Sennheiser HD 600 Impressions Thread
Jul 20, 2020 at 4:17 PM Post #20,761 of 23,416
Wow, cool explosion here... 600 is great, esp with a real cable, and a little felt and dynamat on the back. Some may not believe it but the bass has some extra resonances, clean those up and get an EQ to boost low bass and sit on the mid-bass -> midrange slightly, curtail the 3850 and 8000 Hz peaks and you are almost home) and you're cooking. The 800 is like a very talented member of the family that exceeds on a few things and is frustratingly irritating on other things - better on OTL than SS.

If the 600 had a soundstage better than on BH Crack - someplace between a HE-500 and a HD-800S, and there would be a lot less folks looking for cans.
Can you please post a pic how your dynamat and felt treated HD600 back looks like? Would be appreciated
 
Jul 21, 2020 at 7:26 AM Post #20,762 of 23,416
Can you please post a pic how your dynamat and felt treated HD600 back looks like? Would be appreciated

Here it is. Not sure about the efficacy of the felt, it did seem to warm up the treble and cut some sharpness, But the cable change stock (SE) to Custom Cans (XLR) was more important - my amp runs much better in balanced than SE, so...

But the dynamat is clearly audible. See the bright silver spots. Also note that I covered no holes. The mid bass and upper bass become firmer, (remove non musical resonances (the can is quite rife with them) impact is increased, but you do lose a bit of db's (but its not music). This helps keep the upper bass from affecting the low mids. An EQ (or OTL amp) can easily add back the bass (OTL gives more low bass 30-60 Hz than most transistors - even my Ragnarok 1). But not doing - you lose a spate of subtle details that add to this can as a reference of near legend. After my busy season is over (Labor Day) I'll finish my BC Crack - bought for the 600 alone)

20200720_204354_HDR.jpg
 
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Jul 21, 2020 at 11:24 AM Post #20,763 of 23,416
Here it is. Not sure about the efficacy of the felt, it did seem to warm up the treble and cut some sharpness, But the cable change stock (SE) to Custom Cans (XLR) was more important - my amp runs much better in balanced than SE, so...

But the dynamat is clearly audible. See the bright silver spots. Also note that I covered no holes. The mid bass and upper bass become firmer, (remove non musical resonances (the can is quite rife with them) impact is increased, but you do lose a bit of db's (but its not music). This helps keep the upper bass from affecting the low mids. An EQ (or OTL amp) can easily add back the bass (OTL gives more low bass 30-60 Hz than most transistors - even my Ragnarok 1). But not doing - you lose a spate of subtle details that add to this can as a reference of near legend. After my busy season is over (Labor Day) I'll finish my BC Crack - bought for the 600 alone)

Do you also have Dynamat under the felt?

Also, have you covered the 2 black spots that are to the left and right on the driver circle with felt and/or Dynamat?

And the 4 white spots, 2 above and 2 below the driver circle, have you semi covered them with felt, or are they not covered at all? It's a bit hard to see.

I would love to cut down upper-mids resonances on my HD650, I already have multiple layers of duct-tape in similar spots on the backside like you have, but I'm wondering if felt will be more effective.
 
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Jul 21, 2020 at 5:35 PM Post #20,764 of 23,416
Do you also have Dynamat under the felt?

No.

Also, have you covered the 2 black spots that are to the left and right on the driver circle with felt and/or Dynamat?

And the 4 white spots, 2 above and 2 below the driver circle, have you semi covered them with felt, or are they not covered at all? It's a bit hard to see.

I was careful to plug no holes, a few holes have adjacent felt, but nothing directly on. Now its possible I mis identified, and I'm loathe to open it up and hunt around to check.

I would love to cut down upper-mids resonances on my HD650, I already have multiple layers of duct-tape in similar spots on the backside like you have, but I'm wondering if felt will be more effective.

duct tape isn't absorbing that much. Felt would suck in more mid/highs. duct tape might have some effect like dynamat, or white or blue putty, but I found dynamat is the best practical material and its cheap. Sorbothane is better but the glue is pretty lame. Good for equipment feet, or to lay in a very live metal cabinet. I used some in my HE-500, and it just falls off.
 
Jul 21, 2020 at 5:44 PM Post #20,765 of 23,416
No.



I was careful to plug no holes, a few holes have adjacent felt, but nothing directly on. Now its possible I mis identified, and I'm loathe to open it up and hunt around to check.



duct tape isn't absorbing that much. Felt would suck in more mid/highs. duct tape might have some effect like dynamat, or white or blue putty, but I found dynamat is the best practical material and its cheap. Sorbothane is better but the glue is pretty lame. Good for equipment feet, or to lay in a very live metal cabinet. I used some in my HE-500, and it just falls off.
Where have you bought that felt that sticks, like on your HD600?
 
Jul 21, 2020 at 5:51 PM Post #20,766 of 23,416
Where have you bought that felt that sticks, like on your HD600?

Heck. I bought a big roll - felt one side and sticky stuff on the back. It's about an inch wide and maybe 20' or 25' long. I gave some away and used a lot - I'm down to about 4', otherwise I'd send you some.
 
