Help, my new SVS is "clacking" (1 Viewer)

[Craig_B]

I just set up my 20-39cs and Samson S700 last night and the difference from my old Energy ES-10 is amazing. My wife had to send my son down to tell me to turn it down as I was "shaking the whole house". Other equipment is a Denon 3802 and the room is about 1,300 cf. I hooked everything up according to the manual that came with it with the amp cranked all the way up and calibrated using the Denon's internal test tones and the Ratshack spl meter. The only factor that I can change is that I did have the door to the adjoining equipment room open while I was doing the calibrating, and I'm not sure if that affected the spl levels.

The problem I am having is that on the really heavy bass scenes, like when the ground opens up under Buzz at the beggining of Toy Story 2 or some parts of the pod race in TPM, the sub started making this awful clacking sound, which i am assuming is the driver bottoming out. I originally calibrated the sub a little "hot" at about 5db over the rest of the speakers whcih was +1db on my Denon 3802. This produced lots of clacking, so I brought the sub down to 75db like the rest of the speakers, which is about (-3db) on my Denon. When I replayed the scenes at 0 master volume (reference level) there was still an occasional clack at the really low bass parts. So I turned the master volume on the receiver down to -3 and that seems to have pretty much stopped the clack. Does this meen that I need to calibrate the sub to less than 75db if I am going to do any listening at reference levels? I know it is rare for movies to have this much low bass and I picked two very demanding scenes for my test, but if I calibrate so the sub won't bottom on these scenes, will I be missing some of the bass on less demanding stuff? Thanks for any advice, that "clack" sound is awful and I don't want to hurt the speaker.

 

[jeff lam]

It just means that if you want to run full reference levels with those demanding DVD's you need more woofage. What were the SPL readings on the heavy scenes at full reference?

Sounds to me like you get pretty close to reference levels anyhow so I don't think you really need more woofage. Just bring down the overall level when you play the TS2 or TPM DVD's. BTW, just so you know. If you play at full reference, you should not calibrate the sub 5dB hot. If you do, make sure the max you listen to the master volume is 5dB less than reference. This way, the max output from the sub will be full reference but the mains will be 5dB under.

IMO, nothing should be played over reference level. EX: if you calibrate your sub 10dB over refernce, you should consider your new reference at 10dB less than before, etc...

 

[Terry Flink]

The clacking is probably the sub bottoming out and WILL damage the driver...be careful. I bottomed out my SVS 20-39CS on the same material when I first got it...cause I was running it too hot.

 

[Craig_B]

Jeff,

So you are saying to leave it as is and just not crank it up to reference on those couple of titles? Or should I tweak it down a little so it will never bottom? Or since I typically listen to movies at -10 to -15, should I even tweak the sub up a little for standard viewing and just readjust the sub down when I am doing a demo?

Finally, is this a common issue or am I just pushing the sub too hard? I never bottomed my Energy ES-10 sub (also calibrated to about 75dbl) even when I had the master volume a few db above reference.

Thanks,

Craig

 

[jeff lam]

Or since I typically listen to movies at -10 to -15, should I even tweak the sub up a little for standard viewing and just readjust the sub down when I am doing a demo?

Exactly!

Don't know about your energy sub but yes, leave it calibrated at 75. Or if you don't always listen at reference you may want to run it a little hot. Just know that if you run it hot, you have set a new reference level for your sub. If you use the old reference level(0 on your receiver) with the sub hot, the sub will play above reference and this can cause bottoming problems. TS2 and TPM are both sub killers so just back off the overall volume on those DVD's.

 

[Nick P]

Craig,
I think you've got it figured out. If you play at full ref. turn the sub down. If you play 10db under ref run it a little hot if you like it that way. Of course the third option is to add another 20-39 to the S700 for some real fun!

 

[Craig_B]

Thats what I was afraid of. Do you think I would have this issue if I had gone with the cs+? I was agonizing between the cs and the cs+ and ended up going with the cs because I thought it would be enough and to save some $$. I really do not have the room to add a second sub in the ame corner. I guess I could always return the cs within the 45 day window and get the cs+ though.

 

[Brian Fineberg]

I would say to upgade to the plus. I did and it makes the world of difference but you will need to upgrade the amp too. Just my opinion but you have my vote to ugrade.

-B

 

[jeff lam]

You don't HAVE to upgrade the amp too. I'm sure 350W is plenty for the plus too but SVS just recommends the s1000 with the CS+
Craig,
Do you really think you will need that extra woofage? If your sub got to reference on everything but the two loudest/most powerful bass scenes around, do you really think you need it? I don't think you would even use the extra headroom unless you listen at full reference all the time. Anyway, it's up to you, but I personally think you're fine.

 

[Rick Radford]

Craig,
You may want to take some measurements of your room. If you have a huge peak at one freq, you may well be cheating yourself of significant bass at other freqs due to room response which could be EQ'd out.
OTOH, if your HT room is open to other rooms, you may be woofing a lot bigger area than you think. I thought I was just woofing a small 1100 cu ft room. Then I discovered that my 2 large openings to the rest of the first floor meant I was really woofing over 7500 cu ft!
You can get an Excel worksheet here to help graph your room response. You'll have to wade through some of the site to find it. But it's a good read and will be an excellent guide should you have an interest in the EQ'ing process.
Eq'ing may be the least expensive and most effective tweak you can do. You can spend as little as ~$135 .. depending on how you decide to go about it.
1) consider the eq (take some measurements to know what you need)
2) if your room response has peaks and valleys, get the Behringer (BFD) 1124p Feedback destroyer (~$135 shipped). Check out the online guides for setup help.
(to automate the data gathering process, get some software like ETF for ~$150, free demo).
3) Add a 2nd cs and EQ both of them for best results!
Do a search for BFD, ETF, etc. for more info.

