R-Series Crossover Questions When Connected to Onkyo TX-SR605...

RCSi30PSW10

My Onkyo TX-SR605 is driving a 5.1 Polk array that's a few years old now; they consist of R20 bookshelf mains, CSi30 center, R15 smaller bookshelf surrounds and a PSW10 sub. In the receiver's setup menu, I have all the speakers -- that is, the larger R20 bookshelf mains, the CSi30 center and R15 smaller bookshelf surrounds -- set to cross over at 80Hz, so the 10" PSW sub can handle the rest. It sounds okay when actual material is played through the system, but I notice with a Allsop Calibration/Laser Lens Cleaner disc I use to test levels and clean my Blu-ray player, there is a distinct lack of "punch" to the lower ends of the LFE when the sub is tested during the laser lens cleaning part of the disc. It's almost as if part of that LFE signal is being "robbed" from the sub at a certain frequency. I am thinking "80" may not be the correct frequency cutoff for these "R" series speakers and they may need less of a load to carry so the sub gets more -- could this be? If so can someone suggest a better cutoff frequency for these speakers (without using my receiver's Audessey setup which I found to be "off" compared to my settings)? Should they perhaps be set to 100 across the board? I'm not sure; I was using the THX specifications of 80...

Again, the two mains are R20 bookshelves, and the surrounds are R15 smaller bookshelves; the center is a CSi30.

Thanks in advance to anyone that can help.

zingo

As you, I feel 80Hz is too low for the smaller speakers. 100Hz would be a good place to start, but you may need to go a little higher depending on how it sounds.

RCSi30PSW10

zingo wrote: »

As you, I feel 80Hz is too low for the smaller speakers. 100Hz would be a good place to start, but you may need to go a little higher depending on how it sounds.

Hi Zingo,

Thanks for the reply. May I ask you a couple more questions regarding your statements?

Do you recommend changing ALL my settings for EVERY speaker in the system to 100 (at least until I hear if that's "good enough")? That is, the larger bookshelf R20s AND the smaller R15s...AND the CSi center? They should all be upped to 100?

Could you explain a bit more about why I'd be going UP in the frequency range from 80 to 100 instead of the other way around -- is this because the higher the number, the less those speakers have to handle? Do I have this right?

Thanks again.

John K.

RC, welcome. Polk specs the -3dB points of your speakers from 55 to 65Hz, so the 80Hz crossover done by your 605 should be about ideal and a higher setting wouldn't be justified. Since your PSW10 doesn't have an LFE input which would bypass the internal low pass filter(not a full crossover, just a low-pass on the sub alone), be sure to turn the frequency control on the back all the way up to get it out of the way of the 80Hz crossover that your 605 is doing, so that it doesn't interfere and possibly cause some bass weakness.

I'm not familiar with the Allsop calibration disc, but I'd suggest that you give more weight to the good results which you report getting on actual program material.

RCSi30PSW10

RC, welcome.

Thanks so much, John! Was always a Polk junkie; found the board and hope to make new friends!

Polk specs the -3dB points of your speakers from 55 to 65Hz, so the 80Hz crossover done by your 605 should be about ideal and a higher setting wouldn't be justified.

So, we're talking the "R" series bookshelves and the CSi center, yes? I keep them all on "80" to keep with the THX specification; seems your result/suggestion is in a bit of contradiction to the member who replied first -- finding that these bookshelves seem to perform better with the 100 setting. Does keeping them all on 80 mean that the speakers will have to work harder on mid bass?

Since your PSW10 doesn't have an LFE input

But doesn't it have an LFE input? I'm going SUB OUT (preout) from the 605 to the line in of the sub with a Monster sub cable; is this not correct?

which would bypass the internal low pass filter(not a full crossover, just a low-pass on the sub alone), be sure to turn the frequency control on the back all the way up to get it out of the way of the 80Hz crossover that your 605 is doing, so that it doesn't interfere and possibly cause some bass weakness.

I'm a bit leary here because the sub is installed in a position I can't really get to; what I can say is that the volume control of the sub is a bit over half way...is this okay at least?

