[Redskin]

I have a JL Audio F113 sub in a dedicated room. Tonight, I am going to find the best place for the sub. I have sine waves burned to a cd to plot my room response. I would rather not have to move this heavy sub around to 5-6 different places to test it.


Does it really work to place the sub at the listening position, and then place the spl meter at the potential places for the sub, and take measurements? I was thinking about putting the sub up on a sturdy end table to get it to approximate ear level at the listening position, and putting the spl meter down close to the floor to simulate the approximate sub position.


If this is not really that accurate, I will just move the sub around to the potential positions, and take a bunch of Advil afterward.

 

[JBLsound4645]

Raising it off the floor at the front will show some difference in db level. But unless you have items to place in the position and then lift the sub off, the floor and set it on another speaker that isn’t been used say a stool anything. Take a few readings on the floor then you, can move it side to side over the front, and then try raising it off the floor.


Take notes on paper use tape measure to mark its position use masking tape to stick on the floor to show where each one was placed and tested. Then after you’ve settled on the best overall position, go with that position.


LOL there’s a lot of position here?

 

[ransac]

It may prove easier to put the sub at the LP, close to ear hight, then crawl around at about sub level while playing some good bassy music. Then just listen for the best sound. If you measure, you would only get one frequency or would spend a lot of time measuring sweeps or steps. Listening to music gets complex sounds and using your ears if quicker.

 

[Redskin]

Just to report back. Tonight, I put the sub on a small table at the listening position. I measured and graphed the frequency response of 6 different spots around the room. The best spot was nearfield, in the back left corner behind the couch. It was pretty flat from 16 hz to 160hz. I then put the sub in that spot, used ARO to eq one small 4dB peak, and now I have an almost perfectly flat response.

 

[JBLsound4645]



Quote:
Originally Posted by ******* /forum/post/15411390


Just to report back. Tonight, I put the sub on a small table at the listening position. I measured and graphed the frequency response of 6 different spots around the room. The best spot was nearfield, in the back left corner behind the couch. It was pretty flat from 16 hz to 160hz. I then put the sub in that spot, used ARO to eq one small 4dB peak, and now I have an almost perfectly flat response.

At the same height level as the table, placed in that corner?


Happy New Year

 

[Redskin]



Quote:
Originally Posted by JBLsound4645 /forum/post/15411965


At the same height level as the table, placed in that corner?


Happy New Year

No, I placed sub on a table at the listening postion to simulate ear height while seated. I placed the spl meter close the floor, to simulate the height the sub would be placed. Once I placed the sub in the best/final corner, it was placed on the floor. I thought I had read somewhere that this is the best way to do it, because the bass frequencies interact the same way in both directions, thus why the "crawling for bass" method works. Anyway, it worked perfect for me.


Happy New Year as well.

 

[sivadselim]

The problem with doing the "crawl method" is that you can very easily end up enhancing an unwanted room peak.

 

[JBLsound4645]



Quote:
Originally Posted by ******* /forum/post/15414395


No, I placed sub on a table at the listening postion to simulate ear height while seated. I placed the spl meter close the floor, to simulate the height the sub would be placed. Once I placed the sub in the best/final corner, it was placed on the floor. I thought I had read somewhere that this is the best way to do it, because the bass frequencies interact the same way in both directions, thus why the "crawling for bass" method works. Anyway, it worked perfect for me.


Happy New Year as well.

Oh, yeah that makes sense never thought of putting it that way. Well I lifted my large JBL cinema diy sub bass upwards, was it last week or the week before? tested it out on a few frequencies (spot size wave) noted the difference from its previous position and it showed a good range where it was missing on a few upper frequencies 50Hz 60Hz 70Hz and 80Hz.


Besides I don’t really have lot of room space to experiment with. I have large CRT SONY that stands in the middle now. The sub used to be in the middle laying sideways on the floor. Now been just shifted over by as much as 45” to the left and it seems fine with the upper frequencies.


I was just thinking of placing the sub up has high as can place it. No not the smaller sub the LARGE one! Now what do I need??? Timber build a strong stable support structure and place the sub 5 feet 6” off the floor above the CRT and the centre channel. Now who dares me?

I think I’ll try the smaller one first it would take a few hours to build then I’ll need a mate to give me a hand and then its loading the sub enclosure up with the sub bass driver as I’m not lifting it over my head with that damn thing inside it, weight of that sub alone is too heavy.

 

[Redskin]



Quote:
Originally Posted by sivadselim /forum/post/15415002


The problem with doing the "crawl method" is that you can very easily end up enhancing an unwanted room peak.

I thought about that, which is why I measured, instead of just crawling around and just listening. Since I wasn't 100% sure that the bass waves would interact the same way in reverse, I re-measured once I put the sub in its final resting place. Pretty darn near perfect. I don't claim to be an expert, and don't know if this works in every situation, but it worked out great for me.

 

[Eskimo1]

Best idea is to do a REW sweep from various possible locations..

 

[JBLsound4645]

And you’ll need a

Behringer ECM8000 calibration microphone

Behringer MIC100 preamplifier

Behringer FBQ2496


and one free download copy of REW once you have registered with Home Theatre Shack.

 

[sivadselim]



Quote:
Originally Posted by ******* /forum/post/15422489


I thought about that, which is why I measured, instead of just crawling around and just listening. Since I wasn't 100% sure that the bass waves would interact the same way in reverse, I re-measured once I put the sub in its final resting place. Pretty darn near perfect. I don't claim to be an expert, and don't know if this works in every situation, but it worked out great for me.

And what did you measure? If you simply measured output with pink noise, then all you may have done is optimized a room peak.

 

[Roger Dressler]



Quote:
Originally Posted by sivadselim /forum/post/15433948


And what did you measure? If you simply measured output with pink noise, then all you may have done is optimized a room peak.

He reported: >>I measured and graphed the frequency response

 

[Redskin]



Quote:
Originally Posted by Roger Dressler /forum/post/15435830


He reported: >>I measured and graphed the frequency response

 

[RMK!]



Quote:
Originally Posted by ******* /forum/post/15439009


Yes, I used sine waves and graphed from 16 hz up to 160 hz.

Good job *******, your methodology was sound (pun intended) and if the results are improved bass response no worries.