SVS 20-39CS

ken brydson

Airplay355 wrote: »

I never realized there was a model number sticker on the bottom. So I've got a CS Ultra model 0204-0480. The guy I bought it from gave me a PCi manual and I thought I was getting a CS+. Oh well He only told me it was a CS 20-39.

Here are some pictures of the driver.



What do you guys think?

Call SVS. Their cs is excellent.

Airplay355

Good idea! I shot them the pictures and asked about treating the surround.

Airplay355

Alrighty the Crown came today. It's pretty awesome. I'm running it at 1'oclock with the preamp at -6db for the LFE. I put the HPF at 120 and have the mains LPF at 60 and surrounds/center at 80. This is off one channel. I'll try bridging it but I'm a little scared haha.

SVS got back to me and told me to Armor All the surround. I'm not so sure that's good advice. I'll keep looking for other options.

I'm still trying to dial in the sub by making sure I'm not clipping the signal. I initially had the gain higher but had to dial it back a good bit because bass heavy scenes would briefly clip. The lights on the front are very useful. I'm trying to set it up so that only the -20db light occasionally lights up. Do I need to tone it down to make sure these lights never light up?

I've only got streaming sources at the moment but it seems that Batman vs Superman on HBO Go has good enough quality audio to try setting this up.

I've still heard what sounds like distortion sometimes. Less so now that I dialed things back a good bit. Original settings were with the LFE at 0 and the gain around 4 o'clock. The subwoofer driver becomes audible (as in a vibrating frequency you can pinpoint) like something flapping in the wind. I suspect that I was just asking for too much SPL from a single 12" driver. I've never really had a subwoofer though so can you guys confirm I'm probably hearing distortion from the gain being too high?

Airplay355

I saw a few posts saying, run the amp wide open and adjust from your AVR/PRE. Well, they must be nuts. Cranking the knob off this thing is going to break something.

Airplay355

Forgot to mention, I set the amp to it's sensitive input setting. The outlaw has 2v preouts but I figured with the HPF inline, I would lose some voltage. The manual recommended using this setting when using RCA inputs.

Airplay355

I bridged the amp and that seemed to help with the impact and dynamics of the bass. Supposedly that's 1550 watts but who knows what's actually going to the sub since I've got the gain and trim low. I didn't have a problem with those aspects before but it feels better now.

I still don't get earth shattering, pants waffeling SPL but I think that's more of a subjective opinion rather than a fact. I also realize I've got a largish room. I never realized why people wanted 2, 3, 4 subwoofers in a room. And an IB setup, those people must be insane. Now I get it. I think I'll eventually try out an IB setup. With only $150 in the sub and $300 in an amp, I'd say this is working out pretty well though.

Airplay355

After watching game of thrones this weekend, I noticed some distortion when the dragon landed back in Dragonstone. Anyway, this annoyed me and led to some tinkering.

I took the driver out and noticed that there's high pitched noise that comes from the voicecoil below 35hz even at low db levels (less than 70). This can't be normal, right? The sub doesn't seem totally blown as I can't feel or hear any rubbing when I manually move the driver. Is this what bottoming sounds like?

When hooked up the way it should be, the driver moves in with more force than out. Is that because it's a ported sub? Reversing the polarity causes the driver to move outward with much more force (but no less squeaking).

I tried a smaller SVS driver I had laying around and it also squeaked a little in the low frequencies but it's equally as old so could be having the same problems. These drivers are 13 years old or so.

EndersShadow

Is this with or without that SVS rossover box? Maybe try it without, being careful to not play any test tones below 20hz lol...

See if that helps as it could be that box. Have you tried different interconnects to see if Thor change anything? Have you tried the other channel of the amp?

Lots of variables to check.

Airplay355

I took the driver out of the enclosure. I was worried the enclosure might have an air leak that was making noise but there's still some sound coming from the driver itself.

This is with the subsonic filter. I'll remove it and see what happens. I've swapped out interconnects and used a single channel of the amp, bridged and it did this before with the monoblock but I attributed it to clipping from an underpowered amp. The Crown has clipping lights on it and occasionally the -20db light pops on during a loud scene but that's it.

Airplay355

You sir are a genius. I unplugged the box and the problem is gone. The overall volume is much less now so would that suggest it has something to do with the gain knob on the SVS box? I had it all the way up but maybe that was a poor choice. There are so many volume controls for the one speaker I'm not sure what should be what.

I've got the preamp level, gain on the SVS box and gain on the amp. Should be using something like 75% on the box and amp and use the preamp to adjust the level?

EndersShadow

So you've got the Crown XLS1502 right? There should be a .775 and 1.4 VRMS setting on the amps menu...

Make sure your at .775. 1.4 is the default (you will find that making it .775 CHANGES THE GAME FOR YOU)....

Then put the gain on the Crown wide open, then adjust the SVS box to maybe 25 - 50% (make sure its not making a noise). Personally I'd start with it @ 25% and adjust up as you feel comfortable, paying attention to the driver to make sure its not making any noise .

That input sensitivity change on the Crown will really make a big difference IMHO.