I'm not familiar with the Allsop calibration disc, but I'd suggest that you give more weight to the good results which you report getting on actual program material.

What made me curious about all this and sent a flag up was that this exact disc, used in a previous system being driven by an Onkyo TX-SR600, used to RATTLE the walls with walloping LFE during the laser cleaning run, where LFE test bursts are put out while the disc cleans the lens...in my new apartment, with the 605, the same scene does not do the same -- it almost sounds or seems like some bottom end is getting "robbed" as if it's a bit shallow. Now, of course, this CAN be because the sub is in a totally new location in a new room and system and the acoustics are totally different, but I thought this MAY have something to do with the crossover in the receiver...

Also...the R20 mains are bigger bookshelves than the R15 surrounds; should they all be set to 80 for crossover?

Thanks so much for your help!

adam2434

Your sub does not have an unfiltered LFE input, so as John indicated, you definitely need to have the sub's low pass filter turned all the way up to ensure that you're not getting any filtering (loss) of the bass frequencies you are sending to the sub. For example, if your receiver is set at 80Hz and the sub is set at 60Hz, you will loose a lot of the bass between 60-80Hz no matter what.

Your volume control setting is OK, assuming you are able to calibrate the sub level at that setting (which you probably can given that your receiver's sub level probably has a +/- 10dB range).

I assume all of your speakers are set to "small", which is what you need.

As far as 80 or 100Hz, I would try both and determine which sounds best. I've used 100Hz with speakers that were -3dB at 57Hz simply because it sounded better than 80Hz in the particular room/system.

And yes, the new room/location can have a dramatic affect on the bass. My sub would rattle the walls and floor when it was on the main floor, but when I moved it to my basement (concrete floor), the bass was much less visceral. I bought a bigger sub to compensate :-).

RCSi30PSW10

Your sub does not have an unfiltered LFE input, so as John indicated, you definitely need to have the sub's low pass filter turned all the way up to ensure that you're not getting any filtering (loss) of the bass frequencies you are sending to the sub. For example, if your receiver is set at 80Hz and the sub is set at 60Hz, you will loose a lot of the bass between 60-80Hz no matter what.

Adam,

Thanks so much for your input, as well. I will try to get to the back of the sub to check on what you specify here, but let me in the meantime reply to this below:

Your volume control setting is OK, assuming you are able to calibrate the sub level at that setting (which you probably can given that your receiver's sub level probably has a +/- 10dB range).

Yes, my receiver has a subwoofer calibration control range of +12dB/-15dB if I am not mistaken; I have it set to +6dB as any more than that usually bottoms out the sub with loud demanding material.

I assume all of your speakers are set to "small", which is what you need.

That's not how this new receiver measures the speaker setup; in my old Onkyo TX-SR600, there were only options for small or large with speaker setup. This new 605 only has crossover specifications for any speakers you're not running full range. So I set them all to 80Hz.

As far as 80 or 100Hz, I would try both and determine which sounds best. I've used 100Hz with speakers that were -3dB at 57Hz simply because it sounded better than 80Hz in the particular room/system.

I am just worried that my 80Hz setting is somehow robbing the very bottom end of LFE signal; it seems there is a standard that these R series speakers are specified through according to Polk and the previous member who replied, and that seems to be 80 as being okay. But the first member to reply claimed 100 would probably be best for smaller speakers. I have R20 mains and R15 surrounds, and I don't know if 80 is the correct rolloff for them. They are bookshelf sized Polks with the 15s being smaller versions of the 20s.

And yes, the new room/location can have a dramatic affect on the bass. My sub would rattle the walls and floor when it was on the main floor, but when I moved it to my basement (concrete floor), the bass was much less visceral. I bought a bigger sub to compensate :-).

I'm sure this had something to do with it. My last system was in a huge room with a vaulted 12 foot ceiling and this PSW10 had no problem rattling everything in it -- suddenly I move to a new apartment and the much smaller living room the system is in doesn't seem to be reacting the same way to the same sub...so I don't know if it's the room or my crossover frequencies.