Any Beyerdynamic DT990-Pro users here? Are the new models worse?

[GotNoRice]

I have a pair of Beyerdynamic DT990-Pro 250ohm headphones that I got back in 2008 or so. I enjoyed them for those 15+ years, but they are showing their age and have developed some glitchy cable issues in addition to a deteriorating headband, earpads, etc; so I decided to just get a new pair.

I went with the DT990-Pro 250ohm Limited Edition version with the black ear-pads and the straight cable. This was mainly because I strongly prefer the straight cable (my DT770-Pro has a straight cable also).

They arrived today and I am very surprised by what I'm hearing. The DT990-Pro 250ohm Limited Edition headphones are noticeably more quiet, and significantly lacking deep bass, compared to my older DT990-Pro 250ohm headphones.

I'm powering them with a Little-Dot II+, which is an OTL Tube Headphone Amp that I've used since 2006; it's a predecessor to the current Little-Dot MKII. I've used it to power my DT990-Pro 250ohm the majority of the time that I've had them since ~2008, and it's always been a great match.

Still having my old DT990-Pro headphones in a mostly-functional state (just have to jiggle the cable sometimes), I can easily do a back and forth comparison between the new and old DT990-Pro headphones using the same amp, at the exact same volume setting, etc.

Without a doubt, the DT990-Pro 250ohm Limited Edition headphones are noticeably more quiet and lacking bass, by more than just a little bit, at the exact same volume setting. Also, at higher volume settings, it sounds almost like my headphone amplifier is soft-clipping trying to power the DT990-Pro 250ohm Limited Edition headphones, especially during deep bass. It would be tempting to suggest that these 250ohm headphones are simply difficult to power, but:
1) My OTL Tube amp actually puts out MORE power into higher impedance loads, which is why it's always done great with my DT990-Pro 250ohm headphones in the past
2) My amp has NO problem powering my old DT990-Pro 250ohm headphones.

I'm extremely confused at this point. I thought that I was basically getting a replacement of what I already had and was going for what seemed like a safe choice. How can the behavior of the two headphones be so different when they are the same model and the same impedance?

The only thing I can think of is the fresh pads on the new headphones vs the worn-in pads on the old headphones, but while I can believe that might explain some of the differences I'm hearing, I don't think it can explain all of it. The volume difference between the two models at the exact same amplifier volume setting is just too large. I have to wonder, do these new DT990-Pro 250ohm Limited Edition headphones even have the same headphone drivers in them as my old DT990-Pro 250ohm headphones? Did they do some serious cost-cutting with the new models or something?

 

[D-EJ915]

There is variance between the drivers but most likely the difference is just the pads, switch them from one to the other and they should sound fairly similar.

 

[Xstatic]

This is great info as I've been recommending these often to anyone that brings up headphones. So knowing there may be a significant difference in sound and quality is great to know.

 

[uOpt]

FWIW I have the DT-770 in both 80 ohm and 250 ohm. They sound noticeably different, with the 80 ohm having much more of a rumbling bass and the 250 being very linear to my ears. However, I don't know whether the ohmness is responsible for the difference, because the 250 ohm is much newer. If they changed manufacturing that could explain it also.

 

[Algrim]

My understanding is the DT-770 was designed around 250 Ohms and it’s why it’s more linear. I don’t know that is really the case as my wife has the 80 Ohm version that I’m currently trying to break in which sound really good to my ears, though the bass seems to be more extended than my Sennheiser 630 VB set to neutral but I think that’s related to the 770s being more closed back than the Sennheisers.

 

[GotNoRice]

After using them for over a week, I do think that the black ear pads are the main factor here. If I really push the headphones into the sides of my head, artificially compressing the pads, it actually changes the sound in a very positive way. With my old pair of DT990-Pro 250-ohm headphones, I bought fresh official replacement velour pads (grey) multiple times. The new grey pads were more stiff than the old worn grey pads of course, but there was never this pronounced of a change in sound during any of the times when I replaced my old worn grey pads. I really think that these black ear pads are different than the grey ear pads in more ways than just color. They seem stiffer, maybe a different foam inside the pad? The main result being that it keeps your headphone driver farther away from your ear.

I can't say that I'm super thrilled, but I hope it will get better as the pads continue to break in, and then at some point I'll eventually replace them with new grey velour pads. The black pads are very comfortable at least, and I am curious how quickly they will wear out compared to the grey pads.

 

[D-EJ915]

FWIW I have the DT-770 in both 80 ohm and 250 ohm. They sound noticeably different, with the 80 ohm having much more of a rumbling bass and the 250 being very linear to my ears. However, I don't know whether the ohmness is responsible for the difference, because the 250 ohm is much newer. If they changed manufacturing that could explain it also.

Typically higher impedance = tighter bass. This is because of the damping factor being higher which gives more motor control to the driver/amplifier circuit.

https://us.kef.com/blogs/news/damping-factor-explained

Another thing to keep in mind is when the voice coil is changed on a speaker it will change the characteristics itself as well, we have this in guitar amps too where some people prefer 16 or 8 ohm drivers.

 

[uOpt]

Typically higher impedance = tighter bass. This is because of the damping factor being higher which gives more motor control to the driver/amplifier circuit.

https://us.kef.com/blogs/news/damping-factor-explained

Another thing to keep in mind is when the voice coil is changed on a speaker it will change the characteristics itself as well, we have this in guitar amps too where some people prefer 16 or 8 ohm drivers.

In guitar amps with cabinets it also plays a role that switching between 8 and 16 ohm cuts out half of the output transformer. It is nicely complicated. Thanks for the voice coil explanation.

 

[D-EJ915]

In guitar amps with cabinets it also plays a role that switching between 8 and 16 ohm cuts out half of the output transformer. It is nicely complicated. Thanks for the voice coil explanation.

yeah it gets complicated with multi-tap transformers on tubes don't correspond the same way as a usual transformerless solidstate circuit and such as well. Plus how you wire the speakers can impact the way it sounds too. I've got a Rivera KR7 and the "focus" knob is basically just a damping factor control.