Help to Optimize AVR Settings

Cucuy

Hi All I recently purchased a RM7600 sytem bundled with a PSW303. I have setup everything, done calibration etc. I just want to make sure that I am not missing anything important that will improve my sytem performance. I have a question about the x-over setting. I have my left/front going thru the sub and then from there to the AVR (as recommended by Polk). The sub has a x-over setting and the AVR has another setting. Which one should I set up? Both? Is one not doing anything? My left/front are set up as large (as recommended in the manual). Everything else is setpu as small. I also set up the bass as No in the AVR per manual instructions. Is there a way to setup an optimal crossover frequency for my system? If so how and which of the two I set? I have avia and an SPL meter. Thanks

LoboTiger

From my understanding, if you have the F&L going into the sub and sub=no in the receiver's setup then all low frequencies are sent to the sub. It's then the sub's job to take care of the crossover. I think the crossover on the receiver is only useful for whatever speakers you've chosen as small.

hoosier21

LoboTiger nailed it, it you are using the Polk set-up of Fronts set to large, Subwoofer = no, then the AVR's subwoofer settings are no used.

Tour2ma

Cucuy, welcome to the Club...
Is your name as in "Cucuy, Cucuy, lend me your comb"?

All,
Not familiar with the RM series, but something is not making sense to me.

Originally posted by Cucuy
I have my left/front going thru the sub and then from there to the AVR (as recommended by Polk).

Only the left speaker run goes thorugh the sub, not the right?
What is going "from there to the AVR"?
Does the AVR have independant large small settings for the left main and right main channels?

McLoki

What AVR are you using? If your AVR has a variable crossover that you can set to 150hz you can hook the sub up to the AVR with an RCA cable hooked to the sub output and set all speakers to small, sub output to on and all crossovers to 150hz.

If it does not (mine didn't) you hook the speaker out (front right and left speaker) to the speaker level inputs on the sub, then from the speaker level outputs on the sub to your front two speakers. At the AVR you would set all speakers to small except your fronts - those go to large. You then turn the sub output to off.

I think the first option would acutally give you the best sound, but you are limited by what the crossover in the AVR can do for you. If you cannot set the crossover at 150hz (80hz is a more common crossover) then option 2 will be your best bet.

Good luck,

Michael

Cucuy

Originally posted by Tour2ma
Cucuy, welcome to the Club...
Is your name as in "Cucuy, Cucuy, lend me your comb"?

All,
Not familiar with the RM series, but something is not making sense to me.
Only the left speaker run goes thorugh the sub, not the right?
What is going "from there to the AVR"?
Does the AVR have independant large small settings for the left main and right main channels?

Thanks for the welcome. Both left and right speakers go into the sub. I then route the out from the sub to the AVR. The AVR has independent settings for large/small settings.

McLoki

Can you change the crossover setting in your AVR or is it fixed? (most are fixed at 80hz or so)

Michael

Cucuy

Originally posted by McLoki
What AVR are you using? If your AVR has a variable crossover that you can set to 150hz you can hook the sub up to the AVR with an RCA cable hooked to the sub output and set all speakers to small, sub output to on and all crossovers to 150hz.
I think the first option would acutally give you the best sound, but you are limited by what the crossover in the AVR can do for you. If you cannot set the crossover at 150hz (80hz is a more common crossover) then option 2 will be your best bet.

Michael

I have a panasonic xr50 which is having trouble driving my polks at high/loud spl's but that's another story. The avr has filter settings for 100, 150, and 200Hz. Is the change in sonic performance worth the extra ~50 bucks for the sub cable?

And as far as setting the ideal setting on my sub for the fronts and the on the avr for the satellites/center (smalls) (assumming I stick with the connection scheme I currently have) would that be around the 3dB lower end of the freq range of my mains. So if my left/right low freq 3dB point is 80Hz I set the xover there? And if my satellites low freq range 3dB point is 150Hz I set it up there on teh AVR? I have AVIA but have not found a way to use it to set my x-over settings.

