Fluttering noise from my RT800i's, Why!

hamzahsh · March 2003

Last weekend I watched Final Fantasy, Star Wars: The Phantom Menace and Attack Of The Clones and I heard the RT800i's woofers fluttered. Especially in the beginning of Final Fantasy when a lot of deep bass is about to hear. Also in SW-EP1 during the begining of Pod Race when engines were ramming and lastly in SW-EP2 in the beginning of chase chapter.

One of the reasons I think that RT800i's are not capable of handling extreme low bass and to move enough air. Right now I have an old sub but its too small and not clean and loud that's why I turned the sub-off into my receiver and cranked the bass knob to max. of my receiver in order to get full advantage of bass through my speakers. I have the following:-

Fronts: Polk RT800i's
Center: Polk CS400i
Surrounds: Polk F/X 1000

All speakers are set to large setting to get full range signal of my Technics SADX940 receiver.

I know that I really have to get the sub but my question is, is it normal for the drivers to flutter, I'm also worried that if is there any risk involved to damage woofers.

Should I stop using them for bass!

HBombToo · March 2003

I have my 800i's on Large and have never heard that problem. I wonder if your amp was clipping?

The 800i's are a beast and I really enjoy their sound from high to low.

HBomb

STUFFMD · March 2003

You know Hamzahsh,
I used to get the flutter you are describing in extreme bass situations, I also have the 800's. I just recently upgraded my wire as listed below and the flutter is completely gone, I really noticed it in my Telarc multichannel sample CD there is a F-16 take off I noticed an awsome difference.
I have seen some bad reviews on on Monster Original but I have found it to pair up very well with the RT line personally. I'm thinking the new 2 series by Monster would be even better.
With the Monster Originals I found the Kimbers to have outstanding imageing but to be a little harsh on the HF, but outstanding on LF. I put the Monsters on the Hf to play around and found the highs to sound as good as the Kimbers but imageing was missing. I compensated for MOST of the imageing loss by pulling the 800's out about 6 more inches from my entertainment center.
I hope this helps you out. Stuff

hamzahsh · March 2003

HBombtoo, are you using the sub!
If not then it could be my amp that was clipping. BTW, what is clipping and why it happens. I think this is common among cheap receivers like the one I have which is Technics SADX940 that's why I'll buy the Denon AVR-3803 or new Harmon Kardon AVR-7200 which would be out in this month. Hope the clipping didn't damage my speakers.

HBombToo · March 2003

Right now there is NO sub in my system because of a 2.5 year old thinking it was a spring board...

Thats why I thout it was clipping. If you take an amp past its power rating what you'll see if looking at an O'Scope would be flattened peaks. I know I like to play up to 85-90 dB SPL and that could really swamp a little amp. StuffMD raises a valid with different wire... a lossy line could prematurely make an amp hit its limit. What guage wire are you running?

Hope this helps.

Dr. Spec · March 2003

Originally posted by hamzahsh
that's why I turned the sub-off into my receiver and cranked the bass knob to max

The RT800i only has a 6-1/2" bass driver. You are asking it to shake the hell out of your room. It has neither the extension nor the air moving capability to create the kind of bass you are looking for.

You are overdriving the 800's, you are overdriving your receiver, and your system is not properly calibrated. Keep it up and you will wreck something - and it won't be cheap to fix.

If you are looking for spectacular bass effects for HT, I strongly recommend a high quality dedicated subwoofer and high passing the 800's at no lower than 60 Hz, preferably 80 Hz if you will be really blasting sci-fi DVDs.

Dr. Spec · March 2003

Originally posted by HBombToo

Right now there is NO sub in my system

I know I like to play up to 85-90 dB SPL

That's about to change for the better.........and try more like 110 at the couch.

:cool:

F1nut · March 2003

Originally posted by Dr. Spec
You are overdriving the 800's, you are overdriving your receiver, and your system is not properly calibrated. Keep it up and you will wreck something - and it won't be cheap to fix.

Well said, Doc, well said!

hamzahsh · March 2003

Hbombtoo, I'm using 2 AR Pro Series 16 AWG for each speaker into my receiver's binding posts as a bi-wiring process for all of my speakers.

