Confused about MPT

[HarrySound]

Can I just ask should I use MPT or non-MPT IRs?
Is this correct...

1) For use inside the box (Axe FX) use MPT

2)for any kind of IR mixing like Cablab or using stereo cab blocks then use non-MPT

?

 

[PumpkinKing86]

I think you wanna use MPT IRs when mixing different IRs (especially from different manufacturers) to prevent that hollow-sounding phase effect. If you're just using a single IR in your cab block, then I suppose it wouldn't matter if it were MPT or not.

I'm sure brighter minds will chime in.

 

[HarrySound]

See that's wierd then.
if that is the case then why include non-MPT IRs and potentially take away the ability to mix them properly.
Confused.....

 

[barhrecords]

See that's wierd then.
if that is the case then why include non-MPT IRs and potentially take away the ability to mix them properly.
Confused.....

I believe the purpose of Minimum Phase Transform in regards to Fractal IR's, is to allow IR's to be mixed and matched with fewer comb filtering side effects.

If you are not mixing IR's, the non-MPT can be desirable since they ostensibly represent the original intent of the IR creator. I.e. "unprocessed".

From some IR makers, I find the non-MPT IR's to sound better to me. But personal taste is at play.

 

[HarrySound]

That's great. I will probably never mix IRs in the box. In fact I've only done it a handful of times in cablab.
I fancy having a clear out of my IRs so I'll try and keep them to a minimum and use non-MPT

 

[axifist]

[...] the non-MPT can be desirable since they ostensibly represent the original intent of the IR creator. I.e. "unprocessed".

The question is, what exactly does e.g. CabLab when it processes IRs to be MPT? For all I know it only cuts out a bit of the silent beginning of the file so the peak sits at the same point on the timeline for every IR. This has different lengths for different raw IRs because of different distances of mics to the speaker. If my thinking is correct, there shouldn't be any audible difference. Sure, it's processed, but digitally processed, which doesn't introduce any changes except of the lost phase information.

 

[barhrecords]

The question is, what exactly does e.g. CabLab when it processes IRs to be MPT? For all I know it only cuts out a bit of the silent beginning of the file so the peak sits at the same point on the timeline for every IR. This has different lengths for different raw IRs because of different distances of mics to the speaker. If my thinking is correct, there shouldn't be any audible difference. Sure, it's processed, but digitally processed, which doesn't introduce any changes except of the lost phase information.

You can Google minimum phase transform and see explanations and the math. IIRC Cab Lab is doing a straight up mathematical minimum phase transform.

 

[HarrySound]

Last night I deleted all of my IRs and then converted the 200ms folders to Fractal format WITHOUT auto trim or MPT. I'm noticing that they are sounding more organic now. Obviously they are all ultra res too, something I had a problem nailing down during the conversion before hand.

Excited to get home and play again!