DP24SD--Rec Monitor vs Playback Sound

[SocProf]

A few months ago I mentioned that the sound I was hearing while monitoring a recording on my DP24-SD was different from the sound I was hearing during playback. Some people responded that, according to the schematics, it should be the exact same sound. The analog input signal had already been converted to digital and split, with one going to the monitor output and one going to the SD card. I said I would try listening again next time I did a recording.

Today was the next time. I listened carefully while I recorded an acoustic-electric guitar + Zoom effects (effects added prior to the input) track and then played it back for comparison. I confirmed that the EQ and internal effects were off and adjusted the volume control as necessary. Here is what I concluded:

1. The two sounds are definitely different.
2. The playback sound is duller, to the point where it degraded from audiophile quality to demo quality.

Has anyone else experienced this? Is it possible I have a defective unit?

In the short term, I will try recording into my laptop with Audacity and using the DP24-SD for mastering effects. Long term, I plan to get a Model 24 unless Tascam comes out with a new line of DP units.

 

[-mjk-]

@SocProf Are your inputs assigned to the stereo bus also?

Where did you confirm that the EQ and effects were off? On the inputs or the tracks?

Also, what exactly do you mean when you say that you adjusted the volume control as necessary? Didn't the machine play the tracks back at the same volume as you heard during recording?

Unless you reset the machine back to a known (original) state, and try a brand-new recording, all you're doing is inheriting the same issue from the previous session. Reset, create a new song, route your source to a track, arm the track and bring up the fader until you hear it. Record it and play it back without touching anything else but the transport buttons. See how that sounds.

If you skip the reset, creating a new song just carries everything forward and you will not be starting from a clean session.

 

[SocProf]

Thanks for the suggestions, mjk.

While I didn't do a full reset, I did attend to the issues you mentioned. Going to the assign screen, the stereo bus assignments were empty. The only assignments were inputs A and B going into the first stereo track.

I went to mixer and saw that it had indeed remembers the last EQ setting (slight bass and treble boost) which I flattened and then turned off. And I set the effects send to off. In any case, the last effect I had used was hall reverb, which would have had an obvious sonic signature.

But I'll try the full reset and see if it sounds different.

And, yes, the play back sound was a little quieter than the monitored sound. Why this was the case, I don't know.

 

[-mjk-]

@SocProf ok, thanks for the reply. All things being equal, if you have everything reset and just a single source routed to a track, it should play back identically.

 

[SocProf]

PS How do you do a reset? All I could find in the manual was initializing the preference menu.

 

[-mjk-]

If you do a factory reset from the menu, that will do it (that is what you were referring to). After that, you have to reset your preferences in the menu. Phil has an excellent video that talks about resetting the machine to a known state by using a special song created as a reset template. I made one of those templates and I load it before creating a new song, every time. Phil's video really is worth viewing.

 

[SocProf]

Thanks again. I should probably update to the latest firmware while I'm at it. And reformat my SD card after backing up the files.

 

[Mark Richards]

SocProf,
Have you tried a simple unity gain test?

Feed stereo white noise into a Track. White noise encompasses the entire audible frequency range. The easiest available source for white noise is FM inter-station noise. Just put a mic in front of an FM radio's speaker.

Keep the Trim Knob full CW and use your mic placement and the FM radio's volume control to bring the Track Meter level to or as close to 0 dBFS with no excursion into red.

Set the Track Fader to Unity Gain - 0 dBFS position.

Set the Stereo Master Fader to Unity Gain (all the way up).

Set the Track pan full left.

The Stereo Master Meter and the Track Meter should read identically.

Monitor/listen to the white noise long enough to familiarize yourself with the sound.

Record about 15 seconds of the white noise.

Rewind and play back.

The Stereo Master Fader should read exactly the same as it did before hitting record. The audio should sound exactly the same as it did before hitting record.

Play back the recorded sound over your monitors and play the radio's inter-station noise at the same time and at the same level. They should sound identical.

You can also use a free SPL (sound pressure level) smartphone app to measure the audio level of each at the speaker to be sure the audio levels are identical. If they aren't, adjust amplifier volume controls until they are.

 

[SocProf]

Thanks, Mark. I have a synthesizer with a white noise generator that should work for this.