[grizzlybeast]

  SOOOO....
 
I think part of modding is knowing what volume you will be listening at. Once you turn it up past a certain level some of those frequencies push themselves past all of your materials. Well. I modded mine as well using acrylic felt and foam inside as well as studio foam over the driver hole.
 
Also the front of the driver is surrounded by this paper fiber stuff. Well I ripped that off and blocked it with rubber mouse padding that I cut up. This trapped more bass and forced it through the ports for a bit more oomph but it doesn't seem as tight, but still very good and a little more. 
 
Also the imaging is better and at regular listening levels the treble is A LOT MORE TAMED. This is magical like you said and I feel like I have a rare gem that no one has. I think I put to much felt over the covering but its less bright and still clear. I have chopped that treble down some. 

next step is to drill a bigger hole in the bass ports on the inside.

 

[AdamTR]

  SOOOO....
 
I think part of modding is knowing what volume you will be listening at. Once you turn it up past a certain level some of those frequencies push themselves past all of your materials. Well. I modded mine as well using acrylic felt and foam inside as well as studio foam over the driver hole.
 
Also the front of the driver is surrounded by this paper fiber stuff. Well I ripped that off and blocked it with rubber mouse padding that I cut up. This trapped more bass and forced it through the ports for a bit more oomph but it doesn't seem as tight, but still very good and a little more. 
 
Also the imaging is better and at regular listening levels the treble is A LOT MORE TAMED. This is magical like you said and I feel like I have a rare gem that no one has. I think I put to much felt over the covering but its less bright and still clear. I have chopped that treble down some. 

Sounds to me you made the HRM-8 !! lol 

After some comparison with the DT150 and DT250 I do notice how much highs these babies have but still like them for their detail/resolution it's one of the best I've heard so far.

 

[grizzlybeast]

  Sounds to me you made the HRM-8 !! lol 

After some comparison with the DT150 and DT250 I do notice how much highs these babies have but still like them for their detail/resolution it's one of the best I've heard so far.

pretty much bro!
 
I finished my mod and its pretty much my best headphone under 600 dollars to date. 

 

[DooberKnob]

These look interesting. Are there any measurements yet?

 

[grizzlybeast]

MODDED PIONEER HRM-7​

​

 
So these things modded are down right awesome!!! They still need a good amp pairing imo because even though I tamed some of the highs they are still prevalent. ESPECIALLY through the bright headphone out of my GEEK PULSE INFINITY. They now have more bass than my ZMF OMNI and hit harder just not as tight. 
 
Differences: More bass, less tight, more impact, less highs, less caveronous, better imaging. 
 
Things I did:
 
 
 
TRUST me I am no experienced modder but with some work I am sure you guys can do a lot better than I did. As is  I find it quite enjoyable.

 ​

• drilled bigger holes for bass ports in the top and bottom as well as inside to allow more bass flow
• cover the front holes that surround the drivers...please excuse the yucky looking glue and really rough cut of the mouse pad I used.                                                                                                                                                 
                                                                                                                                                   
• covered the front of the driver with a very roughly cut piece of studio foam                                         
• cut some acrylic felt and put a small a piece of insulation to further trim some highs down. I placed it inside of some ZMF cowhide leather pads.                                                                                                                           
• inside the cups (sorry no pics) I used some double sided adhesive foam and felt on the bare areas of the cup surfaces inside and put some rock wool insulation inside.

 

[killz4gold]

Can anyone compare them to M40X or Soundmagic HP150 or SHURE SRH840 in terms of musicality ... please
As I love SRH840 clarity and details but missing bit of warm.musicality and details on highs
 
Meanwhile Have found tech review of whole series of HRMalready posted in HRM5/6 thread)
http://prosound.ixbt.com/monitors/pioneer-hrm-6.shtml
 
HRM-7 FR:

 

[bizzazz]

I know this thread is old, but I picked up a pair of the HRM-7 for cheap on eBay during one of their coupon sales for $85. They sounded way too bright stock. All the mids just get drowned out by the highs. So I got to modding using some of the previous posts here as a rough guide.

