CSi40 bottoming out?

frodaddy

I'm not the original owner of my CSi40, so I got a price to replace the woofers in another thread. I'd like to see if anyone has suggestions before I do that, though!

95% of the time, the CSi40 sounds absolutely incredible. But about 5% of the time, sometimes on seemingly innocent scenes, they will bottom out. It isn't a loud clack, in fact it's masked so well that I was thinking "did something just distort?" After investigating it, I've also noticed that the right woofer tends to bottom out before the left one? Are these crossed over differently?

It takes an extremely strong bass scene to get it to bottom out, though. The right one will do it in the 2nd Lord of the Rings movie from the Ent's footsteps when he is walking through the forest with the hobbits are sitting on his shoulder. Both of the woofers do it on the Bridge of Kazza(sp?) Doom scene on the 1st movie. I've also thought that it might be the source material since I'm using the plain widescreen versions of the movies?

I've got a Denon AVR4800 powering it through HD14 wire. Of course I can use my built-in 80hz crossover my amp has, but then I loose a lot of overall fullness. I think I'm hitting around 95dB (all speakers on) on both movies when they bottom out during those scenes, but I can't be sure until I get my hands on an SPL meter. That seems low, and it is because I don't have very good subs right now for the space I'm trying to fill up.

I was thinking about using a jumper with a high pass f-mod from my center channel line out to line in, but logically that doesn't make sense. I don't have a pre-amp so I can't go that route either. Does anyone have any suggestions? Or is this normal for my center channel?

Dennis Gardner

Yes they are cascade crossovers. Similar to a 3-way design. Set your center channel to the small setting with the crossover around 80hz and turn it up. That should take care of the bottoming.

dorokusai

There is no reason to set a CSi40 to the "Small" setting on any AVR.

Dennis Gardner

dorokusai wrote:

There is no reason to set a CSi40 to the "Small" setting on any AVR.

Then tell him what is wrong.

dorokusai

I believe that answer to be in his original post if you read closely. Overdriven...questionable setup...no calibration...and at this point, maybe even blown woofers.

frodaddy

dorokusai wrote:

I believe that answer to be in his original post if you read closely. Overdriven...questionable setup...no calibration...and at this point, maybe even blown woofers.

Please, if you get a chance let me know what is questionable about my setup because I want to fix it!! I'm open to any help!!

Our amplification is very close to each other: My Denon AVR4800 is a THX Ultra certified receiver pushing 125 watts/channel. Your B&K AVR317 has the same cert, but is pushing 150 watts to your CSi40. However, most of the newer high-end receivers has built-in adjustable crossovers for each channel and some even have EQ's!! All mine has is the Large or Small setting.

Other than setting the dB level with an SPL meter and the time delay, is there other calibration that I should try?

But you're right, what it boils down to is the speakers themselves. I was hoping someone with a similiar setup could tell me that their CSi40 does/doesn't do the same thing on those same scenes. The speakers don't sound blown to me, but I guess that definition is open to interpretation.

What I'm going to do today is look into the jumper idea, try different source material (the extended version of the LOTR movies since they are encoded better), and I'm even thinking about swapping the woofers out with each other. The reason for the swapping is because if one of them is crossed over lower than the other, maybe one of them is worn out so the other would be in better shape? I don't know if that makes sense, but I'm really open to suggestions at this point.

Thanks for the responses thus far!! I really appreciate it.

dorokusai

The questionable setup comment was directed at how you have everything setup. As in, you didn't offer much detail as to the parameters that you have defined in the AVR. It looks as though you're limited from your recent reply.

My CSi40 has never bottomed out on that particular DVD selection.

I don't use time delay, room equalization or EQ....only Large and 80Hz crossover adjustment. If I didn't have that crossover point, I have the feeling that my CSi40 would start to sound like yours.

frodaddy

dorokusai wrote:

The questionable setup comment was directed at how you have everything setup. As in, you didn't offer much detail as to the parameters that you have defined in the AVR. It looks as though you're limited from your recent reply.

My CSi40 has never bottomed out on that particular DVD selection.

I don't use time delay, room equalization or EQ....only Large and 80Hz crossover adjustment. If I didn't have that crossover point, I have the feeling that my CSi40 would start to sound like yours.

On my AVR, the only thing the Large/Small setting does is use a high pass 80Hz crossover. My center won't bottom out on that setting either, but I can tell that I'm loosing alot of fullness during action scenes. I can't tell a difference with voices, however.

