I've been rocking Sennheisers for a long time, and really enjoy the 650's, but when going from my speaker setup to headphones the lack of bass sometimes really bothers me.
You might have to adjust your expectations, even if you upgrade.
First off, the
actual (upper) bass performance in speakers can be inherently stronger without much of a hit in performance (unless you run into room modes) since you have larger drivers in a larger cabinet with a tuned port and you're comparing that to a 50mm free-air driver.
Second, the
perceived bass performance in speakers is also stronger (again, unless you run into room modes; or at least, the ones that will impact the bass quantity negatively) because you have the bass soundwaves travelling through the air in the room. That it will dissipate and not be audible is offset by the fact that 1) you have a tuned port (and the possiblity that your room may be boosting the bass), 2) the frequency response variation due to distance is not exactly similar (ie moving 2m away from the speakers doesn't make you lose as much bass as pulling on a headphone cup to give it another 20mm away from your ears) and so the speakers will still have more bass, and 3) even if you're sitting at a distance where bass quantity is leveling off, what bass does make it towards you still slam your entire body, giving it more of that sensation of bass that adds to the ears. In other words, not only do speakers work very differently from headphones, but on your end, speakers is like having Dual Shock or Rumble vs the cheap pre-PS controller of the headphone.
Additionally, If you're using active speakers, then the lack of a large tower and multiple drivers (and presumably a good stereo amp or monobloc pair) will be offset by having four amp channels that even out of the box (and you have not touched) may bias the output for the midwoofer, hence you're not getting auditory masking; by contrast the headphones can only use one channel of amplification for each fullrange driver on each side (if you go for BA or hybrid DD+BA IEMs you can get one that has basically had its crossovers tuned to bias the low freq driver/s).
Third, and sort or related to the prior point, noise affects them differently. I had my Wharfedale Pi10 and HD600 in the same room and turning on the A/C didn't affect the Wharfedales that much given how I sit. When I gave up on the other acoustics issues (the soundstage was more forward on the side with the glass and concrete exterior wall) and went to headphones and rearranged the room, the seat location where my desk was was cooler since it's right on the path of the A/C, but now it's blowing onto the left earcup; turn the fan and compressor down, and what noise there is is still more audible than when I sat another 1m farther from the A/C. Basically, since there's less perceivable bass out of the headphones, it's far more vulnerable to losing to the noisefloor.
Fourth, that Beresford is a good DAC and HPamp for the price, but I wouldn't consider it amazing, so be open to upgrading that too...and maybe still not getting the bass you like because headphones and speakers work differently.
Lastly, you have to bear in mind that a lot of the reviews tend to not have background on what other systems people use or have used or have tried out, so one guy praising one headphone's bass doesn't tell you that that's all he's had apart from some live music and the occasional Audiobahn-equipped Escalade driving past. By contrast, I'm explaining all this and accepting my HD600's limitations after having had enough of the uneven soundstage in the room I moved back into after using my Wharfedale Pacific Pi10 and NAD 304 in a condo my brother and I rented near our college while I also meticulously tuned the time alignment and crossover settings so I can hear a 10in Polk Audio then later 12in JL Audio subwoofer like it's coming from the dashboard perfectly synced with my Focal 165VR midwoofers and Vifa BC25 tweeters up front. So basically you have some people who've only had headphones for serious listening, but then some guys just live with their headphones and love them for what they are...until they get into their car and the Yokohama AVS dB are still new on the car or they get a new house with a room that can get acoustic treatments all over (including covering up windows).
Is there anything out there that'd be pretty similar, but with more bass?
I listen only from my computer, Beresford 7520 DAC with swapped out opamps(don't ask me which, can't recall).
Swapping the amp isn't out of scope if it comes to that.
Audeze LCD-2 Classic.
Maybe pair that with a Meier Jazz FF or Classic FF. If the Beresford has a fixed voltage DAC output just hook that up to the Meier amp.
Would getting a hardware equalizer be a nice choice?
Hardware EQ can't really change settings like center freq and you have to pay for it because somebody had to put it together in some factory somewhere.
Software EQ can change center freq, curve type, and Q factor depending on the specific app you're using. I had this on my Android when I was using it to feed my desktop DAC via USB OTG (software issues forced me to switch to a DAP and now using its line out, then control it via remote app so it just sits next to my amp).
Band 1 : Low shelf, Q1.0, 40hz, +3dB
Band 2 : Peak, Q0.8, 3500hz, -3dB
Band 3 : High shelf, Q1.0, 5500hz, -3dB
That reduction of the 3500hz peak and the rest of the higher freqs doesn't just make for less sibilance, it also makes for less auditory masking by the higher freqs vs the bass.
