'm missing something here.

He needs to connect speaker level to the 404 and then speaker level back to the sats.

I agree with the 150 Hz crossover frequency.

I don't have the owner's manual on-line, so I'm guessing the switch should be set to full range and the low pass filter cranked up to 140-150 Hz.

Doc

TonyPTX

Originally posted by Dr. Spec
Tony:

Setting the mains to large and the sub to no/off will terminate the output to the receiver sub pre-out. Unless I'm missing something here.

He needs to connect speaker level to the 404 and then speaker level back to the sats.

Correct! The "Polk Way," if you remember sumflow (the guy with the annoying colors ), states to use speaker line level rather then sub pre-out (LFE) for a sat/sub combo speaker system. I agreed with them here since you had better control over the blending between the two.

Originally posted by Dr. Spec
I agree with the 150 Hz crossover frequency.

I don't have the owner's manual on-line, so I'm guessing the switch should be set to full range and the low pass filter cranked up to 140-150 Hz.

The switch being referred to only affects the signal going "OUT" to whatever is connected to the subwoofer line level outs. In this case, the front L/R RM6700's. Due to the nature of how the RM6700's are designed this switch really can be in either position as the 6700's have an internal 150Hz x-over built into each speaker and won't see much below that.

Dr. Spec

Originally posted by TonyPTX
Run the line level to the sub, and then wire to the front sats.
Tony (a previous RM6700/404 Combo owner who saw the light)

Note the term "line level" in your recommendation. That's what prompted me to make the post. The line level is dead when the speaks are set to large and the sub sub is set to no/off. I think you really did mean to say "speaker level" at that point, right?

Doc

TonyPTX

Originally posted by Dr. Spec
Note the term "line level" in your recommendation. That's what prompted me to make the post. The line level is dead when the speaks are set to large and the sub sub is set to no/off. I think you really did mean to say "speaker level" at that point, right?

Yeah, you got me. I'm getting sloppy with my terminology.

vdoguy

Actually, I tried all these suggestions even before I ever posted with no improvement. However, it seems to have fixed itself as the missing range has filled-in nicely. Strange!

But I'm still worried about blowing the sub. The best sound I get is to use the sub output and crank the sub level on the receiver. Otherwise, I don't get enough bass. I figure this is safer than using the subs amp. The sub is at 12 and the receiver is +5 (on a range of -5 to +5). I'm not convinced this is actually safer, but it can't be worse.