 

[Nick P]

Craig,
Jeff makes a good point. You don't need more woofage but I find the word "need" to be a funny term. No one needs a Corvette or a Porsche but they sure are fun to drive. If you're only bottoming at full ref. on these two disks then that's easy to correct.

 

[Tom Vodhanel]

Craig, everyone pretty much hot the nail on the head here.

*a little hot*...5dBs over? That is about 8dB actual(when factoring in the meter rolloff down low).

So at 3dB under reference on the master volume...the single SV was trying to reproduce TPM 5dB OVER reference levels.

TV

 

[Craig_B]

Just to clarify, I only had the sub calibrated "hot" (about 78 - 80) for the very first test with music and then Toy Story 2. As soon as I heard the first clack, I re-calibrated it down to the 75 on the meter, which I now realize was actually 78. I then ran that same scene again as well as the TPM pod race, and had a few intermittent clacks at near reference levels on the really heavy bass parts, and I would turn down the volme immediately every time I heard one so as to not damage the driver. So now I guess I will calibrate the sub down to 72 and see what happens.

The sub is awesome and I love the low clean bass it produces. Once I get it calibrated correctly I am sure I will have no more "clacks".

 

[David Giles]

So now I guess I will calibrate the sub down to 72 and see what happens.

Craig,

If you mean you'll calibrate down to 72 just for demo-ing heavy bass scenes at full reference, I agree. But if you then leave it at that level for everyday listening, you'll have less than impressive bass. What I'd do if I were you would be to leave it 2 or 3 dB's hot for everyday listening. Just remember to back down the sub before demo-ing super-heavy bass scenes at full reference.

David

 

[MarcVH]

This certainly is far from the first example of somebody who could use a second SVS sub, but says they can't find the space for it. Sounds like somebody should work out an "SVS space doubler kit" to hang them from the ceiling. I can just picture a pair of them, in a corner attached to the ceiling, with the drivers pointing up and the ports pointing down, like sleeping bats.

 

[Hugh Scrivener]

What...? Don't tell me this guys! I am so ready to order a 16/46 but now I'm starting to wonder if I should. I'm considering the PCi version. Anyone having this same problem there? I really enjoy my movies and music with maximum impact and am trying to escape this problem...the same I'm having with....well, a woofer in a box.

 

[MarcVH]

Unfortunately, a number of us are guilty of overindulging in bass after getting a good taste of it. We're also guilty of picking a small handful of bass-heavy demo scenes and playing them over and over at high volume to impress friends. You may not choose to use your sub in this manner.

I'm sure there won't be anything wrong with the 16-46 PCi, but remember you're talking about the least powerful sub SVS sells. If it were cable of producing reference bass in a typical room, they probably wouldn't bother making any others.

 

[Tom Vodhanel]

>>>What...? Don't tell me this guys! I am so ready to order a 16/46 but now I'm starting to wonder if I should. I'm considering the PCi version. Anyone having this same problem there? I really enjoy my movies and music with maximum impact and am trying to escape this problem...the same I'm having with....well, a woofer in a box.

 

[Tom Vodhanel]

Craig,

You might also see some benefit from adding our *blackbox*. You don't need the voltage gain feature...but it does have a 0-180 degree continuous phase knob which can't hurt...and a 3 position subsonic filter switch(15-20-25hz). If you wanted to run the levels a little hot on DVDs that had very strong

 

[Craig_B]

Things are always darkest before the dawn...an update to my continuing calibration saga.
Well I went ahead and recalibrated the sub again down to 72 using the Denon's internal test tones, because I just had to hear what the intro Toy Story 2 sounded like at full reference. I guess I was not playing the heaviest bass parts before, (which seems to be when the Toy Story 2 logo first appears) but now my sub was now bottoming on this scene at anything over -7 on my reciever, which is not that loud! OK, so now I am truly annoyed and perplexed, as I can not believe that this big ole subwoofer can not handle anything above 7 dbl's below reference levels in my relatively small room. So I went over to my neighbors and got back my copy of Video Essentials I had lent to him and ran the pink noise tests with the receiver set to 00 (reference) volume and the Ratshack meter at 70. While the surround speakers came in right at 75 as I had set them with the internal test tones, the fronts and the centers were all at about 78, a little high, but at least within reason. Well, when it got to the LFE test..... the meter pegged all the way to the right!!!! According to VE, my sub was actually set at about 80-81db not the 72 my internal test tones indicated. I went back and checked the internal tones again, and sure enough, it was still around 71-73. Needless to say, I re-calibrated for what seems like the 127th time to 75 for the fronts and 72 for the sub (sub is now at -11 out of a possible -12 on my 3802) using the VE signals and HALELULAH, I can now play the TS2 intro at full reference level! I am even thinking of bumping the sub back up to 75 and see if it bottoms or not, although I don't know if I should push my luck
Does anyone know why the internal test tones and VE would be dead on for the surrounds, slightly off for the fronts and center and not even in the same ballpark for the sub? I am guessing that since my sub was bottoming out so easily, the VE is the correct measurement and something is wrong with the Denon's test tones. Or was I doing something wrong?
Tom, do you think the black box would still be a help? I thought it was just to increase the signal strength so I guess I'm not clear on what exactly it would do for me.