SFZ multi-instancing causes VU Overload by 76 Db

We need more info about the computer and the sound card. Also let us know what the operating system is..... XP, Vista, etc.... I don't know what DFD mode is. 

In MC4 I used to use SFZ a lot. But I stopped using it totally when I got the Cakewalk Sound Center (CSC)  in MC5 (MC6 also has it) since it was backward compatible and it had samples that sounded so much better than the ones I was using in SFZ. 

Try loading the CSC and experiment with it. I think you will find it sounds better. 

When you say the VU meter jumps to +76db.... are you referring to the tracks or the master buss VU?   Remember in the master buss, things do tend to become a bit cumulative.... so it is often necessary to lower the individual track levels a bit to compensate for that occurrence. 

In the last line you mention dropped notes.... this is a classic symptom of using a factory sound card. It can not handle the midi calculations needed to render the music in real time as the project plays. THis could also explain the db levels being crazy with 2 instances of SFZ running.  

I have used SFZ in the past and had multiple instances of it in the project AND running in real time....problem free, BUT, I also was, and continue to use a dedicated soundcard/interface that is designed to do music professionally. Using a dedicated music interface is often the solution to the problems you are describing.  M-audio, Presonus, Focusrite, are some of the better USB based ones on the market which use ASIO drivers and perform exceptionally well.

A work around for now, would be to freeze the track... this process of freezing converts the midi & synth to an audio track eliminating the need for the real time conversion..... and generally you can play several audio tracks without to many problems on a factory sound card. 

But ...... if you are serious about recording and working with music in MC6, you will certainly want to start looking for a better USB interface to use. 

I use a Focusrite Saffire interface. It has the 5 pin midi jack as well as the audio inputs for 2 channels. 

M-audio has some nice audio interfaces, as do Presonus and Focusrite. Most are priced under $250.  If you work with midi mostly, a simple 2 channel audio interface will work well and save you money...... I would buy one that also supports the 5 pin midi jack...... 

This one would work well>>>>  http://www.m-audio.com/pr...n_us/FastTrackPro.html 

If you live close to a Sam Ash or Guitar Center, go and visit their pro audio section and talk with the guys there.....also you can call some of the online stores and chat on the net..... see what they recommend and then, after gathering the info, decide which one is best suited to you and your budget and needs.... then, and only then, spend the money. 

It all depends on what you need to compose. If it's just you, working alone just about any nice USB based interface will do the job. 

Does the keyboard you use have a normal 5 pin midi jack or does it use a USB port?  If the keyboard/controller has a USB port, you do not need to spend the money on an interface with a midi jack on it. 

The interface will be the soundcard through which your software processes the midi into music in real time. It will do a much better job with ASIO drivers than the factory card could ever do. You should easily be able to run multiple soft synths (the actual number will depend to a large degree on the computer's processing power and speed and memory size) Assuming a relatively modern computer with sufficient memory and processing power & speed, you can run several instances of some of the biggest synths and a bunch of FX as well,  with no noticeable latency in the sound. Anything under 10ms is good and just about impossible to hear. Most interfaces will easily deliver that and lower.... I think I'm running about 8ms on a bad day. For me, latency is not a problem. 

Even though I have a really nice interface......One thing that I do is to bounce the synths to audio (or freeze them until I bounce) once I get the tracks right. This reduces the processing of that synth and lets the processor work on other things. 

The thing to keep in mind would be the midi import method. If everything is USB you don't need the midi port on the interface that's fine, BUT.... if someone comes over to your studio and has a drum kit or a synth keyboard that uses the 5 pin midi port, you will need to have an interface with that matching 5 pin jack.....so I would probably recommend that just to play it safe, plan to get an interface that supports that 5 pin connector even if you don't see a need for it right now. 

yes, the Roland Mobile Studio Canvas  is a synth AND a soundcard according to the specs on the roland website.

I don't know why your meters would be peaking like that.  I haven't used SFZ in several years myself.  there just aren't enough quality instruments for it, IMO.

personally I would tend to lean toward blaming the soundfonts before I'd blame SFZ.  SFZ is a very mature product and I'm certain that problem doesn't exist often or it would have been fixed long before now.