iRig HD Latency on iMac

[Firebird967]

I have an iRig HD. It came with three cords: USB, Lightning, and 30-pin.
I use it with AmpKit.
It works fine with my 2017 iPad Pro.
It works fine with my iPad2.
On the iMac, however, it is unusable. The latency with AmpKit as at least a full second.
I tried GarageBand. Nothing but noise/feedback/distortion… you name it.
I feel like this might be a Mac issue, not an iRig issue, since it works with the two different iPads.
I have tried going into Audio Midi, but that just makes it more distorted.
I thought maybe it’s the cord, but the sound quality is fine. It’s just the latency.

What makes this more frustrating is that I used to plug a regular cord (1/4 on one end, 1/8 on the other) with no interface directly into my old Core2Duo’s mic port. It worked beautifully.
Now, I have no mic port.

Suggestions are appreciated.

iMac (Retina 5K, 27-inch, 2017)
4.2 GHz Intel Core i7
8 GB 2400 MHz DDR4

[NickHinde1958]

Hi, I don't know if this is going to be any use to you but I had same issue with Windows 10 PC. IRig 2 HD was perfect with zero detectable latency on iPhone 12 and iPad (5th Gen) but near a second on PC. I put the sample rate down from default (which I think was 2048 or 1024 from memory) to 512 (better) then 256 which is where I ended up and I cannot now detect any latency. (Its a fairly quick PC and I'm using ASIO in and out). I tried 128 sample rate but sound got crumbly. At 256 its really good.
I hope this is of some use