IS THE STAX LAMBDA SIGNATURE SUPPOSED TO BE DAMPED? ON SECOND THOUGHT, DITCH THE FOAM BACKING...

By which I mean is there any material behind the drivers, on the side away from the ears?

I picked up an old Stax Signature some months back, the original Signature , not the Nova Signature or the 404 signature. Like many phones of that vintage it had deteriorated earpads, missing the foam between the drivers and the ears. I also noted that one side only had foam on the back side away from the ears. When I opened the case and examined this foam, it crumbled to the touch could not even be picked up.

I assumed the model originally had foam behind it and that it had fully disintegrated on one side.

I was able to swap an old set of Lambda earpads with earside foam and didn't notice any appreciable change in the sound of these phones. Finally I got tired of the swapped pads because they had a crack in them and got a new set of 404 pads from Yamasinc. The original dark brown Signature pads were no longer available, but the medium brown 404 pads look very nice. (BTW I have better luck getting Yamasinc to reply to e-mail than phone calls.)

At the same time I enquired about getting some more foam to put behind the drivers which they also provided for $12.00. The foam is very thin, but folds over to cover the bottom and sides of the case behind the driver. Upon inserting the foam, I am not sure I like the sound as much as before, although I intend to leave this in place for a while to be sure. It seems to bring the midrange up somewhat, which is good, but to also increase the treble etch.

As I was Googling around, I noted that the Wikiphonia entry on these phones says that this "was the first Stax headphone to use no mechanical damping whatsoever," presumably meaning no foam behind the drivers. I noted that their picture showed an old model with no foam even on the inside, suggesting to me that it was possible that it had damping foam, but, like my set had disintegrated.

Does anyone have any other information about the original damping of this model?

(SEE MY COMMENT FROM SEPTEMBER 8 RE USEFULNESS OF FOAM.)

Ok so you had foam too initially. The foam I just got from the dealer makes a fairly significant difference to the sound, but as I say, I must do some more listening.

I checked my 404 and Nova Classic and they do indeed have the foam.

As whether the foam has any real damping effect, all I can say is I much prefer my Signature without the foam. I have been listening for about a week now to the raspy sound of these phones with their new foam backing and finally removed the foam. I much prefer their sound now, you lose some mid range, which is needed, but the phones have a much more open and less etched quality. Frankly I wouldn't buy a Signature based on what I heard with the foam backing, but without the foam they are are a very listenable pphone.

2 further points I would make.

1. I suspect that much of the allure of these old phones is based on the fact that they sound better without the back foam and that in most old phones the foam had largely or wholey deteriorated so that it had little effect on the sound, especially the infamous treble etch.

2. I suspect I will be trying to remove the back foam from my 404's to see what the effect is on sound. I was initially concerend about the protection provided to the drivers by this foam, but I see that the Signatures already have a dust cover. Also my Sigma's have no such foam so evidently that is
not a big issue.

70 sets! That makes you the LAMBDA QUEEN.

I wish some-one would give us a proper review of the 404LE as to what it sounds like with different types of music, instruments etc.

I am not saying that we generally prefer the older phones, rather that some older phones are not up to spec because the back foam is shot. On my Sigs, there was no foam at all on one side and on the other the foam turned to powder upon being touched. Many old phones are sold lacking the front foam but no-one generally comments about the condition of the back foam. And my Signatures sound better without the back foam.

I was surprised by this because I spent $12.00 to get new foam. With the foam I would say the Sigs are close to being unlistenable, certainly worse that the standard 404. Without it, they still have a treble peak but it is no where as obnoxious as with the foam and the phones have a nice "open" quality.

Possibly so. I have just removed the foam from my 404 and it seems a bit thinner than what I had with the Siganture. Maybe age thins the foam or else Stax hasn't kept to the same specs of foam thickness.

The 404 also changes its sonic signature with the removal of the foam. I will have to do more listening but my first impression is that it changes somewhat in the way the Signature changes, i.e. a reduction in upper mid frequencies. Certainly the 404 has, to most ears a mid range peak, so this may be a good way to get rid of that. However, I do not find the foamed 404 as objectionable as the foamed Signature which I found harsh to the point of being unlistenable.

Didn't Sprizter do some comparisons of backings for Lambdas on another forum?

It seems to smell up the sound too. Certainly the Signature is much better without foam. I must spend more time with the 404 to be sure what it's doing but my initial reaction is in favor of eliminating the foam here too.

So little time!

So many headphones!

IMHO THE BACK FOAM CAUSES AN ETCHED SOUND

I have been listening to my three Lambdas from my home system using the Stax 717 amp. The 404 and Signature have had the back foam removed, the Nova Classic has not.

It's kind of hard to do an A/B of the same phone because it takes about 5 minutes to get the foam out or in and frankly I don't want to be messing with the phones that much.

Basically what strikes me is that the Nova (with foam) has a more prominent midrange than the Signature(no foam) and 404 (no foam). I do think the Nova has a very good balanced presentation and that both the Sig and 404 are recessed by comparison. The advantage to the Nova is a consistent level of detail. However that detail also comes with a certain amount of harshness which is removed from the other 2 phones, and oddly enough a narrower soundfield

The effect of losing that midrange is quite appealing, especially on the Sig. It gives them a wider soundfield and a somewhat distant perspective which isn't all that bad for headphones because it tends to counteract the "in-the-head" characteristic of headpone listening. If it wasn't for the sizzle at the very top for the Sigs, not always present, but which sometimes appears as a tizzy sibilance I would rank these number one of the three.

Interestingly even the 404 loses some of its midrange hump and etch with the foam removed. It still retains its somewhat boomy bass which like the Sig sizzle is only heard occasionally. It has a similar wider soundstage as the Signature does. On balance I give it a higher grade because it retains more midrange and the Sig loses some detail on quite a few occasions.

As a follow-up I tried the fllowing simple experiment: take the left-over 404 foam and hold it against the back of the 404 and Sig as these are on my head. Then leaving my hands in place, letting the foam drop off. To my ear there is a fairly obvious opening up of the sound with both phones when the foam drops. The soundfield opens up, the mids seems to decrease and the sound sweetens.

Presumably there would be similar effect if I were to remove the back foam from the Nova but since it is currently being advertised for sale, I don't want to mess with it.

Listening without the back foam is something any Lambda owner may want to experiment with especially if you are annoyed by their occasional raspiness or etch. Also you might want to hear this mod if you haven't got $2K to plunk down for an 007.