[lejaz]

Yikes, your experience is totally different than mine. My k702 is much warmer, and the DF, which is considered 'bass light' by many here, has much better lows. Could it be the LD mkV amp? Maybe it's not meant for 25ohm phones? I'll have to check the seal.

 

[lejaz]

O.K. take what I wrote with a grain of salt. I just hooked up an impedance adapter and I'm getting somewhat better lows. There obviously has to be good synergy between the amp and the low impedance dt48's. I'm not sure if I even have the proper values of resistors in the adapter to work with the LD mkV, so I'll have to check with the manufacturer.

 

[EYEdROP]

The adaptor wont make a big change in bass, and neither will another amp. I personally dont like the adaptor. It seems to kinda smooth things over and warm the sound up too much. 
 
My only suggestion is to stop comparing them to other headphones and start listening to them by themselves for a little while and see what you think. 

 

[kool bubba ice]

With the DT48 it can be any thing..They are very hard to nail down & so damn unconventional, especially the vintage models.. It has many strength & many flaws, or at least perceived flaws.. The DT48 is very picky about upstream components but not as finicky as the 701.. With the wrong amp the 701 can literally sound like sheet.. I never had this problem with the DT48.. I heard them under whelming but never awful, unless it's the source.. Just be happy you have the 240DF & the DT48.. They compliment each other very well.. & offer a nice preference & alternative for whatever mood you are in.. I still think the new DT48e would suit you better.. I have a 120ohm adapter with my 8ohm DT48 & it's like having a tube amp.. The added weight, richness, warmth, body is all there in spades..
Quote:

Yikes, your experience is totally different than mine. My k702 is much warmer, and the DF, which is considered 'bass light' by many here, has much better lows. Could it be the LD mkV amp? Maybe it's not meant for 25ohm phones? I'll have to check the seal.

 

[lejaz]

The adapter my friend rigged up for me is open so it can easily be modified. He used alligator clips to make some of the connections so I could experiment with different resistors, and I had literally got the signal crossed inadvertently so it wasn't working correctly. Now I am noticing an improvement in the lows with the adapter. Without it they are really bad. I have to search for the exact output impedance of the mkV to see if I need to change the resistor values to get even better synergy.

 

[Soaa-]

That's odd though. Last I heard, it was better to have the output impedance as low as possible relative to the headphone's impedance. There was something called damping factor, which is the ratio between the headphone's impedance and the amp's output impedance. Supposedly, a higher damping factor improves bass response and control.
 
From what I've read, impedance matching was required back in the days of very long telephone lines, where it was important to match impedance on both ends to eliminate any feedback. The issue is non-existent on relatively much shorter headphone cables.
 
In fact, what appears to be required for the DT 48 is an amp with an output impedance that's near zero, and that has the ability to output massive amounts of current (Amperes). Sadly, I haven't found an amp that has such specs, yet. Maybe someday, if I learn more about circuitry, I could build one?

 

[lejaz]

The sum of the impedance of the headphones plus the impedance of the adapter should closely match the impedance output of the amp according to what an electrician friend tells me. So if your amp impedance is 300, you have to add an impedance adapter of around 300ohms to get the most out of your 8 ohm dt48 with that amp. With the adapter you're basically turning the dt48 into a 308ohm headphone. This is what I've been told, anyway.

 

[nilanjan]

Lejaz, your electrician friend is quite right but not in the context of headphones.
 
Matching the input impedance of the load to the output impedance of the source is necessary in electrical power transmission for maximizing power transfer and minimizing reflections from the load.
 
The ratio of the input impedance of your headphone to the output impedance of the amplifier should be as high as possible to avoid interacting with the load. I am guessing that your adapter is increasing this ratio by raising the input impedance of the headphone. This can be useful for an amplifier with a high output impedance. A guy called Paul Spelz sells such a device for loudspeakers, typically when driven by tube amplifiers. 

 

[kool bubba ice]

Interesting.
 
Quote:

Lejaz, your electrician friend is quite right but not in the context of headphones.
 
Matching the input impedance of the load to the output impedance of the source is necessary in electrical power transmission for maximizing power transfer and minimizing reflections from the load.
 
The ratio of the input impedance of your headphone to the output impedance of the amplifier should be as high as possible to avoid interacting with the load. I am guessing that your adapter is increasing this ratio by raising the input impedance of the headphone. This can be useful for an amplifier with a high output impedance. A guy called Paul Spelz sells such a device for loudspeakers, typically when driven by tube amplifiers. 

 

[lejaz]

 
Quote:

Lejaz, your electrician friend is quite right but not in the context of headphones.
 
Matching the input impedance of the load to the output impedance of the source is necessary in electrical power transmission for maximizing power transfer and minimizing reflections from the load.
 
The ratio of the input impedance of your headphone to the output impedance of the amplifier should be as high as possible to avoid interacting with the load. I am guessing that your adapter is increasing this ratio by raising the input impedance of the headphone. This can be useful for an amplifier with a high output impedance. A guy called Paul Spelz sells such a device for loudspeakers, typically when driven by tube amplifiers. 

Very helpful thanks. I can't find the specs for the LDmkV anywhere, and the manufacturer doesn't seem to have a website. I think it was designed for use with headphones with impedance between 32 and 600ohm. A three hundred ohm adapter should land my dt48e right in the middle at 325ohms.

 

[Soaa-]

Ah ha~ I just successfully recabled my DT 48. They're good as new now, with a brand new cable and a Canare 1/8" connector I got from Addison.
 
That store is great; they have plenty of parts and supplies for DIYers.

 

[kool bubba ice]

Any sound improvement? I love my futuretech 1/4 plugs.
 
Quote:

Ah ha~ I just successfully recabled my DT 48. They're good as new now, with a brand new cable and a Canare 1/8" connector I got from Addison.
 
That store is great; they have plenty of parts and supplies for DIYers.

 

[Soaa-]

I don't hear any sound improvement, other than the fact that the sound is no longer intermittent when I move my head.
 
I'm starting to think the impedance adapter didn't improve the sound either. There's no more or less bass on any of my sources whether I use it or not. Surprisingly enough, my cellphone seems to be the one giving me the best bass response. The quality of its output is, to me, indiscernible from that of my Samsung P2 media player or my laptop.
 
The issue of me not having an amp still, of course, exists.

 

[SunDevil]

Hi to all from Germany 

,
 
It's great to read so much about our oldie DT 48 E. 
 
The first DT 48 was manufactured around 1937!!

And not much has changed since than. Only some outer things have been changed, the driver is actually the same. Aluminum (no foil like most headphones) diaphragm embossed with compressed air instead of a stamp. The magnet is even also a ring (just like the Tesla drivers), no neodymium though. 
 
Concerning the marketing on the DT 48 E...honestly...there is non. It basically sells itself after so many years and is mostly known in the professional market only, since that is what the DT 48 E was designed for in the first place:
http://europe.beyerdynamic.com/shop/hah/headphones-and-headsets/studio-and-stage/studio-headphones/dt-48-e.html
 
The marketing of the DT 48 E is a future plan though, therefore I read all your posts and realize that many (relatively) of like it pretty much.
 
Many regards,

 

[Roger Strummer]

Quote:

 
 
The first DT 48 was manufactured around 1937!!
 
And not much has changed since than. Only some outer things have been changed, the driver is actually the same. Aluminum (no foil like most headphones) diaphragm embossed with compressed air instead of a stamp. The magnet is even also a ring (just like the Tesla drivers), no neodymium though. 
 

Great to read someone from Beyer posting about the DT48!
 
But one question though, what is the material (still) used for the magnet? Alnico?