BFD Connectivity

**gharnden** · **02-06-08, 10:50 AM**

Hi all!

I'm a newbie to this forum but have been doing a lot of work on my media room to improve the audio. The size of my room is 13' x 16' x 9' and, as you can surmise, I have some huge room resonances in the 35hz - 36hz range and the room is pretty boomy. Plus, I'm losing out on the 60hz - 80hz range. I've done plenty of playing with sub position using measurements out of RoomEQ and have the frequencies tamed as well as I think I can.

So, now looking at using equalization to get things the rest of the way under control. I have a DIY acoustic panel project underway that will put super chunk bass traps in the front two corners, 2" panels at the first reflection points on the side walls, and 4" panels on the back wall to both absorb and break up the flat wall. However, I'm pretty confident from everything I'm reading that these panels aren't going to be enough.

The key for me now is to ensure that I'm not going to run into connectivity problems with a BFD. My equipment consists of:
Denon AVR-5800
Sony BD-1 Blu-ray
Sony SCD-555ES (SACD Changer)
Sonus Faber Grand Piano Home (L/R)
Sonus Faber Solo Home (C)
Sonus Faber Wall Home (SL/SR)
REL Strata III

Connections into the Denon for music are through the EXT-IN jacks that don't provide for any bass management since I listen to a lot of SACD and don't have the option of passing the signal to the Denon digitally. Connections into the Denon for movies are through digital coax and bass management functionality is available. Based on these two connections, I have the REL connected both high and low level - the high level is through the neutrik connection that REL provides. Plus, since I'm using the high-level connection to the REL I'm passing a full-range signal through the Denon to the mains.

My question is how I could best connect the BFD to tame low frequencies in both the sub and the mains.

Looking forward to some answers cause my finger is on the trigger to order the DSP1124P.

Thanks in advance.

**Wayne A. Pflughaupt** · **02-06-08, 11:36 AM**

First, welcome to the Forum!

Not sure I get how the high/low level connections are working for you. Which is for movies, and which is for SACD?

Quote:

My question is how I could best connect the BFD to tame low frequencies in both the sub and the mains.

The BFD won’t work on the mains unless it’s connected in front of the amplifier – just as with a powered subwoofer. However, you don’t want the BFD in your main-channels signal chain. It’s know to degrade sound.

Regards,
Wayne

**gharnden** · **02-06-08, 11:43 AM**

The low-level is for movies since the connection from the source through the amp is made digitally. The high-level is for music since the connection from the source (SACD) through the amp is made analogue with no option for bass management.

Having the connection high-level for music is why the speakers are set to full-range in the receiver to ensure that low frequency info is sent out through the speaker terminals and can be passed on to the sub.

**brucek** · **02-06-08, 12:18 PM**

Question: Is the line level subwoofer output from the receiver active (full range or otherwise) when you select the EXT-IN for SACD?

brucek

**gharnden** · **02-06-08, 12:42 PM**

As it turns out, according to the Denon manual, signals that are input through the EXT-IN SW jack on the 5800 are passed through to the PRE OUT SW jack.

So, this would seem to indicate that even though I have to use the EXT-IN jacks for SACD playback, the subwoofer signal coming out of the SACD player and going into the EXT-IN jack is simply being passed through to the PRE OUT SW jack as though it had come in digitally.

If I'm reading this right, then I'm guessing that I can simply route the line out from the PRE OUT SW through the BFD and then into the sub regardless of whether I'm listening to music or movies.

Sound right?

**brucek** · **02-06-08, 12:52 PM**

Quote:

Sound right?

Yep, that was what I was getting at.

But, the rub is that the mains would be full range when using EXT-IN (is that correct?), and if so, then you may need to use a different program in the BFD for music and HT.

The HT program filters would be set up with the mains utilizing full bass management, but the music program filters might have to account for the different natural full range roll off of the mains. No big deal to have two programs in the BFD though (if it's needed).

brucek

**gharnden** · **02-06-08, 01:14 PM**

Ok - I see where you're going. And you're right, if I'm listening through the EXT-IN then the mains are going to be full range.

So, now I have two questions that I'm not sure I have a good answer for.

First, the only time I'm going to get a signal for the sub out of the PRE OUT SW jack when using the EXT-IN is if there is a signal coming in on the EXT-IN SW channel. For multi-channel music that works fine. However, for normal 2 channel music nothing is going to get output to the sub b/c nothing is coming in on the EXT-IN SW channel. That is the reason for having the high-level connection to the sub - so I can leverage the sub for enhanced bass output on standard 2 channel music. It seems as though I'm going to lose the sub for 2 channel output unless I can figure out how to run it through the BFD - right?

Second, if I was going to handle the mains full-range capability on the EXT-IN would it make more sense to have a second BFD in place in front of the L/R EXT-IN inputs that i can apply the same / similar low-frequency filtering since I still really have limited bass management coming out of the SACD player?

Thoughts?

**brucek** · **02-06-08, 01:40 PM**

Quote:

However, for normal 2 channel music nothing is going to get output to the sub b/c nothing is coming in on the EXT-IN SW channel.

Ahh OK, I thought the SACD might be providing a full range mix of left plus right on the SUB out of the SACD for you to do what you pleased, but I guess not - so that's a problem indeed. I really don't see any easy way around it.
I solve that problem myself by feeding the two channel analog output of my SACD to an analog AUX input of my processor, which in bypass mode provides a full range analog mix of the left plus right output at the subwoofer jack to do with what you like. I guess your processor doesn't do that?

