FBQ2496 Problems need help?

**golfman** · **01-07-09, 03:33 AM**

I just received my 2496 today hooked it up as per the instructions on this forum. I took sub out rca from the receiver converted to 1/4 jack and plug it into the output on the back of 2496 marked right channel. I bought a single rca cable converted it to 1/4 jack and plugit from the right input channel of the 2496 back to the sub preout on the reciever. First issue is I get no level output from the front display on the 2496, second problem is no signal is coming through to the subwoofer unless I hit the bypass button on the 2496. Also when I do hit the bypass button I get a hum at 60hz. Last but not least the midi connection says it is outputing from the computer but the midi light isn't lighting up on the 2496. So it appears that no filters are getting loaded from the REW. I think this thing is broke.

I tried pretty much everything to get it to work. I aslo verified that the midi is on and on channel number one.

Any help or thoughts would be great.

Thanks

**grn1969c10** · **01-07-09, 06:10 AM**

Quote:

I took sub out rca from the receiver converted to 1/4 jack and plug it into the output on the back of 2496 marked right channel. I bought a single rca cable converted it to 1/4 jack and plugit from the right input channel of the 2496 back to the sub preout on the reciever.

I didn't follow how you made your connections. If the 2496 is similar to my DSP1124, you would connect the receiver's RCA sub-out to a 1/4" input of the 2496. (You can use either the left or right channel of the 2496, it doesn't matter.) The 1/4" output of the 2496 would then be connected to the RCA input of your subwoofer.

I have never used the midi connections, so I can't help you there. The hum is usually related to a ground loop issue. When it's humming, try disconnecting your TV coax cable from the wall and see if the humming stops. If it does, an isolation transformer might solve it. My buzzing diminished, but did not completely stop; so as a quick fix, I used a 3 prong to 2 prong power plug adapter (Ground lift) on my sub.

**Wayne A. Pflughaupt** · **01-07-09, 09:47 AM**

If I read your post right, you connected a cable from the receiver’s sub output to the 2496’s right channel output? And then from the 2496’s right input back to the receiver’s sub output?

In-line connections between components will always be: output -> input/output -> input.

This pic shows the correct connections for a receiver to BFD to sub. (Ignore the cabling for sound card and SPL meter).

Regards,
Wayne

**golfman** · **01-07-09, 09:48 AM**

I think we are saying the same thing, I connected a rca cable from my reciever's sub out to the input on the 2496 using a 1/4" adapter on one end. Then I connect another rca with an 1/4" adapater on one end to the output of the 2496 and the other end to the LFE channel of the subwoofer itself. I get no level display on the front of the 2496, I even switched the connections just to see if I did it wrong and it didn't make a difference.

**golfman** · **01-07-09, 10:08 AM**

Yes this is what I did, receiver sub out to 2496 input and 2496 output to the subwoofer LFE input.

**brucek** · **01-07-09, 10:38 AM**

Well, you have said that when you engage the bypass button the sub works, so I can conclude it's hooked up correctly.... (you can work on the hum problem later).

You either have a faulty unit, or you haven't set something correctly. Read the manual and play with the front panel and see if you can get anywhere.....

brucek

**golfman** · **01-07-09, 03:11 PM**

I noticed that I am using 1/4" stereo adapters to rca instead of mono 1/4" adapter to rca. could that be my problem?

**brucek** · **01-07-09, 03:43 PM**

Quote:

could that be my problem?

Yes, they must be mono to short the negative differential amp to ground inside the BFD (unless you modify the stereo TRS yourself)...

brucek

**golfman** · **01-07-09, 04:44 PM**

That was the problem, I have signal now. I also have a nice hum. I guess that is my next task to complete. Any great suggestions, I haven't done much research on this yet.

**brucek** · **01-07-09, 05:16 PM**

Quote:

Any great suggestions

Lot's of reading to do here.........

**golfman** · **01-07-09, 11:45 PM**

I got everything working now. My question is now after reading the BFD pages on the forum, it talks about setting the input level on the BFD. I used audessy to set all the levels originally before adding the BFD. My sub level is set to -11 db right now in the receiver. I looked at the input level with the BFD in bypass mode and they don't quite get to the yellow level on deep bass. Should I change the DB level for the sub in the receiver? If I do that won't I have to rerun the REW again because of the change and apply all new filters? It also says you can adjust the sub level directly at the sub after you make your corrections with the BFD. Won't that change the adjustments as well?

One final question do you have to have the in/out button onthe BFD for the filters to be active?

Here is a graph with the BFD hookup and the in/out button on?
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**Wayne A. Pflughaupt** · **01-08-09, 10:06 AM**

The level you’re getting on the BFD is fine. It’s not imperative to “top out” the meters; a little headroom is never a bad thing.

