Sanity check: Bad Sub ? (REW Sweep results)

[Linwood]

I have an old Klipsch subwoofer (SW-350) and just got brand new KEF speakers but kept this as I thought it was adequate. This is on a Denon X3800H.

Sounded a bit funny in doing the room setup, so got REW and did a sweep of it with a UMIK-1 mic, and got the attached. This is running in pure direct mode, so no EQ adjustments from Audyssey.

That huge dip in its primary frequencies seems... wrong. Or am I misinterpreting?

And during the sweep to the hear you hear the humps, loud, soft or none, loud, taper down (as expected).

Crossover in the speaker is bypass (off).

I tried moving it a few feet away, just to see if it was a weird spot in the room (this was near a wall) but while it changed a bit, it's still a huge double dip.

Is there anything I may be missing? Or is it just time for a replacement?

Linwood

 

[TLS Guy]

I have an old Klipsch subwoofer (SW-350) and just got brand new KEF speakers but kept this as I thought it was adequate. This is on a Denon X3800H.

Sounded a bit funny in doing the room setup, so got REW and did a sweep of it with a UMIK-1 mic, and got the attached. This is running in pure direct mode, so no EQ adjustments from Audyssey.

That huge dip in its primary frequencies seems... wrong. Or am I misinterpreting?

And during the sweep to the hear you hear the humps, loud, soft or none, loud, taper down (as expected).

Crossover in the speaker is bypass (off).

I tried moving it a few feet away, just to see if it was a weird spot in the room (this was near a wall) but while it changed a bit, it's still a huge double dip.

Is there anything I may be missing? Or is it just time for a replacement?

Linwood

View attachment 76736

Typical type of response from a lousy sub. Lots of those.

 

[Linwood]

So you don't think it has failed in some way, that's probably how it always was? That's the problem with improving the quality of the things that surround it, the weakest link is left behind and obviously so.

Thinking of a SVS PB-1000 Pro to replace it.

 

[dolynick]

Looks like a pretty typical (and/or unfortunate?) room interaction with a sub measured at a listening position some distance from the subwoofer to me. It probably looks worse (with that 1/48 smoothing setting) than it will sound in actual use outside of test tones and sweeps.

The steep roll-off below 30Hz would be more concern for me.

I do suspect that you're also just looking for an excuse to pick up the SVS too And that's ok. It would not surprise me to hear that the SVS shows some similar uneveness in the same regions though, if used in the same room and placement. It should give you better extension down to around 20Hz though if that's not also just the room and your old sub really is giving out under 30.

 

[Linwood]

I moved it out from the wall about 3' closer to the center of the room (where the cord reached). I got pretty much the same curve.

I just moved the mic to about 0.5m from the sub. It's a downward facing sub by the way and LVP (hard) flooring. It's still a pretty good sized dip, but not nearly as large.

The drop off below 30 worries me less as I have 70 year old ears. I mean -- it's wrong, but I won' thear that. 35-40 and up though...

But sure... There is definitely a component of me that says "why did you buy everything new but the sub"?

Here's the 0.5m measurement without smoothing. The smoothing I was doing by habit to look at the other speaker, doesn't make a lot of difference here.

 

[everettT]

I moved it out from the wall about 3' closer to the center of the room (where the cord reached). I got pretty much the same curve.

I just moved the mic to about 0.5m from the sub. It's a downward facing sub by the way and LVP (hard) flooring. It's still a pretty good sized dip, but not nearly as large.

The drop off below 30 worries me less as I have 70 year old ears. I mean -- it's wrong, but I won' thear that. 35-40 and up though...

But sure... There is definitely a component of me that says "why did you buy everything new but the sub"?

Here's the 0.5m measurement without smoothing. The smoothing I was doing by habit to look at the other speaker, doesn't make a lot of difference here.


View attachment 76737

Is this through the RF receiver? You should also limit your sweep to 200hz. Other than the dip it doesn't look to terribly bad for what it is. Changing the sweep will give you a better picture along with increasing the scale 20db

 

[Linwood]

No. The RF Transceiver is not working properly for the sub, so I moved it to the other side of the room and it's wired directly to the AVR. Here's same length (in time) sweep only up to 200hz, scaled, mic at 0.5m sitting about 1.5m from the wall.

 

[everettT]

No. The RF Transceiver is not working properly for the sub, so I moved it to the other side of the room and it's wired directly to the AVR. Here's same length (in time) sweep only up to 200hz, scaled, mic at 0.5m sitting about 1.5m from the wall.

View attachment 76738

The only thing you can do about the dip is move the sub around the room or reduce the peak after it. You can't bring it up because your sub doesn't have that much power to correct that way. I'd start with location and see where that gets you. REW has a simulator to help with placement.

 

[Linwood]

I just pulled the trigger on the SVS. I'm hoping it won't have the same dip.

Due to a variety of issues I do not have a lot of choices where I can put it.

 

[everettT]

I just pulled the trigger on the SVS. I'm hoping it won't have the same dip.

Due to a variety of issues I do not have a lot of choices where I can put it.

The dip is due to your room, not the sub. It's definitely a better sub but if placed in the same location it will still have the dip. Flexibility with placement is your best friend.

 

[everettT]

I just pulled the trigger on the SVS. I'm hoping it won't have the same dip.

Due to a variety of issues I do not have a lot of choices where I can put it.

You're definitely trying to make the right decisions but understand that your room plays the biggest interaction with low frequencies.

 

[Linwood]

The dip is due to your room, not the sub. It's definitely a better sub but if placed in the same location it will still have the dip. Flexibility with placement is your best friend.

Yeah. The issue is that at present I'm limited to this wall. The large openings beside won't let me run a wire along the floor, and the RF rear speaker gadgets I got apparently can't handle a subwoofer properly. So... left or right side (there is actually room for the KEF Q11's and the woofer on either side).

So I'm hoping one side or the other will work out.

The current one (shown far left) is down-facing. The new is out-facing. That alone should make some difference in where all the reflections are.

 

[ski2xblack]

Not really. At those freq, and measured a half meter away, you'll still be measuring the sub AND the room's influence. That's just the nature of it. (The SVS is a better sub, and with its own dsp you can probably help improve things...and a heads up: that dsp also adds enough latency you'll also need to fiddle with distance settings for the other speakers to compensate,)