Denon 3805 and Polk RTI 12's

[Johnny Canuck]

Hello everyone...first time poster but a long time reader. I appreciate all the advice and it has been extremely helpful since I have discovered this hobby. With no NHL hockey, i have had to find something else to ammuse me.

Let me start by mentioning my equipment and then I will ask for your help. I have a Denon 3805 receiver, Polk RTI 12 mains, Polk center and rear surrounds and an Infinity rear center that is old and not really important. Polk PSW 404 sub that is ok but after hearing my friend's velodyne, it pales in comparison. I also recently purchased a Tripplite HT Powerbar 10 after reading some good things here about it. My cables are OK, nothing fancy...

So here is my dilemma. I moved into an apartment and had an old set of Technics speakers (SB CX-700)...space limitted me to put them beside my TV. Well they are old and made my TV go green so i had to go buy some new speakers. Before I got serious about stereo equipment, I bought some Polk RTI 12's....good value for the money I was told. I like their sound but a tad bright, especially in my condo with hard wood floors. They are power hungry beasts. Can take 500 W. There isn't a receiver on the planet that can do them justice. I got a good deal last week , $200, for a NAD 2200 power amp. It is rated at 100W but with 6db of headroom it equals approx 400W, so i have been told. I hook it up, bi wired to the Polks and now it sounds WAY too bright. TOO clear if that makes sense. And I have read these Polks should have "earth shaking" and "chest pounding" bass from other people who have them. I DON"T HEAR IT!! I have tried everything and i don't hear this so called bass. My 10 year old Technics kick their *** in the bass department. They have a passive radiator.

My question is should I just send the power from the amp to the subs on the Polks and use the receiver to run the mids/highs? Might take some brightness away. Isn't that what the cross over does if I bi wire? Am I getting more juice sending power straight to the lows? I will try it today. I also don't understand crossovers. Most here say to set it at 80hz but when i put it to 125 or 150hz the bass is WAY louder. My internal crossover on the Polks is set at 125hz..There is also the LFE and LFE AND MAIN setting on the Denon. Which one? I should take advantage of the woofers in the Polks, set it to LFE and Main and have a fuller sound (so the manual says)

I also want to comment on the Bi amping 3805 with Zone 3. polk site calls this "ghetto biamping". I tried it and the hum was way too annoying..also the words "tonal imbalance" come to mind. The experts where I live tried it too and said it was just plain brutal. The Zone 3 amp is no where near as good SQ as the main zone. And you can't use the rear centre...I tried this back and forth so many imes and they are right. SQ is severly degraded doing this. I do however want to thank Jason Coleman for all his work and advice...

so...please...any advice on how to get the best out of my system?

 

[Xsound]

Can't comment on the 3805. I have the pioneer vsx-54, and the directions for bi-amping are very simple, and listed in the manual. I figured if the manufacturer includes instructions on how to do this, they must see this as a legitimate use.

I don't have any problems with hums or noise. Runs quiet. I am very pleased.

 

[MDS]

I never heard anyone describe Polks as bright and that was not my impression of them either when demoing them. However, your ROOM affects the sound more than anything else.

Hardwood floors, lots of windows or other reflective surfaces == bright. Something as simple as a large throw rug or heavy curtains will tame the brightness quite a bit. Additional furnishings like book cases, large couches, and other things help too. If that doesn't get the sound to where you want it, then it's time to look into proper acoustic treatment like treating the first reflection points on the side walls. Lots of good articles on this site about room treatments.


For the bass managment stuff, this current thread is all about the Denon 3805 and bass management:
http://forums.audioholics.com/forums/showthread.php?t=7574

 

[Leprkon]

My question is should I just send the power from the amp to the subs on the Polks and use the receiver to run the mids/highs? Might take some brightness away. Isn't that what the cross over does if I bi wire? Am I getting more juice sending power straight to the lows? I will try it today. I also don't understand crossovers. Most here say to set it at 80hz but when i put it to 125 or 150hz the bass is WAY louder. My internal crossover on the Polks is set at 125hz..There is also the LFE and LFE AND MAIN setting on the Denon. Which one? I should take advantage of the woofers in the Polks, set it to LFE and Main and have a fuller sound (so the manual says)

You really won't be helping yourself to run power from the amp to the subs and from the receiver to the mains.. unless you actually break into the speaker cabinet and take out the speaker's crossover. As long as the crossover is there, you still have an electrical circuit connecting all the input power and the speaker will distribute the signal as it sees fit.

I think your best bet is to move the sub around to several different spots and see if the room acoustics are playing havoc with your bass.

Low bass is omnidirectional. Human ears can't really locate a source, so it makes the sound appear all around you. I would leave the cross-over set at 80, because as you go higher than that, you begin to be able to pick out where the signal is coming from. If you can tell where the signal is coming from, you will start to need a second sub, or every explosion/star destroyer engine/earthquake/tornado you hear will sound like it comes directly from the sub, rather than if you were in the middle of the explosion...

Too high a crossover just defeats the purpose of the point 1 in 5.1.. I would also leave the LFE to go only to the sub since that's what it does best.