McLoki

Originally posted by Cucuy
I have a panasonic xr50 which is having trouble driving my polks at high/loud spl's but that's another story. The avr has filter settings for 100, 150, and 200Hz. Is the change in sonic performance worth the extra ~50 bucks for the sub cable?

I think it would be well worth trying. You will have better luck with your amp driving the speakers if it only tried to power them above 150hz. (all speakers set to small) It could help your amp issue quite a bit.

I would definately try hooking the sub up to the AVR with a sub cable and in the AVR setting all speakers to small, crossover to 150, and sub to yes. This will keep your amp from trying to recreate the lower frequencies (which burns the most power) and will allow all your speakers to cross over correctly. (they roll off at 150 hz) If you dont like the sound you can always return the sub cable. (another inexpesive option would be to order from here: Blue Jeans Cables It would be very high quality and sound better than your average monster brand.

I bet you will really like it.

Michael

dorokusai

Get your system 100% before you go buying additional items.

Getting a subwoofer cable should be the least of your worries now. There are many other brands on the market other than Blue Jeans Cable.

McLoki

Originally posted by dorokusai
Get your system 100% before you go buying additional items.

Getting a subwoofer cable should be the least of your worries now. There are many other brands on the market other than Blue Jeans Cable.

You are correct that you need to get your system 100% before purchasing additional items. I do not think he will be able to get there without a sub cable though. (granted, almost any sub cable) It will help with the roll off of his speakers as well as the power issues he is having with his amp (not getting as loud as he likes)

I agree that there are many other options besides blue jeans cable to purchase a cable at, but based on his reply of $50 for a sub cable and his choice of AVR and speakers I assumed (perhaps incorrectly) that he:
1) did not currently own a sub cable
2) was going to purchase a cable locally at a higher price than he needed to spend for the quality or quanity (length) that he may recieve.
3) Wanted to keep cost as low as possible for a decent quality.

If you have any RCA cable that you can just try out - I would try that first if you can. The bass will improve with a decent cable (pick your manufacturer, but realize that there are many options other than monster cable)

Just play with what you have first (if you can) while you are deciding what setup will work best for you.

Michael

Tour2ma

Could be wrong, but I am under the impression that either way you utilize a sub, i.e., AVR set to small with cable or set to large with the speakers wired through a powered sub, accomplishes the same "load lightening" of the AVR...

Cucuy,
Agree... exhaust the possibilities of what you have before you run out and buy more anything...

Set mains and surrounds to large. With your mains wired through your sub as you've indicated they are, play with your sub's x-over point and position. If you have separate control over your AVR's center ch output, try it both ways, large and small.

While ideally you'd set the sub's x-over at 80 Hz (or less) and corner place the sub for room loading, that is not doing much to assist your AVR.

The higher you set the sub x-over, the more you are going to be able to localize it as the source of some of the "info" you are hearing. It's likely that as this occurs you will want to move the sub more towards the center of your front soundstage. Of course, as you move away from the corner, room loading will likely diminish. It's a compromise you will need to work out for your ears.

One set up that can potentially do "it all" is placing the sub in a corner and the TV infront of the sub on a angle...

McLoki

Originally posted by Tour2ma
Could be wrong, but I am under the impression that either way you utilize a sub, i.e., AVR set to small with cable or set to large with the speakers wired through a powered sub, accomplishes the same "load lightening" of the AVR....

I was under the impression that hooking the sub up in line with your front speakers and setting speakers to large and sub to off that your AVR then tried to create the entire signal (it has no idea that the lower frequencies are powered somewhere else down the line). The only way to lighten the load is to have the AVR not try to create them. (crossover in the AVR not further down the line at the sub) - I could be mistaken in this, so don't take it as fact.....

The RM series has a -3db point at 150hz. This was always my biggest problem with it. (and why I wish my AVR had a crossover point higher than 80hz.) you kind of miss out on all the info between 80 and 150hz with everything except your front speakers. (since they are set to large and your sub crossover is set close to 150hz.)

One thing I did not think of (since my AVR will not do it) try and set your front speakers to large (sub set up in line like you have it) and crossover all your other speakers at 150 hz. (center and rears) this should push all frequencies below 150hz to your front pair and let the sub take care of them. It still will not lighten the load of the speakers on the avr, but will get the sound close to what I was thinking of.

