SVS Subs

Ron Temple

Yep, you're overdriving it. There have been some folks that have encountered popping sounds with the Ultra. In each case, it looks to me like they've got Audyssey calibrating for them and dynamic eq engaged. The problem being you can't see what cuts or boosts are being applied with the FR. Everything has it's limits and trying to do 10hz at high volumes is extremely demanding of the amp and driver. Running the sub hot at -5 MV is definitely the problem, especially with blind eq engaged.

For example, I can do reference in my modest room. However, I cut mine at 60hz, no eq, just the PEQ on board in 15hz tune, sub + mains, speakers large, calibrated 2dbs cold. I've got plenty of amp power for my mains and running the sub cold allows me headroom there. WOTW and the Haunting give me 115dbs at 3M. I only do this for demos, because it's just too loud. With your calibration, I couldn't come close without distressing the sub. You're going to need to back off on your AVR trims and calibrate manually, if you're going to try to get that loud. Also, you should bring your tune down to 15hz. It will take a db or 2 of your headroom above 20hz, but put it back below.

BTW, I've watched TIH a couple of times and it has lots of deep bass, but on my system, the cannons are evident, not overwhelming. I don't even try to get them at -5. -10 is plenty for that scene.

danz1906

polkatese wrote: »

+5dB is extremely hot. Is it possible that the sub is too small for the room? I am not familiar with SVS PB 13 Ultra, but I can't imagine running any sub at +5 dB in most setup. Just as a comparison, I am running Velodyne DD-15, and for my setup, I am running +1 dB, and it rattles the windows if I play it a few dB close to reference. My room is 18' by 35'

+5 is too hot for the Sub. I have my Klipsch THX Ultra2 subwoofers
set at -2.5dB.

Ron Temple

mufsoman wrote: »

I was recently looking at the Epik subs spec sheets and was suprised to see that a speaker cone is made from kevlar impregnated paper-pulp. I know kevlar is strong, but a paper cone? Maybe it's just my rookie skepticism, but paper? Is this durable? I thought most cones these days were injection molded plastic or other durable materials. Should we be concerned about life expectency of paper. What about humidity levels affecting performance then?

Foam surrounds wear out. Doped paper/kevlar is fine. The amp will go before the driver in most cases. Polk's MWs from 30 years ago are still going strong if the motor, spider and surround hold up...sound good too...and they're doped paper.

McLoki

kuntasensei wrote: »

To put things in perspective, you should realize that adding a second identical sub would only give you an effective 3dB more headroom, so what you're doing by asking it to run 5dB hot is basically asking it to do the work of three subwoofers.

close, but not quite.

If separated by more than about 10' (technically, 1/2 the length of the sign wave in question), you add +3db (and may smooth out you in-room frequency response) when doubling the number of subs.

If close to each other (co-located) you add +6db volume (no additional freq. response smoothing takes place) when doubling the number of subs.

when colocating - 2subs is +6db, 4 subs are +12db. if 2 subs are colocated and there are another 2 subs across the room, the increase is +9db.

make sense?

Michael

bevo

kuntasensei wrote: »

Okay... this is one of those moments where I want to say "Here's your sign." You do realize that having your sub 5dB hot pretty much guarantees a quick death if you put it anywhere near reference level, right? No wonder you're pushing the driver to overexcursion.

Yeah, that scene has some serious 10Hz bass... but the subsonic filter on your Ultra should be keeping it at a tame enough level to prevent bottoming of the driver due to just that. I'm running an older 20-39CS+ with the 12.3 driver, and at -5 from reference, I saw the clip light on my amp flicker but didn't bottom the driver. I'm running a subsonic filter at about 16Hz, but I'm running my sub at the same level as my other channels, equalized for the room with Audyssey MultEQ XT.

So the short answer is: The only thing wrong with your sub is that you're running it 5dB hotter than the other channels and expecting it to keep up. To put things in perspective, you should realize that adding a second identical sub would only give you an effective 3dB more headroom, so what you're doing by asking it to run 5dB hot is basically asking it to do the work of three subwoofers.

I wasn't running the volume even close to reference when it popped. I had the volume at -30, 0 being reference level. I am going to go and lower my subs level right now though. I'm going to put it at 73db on my spl, which I think will run it about 1db hot and see how that works.

danz1906

bevo wrote: »

I wasn't running the volume even close to reference when it popped. I had the volume at -30, 0 being reference level. I am going to go and lower my subs level right now though. I'm going to put it at 73db on my spl, which I think will run it about 1db hot and see how that works.

How do you like the Ultra-13 subwoofer?

bevo

danz1906 wrote: »

How do you like the Ultra-13 subwoofer?

The more I tune it in, the more I like it. It is by no means, a sub that you can just plug in, and play. It really does take some tinkering to get it to sound right. I guess that's half of the fun of it though. I really just don't have the time I need to get it perfect, but with the help of the polk and AVS forums, I am getting pretty close.

I'm really starting to be amazed by it. It is by far the cleanest sounding bass I have ever heard. In home theater, or car stereo. It's so smooth, you almost forget that you have a 155 pound sub taking up an entire corner of your room. But when it's called for, it will literally shake the entire house without any sound at all coming out of it. I really didn't know what bass was until I got the ultra tuned in.

It really makes me want to upgrade to the RTi A9's for more mid bass, but that would cost me a small fortune. A new receiver, amp, and center would have to come first. My 1909 with it's 90 watts, just wouldn't do the A9's justice.

I really don't have any other high end subs to compare the ultra to, but I really don't think a sub could sound smoother and more accurate. Maybe louder, but not any better.

My wife doesn't care for it at all, because of how it brings out so much bass that we never heard before. She thinks it's to much, and my sister says the subsonic bass actually makes her sick. Sounds pretty good to me though. It really has doubled the impact of my system. I think the upgrade bug will be gone at least until we build a house one day, and I get a dedicated home theater in the basement.

bevo

I turned it down from +4 to -3.5 on my sub level in the receiver, and turned my gain down on the sub from 1/2 to about 1/3, and that took it from 85 to 73db at reference. Now it's almost perfect. I do have to turn it back up for cds to +3 on my receivers level. I wish there were presets that you could switch between on the receiver for different sources, and different seating positions. When I watch movies, I'm about 14 feet away, for games and music about 9 feet, and for my racing game setup about 5 feet. It would be really nice to be able to change the surround perimeters for each positions.

danz1906

bevo wrote: »

I turned it down from +4 to -3.5 on my sub level in the receiver, and turned my gain down on the sub from 1/2 to about 1/3, and that took it from 85 to 73db at reference. Now it's almost perfect. I do have to turn it back up for cds to +3 on my receivers level. I wish there were presets that you could switch between on the receiver for different sources, and different seating positions. When I watch movies, I'm about 14 feet away, for games and music about 9 feet, and for my racing game setup about 5 feet. It would be really nice to be able to change the surround perimeters for each positions.

Congrats, the subwoofer is a huge part of HT.:D
Check out my thread on my Klipsch THX Ultra2 subwoofers, there's
good info on the SVS subwoofer there.

http://www.polkaudio.com/forums/showthread.php?t=80691

jolax73

Does anyone has any experience with Epik Sentinel? How is this sub compare to SVS PB-12 Plus? Which one is a better buy?