CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS

Lobby => Headphone Measurements => Topic started by: Bill-p on August 11, 2015, 06:30:57 PM

Title: Oppo PM-3 measurements
Post by: Bill-p on August 11, 2015, 06:30:57 PM
Here's how this one looks like on my rig. Just the right channel since left is pretty much the same deal, just slightly off due to my poor seating skills.

Subjectively, it sounds... a lot brighter than it looks here. I almost thought I was listening to an HD800 at first, minus resolution and soundstage. After a while, the headphone calmed down (read: diaphragm loosened up), and it started sounding okay, although kinda bloated. Meh, I didn't expect awesome detail and plankton extraction out of this one anyway. HD600 is my go-to for that.

Upper mid and treble is kinda grainy.

Soundstage is pretty much non-existent. It's as closed-in as can be, though not as bad as PM-1 or PM-2.

Imaging is blurry.

It's not the furthest I have seen and heard from neutrality, but it is no where near that, either. Perhaps others heard a more neutral first version, and mine is a revision? Who knows...

Note that Innerfidelity has measurements of a second PM-3 that kinda looks like the one I just measured here, and the other pair that Tyll measured looked fantastic!

Anyway, not a lot of ways to open the innards up, but I'm seeing some potentials for front damping, and I think that's all this one will need. It's pretty close, though not quite.
Title: Re: Oppo PM-3 measurements
Post by: takato14 on August 12, 2015, 03:19:01 AM
Orthodynamic drivers tend to exert more force when they're in a sealed enclosure due to the air pressure. This will show up on square wave graphs as a severely overshot attack, a 'la LCD-XC (http://www.innerfidelity.com/images/AudezeLCDXCSample2.pdf), and IME it generally sounds quite aggressive and bright. Some other examples to note (that I've heard) are the LCD-1 (http://www.innerfidelity.com/images/AudezeLCD1.pdf) and Sony DR-Z7 (http://www.innerfidelity.com/images/SonyDRZ7.pdf), though the LCD-1 is actually open. Both of these are pretty damn bright sounding.

The smashed soundstage on the PM-3 likely amplifies this perception.
Title: Re: Oppo PM-3 measurements
Post by: Bill-p on September 02, 2015, 05:46:30 PM
Anywho, I modded this thing. Unsurprisingly. :&

Mid distortion would "seem" to be higher than stock, but if you look closely, stock measurement had higher D3/D4 contents. The environment at the time I made that measurement was noisy as hell, so... well, not very reliable. But distortion at low freqs seem genuinely improved, and I can hear this as well. It's not the best, but not bad, either.

Mid is much more even now. I brought up the 500Hz and other ranges to be about even with the peak at 2KHz. As a result, the mids are now "neutral".

Bass somehow got boosted, though whether the impact is actually that crazy is... well, I'm not sure. It doesn't sound like it has more impact than my HD600, and the HD600's graphs look a lot flatter there. This may just be a result of seal on my coupler. In practice, this headphone is now pretty close to my HD600 tonally. That's intentional since I used the HD600 as reference.

I like it a lot more now than I did when it was at stock. Maybe the extra bass emphasis is preventing it from sounding as clean as I'd like (again, using the HD600 as reference here), and the highs can use a bit more extension, but... meh. I think this is as far as I can get with front damping. I have an idea for some pad mods, but will hold off until Oppo provides spare pads for this one. I kinda like its balance as is.
Title: Re: Oppo PM-3 measurements
Post by: Armaegis on September 02, 2015, 08:10:05 PM
Did you manage to open up the cups, or did you just fiddle with front damping?
Title: Re: Oppo PM-3 measurements
Post by: TMRaven on September 02, 2015, 08:15:49 PM
I actually wish I had kept the beta version 1.  Even though it suffered a bit from lack of energy, it had a bass and lower midrange to die for.  Vocals never sounded better.
Title: Re: Oppo PM-3 measurements
Post by: Bill-p on September 02, 2015, 08:29:24 PM
Only front damping, but I think that's all this headphone needs.

I have a few ideas on how to improve bass and low mid quality, but I'll wait to implement them another day.
Title: Re: Oppo PM-3 measurements
Post by: LadyMacklebee on September 12, 2015, 05:27:07 PM
Such a wide range of opinions on these, makes me think oppo has a box of chocolates on their hands. I guess I'll just have to bite the bullet and get me a pair, but I'm actually really digging the focal pros. It took months but they are finally becoming wearable and sounding really good. Dat brain burn in brah
Title: Re: Oppo PM-3 measurements
Post by: Bill-p on September 12, 2015, 06:07:00 PM
I'd say... if you don't want to spend time modding this headphone, then even something like the ATH-M50 is easily the better recommendation from me IMO. This headphone does have the potential to be great, but its stock tuning misses the mark by quite a good margin.

So grab the Focal Spirit Pro instead. I think you'll find it to be the better choice in the long run. No need to fiddle with mods and all.

I'd actually call the Oppo PM-3 another missed opportunity by Oppo. They had something great that they could make better than the PM-1/2, and yet they seemingly can't get the tuning right.
Title: Re: Oppo PM-3 measurements
Post by: Psalmanazar on September 12, 2015, 07:55:13 PM
I'd say... if you don't want to spend time modding this headphone, then even something like the ATH-M50 is easily the better recommendation from me IMO. This headphone does have the potential to be great, but its stock tuning misses the mark by quite a good margin.

So grab the Focal Spirit Pro instead. I think you'll find it to be the better choice in the long run. No need to fiddle with mods and all.

I'd actually call the Oppo PM-3 another missed opportunity by Oppo. They had something great that they could make better than the PM-1/2, and yet they seemingly can't get the tuning right.
$400 is just too much. The PM-3 costs more and sounds worse than the competition. It's only 100 less than the Paradox too.