Horrible results with REW and Sub.. help!

[Damo]

Well, its almost an exact opposite of what I should be getting, I suppose, but I am fairly new to the whole REW thing.

I trust the readings are correct, though!

There seems to be a huge notch just over 40Hz, and I have no idea if I can get any of it back, via movement of the sub - Would I be moving the sub further from the wall or closer to it to get better response below 30Hz from it, or is it as I suspect in that the sub probably cant reproduce the frequencies, no matter what I do?

It also looks like I may not have the crossover set properly on the sub, either, but Ill try getting some more readings tonight.

Man, I have some work ahead of me!

Any suggestions? Im running a smallish/crappish Yamaha YST-SW225


and expanded further...




Also, thanks to the makers for such a great program!

[Wayne A. Pflughaupt]

Welcome to the Forum Damien!

It also looks like I may not have the crossover set properly on the sub, either.

Correct. Actually, it looks like there is no crossover at all (unless the measurement includes your main speakers as well).

There seems to be a huge notch just over 40Hz, and I have no idea if I can get any of it back, via movement of the sub -

It’s possible. Try some different locations, if that’s an option.

Would I be moving the sub further from the wall or closer to it to get better response below 30Hz from it, or is it as I suspect in that the sub probably cant reproduce the frequencies, no matter what I do?

Yeah, budget 8” sub – 30 Hz is probably as good as it gets, but you might try a corner, if one's available. It’s only rated to 28 Hz to begin with, though...

Regards,
Wayne

[glaufman]

Welcome Damien! +1 on what Wayne said, but even if you do get lower response in a corner, you can expect that to create more/deeper peaks/dips in the rest of the response.

No harm in trying though. Sometimes it depends on your personal goals, whether you prefer boom at the expense of clean sound.

Without knowing the layout of your room, you can also try different listening positions.

[Damo]

Thanks for the responses, guys.

Im investing in an SVS PB13 and some acoustic panelling at some point down the track, so Im not too concerned at this point, until that happens.

I know Ill be fighting with the wife for placement of the sub

Any idea what the problem may be at 40Hz? Is it some sort of wave cancellation effect or something?

[Wayne A. Pflughaupt]

Yeah, something like that. Those sharp, deep depressions like that - usually can't do anything about them except move the sub.

Regards,
Wayne

[glaufman]

Somtimes moving the LP can help those too... the best placements should be the same regardless of the sub so you might want to try experimenting now just to put the bug in her head to fester...

[Damo]

Forgive my n00biness, but LP stands for?

Ive got the guy down at my local HT store trying to get me onto a Velodyne SPL-1200 Ultra, but I'm reading better reports on the SVS PB13 Ultra. Both will make a huge difference in low end response compared to what I have, for sure, but still undecided which way to go there!

[laser188139]

LP is for listening position.

Besides running sweeps, you can pursue Greg's suggestion to try different listening positions by using REW's RTA capability. This lets you enable the generator for subwoofer pink noise and move the microphone looking at changes in the spectrum. Then you can verify this with a sweep when you have found someplace interesting.

Bill

[glaufman]

Damo wrote:

Forgive my n00biness, but LP stands for?

What Bill said!
Sorry... I tend to slip into lingo when I'm busy and multitasking...
SVS has a very decent audition policy, so you can listen before you fully commit... perhaps you can talk your local guy into an in-house audition of the Velo also...
Check out our archives of some subwoofer tests done...
http://www.hometheatershack.com/forums/subwoofer-tests-archived/6015-index-subwoofer-tests-manufacturer-model.html
The PB13U was done in all different tuning modes... the SPL1200 was done also, but the Mk2, which I assume is not the same as their Ultra. If it is, comparing to the SVS in "sealed" mode makes the comparison fair I think)...
Admittedly, some of the decision will come down to how you're going to use it. Music/Movies, open room vs sealed, etc...
One thing I love about the SVS is the different tuning configurations you can put it in. It could be argued that could increase the chances of you being happier over the longer haul. One thing that bothers me about the Velo that Ilkka tested is the size of the sealed enclosure as compared to the size of the driver.

[Damo]

I suppose I should have clarified.

99.9% of the time we're using it for movies only, and within a sealed room.

The issue with the SVS is that the nearest dealer is over the other side of the COUNTRY