Thanks Dr. Spec to scare the hell of out of me. I'll be extra carefull now. In the meantime I'll use my 7 year old sub untill I get some money to buy Velodyne CHT-15.

I love my polks and want to use them as long as I live. I'll take your advice Dr. Spec!

Thanks.

HBombToo · March 2003

Originally posted by hamzahsh
Hbombtoo, I'm using 2 AR Pro Series 16 AWG for each speaker into my receiver's binding posts as a bi-wiring process for all of my speakers.

Thanks Dr. Spec to scare the hell of out of me. I'll be extra carefull now. In the meantime I'll use my 7 year old sub untill I get some money to buy Velodyne CHT-15.

I love my polks and want to use them as long as I live. I'll take your advice Dr. Spec!

Thanks.

Yep! the Doc nailed it.

HBomb

Dr. Spec · March 2003

Originally posted by hamzahsh
untill I get some money to buy Velodyne CHT-15.

Now THAT driver will move some air for you - a good choice for your listening tastes!

BeginnersLuck · March 2003

Just for kicks I tried running my 800i's in full range with my mono blocks and the mono's murdered them! The 800i's are not meant to be run in a large speaker config...I have been playing with the crossover setting on my AVR and 60HZ seems to be a good settling point for the 800i's.

-BL

danger boy · March 2003

BeginnersLuck, i beg to differ. I am running my 800i's off mono blocks as well. and they did not murder em. how hard are you pushing them 800's? I can push my 800's up to about 115db before they show signs of hitting their limits. what happens when you push them that hard? do they bottom out or what? My 800i's can handle either large or small settings.

Do your mono's have a output gain control on them? My mono's are Marantz MA500's with 125w. I'm very interested in what you find out.

thanks, Al the pal

RuSsMaN · March 2003

Originally posted by hamzahsh

I turned the sub-off into my receiver and cranked the bass knob to max. of my receiver in order to get full advantage of bass through my speakers.

Hello? McFly?

Sorry Doc (Pete), call me Re-Pete.

mantis · March 2003

Yes I completely agree with Russ,
People can I have you attention???????PLEASE LEAVE THE TREBLE AND BASS CONTROLS AT FLAT.PLEASE STEP AWAY FROM THE TEMPTING KNOBS AS THEY ONLY CAUSE GRIEF.

Here's what My thoughts are on bass and treble controls.If you feel the need to tamper with them, then by friend and this is only my opnion,take it for what it's worth,then you don't like the way your speakers/receiver/amp/wire/source sounds like together.

Running up the bass to max,running no sub and driving the hell out of any speaker will cause this.I hope you didn't do any damage in your travels,but then again we all have to learn someway.

STUFFMD · March 2003

Yea but guys in my situation it would do it even at flat and at lower levels on some recordings, again the F-16 take off and Poe's Haunted album are 2 that come to mind. Now that I have upgraded my wire I don't have any excess vibrations at all even at high levels, I've gone to 70% level with no noticeable distortion, compared to th old XP wire.
Yea I agree with you the 800 can't be over bassed especially with an inferior amp, but before upgrade I noticed some breakups. My setup is Mains SMALL and Sub/LF on.
Somthing to chew on guys. Stuff

danger boy · March 2003

Originally posted by mantis
Yes I completely agree with Russ,

Wow, this is a first!

sorry boys, i just couldn't resist. it was to easy to ignore.

jmasterj · March 2003

hamzahsh,

I read your post and a quote from Clint Eastwood comes to mind ie, " A Mans Got To Know His Limitations". This is very true when it comes to your equipment. Be careful buddy. I don't want you to blow those speakers by asking them to do more than they are able to do. Get that sub.

Dr. Spec · March 2003

Treble and bass controls don't work during DD or DTS. I think he meant he turned the sub level control and/or the LFE level control (some receivers have both) at the receiver all the way up.

The end effect is essentially the same as turning up a conventional "bass" control though.

danger boy · March 2003

my receiver must be different that you all's. i can adjust the treble and bass in either DD or DTS but not when using the analog inputs for DVD-audio.