Jul 21, 2020 at 7:36 PM Post #20,767 of 23,416
Heck. I bought a big roll - felt one side and sticky stuff on the back. It's about an inch wide and maybe 20' or 25' long. I gave some away and used a lot - I'm down to about 4', otherwise I'd send you some.
Btw, wouldn't Dynamat be overkill for a headphone, since it's used for car panels?

It's also harder than duct-tape, and has relatively the same feel when you touch it. Ofcourse I used it only once, but I'm just guessing here if duct-tape would do the job equally well if applied in multiple layers?
 
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Jul 21, 2020 at 8:23 PM Post #20,768 of 23,416
Btw, wouldn't Dynamat be overkill for a headphone, since it's used for car panels?

It's also harder than duct-tape, and has relatively the same feel when you touch it. Ofcourse I used it only once, but I'm just guessing here if duct-tape would do the job equally well if applied in multiple layers?

No. Sucking up mid/treble is one battle (felt, padding, diffusion, etc) Bass vibrations need something to absorb them, felt isn't proper for that. I have it on the HE-500 and HE6se and it works great for them.

There are different kinds of dynamat - get the stuff thats in sheets of 1' x 1' its about 1/5" thick in total. It's cheap IMO and works better than putty, blu-tak, white-tak. that plastic Senn frame resonates quite a bit, but do what you like. Look up dynamat in H-F, it's used a lot.

Duct tape is mono material, dynamat is two types designed together to eat vibrations. I've got about 15 rolls of duct tape for different purposes and I cannot image it working as good as dynamat for this purpose.
 
Jul 21, 2020 at 9:01 PM Post #20,769 of 23,416
No. Sucking up mid/treble is one battle (felt, padding, diffusion, etc) Bass vibrations need something to absorb them, felt isn't proper for that. I have it on the HE-500 and HE6se and it works great for them.

There are different kinds of dynamat - get the stuff thats in sheets of 1' x 1' its about 1/5" thick in total. It's cheap IMO and works better than putty, blu-tak, white-tak. that plastic Senn frame resonates quite a bit, but do what you like. Look up dynamat in H-F, it's used a lot.

Duct tape is mono material perhaps effective at mid frequencies, dynamat is two types designed together to eat vibrations. I've got about 15 rolls of duct tape for different purposes and I cannot image it working as good as dynamat for this purpose.
 
Jul 22, 2020 at 12:35 PM Post #20,770 of 23,416
No. Sucking up mid/treble is one battle (felt, padding, diffusion, etc) Bass vibrations need something to absorb them, felt isn't proper for that. I have it on the HE-500 and HE6se and it works great for them.

There are different kinds of dynamat - get the stuff thats in sheets of 1' x 1' its about 1/5" thick in total. It's cheap IMO and works better than putty, blu-tak, white-tak. that plastic Senn frame resonates quite a bit, but do what you like. Look up dynamat in H-F, it's used a lot.

Duct tape is mono material, dynamat is two types designed together to eat vibrations. I've got about 15 rolls of duct tape for different purposes and I cannot image it working as good as dynamat for this purpose.
Can you please link me to the Dynamat you used? I'm not sure which Dynamat is the thinnest one, it would be really appreciated if you could link me.

Also, for the felt, would this adhesive felt do the job as well as your felt? It's 1/16 inch thick. Or does it need to be thicker? If so, how thick? (There are thicker options available as well)

https://www.vloerglijders.nl/plakvilt-op-rol-2-mm-zwart.html
 
Jul 22, 2020 at 4:27 PM Post #20,771 of 23,416
Can you please link me to the Dynamat you used? I'm not sure which Dynamat is the thinnest one, it would be really appreciated if you could link me.

Also, for the felt, would this adhesive felt do the job as well as your felt? It's 1/16 inch thick. Or does it need to be thicker? If so, how thick? (There are thicker options available as well)

https://www.vloerglijders.nl/plakvilt-op-rol-2-mm-zwart.html

Adhesive Backed Red Felt Tape - 50 Ft Long Roll, 1/16" Thick and 1" Wide @ amazon

AND

Dynamat Xtreme 1.4 Sq. Ft. Speaker Kit; 2 Pcs 10"X10"
 
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Jul 22, 2020 at 8:51 PM Post #20,773 of 23,416
Thanks a lot, ordered both.

Just a question that comes to mind; wouldn't thicker felt be better at damping than the 1/16'' inch version, or is the 1/16'' effective enough?
I meant to say something, I'd like 5 different thicknesses 1x up from this thin one, then you can vary them and get different frequencies handled, mix all 5 in one can I'd say (or even 3) that the results would tend to be better. OTOH I stripped it off my HFM's except the "fuzzor" mod - HE-500, HE-5LE, HE6se, MD 4xx, it doesn't do anything on the back side along the edges but dynamat sure does.
 
Jul 26, 2020 at 1:57 PM Post #20,775 of 23,416
I just ended up buying another used set of HD600's, although these are supposedly much newer.

I owned a set of these in the winter and was, for the most part, underwhelmed. But when I put them on my tube amp, they really sang. However, I decided to move them on as a one trick pony. Well now several months later my tube amp is kind of bored and wants a new playpal, so I decided to get another set.
I am also curious about some other new amps and I wonder if they (SS and hybrid) can bring more out of the 600's than my past models.
 

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