Like I said, just play with the setups and see what you like best.

Michael

Tour2ma

Yup... couple more good "play with it" suggestions..

Michael,
Agree that it would seem that the AVR's amp section would want to produce the full range output signal including the LF the sub takes as its own to reproduce. But with the sub's x-over in play, it no longer sees a load capable of this repoduction. At least this is how it was explained to me once here in the now seemingly different past.

The way I got my gray matter around this was to ask, "what happens to the energy of this 'unused (or if you prefer, underused)' portion of the signal?" It becomes a low energy, line level signal to the sub's amp, so since it produces a relatively negligible level of work being done, as opposed to driving a speaker to produce sound, it is no load on the amp.

TheReaper

Originally posted by Tour2ma
Michael,
Agree that it would seem that the AVR's amp section would want to produce the full range output signal including the LF the sub takes as its own to reproduce. But with the sub's x-over in play, it no longer sees a load capable of this repoduction. At least this is how it was explained to me once here in the now seemingly different past.

In order to reduce the load, along with the low pass filter to the sub amplifier. The subwoofer would also have to have a high pass filter on the speaker out terminals. Maybe some polk subwoofers have this high pass filter, but I don't recall reading anything about a high pass filter on my psw404?

McLoki

Originally posted by Tour2ma
The way I got my gray matter around this was to ask, "what happens to the energy of this 'unused (or if you prefer, underused)' portion of the signal?" It becomes a low energy, line level signal to the sub's amp, so since it produces a relatively negligible level of work being done, as opposed to driving a speaker to produce sound, it is no load on the amp.

I did think about that, but I thought since the sub was using the information, the AVR had to see a load in that area. I just thought (perhaps incorrectly) the sub pushed most of the signal into a resistive load to lower its output to more of a line level then on to the subs amplifier. I don't know how big of a deal this resistive load is on the amp, but sorry if I mislead anyone. (then again, if I hadn't mentioned it, maybe I would have never learned it.......:))

Thanks,

Michael

Cucuy

Originally posted by McLoki

The RM series has a -3db point at 150hz. This was always my biggest problem with it. (and why I wish my AVR had a crossover point higher than 80hz.) you kind of miss out on all the info between 80 and 150hz with everything except your front speakers. (since they are set to large and your sub crossover is set close to 150hz.)

Michael

My RM7600 has -3dB points at 90 and 80 Hz respectively for the sats and center. That is what the manual states. They will probably be a lil' higher in real life situstions/measuremetns. Would these factors change anything? I guess I will have little homework to do.

McLoki

Originally posted by Cucuy
My RM7600 has -3dB points at 90 and 80 Hz Would these factors change anything?

My mistake - you have a 7600 and most of what I have been saying relates to the 6700 - (what I had was the 6600). Sorry about that. 80hz is the crossover that you want. (you could try 100 and see if that works any better.)

I would still play with the crossovers and settings to see what works best for your room and electronics. Sorry I took you so far down the wrong road. Completly my mistake.

Michael

Tour2ma

McLoki,
I'm close to, if not in, the danger zone, here as well. As in the "don't know what I don't know" quadrant. However, I do remember coming from exactly where you are and getting somewhere else...

Reaper,
Pretty sure (as in "I'm around the above mentioned danger zone, again") that most sub's, and all Polks, do have a high pass in their adjustable x-overs. Only way, or at least the simplest way, to marry the rolling in of the sub and the rolling out of the mains.


It may be time for an expert to chime in.... DOC!

dorokusai

"Load Lightening" that's a good one.

If you have setup your speakers per the manual, you are not missing anything.

I am getting that you have the L&R wired thru the subwoofer....the AVR settings for which are explained in the manual.

Speakers - Large, Subwoofer - No.

The subwoofer as mentioned previously is handling the filtering, not the AVR. Restore the defaults in your AVR, and forget about them.

Unless you wire your speakers directly to your AVR, you will not be using the AVR adjustments for filtering.

I recall the satellites being internally filtered for protection, at 150hz, or something like that but again it doesn't really matter.

