SVS vs HSU and which one for 4000 cu ft HT room? (1 Viewer)

[Fernando Saa]

Thanks for the reply Keith, Ed; my room is rather big and it opens into the kitchen, dinnete, dining room, foyer and formal living. I'd been very careful with my sub and I don't wanna press my luck with it by running it too hot. It's just that I don't wanna lose sonic information in the 16-20 hertz region. Would plugging at least one port and setting it to 16 would help it from a possible bottoming? I will probably provide you Ed with all measurements you ask. As of now I can't do that cause I have kids running around the house driving me crazy! but thanks again for your knowledge and help.

 

[Mark Pedley]

Dusten,

First off, thanks for the explanation.

I finally got the time to sit down and do some A-B comparison, ports plugged or unplugged. Amp set at 10db below reference TPM THX intro, ports plugged, about 106 db, ports unplugged about 110-112db, so there is a definite db advantage to keeping them unplugged but I had a hard time telling the difference by ear (or feel).

Next I tried the pod race, the difference was a bit more noticeable but not huge. Also I never once heard port noise, either it never happened or all the other sounds covered it up. Overall I think I will keep the ports open. I also don't think I was at the limits of the sub. Will I hear distortion or will the sub just hit a db ceiling?

On a side note I left the amp at the same setting with all ports open and was getting 100-104 db with the bass from Yello-Essential (Oh Yeah from Ferris Buellers Day Off) Many of the songs on this cd have some good bass. For those of you who like their music a bit harder I was getting 114-116db in several songs from KORN Follow The Leader during bass heavy parts (obviously the rest of the speakers were adding to the sub, but the sub was clearly adding the most db)

Burke,

Back on topic, after living with this sub for 2 weeks, I would strongly recommend it, it will literally make your pants move! and anything else in the room. I have not heard the PB2-plus but can't imagine needing more sub in my room. I am certain you will be happy with it.

Mark

 

[Burke]

Thanks for the follow up, Mark. What an interesting thread!

I've had my sub, the PB2-ISD, on order for about 7 days and should be getting it within 7-10 days.

I'm assuming that the prior discussion re the PB2+ applies to the PB2-ISD?

Thanks to all the contributors to this thread. It really has been educational.

 

[Bill Polley]

Congrats, Burke...welcome to the SVS owners club! By the way, if you want a more tactile feel to the bass in your basement, consider spending a few hundred bucks on a new floor. Just simply buy some 2X4 lumber and lay it down flat on 16" centers. Fill in the spaces in between with 1-1/2" rigid insulation, and nail some 5/8" plywood over the top. Reinstall your carpet and you are done! It is a little work, but it will give you more "feeling" with deep bass, and will make the floor (and the room) warmer!

 

[Edward J M]

It's just that I don't wanna lose sonic information in the 16-20 hertz region. Would plugging at least one port and setting it to 16 would help it from a possible bottoming?

No one wants to lose 16-20 Hz info, but the different sub tunes are a trade-off - the lower you tune it, the less loudly it can play.

To answer your question - yes, plugging a port and running 2/16 is safer than running 3/16. By plugging a port you do add some additional restoring force to the enclosure, which will lessen the likelihood of bottoming the drivers.

But 2/16 is still considered a non-conventional tune and there is still a higher than normal potential to bottom the drivers than say the 2/20 tune.

The IB we just built, for example, has no SS filter and operates in a free-air environment. It doesn't take much power at all to reach the excursion limits of an AV15 in an IB application - maybe 200-250 watts, even though it is rated far higher for thermal power handling.

 

[Edward J M]

Just to point out, this isn't quite true. A flared port has a slightly lower pressure drop than a sharp-edged port, leading to a higher air flow rate. This is probably much les important that the turbulence and noise effects of the sharp edged vs. flare, but I thoguht I'd mention it.

You are quite right, Kevin - good call. But as you alluded (and I agree), the difference will not be significant in the context of this discussion when compared to the effect of the endcap configuration.

 

[Burke]

Regardless, the 3/16 setting is the most dangerous setting in which to operate the PB2+. Tom V has requested users to run the sub as intended or risk potentially instant damage before you can even reach for the volume control.

I still haven't received my sub yet! Can't wait.

I am confused by the 3/16 setting reference. What exactly do you mean Ed? Thanks.

 

[Edward J M]

I am confused by the 3/16 setting reference. What exactly do you mean Ed? Thanks.

Short hand for 3 ports open, SS filter set to 16 Hz.

The standard settings for the PB2+ are:

3 ports / 25 Hz
2 ports / 20 Hz
1 port / 16 Hz

Non-conventional settings are:

3 ports / 20 Hz
3 ports / 16 Hz
2 ports / 16 Hz

The non-conventional settings increase the potential to bottom the drivers, and the 3/16 is the worst in that regard.

 

[terence]

Ed,

Can you break down what exactly are you acheiving in sound performance when you do these Non-conventional settings vs the standard settings?

Are getting more SPL & exstention when you do the Non-conventional settings vs the standard settings? Last how often have you bottom out the drivers doing this with out knowing the limits of material you play? Of coruse this in your room. Thx!

 

[Edward J M]

Tee, my PB2+ review shows the FR for all six states of tune.

I have never bottomed the drivers, but my room is only 2000 ft3. If I am doing demo's or just watching a bass heavy DVD at high volumes, I play it safe and run 3/25 as the designer intended. I have no intention of wrecking my sub. At more moderate volumes, the 3/16 setting provides additional deep extension which can occasionally be felt/heard on a handful of DVDs.

 

[terence]

deep extension which can occasionally be felt/heard on a handful of DVDs.

Defiantly pick up "Finding Nemo" you are in for a treat! Lots of DEEP extension in this flick and i would love to hear your take on this film after you play on your HT system.

 

[Burke]

Ed,

What exactly is the reference level? Is it the volume setting at which the speakers put out a db level of 75 for pink noise? Thanks.