Not happy with my PB13-Ultra, yet.

[GollyJer]

OK, this is my first post so please be kind. I followed the REW online help files to the best of my ability to calibrate my sound card & set things up correctly.
Here is my room:

The five surround speakers are Ascend Acoustic Sierra-1's and the sub is a SVSound PB13-Ultra. The receiver is an Outlaw 1070 in "ByPass" mode (no processing done on the stereo -mono in this case- signal) with crossover set at 60hz.

I've recently replaced a PC12-Ultra with a PB13 and (except for it's awesome physical appearance) am not yet happy. It seems boomy during some things and weak in others. I didn't even know this website existed because the PC12 always sounded so good. Now I've found HomeTheaterShack and am asking for some help. I'd like to do things with my existing equipment (less is more in my book) but am willing to by a BFD if needed.

Here's a REW chart taken with a Radio Shack 33-2055 from the listening position on the couch in front of the center channel speaker.


And here are the controls available on the sub (picture from SVS, not my settings):


My current settings:
Phase: 0
Gain: a little more than 1/4 (set when doing 5.1 channel calibration)
Crossover: Off
RCA Hi Pass: Off
Room Comp: Off
Subsonic Filter: 20Hz
Frequency: 20Hz
Level: Min
Q: High

I know I could turn the Parametric EQ dials and see where it takes me... but it would be great to do things a little less random than that.

Any guidance is appreciated. Thanks!

[brucek]

Any guidance is appreciated

Your response does not appear in line with the specs of a PB13 that says it is: +/- 3 dB 18 Hz-150 Hz (anechoic) in 20hz mode. Yours begins to drop at 35hz..... so there's some sort of problem.

Perhaps the location is causing the abbreviated bottom end. I would first drag the box to the middle of the room and do a near-field response on it. Put the subsonic filter at 10hz.

brucek

[OvalNut]

I was having similar thoughts as bruce, but not sure how to confirm it. My PC13 Ultra powers strongly with level response well below 20hz.

I'd contact SVS in the morning and get their take.


Tim

[Wayne A. Pflughaupt]

Yeah, something definitely isn’t right. With a corner like that, that thing should be going gang-busters on the bottom end.

I’d double check the parametric settings. It almost looks like you have the filter set broad and at 20 Hz drastically cut.

Regards,
Wayne

[GollyJer]

Thanks for the responses guys. Something definitely didn't feel right to me when looking at the graph again. When in surround mode and using the Avia II disk I could feel the 20-40Hz range much more than the graph above showed. This lead me to try one thing different. I switched the receiver to Stereo mode instead of ByPass mode. Viola!

Here's what the graph looked like:


Once I had the "where's the bass?" problem solved I realized why my wife was complaining so much. We had tons of bass at the lower end and a spike around 40Hz. The bass wasn't blending well. The next step was to start filling up the tuning ports and turning down the subsonic filter. Eventually I made it all the way to plugging all three ports with the subsonic set to 'sealed'. This is the resulting graph:


From there I used the Parametric EQ to tame the spike around 40Hz. And with that accomplished I tried each of the six crossover points on the receiver, finally settling on 80Hz. I also tried each of the Room Comp. settings and ended up leaving it on "Large". Here's the graph with all adjustments applied:


Better wouldn't you say? As the Outlaw receiver doesn't have an EQ, I have no way to bring down the 200Hz level so I won't worry about that for now.
We just watched X-Men. The sound blended well and my wife was asking me to turn up the bass. After increasing it a few db's everything sounded awesome.

As this level of sound configuration is new to me I'd like to here your opinions on where I should go from here. I'm happy but think it could be better (famous last words). Should I dive in to the Hard-Knee House Curve? I'd surely need a full BFD configuration in that case correct? Or maybe I should wait for the AS-EQ1 announced by SVSound?

More surprising, and arguably as significant to music and theater bass enthusiasts, is the previously secret technology partnership with Audyssey Laboratories Inc., the first results of which will be the revolutionary AS-EQ1, a cutting-edge "FIR" based room-response correction device optimized for today's ultra deep and powerful subwoofers of any brand (though clearly we favor SVS there). The proprietary Audyssey algorithms and DSP power, combined with SVS's unsurpassed expertise in bass reproduction, will soon result in a rationally priced advanced processor that even the most sophisticated PEQ derived bass correction can't match. Easy to use, professional results, and with features and power that'll make it the "must have" device for any sound enthusiast.

Thanks again for the responses guys.

[Wayne A. Pflughaupt]

Should I dive in to the Hard-Knee House Curve?

Do I really have to answer that?

As far as the 999 - sounds fabulous, but I’ll bet it won’t be nearly as cheap as the BFD.

Regards,
Wayne

[GollyJer]

I suppose you wouldn't have to ask Wayne.

Also, sorry about the weird name (999). I meant the AS-EQ1. The post above has been updated.
It'll be interesting to see where the price ends up.

-Jeremy

[OvalNut]

It is looking better, glad to hear the root problem was addressed with tweaking and not a hardware concern.

A couple thoughts:

1. Yes, go for a house curve.

2. Yes, go with the BFD. I personally have a prefeerence for the FBQ2496 over the DSP1124P, but either will certainly do the job well at a reasonable cost, and available now.

3. Pay attention to any loss of dynamics or added low freq distortion you may be picking up using Sealed mode. Let your ears decide, but be advised that some pretty well done extensive testing has demonstrated that the Sealed and 10hz tunes can produce those effects at more spirited volumes.

Congratulations, and please keep us updated.


Tim

[GollyJer]

OvalNut wrote:

3. Pay attention to any loss of dynamics or added low freq distortion you may be picking up using Sealed mode. Let your ears decide, but be advised that some pretty well done extensive testing has demonstrated that the Sealed and 10hz tunes can produce those effects at more spirited volumes.

Tim, thanks for the feedback. I think I'll place a BFD order this week. As far as dynamics, I did feel there was something lost as we brought the sub down to the target line. Turning up the gain a little seemed to help and I haven't noticed any distortion (haven't spent any time listening to music yet though). Can you point me to any online articles regarding Sealed and 10Hz testing. When I get the BFD I'll start by opening the ports back up and bring the system in line with the house curve using only the BFD. Based on your comments I assume dynamics and distortion issues go away at 20Hz?

Anyway... I'll keep posting as I move forward. Thanks again.

[clubfoot]

The first thing that struck me looking at your room layout is that you're sitting almost in the middle of the room! Which in theory should coincide with a major null in a perfectly rectangular room with close to even dimensions. The first thing I would have done without adding any EQ, was take some more measurements further back and forward of where the sofa presently sits,...but that's just me.
Then again, you've located the sofa and speakers for optimal surround sound too, so if you want to adjust the response any more you'll probably need a BFD.

[GollyJer]

clubfoot wrote:

The first thing that struck me looking at your room layout is that you're sitting almost in the middle of the room! Which in theory should coincide with a major null in a perfectly rectangular room with close to even dimensions. The first thing I would have done without adding any EQ, was take some more measurements further back and forward of where the sofa presently sits,...but that's just me.
Then again, you've located the sofa and speakers for optimal surround sound too, so if you want to adjust the response any more you'll probably need a BFD.

Yup. I ended up doing just that last night. Interestingly, from almost every other position on the couch and in front of the couch, the spike at 40Hz was much smaller. With the EQ adjustment they turned into dips. I ended up splitting the difference on the level adjustment. That seemed to be the most logical choice in hopes of balancing across the listening environment. And yes, we mostly watch movies and TV with this system.