 

[PENG]

The PSW404 is not the right match for the RTi12. In this case, you may as well set your mains to large. I am sure you will hear more bass this way. Let the sub handle the LFE only. Also, make sure you use the unfiltered LFE input at the back of the 404.

One more thing you can try is to flip the phase switch on the 404 between 0 and 180 degree and see if it makes a difference. Your RTi12 can go lower (down to 18 Hz, -3 dB at 30 Hz) than the 404 so you may be getting bass cancellation.

 

[20to20K]

I found THOSE Polks bright as well...

I demo'd those RTI'12's at the same time I bought my LSi15's. I chose the LSi's (over them and several other speakers) because I too found the 12's too bright for my taste. I demo'd them with that same 3805 because that is the AVR that I own (which is NOT bright). I'm not sure where you read those RTi's had earth shattering bass, but from what I heard it couldn't be further from the truth. I brought some bass heavy CD's to demo and the RTi's would not respond. Got MUCH more bass from LSi's....particularly when a 2 channel high current amp (like your NAD) was added. Also, at 8ohms those RTI's should not be hard to drive...just the opposite. I believe their effeciency is at least 90 db as well.
The LSi's on the other hand are 4 ohms with an effeciency of 87.
I couldn't believe that the LSi's cost only $100 more than those RTi's.
They sounded wayyyyy better to me (at least to my ears which is always subjective)

I'm not sure you going to be able to get the brightness out of those RTI's...from what I heard they're just made that way.

I don't know much about that Polk sub, but I listened to the higher model 650 and even that one didn't impress me. I went with the Velodyne 4000 which had a list price of 599 (got it online for $350) so it may be cheaper than your 404 since the 650 had a list price of $800.

 

[mfabien]

...
Low bass is omnidirectional. Human ears can't really locate a source, so it makes the sound appear all around you. I would leave the cross-over set at 80, because as you go higher than that, you begin to be able to pick out where the signal is coming from. If you can tell where the signal is coming from, you will start to need a second sub, or every explosion/star destroyer engine/earthquake/tornado you hear will sound like it comes directly from the sub, rather than if you were in the middle of the explosion...
QUOTE]

Precious info for me...considering adding a sub to my sound system.
http://forums.audioholics.com/forums/showthread.php?t=7491

 

[PENG]

I can see that LSi15 would sound better than the RTi12, but I am sure the RTi12 is capable of producing very decent bass if powered by a reasonably powerful amplifier, including the 3805.

I have listened to the RTi10 several times last year in different Future shops. Each time they were powered by either a HKAVR430 or 630. The only time I was satisfied with the sound in terms of fullness, and not too bright, was when it was powered by the AVR630. I know the RTi12 is more sensitive than the 10 (90 dB vs 89 dB), but even at 89 dB the RTi10 needs lots of power. I don't know the reason, but I do know whether the sound I heard was thin or full, bright or not bright.

Johnny, you may want to try playing a bass heavy CD in "pure direct" mode, just to make sure that bass management settings is not the problem. Also, in pure direct, there is no output to the sub so you won't get bass cancellation between the sub and the RTi12s. If you like the sound in pure direct, then you can focus on your bass management settings, speaker configuration, subwoofer's phase setting etc.

 

[Johnny Canuck]

Thanks everyone for your replies.

The Denon 3805 DOES have bass output to the sub in Pure Direct mode. That's just one of the reasons why it is such an awesome piece. My old POS Panny never did this, unless I played music in analog.

So i did rewire my speakers last night. I have the NAD powering the lows only now. The difference is night and day. Not bright anymore. I would assume the sound of the Denon is just a little warmer than the NAD and that is more noticable on the highs..someone mentioned that I was still getting power to my highs the way i have it hooked up now???

so is there much to disconnecting a cross over? is it recommended? does it void my warranty? can I do damage? As there is no controls on the NAD, i don't see how i will be able to balance everything.

I still prefer to have my fronts large, crossover at 150, and "LFE + MAIN" selected. just sounds better to me. I guess it's all personal preference. I just don't understand how setting it lower is supposed to give me more bass. I don't hear that.

My girlfriend and I are looking to buy a house soon so i won't worry about room modifications until then. hardwood floors look nice but not the greatest for sound obviously...

 

[Rushian]

Vegas Rush Fan

Dear Johnny.

I could not find the thread to respond to your "girls don't like Rush " Just wanted to let you know...this girl....36 from Vegas has LOVED Rush since a young girl and never misses them when they are in town. Have read Ghost Rider several times and one of their songs that I love the most is Available Light...great drumming, and Alex's great guitar work show there and Geddy's voice...great output there.

Have to admit a lot of people don't know Rush or understand their music. For the most part they do not sing about the Sex Drugs and ETC..why? because they are highly intelligent and Neil is a lyrical God.

I have to roll my eyes at people because I have the Red Starman sticker that takes up half of my rear window on my Jetta. I get that (?) look and on occasion I get asked about it.

Thought I would share that with you.