Play with the filter/crossover settings on the sub, not the AVR.

Dr. Spec

Most sub plate amps have a fixed high pass (typically 100-125 Hz, 1st order) on the speaker level outs. This is not universal, though; the STF-2 lacks this feature, for example.

And I agree the Polk HTIB sats have internal filters at around 150 Hz to prevent them from being overdriven.

TheReaper

Originally posted by Dr. Spec
Most sub plate amps have a fixed high pass (typically 100-125 Hz, 1st order) on the speaker level outs. This is not universal, though; the STF-2 lacks this feature, for example.

Thanks for the clarification.
Ditto tour2ma.

John K.

Cu, despite the Polk recommended hookup and language such as "we promise" and "trust us", my view is that it should be disregarded. If you stay with it your XR50 will roll off the center and surrounds below the setting(100Hz is the only reasonable one available)on its filter. The sub will be sent a full range signal, as will the front speakers since the 303 has no high pass on its outputs(the suggested 650 has a 80Hz highpass available). The 303's internal crossover would have to be adjusted in an attempt to get a good blend with the speakers.

Instead, get a cable with an RCA plug on each end (unless it has to be almost 100' long it shouldn't cost anywhere near $50; $10-$15 is more likely)and use the sub out on the XR50 and the LFE in on the 303. This bypasses the internal crossover on the 303 and lets the XR50 handle the crossover duties. Set all speakers "small" on the XR50 and the filter crossover at the lowest 100Hz setting. This should work well with the 80-90Hz -3dB points specified(which appears to be about right, judging from the Jan. '04 Sound&Vision lab results).

Cucuy

Originally posted by John K.

Instead, get a cable with an RCA plug on each end (unless it has to be almost 100' long it shouldn't cost anywhere near $50; $10-$15 is more likely)and use the sub out on the XR50 and the LFE in on the 303. This bypasses the internal crossover on the 303 and lets the XR50 handle the crossover duties. Set all speakers "small" on the XR50 and the filter crossover at the lowest 100Hz setting. This should work well with the 80-90Hz -3dB points specified(which appears to be about right, judging from the Jan. '04 Sound&Vision lab results).

I will certainly try this if at least can lower the strain put on the amp. Right now I am having issues with the Amp driving my setup for demmanding DTS tracks at -20 dB (-10dB is my dolby reference). No issues at the same levels for Dolby Digital in the same tracks (so far Pirates of the caribean and Hidalgo). I will try it out this weekend and post my findings. Thanks for your responses.

Tour2ma

Reaper,
Dont' thank me... I was out on a limb here...

I sure did not know this...

Originally posted by Dr. Spec
Most sub plate amps have a fixed high pass (typically 100-125 Hz, 1st order) on the speaker level outs. This is not universal, though; the STF-2 lacks this feature, for example.

I find it puzzling that you can blend in a sub effectively with a fixed, or no, high pass using the speaker level feed...

From the PSW 303 Specifications
Inputs: Speaker level and line level (filtered), LFE (unfiltered)
Outputs: Speaker level

John K.,
Good catch... I guess if the 303 had a High-pass in play it would be mentioned in the Output spec.

Took a quick glance and saw no mention of high-pass filters in any of the current line of Polk sub's. Had to go back to the "Recent Models" PSW-1200 to find one mentioned (Switchable high-pass filters... at either 40Hz or 80Hz from both line and speaker level outputs.).

Is it correct that none of the current line have high pass filters?

John K.

T2, you're correct that none of the current Polk subs have a high-pass on their speaker level outputs. This is indicated not only by the lack of mention on the output spec, which you noted, but more explicitly by the statement on p.4 of the manual for the 303, et al: "Full range signal is passed to the front speakers, for perfect sub/sat blending".

The "issues" being experienced with the XR50 haven't been described in detail, and may or may not be cured by using the line level connection, but running a full range signal into the front speakers certainly didn't help.

Cucuy

I will try the sub cable, all speakers set as small an play around with the x-over settings to see if it makes it easier on the XR50 if not I will post the issue on another thread along with the details.