What I ended up doing was ordering a sample pack from b-quiet. They're a car audio dampening material manufacturer much like dynamat but based in Canada. The sample pack comes with a butyl rubber based dampener and some foam based ones (along with 2 other kinds but they're not relevant for this mod). I removed the poly-fill and the felt disk from inside the cup. I replaced the felt disk with a same-sized piece of the foam dampener and replaced the poly-fill with a couple of strips of the butyl rubber dampener. I also added a piece of craft felt between the driver and the pad.

Holy crap. These cans are now my new favorite "fun" sounding headphones. The bass is tight and present, the mids are much more forward and realistic sounding, and the highs are tamed yet are still very detailed. When I want to relax and fall asleep with headphones on, I reach for my Senny Hd650. When I want to jam out to my music, these are it.

Overall, I would be happy paying $300 for these with how they sound now. For $85 and 15 minutes of modding, I feel everyone should own a pair. I've done the same mod on 2 other pairs for friends and they love them to death.

Thanks everyone who provided modding info in this thread. The HRM-7's truly are a hidden gem if you show it some modding love.

 

[Luigi Milazzo]

I've done the opposite mod in my hrm6. I was almost returning these because of the exaggerated bass that swallowed everything. Then i totally covered the bass reflex port with a plastic electric tape and BAM! The best closed i've ever owned!!!

 

[Luigi Milazzo]

Can anyone compare them to M40X or Soundmagic HP150 or SHURE SRH840 in terms of musicality ... please
As I love SRH840 clarity and details but missing bit of warm.musicality and details on highs

Meanwhile Have found tech review of whole series of HRMalready posted in HRM5/6 thread)
http://prosound.ixbt.com/monitors/pioneer-hrm-6.shtml

HRM-7 FR:

I can bet the hrm6 with the port closed are miles ahead to the 840.

 

[Mad Max]

Just got an HRM7.

Funny that someone finds it bright stock. I find it mid-centric because of the mildly anemic, moderate bass, I find the treble only slightly bright. A lttle brighter would be okay by me, and consider that I'm a long time fan of K701, SR325is, and T90.
Loving the stock sound as is. I may mod mine later when I feel like it.
Overall very balanced FR, minus the upper mids boost (nothing out of the ordinary), and quite tame in cup resonances (this helps make it well-suited to classical music and stuff many would prefer an open-back can for), so indeed a worthwhile monitoring headphone. I appreciate the lack of the awful 10kHz peak most closed-back headphones suffer from. Very consistent and even clarity throughout the audio band from subbass to upper treble, a bit of a rarity there as most headphones boast extra clarity in the highs or mids, usually the mids or just the upper mids, so HRM7 ends up sounding more coherent in a way. Then it boasts very good isolation and supreme comfort.
Awesome deal.

Get bass in a mix to sound punchy and phat through this baby and everyone else will be in for even more of a treat.

Clarity and resolution that competes with the other $200 and under monitoring closed-backs, DT770-250Ω still edges it out in resolution, but not by much. Deep bass that misses 20Hz by a hair, an upgrade cable will be just enough to give it that tiny boost it needs to hit 20Hz if burn-in doesn't do it, I expect.

Edit: now comparing to my K553 which sounds even more tonally balanced, K553 is noticeably more opaque to the sound than HRM7 is, and HRM7's soundstage just makes K553 look more terrible in that aspect than it already is. HRM7's soundstage is far deeper with far better imaging and layering of the sound, fully besting even my modified DT770 in this aspect (whoa). HRM7's soundstage even has a very "natural" feel to it, something I've only heard in my HD25 so far.
I definitely consider this the very best of the $200-and-under closed-back headphones, it just beats them all at everything with very few exceptions as far as individual, specific aspects of sound here and there. My modified K553 is still a really nice "magnifying glass" into bass, better than anything I've heard, even my modified K701 with EQ or HD8 DJ don't quite beat it at that.
HRM7 is now my reference closed-back for the time being. Just wow.
Most audiophile as well as most mixing-worthy in this price range.

