New SVS owner wondering just how far he can push it... (1 Viewer)

[Doug Clark]

Hello all... bear with me... I'm a rook...

Last Friday, my new SVS 20-39PCi sub came. I calibrated it with DVE to about 83db (this seems to be the standard recommendation for those that like the bass a bit hot). The gain/volume knob on the sub itself is at 1/3. My mains/center (Fluance AV-HTB set) are all set to SMALL.

Reference level on the volume control on my Yamaha HTR-5660 reads -18.5db.

So far the loudest I've had things jacked has been with Attack of the Clones... -27db on the receiver.

As promised (by virtually every SVS owner on these boards), the entire house tends to vibrate now. I'm a bit worried I'm shaking nails loose and compromising structural integrity. *L*

I'm the curious sort... and I want to turn that volume knob even higher... and see what the "cannon in the corner" is truly capable of (house falling apart be damned).

BUT-- I'm also the paranoid sort... I don't want to bottom out and possibly damage my new toy.

How hard can I safely push it? Again, it's an SVS 20-39PCi.

Thanks!

 

[Ralph B]

I wouldn't. just use it as you normally would as it is calibrated now. no need to push as thats not how you will listen to it anyway normally. not worth damage is it ?

I take mine to reference and its good enough for me, thats when I feel like it but rarely do or need to.

 

[Kinson_Y]

Another Newbie's Follow-On:

Not intereted in annoying the neighbors, cracking sheetrock or losing my hearing, but I'm also curious as to how far I could push my sub without going so far as to bottom it out and damage my PC-Ultra.

Related side question: My PC-Ultra (basically a 20-39 on steroids) has it's gain knob at 4.5 out of a 9 total hash marks after calibrating with Avia to 87dB (!2dB "hot").

When I emailed Ron about this he said that this sounded about right. This strikes me as odd, however, as my room is only about 2,150 sq. ft. (with no openings) and BASH is supposed to be about 500watts. How are you folks running your gain knob only a third of the way up in comparable (if not larger) sized rooms?!?

(And yes, I have my sub corner loaded.)

Thanks.

 

[DanielKellmii]

Do you meant cubic feet? Otherwise, good for you. That room is almost the size of my house.

 

[Dustin Harrison]

I tested the limits of my PCi about a week after it arrived. I watched the Matrix scene where Neo catches Trinity from falling at two different volume levels(a great scene to test your sub BTW). First I watched it at -10dB which is just about on the verge of being way too loud. My PCi seemed right at home at this level and matched the other speakers output level. Then I watched the same scene at OdB . The sound at that level was on the verge of making my ears bleed, but the PCi seemed to be at the same output level as the last test. I guess for my configuration, I'll run out of headroom on my sub before the rest of the system. Maybe I'll upgrade to dual PC+ in the future.

I would have to say in short bursts, it's okay to test the limits of your PCi.

 

[Nick Breckon]

Honestly, I pushed my PC+ harder than I ever will on a normal basis the first week I had it, and I kind of regret it now. I bottomed it out once, which didn't damage it, but I wish I hadn't. I have the sub calibrated to way above reference right now, and if it was any higher, it would sound completely unbalanced compared to the rest of the sound. It just overpowers everything else and all of a sudden you're looking at a pretty picture on the screen while your insides are vibrating. That's no fun.

Find a level you like and stick with it.

 

[Erik.Ha]

How do you know when you "bottom out" a sub?

 

[Kinson_Y]

DOH! I did, of course, mean CUBIC feet.

 

[Edward J M]

The SVS is designed to (within reason) maintain the same shape FR curve and low THD at all volumes within its safe operating range. It tends to give no obvious warning or indication it is about to bottom out - like rolling off the extreme lows, or overtly farting/distorting.

A good warning sign is that the sub just won't play any louder on a given passage despite increasing the Master Volume a few more clicks. The sub will start to sound compressed and the dynamics will become non-linear.

Eventually, you will start to reach the mechanical limits of the woofer suspension. The spider and the surround just won't be able to stretch any farther in both directions. And the voice coil former could strike the backplate of the magnet assembly with a loud clack (this is commonly referred to as bottoming out). This is not a good thing. A few times probably won't hurt the driver, but repeated bottoming will eventually ruin it.

If the sub sounds clean, unstressed, and dynamic at the highest volume you would normally play the most bass-aggressive DVDs you own, I'd be happy. If it starts to sound strained, compressed, or outright bottoms, back off a few clicks on the Master Volume and mark that setting/DVD combo as your benchmark for max playback.

