First Measurement, doesn't look good.

**1984911Porsche** · **05-09-07, 09:48 PM**

This was a measurement of my JL F113.

It doesn't look good to me, your feedback?

**Otto** · **05-09-07, 10:09 PM**

Hi Michael,

Could be worse (EDIT: I mean that in the best possible way!). Can you play with placement at all, or is it stuck where it is? What's your crossover point? Were the mains on for this measurement?

**1984911Porsche** · **05-09-07, 10:18 PM**

The sub has freedom to move around the room. It was only the sub on for the test. I have it crossed over at LP Freq on the sub at 130.

**Otto** · **05-09-07, 10:21 PM**

Cool! I'd start by moving it around. I know, I know, it weighs 130 pounds, but you gotta do it! Is it in a corner? Try it in various corners, between the mains if there's any possibility you might leave it there, etc. Try two more location and let's see what you come up with.

The 130 Hz crossover is what made me think that the mains might be on; it's a little higher than we see around here. In the end, when everything's all set up and perfect, where do you think the crossover point will be? Where do your mains roll off, and what mains are you using?

You're on the right track.

**1984911Porsche** · **05-10-07, 10:25 AM**

I am using Dynaudio S5.4 as my main speakers. I am going to move it around the room this week. I also purchased 4 bass traps for the room, so hoping that will also help.

This is a picture of the front of my room.

I am looking for a new rack, and when I find it I will move my gear over to the side, and maybe then can move the sub between the mains.

Michael

**Wayne A. Pflughaupt** · **05-10-07, 10:43 AM**

Quote:

I have it crossed over at LP Freq on the sub at 130.

Probably way too high, considering the capability of your speakers. Typically you want your crossover somewhere between 80-100 Hz.

Quote:

I am looking for a new rack, and when I find it I will move my gear over to the side, and maybe then can move the sub between the mains.

That will probably give much worse response, but it never hurts to experiment.

Regards,
Wayne

**Otto** · **05-10-07, 10:52 AM**

Agree with Wayne. I'd go as low as possible (esp for music) on your crossover point. I'm not sure of your mains' low end rating, but they appear capable.

And, yeah, try that sub in a few different locations. Corner loading is usually the way to go, but the more data you have, the better.

**Wayne A. Pflughaupt** · **05-10-07, 11:06 AM**

Just remembered something from another discussion that might help. Ed Mullen eliminated a null at 40 Hz or so by moving the sub I think it was about 4 ft. from the corner, on the same wall where the front speakers were. It eliminated the depression, and was still close enough to the corner to get the loading benefits. You might try it and see if it helps.

Regards,
Wayne

**clubfoot** · **05-10-07, 11:07 AM**

Quote:

1984911Porsche wrote:

The sub has freedom to move around the room. It was only the sub on for the test. I have it crossed over at LP Freq on the sub at 130.

Make sure you disconnect your mains and set your processor to small with sub to ensure processor xover to the sub.

What I did with my f113 was place it (with my son's help) in my seating location and connected up my RS meter on a low tripod, and ran sweeps with REW. I moved the meter around until I found a location between the front speakers and the back next to my equipment rack that gave the smoothest response that followed the ideal curve. Make sure you deselect ARO, full xover without any slope, no 25Hz trim, zero phase and no polarity,...to start.

I then swapped sub/mic positions and went from there,...allot of heavy lifting later, repositioning sub, mains and even moving my seating location, and advice from brucek and others here, and it sounds fantastic! And I'm not done yet. I have a BFD1124P on order.

Your room has a cathedral ceiling, it will be a tough beast to tame bass wise, without treatments.

**clubfoot** · **05-10-07, 11:13 AM**

Quote:

Wayne A. Pflughaupt wrote:

Just remembered something from another discussion that might help. Ed Mullen eliminated a null at 40 Hz or so by moving the sub I think it was about 4 ft. from the corner, on the same wall where the front speakers were. It eliminated the depression, and was still close enough to the corner to get the loading benefits. You might try it and see if it helps.

Regards,
Wayne

I also had a dip between 40 and 50, ended up moving my seating location instead to cure it, because it showed up on the mains plot as well

**1984911Porsche** · **05-10-07, 10:03 PM**

JL F113

13" in Corner with a GIK Tri Bass Trap in the Corner

Cross Over set at 75

So I have a null in the room at 35 to 45 and then again at 63 to 75.

Thanks for your input.

**brucek** · **05-10-07, 10:16 PM**

I merged your threads. It's hard to follow if you keep opening a new thread each time you post.

Quote:

Am I reading this correctly?

You have your graph set to Linear scale. Change to Logarithmic scale. Press the Freq Axis button in the top right hand corner of the REW application.

Set your vertical scale from 45dB to 105dB. The horizontal scale is fine.

Show the crossover target that you're using (i.e. 80Hz) so we can see how the sub tracks the target.

Normally we worry more about the peaks than the dips....

brucek

**1984911Porsche** · **05-10-07, 10:22 PM**

Does this graph look like what you are talking about?

**Jerm357** · **05-11-07, 12:02 AM**

Yes, but go down to 15hz.

**Otto** · **05-11-07, 12:14 AM**

And add the target curve.

**1984911Porsche** · **05-13-07, 07:07 PM**

Got a chance to move the sub around a little.

What graph do you like the best?

**Otto** · **05-13-07, 07:22 PM**

Hey Michael,

How drastic were your moves? I'm a little surprised at it staying so similar. You've really got that dip at 40Hz!

**1984911Porsche** · **05-13-07, 07:33 PM**

Hey Otto,

I didn't put up this graph. The first graph was in the corner 20" off the GIK Bass Trap. The second was moved over next to the speaker.

This is one on the side of the room.

**Otto** · **05-13-07, 07:39 PM**

Hi Michael,

It might be easier to tell the differences if you plot them all on one set of axes. Just do all the measurements (don't delete them; you can only store nine at a time I think). Anyway, once you get a variety of measurements, you can plot them all together by selecting the "All Measured" tab here:

AllMeasured.jpg

Once you're in there, there will be checkboxes that will allow you to turn on/off the display for each measured (they will be organized by the date/time they were measured).

**1984911Porsche** · **05-25-07, 07:27 PM**

Hi Group,

I put my sub in my seating position, and found the area that 40 registered the highest. I ran the graph and compared the two.

What do you think?

I like the front corner better for music, but the back corner for movies.

**1984911Porsche** · **05-25-07, 07:30 PM**

Sorry, posted wrong file.

**brucek** · **05-25-07, 09:51 PM**

Interesting, the big dip simply moved.......

What happens when the sub is located somewhere away from either corner, does it go away at all?

brucek

**1984911Porsche** · **05-26-07, 11:29 AM**

I set the sub up in 9 differn't locations around the room.

The dip never really went away, but just moved around.

Any ideas, which do you like best?

**Sonnie** · **05-26-07, 11:54 AM**

You know... I had that same 40-45Hz valley for the longest of times, although I had two subs. I finally got to experimenting and found that moving one sub to the rear and leaving one in the front was the only way to solve my problem. Looking at your graph:

... it appears that you could do the same. I realize those JL's ain't cheap, but it would probably solve your problem... just grab ya another one...

**ISLAND1000** · **05-28-07, 08:39 PM**

Is that a room "suck out" at 30hz to 40hz or is that an artifact of the 113? Is that dip in the response audible to you? Or does it bother you because it shows up on the graph?
You haven't told us how extraordinary this excellent sub really is!

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