Build quality seems also very top-notch. DT770-tier, a freaking tank. If it does have an Achilles' heel, it might be the two plastic blocks that hold the headband together, but only time and use will tell.

 

[audiophizile]

Just got an HRM7.

Funny that someone finds it bright stock. I find it mid-centric because of the mildly anemic, moderate bass, I find the treble only slightly bright. A lttle brighter would be okay by me, and consider that I'm a long time fan of K701, SR325is, and T90.
Loving the stock sound as is. I may mod mine later when I feel like it.
Overall very balanced FR, minus the upper mids boost (nothing out of the ordinary), and quite tame in cup resonances (this helps make it well-suited to classical music and stuff many would prefer an open-back can for), so indeed a worthwhile monitoring headphone. I appreciate the lack of the awful 10kHz peak most closed-back headphones suffer from. Very consistent and even clarity throughout the audio band from subbass to upper treble, a bit of a rarity there as most headphones boast extra clarity in the highs or mids, usually the mids or just the upper mids, so HRM7 ends up sounding more coherent in a way. Then it boasts very good isolation and supreme comfort.
Awesome deal.

Get bass in a mix to sound punchy and phat through this baby and everyone else will be in for even more of a treat.

Clarity and resolution that competes with the other $200 and under monitoring closed-backs, DT770-250Ω still edges it out in resolution, but not by much. Deep bass that misses 20Hz by a hair, an upgrade cable will be just enough to give it that tiny boost it needs to hit 20Hz if burn-in doesn't do it, I expect.

Edit: now comparing to my K553 which sounds even more tonally balanced, K553 is noticeably more opaque to the sound than HRM7 is, and HRM7's soundstage just makes K553 look more terrible in that aspect than it already is. HRM7's soundstage is far deeper with far better imaging and layering of the sound, fully besting even my modified DT770 in this aspect (whoa). HRM7's soundstage even has a very "natural" feel to it, something I've only heard in my HD25 so far.
I definitely consider this the very best of the $200-and-under closed-back headphones, it just beats them all at everything with very few exceptions as far as individual, specific aspects of sound here and there. My modified K553 is still a really nice "magnifying glass" into bass, better than anything I've heard, even my modified K701 with EQ or HD8 DJ don't quite beat it at that.
HRM7 is now my reference closed-back for the time being. Just wow.
Most audiophile as well as most mixing-worthy in this price range.

Build quality seems also very top-notch. DT770-tier, a freaking tank. If it does have an Achilles' heel, it might be the two plastic blocks that hold the headband together, but only time and use will tell.

I've owned the 553 and enjoyed them. They ended breaking in multiple ways and had to scrap them. Was looking at hrm7, the dt770 250ohm, 553 mkii and the t40rp mk3. My biggest issue with 553 was that the highs sounded sightly veiled. They had decent detail but those details sounded sightly soft? I'm not a bass head but do like some dynamics. Clarity, separation, and speed are important to me. Thoughts?

 

[Mad Max]

553 MKII, because you want speed and details, but the stock earpads hurt bass and treble clarity, I recommend using oval brainwavz pads for best sound, not the circular XL pads, the oval pads have a bigger ear opening and that matters. I also strongly recommend fiberfill and transpore tape to bring out the full resolution of K553. Alternatively, if you don't mind going open-back instead and sacrificing some subbass and neutral-ness, consider ATH-AD900x, it kills all of these headphones in details and speed, but the stock earpads are a goofed up design that AT went for for unknown reasons, I don't recommend them without tweaking.

 

[audiophizile]

553 MKII, because you want speed and details, but the stock earpads hurt bass and treble clarity, I recommend using oval brainwavz pads for best sound, not the circular XL pads, the oval pads have a bigger ear opening and that matters. I also strongly recommend fiberfill and transpore tape to bring out the full resolution of K553. Alternatively, if you don't mind going open-back instead and sacrificing some subbass and neutral-ness, consider ATH-AD900x, it kills all of these headphones in details and speed, but the stock earpads are a goofed up design that AT went for for unknown reasons, I don't recommend them without tweaking.

No open back possible but I appreciate all of the info! I heard the angled oval pads are good?

