Low pass crossover frequency

Milsivich

Alright, so I current system is:

pair of LSi9
PSW10
Parasound 2100 preamp
Parasound 2125 amp

I know that I want the low pass crossover at about 80 Hz--maybe a tick higher--but I can't decide whether or not I want that limit to be set by my preamp or my subwoofer. I'm sure the difference is slim, but I don't want any double-filtering. Currently I have the low pass on the preamp maxed (0 filtering) and the low pass on the sub set where I want it. Is this the best way to go?

falconcry72

Welcome to CP!:biggrin:

You have to let your ears be the judge. Experiment and see what sounds good to you.

If you let the sub do the crossing over, and you have it set to 80 or higher, you're going to have a good amount of overlap with the 9's. I don't know the exact specs offhand, but I'd imagine the 9's are strong into the 50's maybe even 40's.

What are you using this for, HT or 2-channel music?

For 2-channel music, that sub is going to have a hard time keeping up with the 9's, and you might find you like the sound better without it.

Either way, I'd cross the sub over around whatever the 3db limit of the speaker is, which will probably be around 50hz. It may even sound better set lower if the speakers have lower in room extension than 50, so something like 45 might be ideal.

How low does that sub go? You may need to upgrade to gain a benefit with the 9's.

Edit:

After reviewing the specs, I would not use that sub with those speakers. It will make them sound worse, especially for music.

I'd either go subless or upgrade.

Tbone289

falconcry72 wrote: »

Welcome to CP!:biggrin:

Edit:

After reviewing the specs, I would not use that sub with those speakers. It will make them sound worse, especially for music.

I'd either go subless or upgrade.

What he said...

kuntasensei

Regardless of where you set the low pass on the 2100, the high pass for the speakers is fixed at 80Hz if you use the high pass outputs. I would use the filter in the 2100 rather than the subwoofer itself since it is designed to have the same delay characteristics as the high pass outputs, but the only way to find the best low pass setting is to run frequency sweeps across the 80Hz region and adjust until you have no gap in response across the transition. More than likely, 80Hz will be the best setting regardless, since that's where the high pass is.

Of course, if you're not using the high pass outputs, I would dial it down to around 50Hz (the -3dB point of the LSi9s). The PSW10 isn't the greatest sub, but since the LSi9s will probably be solid down to about 45Hz in-room, the PSW10 may give you a little more oomph at the very low end. That said, the PSW10's -3dB point is 40Hz... which is about what you're going to get out of the LSi9s anyway. I agree with falconcry72 that you might do just as well to go without that particular sub, since you're likely just going to muddy up the sound with it. Ditch the PSW10 and look for something that will give you deeper response to better compliment the natural 50Hz rolloff of the LSi9s.

John K.

Milsivich, welcome to Club Polk. I agree with the previous replies that the excellent Polk LSi9s and Parasound amplification would justify using a more capable sub than the PSW10. Having said that, you have what you have, and you should at least try to use it in the best way possible. If the results don't please you, then don't use it.

Since the PSW10 doesn't have an internal full crossover(just a low-pass filter), you'll have to use the provisions in your 2100 if you want full bass management(low pass on the sub, high pass on the LSi9s). Use either or both of the sub out jacks on the 2100, with the low pass set at 80Hz, to the line level input(s) on the PSW10. Use the Hi-Pass outputs (fixed at 80Hz)to feed your 2125. Turn the low-pass control on the PSW10 all the way up to get it out of the way of the 80Hz crossover that the 2100 is doing.

RuSsMaN

You don't need to pass the LSi9's, run them full range. Set the crossover on the back of the PSW10 to the lowest possible, and play with the gain to find a blend. If you can corner load it, it may help.

I'm willing to bet that with placement tweaks, distance from walls, toe in etc, the 9's should shine on their own. All Polk subs are musical, even a lowly PSW10, but if you feel you need to augment the low end of LSi9's, I would be looking at a DSW PRO or Micro PRO.

You can't really expect an entry level subwoofer to play well with a flagship loudspeaker - it's apples and oranges. That being said, it's up to your ears, and whether or not with some tweaking the PSW10 can do something for you in your rig.

Cheers,
Russ

Milsivich

Wow guys, thanks for the great feedback! For sure my PSW10 is the oldest and cheapest component to my system. I was looking at a MicroPRO 2000 because this seemed to be the biggest bang for your buck (and the bucks I'm willing to spend at the moment are waning!). To answer a few of your questions, I'm the kind of person that sits in a room and listens to music with absolutely nothing else going on. I have pretty keen ears, but sometimes I don't know why, electronically, what I'm hearing is happening, so your feedback about PSW10 muddying up the bass was actually very helpful.

I'm still rocking the sub, because I can't justify unhooking it to my wallet (even though it's about 5 years old), but I turned the low pass down to ~50, which seems to compliment the low-end of the LSi9's much better.

My question now is, is the MicroPRO2000 a good fit for the LSi9s? And once I get a better sub, would it be better to route the LSi9's through the high-pass output on the preamp and let the sub take over for everything below 80hz?

Thanks for all of the help!

TECHNOKID

Posts 8 - 9 reported!

deronb1

Its been my experience to let the subs do as little as possible to achieve the desired results.