EQ Settings for DR250 + T39?

[David Carter]

A while back I started a thread about setting my 31-band EQ for a pair of DR250's. At the suggestion of the folks who replied, I set my EQ curve based using the published response curve for a DR250 with melded array, and I've been very happy with that. The original thread is here:

http://billfitzmaurice.com/phpBB2/viewtopic.php?t=5150

Now, my question is can someone help me find the chart I would need to incorporate a pair of 14" BP102-loaded T39's into the picture. I'd assume that, once I have the right chart, I would just overlay the two charts adjusting the EQ as appropriate for the T39 curve below the crossover point and the DR250 curve above it. Does that make sense?

So, anyone seen a chart for my version of the T39? I did some searching, but couldn't find one that specifically matches it. If it doesn't exist, how far off would I be using a chart for a 14" S2010-loaded T39?

Thanks!

[Tim A]

A chart for BP-102 loaded T-39's doesn't exist.

Use the 14" w S2010 chart but assume a 2.5dB dip from 40-60Hz.

Use the sub chart up to your crossover point, and the 250 chart from there on up.

[David Carter]

Thanks, Tim. Another question I meant to ask but forgot was about recommended crossover point for that T39 + DR250 as well as low-end cutoff for the T39.

Any thoughts on that?

[Tim A]

I cut the 39's off at 35Hz.

As for crossover, the 200's like about 120Hz, the 250's go a bit lower. When I set up my 250's I started around 100 and went from there, but it's been so long since I've used them I can't recall where they ended up, seems like around 105-110. Use your ears and decide what you like. Don't forget you can change it from room to room.

[Tim A]

Use the 14" w S2010 chart but assume a 2.5dB dip from 40-60Hz.

Point of clarification, 40Hz doesn't have a dip. Assume the dip above 40Hz to about 60.

[David Carter]

Use the 14" w S2010 chart but assume a 2.5dB dip from 40-60Hz. Use the sub chart up to your crossover point, and the 250 chart from there on up.

So, I've tried to create a table doing what you said above, and also calculating the required adjustment for each EQ band assuming a center line of 100dB and 105dB. Before I start messing with the EQ, does this approach make sense, and do these numbers seem like they're in the ballpark?

Code: Select all

Freq.	Routing	dB	   100dB	 105dB
31.5	 T39		 84	   16		 21
40	   T39		 95	   5		  10
50	   T39		 92.5	 7.5		12.5
63	   T39		 97	   3		  8
80	   T39		 100	  0		  5
100	  T39		 102	  -2		 3
125	  DR250	  101	  -1		 4
160	  DR250	  107	  -7		 -2
200	  DR250	  105	  -5		 0
250	  DR250	  103	  -3		 2
315	  DR250	  105	  -5		 0
400	  DR250	  106	  -6		 -1
500	  DR250	  107	  -7		 -2
630	  DR250	  106.5	-6.5	  -1.5
800	  DR250	  105	  -5		 0
1000	 DR250	  105	  -5		 0
1250	 DR250	  105	  -5		 0
1600	 DR250	  104	  -4		 1
2000	 DR250	  105	  -5		 0
2500	 DR250	  105	  -5		 0
3150	 DR250	  105	  -5		 0
4000	 DR250	  106.5	-6.5	  -1.5
5000	 DR250	  102.5	-2.5	  2.5
6300	 DR250	  104.5	-4.5	  0.5
8000	 DR250	  108	  -8		 -3
10000	DR250	  108	  -8		 -3
12500	DR250	  105	  -5		 0
16000	DR250	  98	   2		  7
20000	DR250	  97.5	 2.5		7.5

[Bill Fitzmaurice]

Do not boost below 50 Hz, and I wouldn't boost 50 Hz by more than 3dB. At 31.5Hz cut by 6dB and below that you should be pulling the sliders fully down.

[David Carter]

Do not boost below 50 Hz, and I wouldn't boost 50 Hz by more than 3dB. At 31.5Hz cut by 6dB and below that you should be pulling the sliders fully down.

So, if I'm understanding correctly, cut 31.5 by 6db, leave 40 flat, and boost 50 by 3db? Then for everything else, converge on the 100db line (which means mostly cutting once I cross over to the DR250)?

[Dave Non-Zero]

So, if I'm understanding correctly, cut 31.5 by 6db, leave 40 flat, and boost 50 by 3db? Then for everything else, converge on the 100db line (which means mostly cutting once I cross over to the DR250)?

to me that means turning down the dr250 amp channel/xover channel to match the t39. no point in pulling down every freq above 100hz. Bill has said before i believe that you should be cutting and boosting by equal amounts around an 'average' line through the response graph. Hope that makes sense.

[David Carter]

So, if I'm understanding correctly, cut 31.5 by 6db, leave 40 flat, and boost 50 by 3db? Then for everything else, converge on the 100db line (which means mostly cutting once I cross over to the DR250)?

to me that means turning down the dr250 amp channel/xover channel to match the t39. no point in pulling down every freq above 100hz. Bill has said before i believe that you should be cutting and boosting by equal amounts around an 'average' line through the response graph. Hope that makes sense.

Makes sense. I'm still new to the top/sub and crossover stuff. My subs aren't even finished yet (still lacking handles, corners, and Duratex), and my DCX just arrived on Thursday, so I'm very much in the learning stages of getting the subs and tops to blend well with each other.

[Chris_Allen]

I got my DCX last Friday, managed to play with it last night. Fantastic piece of equipment, once I realised that the channels were muted, it was really easy to use.

Had the DEQ running pink noise through a DCX summed 35-100Hz channel to break in my BP102's for my T39s.

Chris.

[David Carter]

I got my DCX last Friday, managed to play with it last night. Fantastic piece of equipment, once I realised that the channels were muted, it was really easy to use.

Had the DEQ running pink noise through a DCX summed 35-100Hz channel to break in my BP102's for my T39s.

Yes, it is pretty simple if you know what you are trying to accomplish. The big question I have right now is that I'm only one input and two outputs, but there is no way to completely dis-associate an output from all inputs if it's unused. I'm wondering if there is any value in assigning one of the unused inputs as the source for all the unused outputs or if it's OK to leave input "A" as the source for everything and just mute the unused output channels.

[AntonZ]

If you don't use an output, I'd say it doesn't matter what gets sent to it. It will not be unhappy for having a signal that's not going to a power amp.

[David Carter]

As for crossover, the 200's like about 120Hz, the 250's go a bit lower. When I set up my 250's I started around 100 and went from there, but it's been so long since I've used them I can't recall where they ended up, seems like around 105-110. Use your ears and decide what you like. Don't forget you can change it from room to room.

For now, I settled on 109Hz as the crossover point (my DCX won't let me dial in 110Hz--it jumps from 109 to 111). What about crossover type and slope? It lets me choose L-R or But (can't recall at the moment what those stand for) and up to 48db/octave slope. I understand what the slope concept is all about, but not sure if there is an optimal number to use. Remember (if it makes any difference) I'm talking about DR250 tops and T39 subs for live band PA use.

Thanks in advance!

[wallywally]

I would use L-R 48db slope. Also make sure to use a hpf on the subs to prevent damage. On the t-39 i'd hp @35-40hz L-R 48 db slope.