Lude Generation

I believe the resonatator only keeps the inlet running quiet, and wont affect performance. You will get a bit more of a throaty inlet noise with it removed, though not as loud as an aftermarket intake.
I've never used a panel filter other than an oem so cant really comment on performance. Have you done a search? I would think its been covered by others.

I thought my K&N made a difference in my 5th (has resonator). It was more noticable when I went breifly back to an OEM filter.

The filter of the K&N etc are literally a lot less restrictive than an OEM paper style filter. R&D have basically developed a happy medium between filtering and airflow.

The resonator also has a butterfly in it that opens up in the higher revs to let a bit more air flow though. (Not sure if it's in unison with the IAB's or slightly before). It helps with low end torque when it's closed and obviously higher end revs when it's opened.

Previous own got ITG to make a custom filter for my Type S. Don't know of any other lude using one but its certainly an induction kit type noise. But can't comment on performance gains.

When Mugen did an intake for the Accord Euro-R - the kit included a K&N panel filter for their carbon air box. They deleted the resonator and added a trumpet style air pipe to the bottom of the air box which hung down into the inner wing space. This space is then blocked off from the engine/radiator with an additional panel. Then cold air is ducted from the front bumper along the inside the bumper molding - and into the inner wing area. This makes the inner wing area act as the "resonator" replacement.

If a K&N filter is good enough for them, its good enough for me.

I noticed a stepped improvment in engine performance (smoother accelleration when past 3k and a lot freer breathing up the top of the rev range) as i added a panel filter and then removed the resonator.

The panel filter will allow a lot more air through for the same amount of time for sure. Removing the resonator is the single best free mod you can do the the H22 imo. For sure the car 'might' feel the tiniest little incy bit less torque'y below 3,000rpm but the difference between 5,500 and redline MORE than than makes up for it. More than.

And to be honest who the funk cares about 3000rpm and below. You only spend seconds there if you are having it If you want low end grunt buy a bimmer. you want top end screamer fun so bought a honda though. removing the resonator just makes it more fun.

2p

I definitely noticed a difference when I fitted the K&N to my UKDM last summer.

Does yours need a clean? You can buy the recharge kits.