Adjusting the sub’s level to blend with the mains does not mean you need new filters for the BFD. A specific level is needed only as a reference point for the initial equalization; after than you can raise or lower the sub level as needed.

Quote:

One final question do you have to have the in/out button onthe BFD for the filters to be active?

I’ve never used the FBQ, but every equalizer I’ve ever seen has an “on/off” button of some kind. The “off” position bypasses the filters.

Quote:

Here is a graph with the BFD hookup and the in/out button on?

Looks good. How does it sound?

Regards,
Wayne

**golfman** · **01-08-09, 01:13 PM**

It's sounds good I think the bass is really clean now, no muddy or bumpy sound through the movie.
Here is what I did exactly to set this up.
1. I used audessy configuration in my onkyo 706 receiver to set speaker levels, distance, crossover points.
2. used my SPL meter to measure 75db at the "best seat" of my theater using test tones from the receiver. I tweaked the audessy setings to make this happen.
3. I disconnected my front speakers and ran the REW on my 2 subs. I set the receiver level at the "best seat" to read 75db on my spl meter and calibrated the REW program to my meter.
4. I ran the subwoofer test tone from REW, than I ran set target level test. I ran the find filters and apply filters , optimized gain PK and Q, adjust PK gains.
5. manually enter the filters into the BFD.
6. pushed the in/out button to stay lit.
Thats it, I hope I did it correctly.
So I guess I can now adjust the subwoofer gain at each subwoofer if I want more bass response without effecting the setting of everything?

**golfman** · **01-08-09, 01:13 PM**

Check the graph below.

**golfman** · **01-08-09, 01:26 PM**

here is a graph of my subs and mains. I didn't change the subwoofer speaker type to full range so I am not sure how good this graph is. Maybe someone can let me know how much that effects the graph?
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Name: graph17.jpg
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**brucek** · **01-08-09, 03:16 PM**

Quote:

Maybe someone can let me know how much that effects the graph?

It doesn't in the case when you are measuring a subwoofer with the mains added in the 0-200Hz range - so you're fine...

brucek

**golfman** · **01-08-09, 04:13 PM**

Does the mains and sub look correct then, or do I need additional level adjustments? Thanks everyone for all the help you guys have provided.

**Wayne A. Pflughaupt** · **01-08-09, 04:33 PM**

Hard to tell when the mains are limited to 200 Hz, but the subs might be a bit low. How does it sound?

Regards,
Wayne

**golfman** · **01-08-09, 05:06 PM**

Quote:

Wayne A. Pflughaupt wrote:

Hard to tell when the mains are limited to 200 Hz, but the subs might be a bit low. How does it sound?

Regards,
Wayne

subs are bit low? So are you saying I need to raise the gain on the subs or do I need to make a change to the sub level in the receiver?

**Wayne A. Pflughaupt** · **01-08-09, 05:20 PM**

Either way is fine, as long as the latter doesn't send the BFD's meters into clipping.

But like I said, this is better determined with a full range response graph. For instance, if across-the-board response above 200 Hz is lower than what we see here, then the sub/mains level might be just right. If it's higher, then the sub level would need to be brought up quite a bit.

Regards,
Wayne

**golfman** · **01-08-09, 07:03 PM**

Here is a graph of full range test of mains and subs. Do the levels look ok?
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Here is mains and subs at reference level 0.0 db on receiver.
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**brucek** · **01-08-09, 07:29 PM**

What mic are you using?

brucek

**golfman** · **01-08-09, 07:45 PM**

radio shack 4055 spl meter. not the best but I already owned it. I loaded the calibration file before testing. I wonder why I have a big hole now at 23 hz when I turn it up to reference level and why my low end bass below 20 hz comes up, also I wonder if I crossover the sub at say 90 or 100hz and raised the crossover on the other soeakers to 100hz if it would fix that hole?

**brucek** · **01-08-09, 10:59 PM**

Quote:

radio shack 4055 spl meter

The upper limit accuracy of a Radio Shack meter is ~3KHz. If you want to measure full range you will require a better meter or microphone (i.e. Galaxy CM-140 or ECM8000 with preamp).

brucek

**golfman** · **01-08-09, 11:10 PM**

Quote:

brucek wrote:

The upper limit accuracy of a Radio Shack meter is ~3KHz. If you want to measure full range you will require a better meter or microphone (i.e. Galaxy CM-140 or ECM8000 with preamp).

brucek

Ya I probably should, but I am more concerned with the sub eq and matching up the main levels at this point. I posted the full frequency to show that my bass level matched up with the mains. Do you know why I have developed a drop around 23hz when listening at reference level.
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