Yes exactly! But I did put IVs on top of a Pyle foam riser platform to prepare for the added bass. I live in top floor condo. After break in I can will put the IIIs back to same spot. I will let the IVs loosen up a bit like 50hrs.
Heresy IVs
Well I just put 7 hrs on the new IVs and compared to my IIIs right off the bat they seem less efficient. I had to turn up my preamp 3 clicks up to get same volume from same song. There will be more bass after woofer loosens up. Possibly a bit more details mids and highs. As someone says could be a bit more refined. Soundstage maybe a bit deeper with better layer separation but not wider. The overall character I feel is a bit leaner and dynamically constipated. Not as fun as the IIIs. When I got the IIIs I was enjoying the music right from the get go. With the IVs I’m analyzing the music more. I personally think they never should have ported speaker. But the changes in the mid driver and treble phase plug seems to be an improvement. Overall it's a lateral move doesn't kill the IIIs in my opinion.