I got my hands on a CD that does slow frequency sweeps, and the center channel never bottomed out when I cranked it (00 dB on the AVR and on up). So I feel that there is nothing wrong with the center channel itself.

Judging from the woofer movement while doing those frequency sweeps, during those scenes where it is bottoming out the freq is around 23 to 30Hz. (Believe it or not, I can actually see woofer movement around 15Hz!! :eek: ) What is going on is the scene is that it is so hot with those freqs through that channel that the actual level in those frequencies is MORE than what I tested on the CD with manually controlling the volume!! This is significant because source material is not encoded very well. Why should so much low frequencies be routed to a center channel to begin with? I also tested the LOTR Extended version with the DTS track, and it was encoded MUCH better and I didn't have any problems. (I had a dB meter and adjusted my AVR volume so the output would be the same between both tracks.)

So this leads me back to protecting the center channel for those movies/tracks that don't have good encoding. I need to cross it over at some frequency, so which one? I definitely am not going as high as 80Hz, so I'd have to get a passive crossover for a lower frequency. The problem is that I can't find one pre-made for my application, so I'm looking into building one myself. If anyone can offer more help with this, please let me know. But I'm well on my way already!

Thanks for the help everyone!

Dennis Gardner

Occasionally, the full range track can contain spikes of sub sonic material that should have been directed to the LFE track. This must be what you've found on the particular DVD that you have. A passive point such as an Fmod would work on the speaker level, or running the center through the RCA lineouts to another active crossover/amp would be another route.

Small or large aside, running towers and centers full range has risks involved with the digtal mixes in movies today. Variable points in the newer AVRs solve the issue. I like mine at 40 or 60hz personally. Best of both worlds.

janmike

I'm a little confused as to what settings the speakers should be set to. My understanding was that the speakers should be set to small with a sub. Currently I have all 5 speakers set to small (RTi100's, RTi6's, & CSi5) with a sub connected. The crossover is at 80Hz. I have played around with the large/small setting and do not seem to notice any difference.

dorokusai

Look on Ebay for a pre-made, inexpensive, passive high pass modules....they are usually called Maggie Mates. You can request them in different configurations. They are cheap enough that DIY is just preference.

aaharvel

jan try a 60hz crossover if your receiver allows it. That's what I use. Works much better, especially for music.

Dennis Gardner

aaharvel wrote:

jan try a 60hz crossover if your receiver allows it. That's what I use. Works much better, especially for music.

His 5 year old receiver has a fixed 80 hz point. Thus the lack of fullness when in use to his ears.

janmike

Andrew, And keep all the speakers to small?
My AVR is a Yamaha RX-V1500.

aaharvel

fixed. yeah that sucks.

janmike

So if I set the crossover to 40 or 60, can I damge anything?

Dennis Gardner

janmike wrote:

So if I set the crossover to 40 or 60, can I damge anything?

No, its the sub sonic stuff just below the resonant frequency of the ported models that cause the woofer to go into over excursion. The woofer goes wild trying to produce the lowest signals and bottoms out.

janmike

I do not think my receiver is fixed as I can set it between 40Hz and 200Hz.

aaharvel

then set to "SMALL" all speakers, 60hz. all speakers.

janmike

Thanks

frodaddy

Thanks for everyone helping me out. I looked at the Maggie Mates and might get one (or more) soon.

I wanted to come back and tell about what I've done today. I finally got a breather at work and called Polk about my woofer with the intention of ordering a new speaker. They told me to swap them in the cabinet, and see if the problem stays with the woofer. Well I just did that, it stayed with the woofer, so it's damaged.

I'm going to order a new one tomorrow to get this thing fixed! By the way, the speaker has been doing that since I've owned it so I didn't blow it with my system. Either way it's my speaker now and it will be right as rain when I'm finished!!

I would have never noticed this if I was using an 80Hz crossover point, and might not have heard it with a 40Hz or 60Hz either! I still wish my receiver had better bass management, though. And one last thing, I plugged my subwoofer into the center channel pre-out just to see how much it responded to the scene I've been listening to in LOTR. Would you believe it had MORE low frequency intensity than the actual LFE channel does!!?!?!? Whoever encoded that scene must have made a mistake!

danger boy

frodaddy, is your center channel set to large or small? A very few times i've had my center CS400i bottom out. it's easy to tell when it does.. it give some kind of "pop" sound to it. sometimes i find that it's the DVD audio track itself and not a problem with the center speaker at all.