 

[Josz27]

Just got an HRM7.

Funny that someone finds it bright stock. I find it mid-centric because of the mildly anemic, moderate bass, I find the treble only slightly bright. A lttle brighter would be okay by me, and consider that I'm a long time fan of K701, SR325is, and T90.
Loving the stock sound as is. I may mod mine later when I feel like it.
Overall very balanced FR, minus the upper mids boost (nothing out of the ordinary), and quite tame in cup resonances (this helps make it well-suited to classical music and stuff many would prefer an open-back can for), so indeed a worthwhile monitoring headphone. I appreciate the lack of the awful 10kHz peak most closed-back headphones suffer from. Very consistent and even clarity throughout the audio band from subbass to upper treble, a bit of a rarity there as most headphones boast extra clarity in the highs or mids, usually the mids or just the upper mids, so HRM7 ends up sounding more coherent in a way. Then it boasts very good isolation and supreme comfort.
Awesome deal.

Get bass in a mix to sound punchy and phat through this baby and everyone else will be in for even more of a treat.

Clarity and resolution that competes with the other $200 and under monitoring closed-backs, DT770-250Ω still edges it out in resolution, but not by much. Deep bass that misses 20Hz by a hair, an upgrade cable will be just enough to give it that tiny boost it needs to hit 20Hz if burn-in doesn't do it, I expect.

Edit: now comparing to my K553 which sounds even more tonally balanced, K553 is noticeably more opaque to the sound than HRM7 is, and HRM7's soundstage just makes K553 look more terrible in that aspect than it already is. HRM7's soundstage is far deeper with far better imaging and layering of the sound, fully besting even my modified DT770 in this aspect (whoa). HRM7's soundstage even has a very "natural" feel to it, something I've only heard in my HD25 so far.
I definitely consider this the very best of the $200-and-under closed-back headphones, it just beats them all at everything with very few exceptions as far as individual, specific aspects of sound here and there. My modified K553 is still a really nice "magnifying glass" into bass, better than anything I've heard, even my modified K701 with EQ or HD8 DJ don't quite beat it at that.
HRM7 is now my reference closed-back for the time being. Just wow.
Most audiophile as well as most mixing-worthy in this price range.

Build quality seems also very top-notch. DT770-tier, a freaking tank. If it does have an Achilles' heel, it might be the two plastic blocks that hold the headband together, but only time and use will tell.

What a surprise, I have AKG K553 mkii and I don't find them veiled, I would say they are crystal clear, they have decent dynamics and have an outstanding soundstage size for a closed back, very good imaging.
I would say that k553 mk ii treble is generally even more clear than stock ad900x, which is significantly more clear than hd 598 treble, are you sure you don't get issues with the fit of the earpads of the akg?

 

[Mad Max]

What a surprise, I have AKG K553 mkii and I don't find them veiled, I would say they are crystal clear, they have decent dynamics and have an outstanding soundstage size for a closed back, very good imaging.
I would say that k553 mk ii treble is generally even more clear than stock ad900x, which is significantly more clear than hd 598 treble, are you sure you don't get issues with the fit of the earpads of the akg?

I still have my K553, my latest mod to it improves the soundstaging dramatically, though it remains unextraordinary, definitely won't become a gaming-worthy can by any stretch. I have never found the 553 to sound veiled, Sennheiser's HD6MIX and the old Beyerdynamic DT440 do, as examples.
Stock HD598 and AD900x don't have good treble clarity due to some fundamental design flaws (inadequate plastic housing for the Senn and non-perforated earpads for the ATH) so that's easy to outdo. No fit issues for me, a poor seal helps clarity and detail a bit, if anything, but at the cost of bass. I use Brainwavz oval earpads, which retain the original sound signature while improving bass and treble clarity and control, but this causes discomfort for some folks depending on their sensitivity to the 10kHz treble peak, which the original AKG pads muffle. The good clarity only gets better if you are not too sensitive to the 10kHz peak. No matter what is done to it, transparency remains a bit low for closed-back at this pricepoint, it is kind of opaque versus HRM7, DT770, Pro7x, K371, and a few others.