solderdude
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Post by solderdude on Apr 15, 2013 18:12:04 GMT
Syd, I only need to alter the filter slightly to better suit your headphone.
When you look at the graphs of the T50 and imagine the dip at 3kHz 'filled' and the roll-off above 9kHz also filled you'll have a pretty flat (sounding) pair of headphones. The biggest question is do you like 'flat'. If you are wanting for a bit more lows the filter can be adjusted to do just that.
Unfortunately this week I need to re-write the filter instructions for the new PCB and do some work for Jeremy on Ember so perhaps by the end of the week there is some time to finish the filter.
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Rabbit
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Post by Rabbit on Apr 15, 2013 18:20:48 GMT
Mine have a lot of deep bass Frans. Flat seems fine to me. The problem is the recordings. If they aren't flat, neither are your headphones!!! They are like a reference for all of my recordings since they don't plant any nasties on the top of the music. They've also made me see the HD650 in a different light. Although the HD650 is a good headphone, it IS actually quite rosy and to my ears, it has a rounded tone that is planted on top of everything that you listen to through it. The T40 just doesn't superimpose much on top.
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Dave
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Post by Dave on Apr 15, 2013 18:36:51 GMT
Hi Ian, It's that cheeky Yorkshire b*gger here, on the scrounge again . Reading that the T50s have replaced your HD650s I wondered if there was likely to be a (very) cheap surplus pair of 650s anytime soon? I've always hankered after a really good pair of cans but bilk at paying several hundred pounds for the privilege. Wot's mi chances? . Dave.
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solderdude
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Post by solderdude on Apr 15, 2013 18:45:00 GMT
Here is another option to repair broken screw posts; www.jbweld.com/product/j-b-plasticweld-putty/The idea came from Alex... I haven't ruined any of my screw threads yet though. As long as you don't tighten them much during modding they stay O.K. for me. to ensure there are no leaks I put tape along the baffle where it meets the cup so it is air tight. Only when finalised I tighten the screws, no need for the tape anymore. My HD650 will remain, if only to act as a reference for my testing rig.
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Rabbit
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Post by Rabbit on Apr 15, 2013 18:56:12 GMT
Not yet, Dave. With recordings lacking in bass, the HD650 puts a bit back!!!
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Dave
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Post by Dave on Apr 15, 2013 19:10:59 GMT
Boo. Hiss. Dave.
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BMF
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Post by BMF on Apr 15, 2013 21:13:18 GMT
Ian, I agree. They sound wonderful once modded and get more head time than my LCD2's. Best, Keith BMF, you're like a breath of fresh air!! Enthusiasm. That's what I really enjoy reading and at this moment, I'm listening to my T40's. Frans at one time said when I was particularly stressed, 'Listen to some music on the T40' - how right he was. It's relaxing and just exhilarating and totally takes me away from thinking about anything else. I still listen now for real relaxation and it never ceases to surprise me what it can reveal in the music I'm listening to. They are just nothing short of stunning. It never ceases to amaze me how deep they can go on some recordings and yet on others, they don't - depending on the recording. They have this deep, powerful sound which is on the 'dry' side if you compare them to the HD650, but the sheer power and depth they deliver is absolutely brilliant. The HD650 seem to be more full of resonances that the T40 doesn't produce. I'm not exactly sure why that is, but the HD650's sound like they are in another room on the same recording. I can't help using them at life volume. They are so enjoyable. In fact, I'm quite happy with them as a straight headphone. Fran's filter brings up the top end, but to me, it really just doesn't change the character of the headphone, but just extends it. I like it so much, I've been looking for a portable that produces enough current to drive it properly. At the moment, I'm trying out the O2 on 6X gain and it's just brilliant to think that you can now get this kind of quality from a portable set up. Syd, Frans got mine absolutely right!! They are really lovely and he teased me with them before he sent them by wearing them and telling me while we were chatting online!!! They seem to make many headphones seem gutless with no real body or even synthetic sounding. I've moved from the DT150 to the T40 for work stuff. It's just streets ahead. Your first feeling is that nothing seems to stand out and on extended listening, you start to discover just how natural sounding they actually are. I would say use a powerful amp though. They soak it up and start to really sing on the end of real power.
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BMF
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Post by BMF on Apr 15, 2013 21:17:06 GMT
I like it. Didn't know it existed. Looks like it may be an easier fix than using super glue. I use the same "tape while you tune" approach simply to "save" the threads. That said, I find there is always a sound quality difference when I move from tape to the 4 stock screws. I think this is because tape cannot create the same "compression factor" as the screws; or maybe it's better seal with the screws? The latter always results in More bass, for me. Here is another option to repair broken screw posts; www.jbweld.com/product/j-b-plasticweld-putty/The idea came from Alex... I haven't ruined any of my screw threads yet though. As long as you don't tighten them much during modding they stay O.K. for me. to ensure there are no leaks I put tape along the baffle where it meets the cup so it is air tight. Only when finalised I tighten the screws, no need for the tape anymore. My HD650 will remain, if only to act as a reference for my testing rig.