Then adjust your pre-amp... I forget, what IS your pre-amp?

Airplay355

Thanks very much!

I had the .775v sensitivity setting on already. It looks like I had my gains all backwards though. I had the svs box maxed, the preamp (outlaw 975) at -3 for LFE and the crown at half.

I'll try out the new way tonight and see how it sounds.

EndersShadow

Airplay355 wrote: »

Thanks very much!

I had the .775v sensitivity setting on already. It looks like I had my gains all backwards though. I had the svs box maxed, the preamp (outlaw 975) at -3 for LFE and the crown at half.

I'll try out the new way tonight and see how it sounds.

Yes. If you want to be slow with things, put the Crown at 50%, the Outlaw at -3, and the SVS at 25. Then turn up the Crown till it maxed, or your happy with things

Your setup is a bit wonky in that you have 3 gain adjustments, but thats also just 2 up from a normal setup, so not that big a deal.

As a FYI with my dual sealed subs, XT32 wanted my Crown gain @ 1/2 to run EQ.... It then set things @ negative numbers (forget what they are) after calibration.

I left those numbers there, but adjusted the gain up.

Just be careful and maybe put that subsonic filter at 20 to start with and get your settings dialed in. Then after a few days making sure your not hearing anything bad, adjust it to the 17hz one if you want.

I'm just concerned with how much wattage the Crown can give that sub that you might send it too much and blow it....

Airplay355

Ok I messed with some things and settled on these settings for now...Crown wide open, LFE @ preamp on -6db, SVS box at...2 of 8 haahaa. The sub definitely sounds better - deeper, louder, better integrated with the rest of the system. Occasionally I can notice some noise from that corner but it's difficult to tell of it's the walls, windows etc vibrating. Either way, it's definitely improved from before.

I haven't gotten a chance to mess with test tones yet - gotta do that when the wife isn't around. Were watching fantastic beasts right now and so far no complaints.

What exactly is that box doing that had things so messed up when turned up? I assumed it would only attenuate a signal and was meant to give you an easy way to turn it down. Clearly that's not the case, right?

Airplay355

Are the test tone videos on youtube a bunch of compressed BS?

EndersShadow

Airplay355 wrote: »

Are the test tone videos on youtube a bunch of compressed BS?

Here ya go: http://realtraps.com/test-cd.htm

Airplay355

Thanks man! You've been invaluable to fixing my issues with this sub. I think I've managed to get them all pinned down so far. They were...

1) Old internal wiring that may have been bouncing around against the driver (and had also turned completely green throughout).

2) Screwed up gain settings sending distortion to the driver.

3) A cabinet air leak around the screws that hold in the base and binding posts.

I couldn't hear the air leaks well during movies but using the test tones they're easier to spot. I used some weather stripping to seal things up a little better. There's still a tiny bit of noise around the binding posts in the 20-25hz region but it's quiet enough now that I shouldn't be able to tell during a movie.

I think I've gotten rid of all the gremlins for now. I managed to play the 20-29hz test tone louder than I cared to listen to it. What an ordeal this has been

EndersShadow

Welcome to the BASS club

Now play Blowout by Crystal Method and giggle like a schoolgirl

sgmsmg

If you are still looking for something to treat the surround on your driver you may want to look into 303 Aerospace Protectant. Definitely a better idea than Armor All. It won't leave a greasy residue either. Sometimes you can find single application samples on-line.

Airplay355

Thanks! I might grab some of that the next time I order from Amazon. I was going to put purified mineral oil on it but if I'm wrong about the surround being nitrile and it's butyl, I'll wreck it. So I've waited haha

Airplay355

Ok, now that I've got things all fixed I feel like I've got more output than I'll need. I've usually got things turned down.

What would happen if I plugged port(s)? Is that possible with this sub? How would I experiment with it?

VR3

That's a bad **** subwoofer. My Dad had the powered version in a 1500 sq Ft room and it could shake the windows with some nice clean bass.

I would leave the surround alone, it's fine.

I believe that driver was made by TC Sounds before SVS started making their own

Airplay355

Thanks man! Yea it's a monster, more than I needed for sure but it was so cheap

EndersShadow

You can always turn it down... you cant always turn it up

Glad you got it all figured out and are loving the stuffing out of it.

Airplay355

@EndersShadow what do you think about plugging some of the ports? Can I stuff one or two with a towel to see what happens or is that a bad idea?

EndersShadow

You could. I'd also contact SVS to see if they can sell you some foam plugs for giggles, but a towel will work ok.

Your gonna want to try and find the manual to figure out what tune plugging a single or dual port results in.

Airplay355

I got a PDF manual from SVS but there's no mention of port tuning. I asked their CS department about port plugging before but didn't get an answer. It's such an old product the guy I e-mailed may not have known about it.

I assumed since it was tuned to 20hz with all ports open because of the name but I'm not sure what the "39" in the name would correspond to then.

Could I accidentally hurt anything or will I be fine as long as I don't crank the knob off?

EndersShadow

Shouldn't be able to hurt anything I think

Airplay355

Sweet, thanks!

I'll try it out and report back

Airplay355

There's some sort of missing post here