BeginnersLuck · March 2003

Originally posted by danger boy
BeginnersLuck, i beg to differ. I am running my 800i's off mono blocks as well. and they did not murder em. how hard are you pushing them 800's? I can push my 800's up to about 115db before they show signs of hitting their limits. what happens when you push them that hard? do they bottom out or what? My 800i's can handle either large or small settings.

Do your mono's have a output gain control on them? My mono's are Marantz MA500's with 125w. I'm very interested in what you find out.

thanks, Al the pal

How's it going?-

Ok, I set my mains to large, powering them with Outlaws new M-200 mono-blocks. There is no variable gain control on the mono's. I was demoing my system with the Pod Race Scene from SWE1. It's hard for me to tell if the 800i's were fluttering or if the quality of bass was just aweful compared to my sub. My subwoofer is very acurate and so switching the fronts to large just sounded plain bad compared to the sub handling the lows. The 800i's are just not designed to handle much anything under 55 ish Hz. So when my mono's were requesting more from the 800i's...they just seemed like they were not up to the task! Muddy bass...fluttering...or whatever I call it...the bottom line is the bass becomes very inacuate.

Side Note: I was at or slightly above reference levels. I think my sub has spoiled me!

Later,
-BL

danger boy · March 2003

well yeah of course I don't think any tower speakers will ever reach as low as a dedicated subwoofer will. it's just not designed to be driven that low.

Dr. Spec · March 2003

Extension and air moving capability are equally important here. Not only does the RT800i start to trail off at 40 Hz, the 6-1/2" bass drivers cannot possibly move the air a dedicated subwoofer can.

Even if the RT800i is flat to 40 Hz, the real question is how loudly can it play 40 Hz clean? Loud enough to shake your room - no way.

As for high passing - I'm right there with BL on this one - no lower than 60 Hz for loud HT. The high pass is not a brick wall - at 60 they will still be asked to play quite a bit lower before trailing off completely. My rule of thumb is to high pass no lower than 1/2 an octave above the rated F3 point of the speaker(s) in question.

We all know the max SPL from any speaker during playback is a bass peak - I cannot believe the RT800i is capable of producing 115 dB bass peaks in a typical size living room.

Danger, was this an off-the-cuff guess, or have you actually measured this with a SPL meter. Even the most powerful subwoofers struggle to hit a clean 115 at the couch in an average size room, and most people need two really good subs to do it right.

Doc

danger boy · March 2003

I do have a SPL meter. and my room is pretty small. this was with the rt800i's biwired and a psw350 sub. yeah the 115 is peak not a sustained level. i'd be deaf if it were by now.

I

danger boy · March 2003

Originally posted by hamzahsh
Last weekend I watched Final Fantasy, Star Wars: The Phantom Menace and Attack Of The Clones and I heard the RT800i's woofers fluttered. Especially in the beginning of Final Fantasy when a lot of deep bass is about to hear. Also in SW-EP1 during the begining of Pod Race when engines were ramming and lastly in SW-EP2 in the beginning of chase chapter.

One of the reasons I think that RT800i's are not capable of handling extreme low bass and to move enough air. Right now I have an old sub but its too small and not clean and loud that's why I turned the sub-off into my receiver and cranked the bass knob to max. of my receiver in order to get full advantage of bass through my speakers. I have the following:-

Fronts: Polk RT800i's
Center: Polk CS400i
Surrounds: Polk F/X 1000

All speakers are set to large setting to get full range signal of my Technics SADX940 receiver.

I know that I really have to get the sub but my question is, is it normal for the drivers to flutter, I'm also worried that if is there any risk involved to damage woofers.

Should I stop using them for bass!

I did this same thing this morning with Final Fantasy and the 800i's and the bass cranked. I thought they did pretty well. I was not looking for bass output. I was looking for that fluttering that hamzahsh was talking about. Yeah it's going to eventually kill your 800's if you use them for bass. As Dr. said.. they don't go that low and I think it was your amp that was clipping and not the speaker itself.

peace, Al

Fluttering noise from my RT800i's, Why!

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