As I understand it, if I add a reverb as an Insert, at 50% wet, it should sound exactly the same as the same reverb used on an FX channel as a Send, 100% wet, sent at 0db (100% full on).
Is this correct?
I’m thinking the insert version sounds different, smoother … or am I imagining this?
It depends. The reverb itself will sound the same if it is the same track type: mono/stereo. If they are different, that could be what you are hearing. The depends part will be if you used the reverb on a FX channel and you have the origin track feeding the stereo output bus simultaniously, you would still have the 50% wet reverb track but with the addition of the origin track.
In addition to all that, Pre and Post fader sends/inserts would sound different too if not at unity.
Surely the master and fx (sending at 0 db) at -6db would match the single track at 0db?
@Mosaic you understand wrong.
The signal(100%) plus FX channel is not equal
The signal(100%) divided by FX and clean.
Hope that makes sense.
Indeed which is why I suggested dropping both channels to -6db.
Indeed, just do as PappaPig says 
Always
Sorry for not acknowledging Your answer, got distracted by the math %-)
Thanks for the replies.
@peppa why -6db?
@peak … sorry, Im not understanding your comment “The signal(100%) divided by FX and clean.” ??
Because -6db is half the volume of 0db.
The mix knob serves as a kind of volume balance between the wet and dry signal.
100% dry should sound the same as if you had bypassed the reverb.
100% wet will sound the same as a 0db send if you muted the dry signal.
At 50% wet, both dry and wet signals will sound quieter compared to a 0db (100%) send. This is what’s making the reverb you’re using as an insert sound softer.
Dropping the FX return fader and the sending channel´s fader level will attenuate the FX return by 12 dB, which is no longer a 50 / 50 relation.
Yes, but i read the 0db send to mean pre fader.
Of course the db scale is logarithmic - you’d probably have to set it like this to match (track 1 and 2 playing the same audio)…
track 1 at 0db with insert reverb at 50% wet
track 2 at -3db sending (pre fader) to send fx
send fx at -3db with reverb with same settings except 100% wet.
The two should sound very, very similar (practically identical) except the stereo imaging of the reverb might change depending on your project settings.
If you use send it adds additional fx signal to the output (higher output)
If you use insert at 50% wet, it devides the signal (lower output)
Sends have the benefit that you easier can control the levels you feed the fx, and can use the output fader on the fx channel to blend in the amount you want to hear.
When using a reverb as a send I often add a stereo chorus plugin after the reverb plugin. Just dial in a tiny amount of chorus to widen the reverb. Or run amok and use pitch shifters or ring modulators
Point being, it is often more versatile to use sends.
Thanks guys for the input.
First, when I said in my original post “…the same reverb used on an FX channel as a Send, 100% wet, sent at 0db (100% full on).” : by “sent at 0db” I meant the send gain level there (the amount of send on the track send) was 0. I kept all faders at Zero, and it was post fader.
I did the -3db drop on faders of the send track (track fader -3db, and FX channel fader -3db). It was similar but not exact. Maybe its the reverb plug-in itself does not always work exactly the same each time …?