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juke
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Post by juke on Apr 15, 2013 22:55:21 GMT
Syd, I only need to alter the filter slightly to better suit your headphone.....Unfortunately this week I need to re-write the filter instructions for the new PCB and do some work for Jeremy on Ember so perhaps by the end of the week there is some time to finish the filter. Hi Frans I'm keen to have the T50s flat, so that I have a proven reference against others. Don't worry about it taking some time, I'm off on holiday Saturday for a week and I hope to have HE6s for company as well when I return, so they'll keep me busy for a while. One thing I've also found, as Ian has remarked on several times regarding the T50s is how they reveal every flaw in recordings. It's a particular problem for me as so many of the tracks I listen to are old and have a great variety of problems. I reckon some of the 'phones I was thinking of selling off will stay as each has its uses within my somewhat varied musical tastes, and revealing can mean almost unlistenable. With my present far-from-well-modded T50s and, thanks to Mick, his HE6s, I've learned that both thrive on high quality recordings. I'm delighted and amazed at the balance you have achieved already between L & R so any further refinement is well worth the wait! Syd
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juke
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Post by juke on Apr 15, 2013 23:09:20 GMT
......I can't help using them at life volume. They are so enjoyable. I have been surprised how much I have cranked up the volume, really only discovering when I take them off when they're still playing. Its worth watching from the hearing damage point of view I guess, definitely I use them much louder than normal 'phones. I'm really looking forward to hearing my new T50s when Frans is ready Ian, but I'll not rush the master I've a a couple of HAs well up to the current T50s so they should do the new ones nicely, whatever I did to the present T50s they need a bit further on the volume control than they did! Syd
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BMF
contributing
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Post by BMF on Apr 18, 2013 22:59:46 GMT
I was wondering if the bass would tighten up - the cups wouldn't breathe if they were completely sealed. Completely sealing the cup vents does tighten the bass and significantly reduces bass quantity. IMO, this reduces bass too much. If a mod configuration needs "bass management," I make a "modified bass port" with a 3 to 5 mm wide opening in only 1 of the 4 vent slots and the rest are sealed. This controls bass bloating and veiling the mids but still delivers good quality:quantity bass. Pix and description can be found in head-fi in "Incremental Mods and Measurements" see Post #1. Cheers, Keith
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solderdude
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Post by solderdude on Apr 19, 2013 5:13:10 GMT
I am on the same page with this as keith is.
When there is a lot of damping materials (wool, rockwool e.t.c.) in the cups a closed or opened port didn't seem to affect the lows anymore.
I also found that closing the port (no wool) has a distinctly different effect than stuffing it with wool.
In Jukes case (to get L and R to measure similar) I had to resort to closing the port on the 'bass heavy' side with a piece of felt (with the glue still on it) and using a certain amount of wool to lower the bass levels to where I want them. On the other (bass light) driver side I had to do the same as described by Keith by taping felt over the bass port with a small 'gap' of a few mm cut out. Had to use less wool to make it the same as the other channel.
Till now (the few I have modded) mostly L and R cups were treated similarly and the amount of wool needed to get R and L differed only slightly. The end results was always close.
It is 'concerning' that replicating 'the trick' doesn't necessarily translate to even bass response even between L and R. It is true that it will become flatter and better controlled. To make one into reference material I suppose you really need to measure it.
Perhaps we could join forces in making (and supplying) cheap kits for measurements.
Thinking of a small 'plank' with a mic in it. On the backside it is connected to a simple fantom supply with a 9V battery clip and a wire with RCA plug. Strap it on the earpiece with rubber bands. Essentially what Keith makes but on a plank instead of an etymotic flange. Also we can supply REW (or you can download that yourself) and we can provide a correction file for the 15kHz peak.
a full measurement kit for the price of a cheap headphone. Takes the guessing out of it. Perhaps make a thread for it or a tutorial on the the website.
Hermetically sealing it will be hard to do and is not recommended. I know Luis (Paradox) claims his versions are hermetically sealed but acc to owners they are not. You would also have to close the hole where the headbandwire enters and completely seal of the cable socket with a blob or something. Also the baffle port would need to be fully closed. and the edges of the baffle would need a sealant as well. The membrane (if truly hermetically sealed) would be pushed inwards and outwards (like a barometer works) depending on the air pressure that day.
Of course you can completely close the port on the back completely and this will lower the bass (as in standard T40 opposite standard T20/T50) but the wool and anti reflection materials are better suited to 'control' the lows.
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Rabbit
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Post by Rabbit on Apr 19, 2013 9:41:36 GMT
That's a neat idea Frans. It would mean that there are other possibilities too where, for instance, the possibilty of comparing the same headphone to check for consistency. What surprised me with the Fostex, given the kind of market they're intended for, is how poor the cup matching is.
Also, it seems that the poor matching runs up to the T50 as well.
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dicky
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Post by dicky on Apr 19, 2013 10:46:47 GMT
Seconded! It would enable checking L/R balance on HPs with known issues - I'm thinking DT1350.
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solderdude
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Post by solderdude on Apr 19, 2013 11:52:56 GMT
Yes... that one seems to have even bigger 'spreads' than the Fostexes The pricetag of them would warrent better QC
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