Quote:

would it make more sense to have a second BFD in place in front of the L/R EXT-IN inputs that i can apply the same / similar low-frequency filtering since I still really have limited bass management coming out of the SACD player?

No, it wouldn't make sense at all. Your reason to own an SACD is for its resolution. You're going to pass that pristine signal through a $100 budget digitizing device like a BFD? Shame on you..

A BFD is suitable for sub duties only......

brucek

**gharnden** · **02-06-08, 01:55 PM**

Quote:

brucek wrote:

Ahh OK, I thought the SACD might be providing a full range mix of left plus right on the SUB out of the SACD for you to do what you pleased, but I guess not - so that's a problem indeed. I really don't see any easy way around it.
I solve that problem myself by feeding the two channel analog output of my SACD to an analog AUX input of my processor, which in bypass mode provides a full range analog mix of the left plus right output at the subwoofer jack to do with what you like. I guess your processor doesn't do that?

Not that I'm aware of - but I can assure you after hearing what yours can do I'll be doing some more research. The other option I considered was to connect the SACD to the receiver using a coax digital connection that could be used much the same as you have done with your AUX input so that 2 channel could be routed digitally and then take advantage of processing in the digital domain - such as speaker sizing and routing of low frequency to the sub.

Quote:

brucek wrote:

No, it wouldn't make sense at all. Your reason to own an SACD is for its resolution. You're going to pass that pristine signal through a $100 budget digitizing device like a BFD? Shame on you..

A BFD is suitable for sub duties only......

Ok, ok - fair enough! Just figured that maybe I could get away with passing the signal through as long as not filters were applied and the I would still have my "pristine signal" and just affect the low frequencies - BUMMER!

Thanks for the help. I still think this is the way I'm going to go. It may just mean an extra little bit of programming for the remote to switch the receiver around to listen to music. No big deal - that's what this hobby is for - right?

**Wayne A. Pflughaupt** · **02-06-08, 02:04 PM**

Quote:

brucek wrote:

I solve that problem myself by feeding the two channel analog output of my SACD to an analog AUX input of my processor…

Ditto that. I don’t see any good reason to use two of the 6-channel outputs for stereo playback!

Regards,
Wayne

**Wayne A. Pflughaupt** · **02-06-08, 02:09 PM**

Quote:

gharnden wrote:

Just figured that maybe I could get away with passing the signal through as long as not filters were applied and the I would still have my "pristine signal" and just affect the low frequencies - BUMMER!

If you’re wanting equalization for the main channels, there are other options.

Regards,
Wayne

**gharnden** · **02-06-08, 02:09 PM**

As it turns out, the L/R 6-channel outputs actually output the same signal that would be output by the 2-channel outputs or the optical/coax outputs if the signal is not a multi-channel signal.

So, by only running the 6-channel outputs I actually save on cable.

But, as brucek as indicated, it would make sense to run more cable if I can leverage the receiver capabilities by routing the 2-channel signal differently in the receiver.

**gharnden** · **02-06-08, 02:11 PM**

Quote:

Wayne A. Pflughaupt wrote:

If you’re wanting equalization for the main channels, there are other options.

Regards,
Wayne

Ok - you've got my attention. What options do I have that could be used to manage the low frequencies of the mains without causing undue harm to the rest of the signal?

**brucek** · **02-06-08, 04:11 PM**

Quote:

it would make sense to run more cable

Yeah, I have basically the same SACD as you except it's the 777ES model. I run digital coax for DD5.1 stuff, and multichannel analog for multi-music and then two analog red/white for my two channel. Once you're into your processor with the two channel analog, so you don't chop your signal up with the processors DAC, many will allow for the analog DIRECT mode or BYPASS mode as some call it to have a signal at the sub out. Perhaps your system does....

Quote:

What options do I have

Wayne's gonna tell you (correctly) that you would need to get an analog equalizer like a RANE unit or something in the $500-$1000 range that has the same noise floor or better than the SACD unit...

brucek

**Wayne A. Pflughaupt** · **02-06-08, 06:14 PM**

Quote:

gharnden wrote:

Ok - you've got my attention. What options do I have that could be used to manage the low frequencies of the mains without causing undue harm to the rest of the signal?

Pretty much what brucek said.

First of all, an outboard equalizer has to be inserted between the pre-amp and amp. The Denon has pre-outs, but no main-ins, so that pretty much shuts you down, unless you want to spring for outboard amplification.

The next problem, if you’re really wanting only to EQ only your speaker’s woofs, is that you can’t do that unless they’re biamped. In that case, the EQ could be inserted in front of the woofer’s amp.

Since you’re interested in full-range EQ, you might want to take a peak at this thread.

Regards,
Wayne

**gharnden** · **02-06-08, 06:27 PM**

Ok - thanks to the help and advice I took the plunge this afternoon and bought a BFD.

Now I'm off to make some adjustments to the cabling to see if I can do away with the high level connectivity to the sub and work strictly off line level regardless of whether I'm listening to music or watching movies.

brucek and Wayne - many thanks for the advice. Now, stay tuned for the myriad of actual equalization and room-tuning questions that I'm sure are on their way.

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