Denon 2106 "(pure) direct" mode question

[QubyB]

The Denon 2106 offers a setting for stereo listening called “(pure) direct” which is described in the manual as bypassing all circuitry and transmitting the input signal directly to the power amps for the “cleanest” sound. In this setting the sub can still be used if “sub yes” is selected. My question is the following.

Suppose I have set up the system with front speakers “small”, crossover at 80 Hz and the crossover on the sub at max frequency, a quite normal setup. Now I switch to “(pure) direct” with the sub on. If all circuitry is bypassed this suggests that the complete unfiltered signal is fed to the power amps, implicitly meaning speakers “large”? And also the complete signal is fed to the sub, meaning the crossover frequency at the sub is now determining the split? But since it is set at max (=120 Hz) there will be an overdose of bass since part of the spectrum is now coming from the fronts as well as the sub . This is also what I seem to hear … more bass … although it is only the part between let’s say 120 Hz (start of sub kicking in) and 40 Hz (lowest freq of fronts) which gets 3 dB extra, it is not always easy to distinguish.

Hehe, now you may ask “If it is not easy to distinguish, what is the problem?” Well, there’s not really a problem, I am just curious … want to understand how this works and the manual leaves me in the dark. If it works like I think it works it is "(pure) direct" with 40-120 Hz lifted +3dB unless I walk to my sub and adjust its crossover to 40 Hz?

Anyone out there who knows?

 

[tbewick]

'Suppose I have set up the system with front speakers “small”, crossover at 80 Hz and the crossover on the sub at max frequency, a quite normal setup.'

If you have the 'sub yes' option on, then the receiver will use a crossover and send the bass to the subwoofer.

'And also the complete signal is fed to the sub, meaning the crossover frequency at the sub is now determining the split? But since it is set at max (=120 Hz) there will be an overdose of bass since part of the spectrum is now coming from the fronts as well as the sub .'

The receiver will only send bass at the crossover you selected, that is with some kind of roll-off for the bass of the main speakers, with the sub then taking over entirely below 80 Hz. This won't be the case if the main speakers are set to 'large', then they'll get all the bass and so will the subwoofer.

The crossover setting on the sub is really there for if you don't have a receiver that has a crossover control, like a non-home theatre stereo amplifier. When you set the crossover to maximum on a receiver using a crossover, I think it just has the effect of bypassing the subwoofer's crossover. You don't need to use two crossovers to do the same thing.

'This is also what I seem to hear … more bass … although it is only the part between let’s say 120 Hz (start of sub kicking in) and 40 Hz (lowest freq of fronts) which gets 3 dB extra, it is not always easy to distinguish.'

If you have the sub turned off in the pure direct mode, then the amount of low bass depends on your main speakers and there room position. With it turned on, you should get very similar bass performance as you would get in the non-pure direct modes, unless you've adjusted the tone controls.

My view is that 'Direct/Pure Direct' modes are there more for specification listings. This allows the manufacturer to avoid giving info on the performance of the tone controls, Dolby Digital decoding performance, DTS performance etc. Amps and equipment made for the high-end market are usually more willing to provide comprehensive specifications. All this stuff about 'ultra-clean analogue pure direct modes, 96 kHz/24 bit etc..' is really just a case of marketing to audiophiles worried about tone control drift. Bypassing the tone controls will probably have a measurable objective effect, ie. maybe the signal to noise ratio will be slightly improved, but this change will probably be entirely inaudible if the tone controls are set to flat. Bypassing of the subwoofer in pure direct does make some sense if the subwoofer is poorly integrated with your mains. This maybe more noticeable on two channel stereo music than with film soundtracks.

 

[shokhead]

The Denon 2106 offers a setting for stereo listening called “(pure) direct” which is described in the manual as bypassing all circuitry and transmitting the input signal directly to the power amps for the “cleanest” sound. In this setting the sub can still be used if “sub yes” is selected. My question is the following.

Suppose I have set up the system with front speakers “small”, crossover at 80 Hz and the crossover on the sub at max frequency, a quite normal setup. Now I switch to “(pure) direct” with the sub on. If all circuitry is bypassed this suggests that the complete unfiltered signal is fed to the power amps, implicitly meaning speakers “large”? And also the complete signal is fed to the sub, meaning the crossover frequency at the sub is now determining the split? But since it is set at max (=120 Hz) there will be an overdose of bass since part of the spectrum is now coming from the fronts as well as the sub . This is also what I seem to hear … more bass … although it is only the part between let’s say 120 Hz (start of sub kicking in) and 40 Hz (lowest freq of fronts) which gets 3 dB extra, it is not always easy to distinguish.

Hehe, now you may ask “If it is not easy to distinguish, what is the problem?” Well, there’s not really a problem, I am just curious … want to understand how this works and the manual leaves me in the dark. If it works like I think it works it is "(pure) direct" with 40-120 Hz lifted +3dB unless I walk to my sub and adjust its crossover to 40 Hz?

Anyone out there who knows?

I thought it said when you use pure direct,turn your sub off. Anyway,i dont hear any difference whenever i've tried it so i dont bother anymore.

 

[MDS]

My view is that 'Direct/Pure Direct' modes are there more for specification listings. This allows the manufacturer to avoid giving info on the performance of the tone controls, Dolby Digital decoding performance, DTS performance etc. Amps and equipment made for the high-end market are usually more willing to provide comprehensive specifications. All this stuff about 'ultra-clean analogue pure direct modes, 96 kHz/24 bit etc..' is really just a case of marketing to audiophiles worried about tone control drift.

There is probably some merit to that idea. If the mode were truly 'direct' and 'bypasses all internal circuitry' as all receivers claim, then how can the xover still be used? The receiver would have to do a/d on the signal so it can apply the xover and then it isn't 'pure analog' anymore, now is it?

 

[shokhead]

It tells you to turn the sub off in order to turn off the dig circult. X over is then mute.

 

[tbewick]

There is probably some merit to that idea. If the mode were truly 'direct' and 'bypasses all internal circuitry' as all receivers claim, then how can the xover still be used? The receiver would have to do a/d on the signal so it can apply the xover and then it isn't 'pure analog' anymore, now is it?

I think the activation of the sub in pure direct mode must, rather confusingly, stop it from being pure direct anymore. Problems with subwoofers ruining two-channel sound would I think be more to do with poor subwoofer integration rather than the quality of the crossover. I mean this in the sense of getting a subjectively worsened frequency response with use of the sub, caused by the phase shift in using the sub, creating a 'bass suckout'. Having one sub positioned so that higher frequency bass modes (near the corner of the room) are excited can also make things sound bad.

I suppose that if you have some mammoth full-range speakers with really high quality amplification powering them, then using the pure direct mode would make sense. Most systems that like to show off having pure direct modes usually aren't in this league. It surely isn't much credit to the engineering of the receiver that the manufacturer feels the seemingly desperate need to bypass a lot of the pre-amp circuitry. To me, 'Pure Direct, ultra analogue,' etc. sounds more like marketing to audiophiles than anything truly useful, technically speaking. Come on, 'pure' direct?!

 

[shokhead]

Bells and whistles. How about better BM,thats what we want isnt it?