 

[Robb Roy]

Erik,

You will hear a loud metal against metal "klack".

Kinson_Y,

I wouldn't worry too much about where your gain is on the sub. Any number of things could affect the setting (open doors to another room, a less than perfect location for the sub, setting the sub hot, or, your setting is just right).

Doug,

One hint that you're nearing the limit of your sub is that it won't be getting any louder as you turn up the volume. Ultimately, though, the only way to truly find the limit is to bottom the sub, so I'll second the advice of setting the sub at the level you like. Relax, watch a movie or listen to some tunes, pour a drink, and enjoy clean, flat, bass response.

-Robb

Edit: I see Ed was in here at the same time providing a much more detailed response (as usual -- that's a guy worth listening to).

 

[WayneO]

I bottomed the 20-39PC+ I had within a week and never wanted to hear that nasty "clack" again, you don't want to either.

 

[Doug Clark]

Thanks much for the responses so far.

I haven't really played with the sub since I posted.

Re: the bottoming-out "clack." I remember reading in another thread what that was supposed to sound like. Will I hear that noise above the roar? *L* That's been part of my apprehension... that I'll bottom and not know it.

Also-- I'm not wanting to go gonzo with it 24/7. *L* I just basically want to know if I could watch, say, FOTR:EE or TTT:EE at reference if I wanted to (and that those two noted "hot" discs wouldn't kill my system).

Does that mean I'll watch at reference all of the time? Heck, no. *L* I know that would be too much. The -10db I have had the guts to play has been a little much at times.

But... the ring drop at reference (on a properly calibrated machine) would definitely be something fun to show-off on occasion.

Is this within the limits of an SVS 20-39PCi?

 

[WayneO]

I bottomed my PC+ on LOTR:EE at -4dB under reference, sub calibrated 2dB hot, but that doesn't tell you squat. Your equipment, calibration and room size are too unique for someone to give you a definitve answer. You will "know" if you bottom it, beleive me.

 

[Nathan Porteous]

u guys are all nuts whats the point of having a big bad sub if you dont tempt fate once in a while and see if u can actually give your self bass related heart failure.
Thats like having a viper and never going over 60 because your scared your gona break something. I'm sure all your svs subs can probally take some abuse. Dont they have a saftey mode or fuse system or some sort of protection for people like me?

 

[Edward J M]

No, it is not within the limits of a 20-39PCi in an average size (say 2000 ft3) room.

I would say you are probably pushing the clean limits of the 20-39PCi at -10RL with a sub level of 83 dB on DVE.

If you really want to play the ring drop at RL, then I advise you buy another 20-39PCi and co-locate them. Even then, it might only get you to around -4RL cleanly. Or you could get a PB2+ and that would probably allow true RL in your room.

 

[Jeff_M]

I have listened to my share of SVS subs and I believe the "clack" noise sounds like whacking a plastic serving spoon on a plastic drum. Somewhat hollow sounding, but very noticeable.

 

[Ron Sc]

LOL Mine takes a beeting and keeps on ticking. Mostly during demos.

http://beyond_gomer.tripod.com/

This 1/12 octive test tone thing has actually made me sick after playing it a fiew times in a row

 

[Mitch Stevens]

Doug,

You're already way over-calibrated at 83 dB for the sub. Of course, DVE is incorrect in the sub reading, but I would not put my sub over 80 with DVE.

I think that Joe Kane once said that the only difference between DVE and VE is 2 dB on the .1 channel. If this is in fact true, and being as how the radio shack meter is 3 dB off, it would mean that you have your sub set about 9 dB hot. You can't really expect ANY sub to play reference levels when it's calibrated so hot. I doubt that even a B4+ could do it.

 

[Edward J M]

Mitch, I thought he was running Avia at 83 dB - thanks for the correction.

Nevertheless, my copy of DVE is grossly out of whack on the subwoofer channel. If I calibrate my system with Avia to 85 dB on the surrounds and 82 dB on the sub, and then pop in DVE without touching anything, I get 75 dB on the surrounds (as expected) and 88 dB on the sub (definitely not right).

I would say if anything, he is probably under-calibrated with DVE at 83 dB, if (and that's a big if) his DVE copy is the same as mine.

The only way to tell for sure is for Doug to compare his copy of DVE to S&V or Avia. JKP might have fixed later production versions of DVE, so it's worth checking before he proceeds further.

 

[ScottCarr]

I can push my PCUltras a lot further than the PB2+. I probably has a lot to do with the cylinders shape making them far easier to push around. Those big PB2+ are tough to push. Is that what you meant?