[tseliottt]

I've had my ER4Ps for almost a decade now. They've served me well. But I've always wanted a little more bass. Back then, there were only a few options for us head-fiers. Now, it seems like there are more IEMs than headphones, and I don't know where to start.
 
So what I'm looking for is a IEM with mids and highs like the ER4P, but with detailed, high quality, rumbling bass like in the Denon D2000s. I also want them to be well detailed, and have the amazing instrument separation of the Etys. Soundstage isn't as important, but I wouldn't mind one with a deep stage. Budget is less than $600. Of course, less is always better. Thanks.

 

[ZARIM]

The CK100Pro, Sony EX1000, PFE232, RE272 and CK10 are close match to the ER4P/S qualities with good bass response and you can always add ZO in chain for better bass experience out of these IEMs. BTW HF5 or ER4P/S with orignal Sansa Fuze, Samsung P2 will produce quite good bass.

 

[kmhaynes]

Keep the ER-4P and get the ZO v.2 bass boost amp.  Save $500 off your $600 budget!

 

[ultrarider]

I've been using my ER4Ps with my Practical Devices XM6 for the past year and love the combo. The +6dB @100Hz Bass Boost button does a good job at fixing the ERPs short comings. Not to mention the 75ohm button basically turns them into the ER4S.

 

[Spyro]

Detailed, high quality rumbling bass with Ety detail does not exist in a universal.

 

[sari0n]

I believe that Unique Melody's triple BA model has a ER4 driver plus dual bass drivers, so it might have the sound that you're looking for.  I know that despite the dual bass drivers it's still fairly analytical and doesn't have a bass heavy sound signature.