AAC 320 VBR question Options

[SpyGuy]

I'm looking at buying a new head unit for my car, a Kenwood Excelon KDC-X896. According to the specs it can handle AAC-LC format from 8-320KBPS.

Here's my question. I'm using Foobar2000 to convert my lossless songs into VBR AAC at q 0.76 which is roughly 300KBPS. The thing with VBR though, is that it swings, on tough passages it might go as high as 340 or maybe even more.

So here's my question. On devices that say they can handle 320 VBR, do these spikes show up as pops or artifacts, are they just not played back for that millisecond? Do I need to find a q setting low enough so that any spikes stay below 320? Or by saying that it can handle 320 VBR, Kenwood is saying it can handle any spikes at 320 (which can go as high as nearly 380 according to some googling I do).

Apparently iPods have this same specification, 8-320kbps VBR, but I'll have to get my hands on one to see how they handle it.

[IgorC]

The mention of transparency of AAC at 150 kbps is dated by 16/10/2004
By that time the best AAC encoder (iTunes) was only CBR.

Later (14/01/2006) there was the public test which has shown that AAC was transparent at ~128 kbps (VBR)
http://listening-tests.hydrogenaudio.org/s...8-1/results.htm