Crispy
500+
"Done me wrong," it's the same old song" - forever
Posts: 631
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Post by Crispy on Mar 16, 2013 20:41:33 GMT
Chris, the isolation is very good actually. I sit in the front room with the TV on and a noisy 7 year old squawking away and I'm ok with them!! Thanks Ian, I am really interested in these phones and if you can sit in front of a noisy TV and 7 year old, then they must have good isolation. Does the music your listening to spill out into the room too much and annoy everybody else though? I can't wait to hear what Mike thinks to these phones once he has finally completed his mods of sexy looking Plasticine and sheep's wool and whatever else he's doing. Ah well I'm off to get a nice cold beer and relax to some music through the good old DT770's - I cant take them off my head Thanks again Ian.
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Post by Rabbit on Mar 16, 2013 20:50:55 GMT
Chris, the isolation is very good actually. I sit in the front room with the TV on and a noisy 7 year old squawking away and I'm ok with them!! Thanks Ian, I am really interested in these phones and if you can sit in front of a noisy TV and 7 year old, then they must have good isolation. Does the music your listening to spill out into the room too much and annoy everybody else though? I can't wait to hear what Mike thinks to these phones once he has finally completed his mods of sexy looking Plasticine and sheep's wool and whatever else he's doing. Ah well I'm off to get a nice cold beer and relax to some music through the good old DT770's - I cant take them off my head Thanks again Ian. No problem, Chris. I'm glad you're enjoying them. Truth is, I've been using the TR40 and TR50 exclusively; even without filtering and I find them absolutely fine. No sound is heard by the wife, but my daughter 'thinks' she can hear it. It's really not a lot. I do find them very neutral which isn't the best for everyone. However, I don't feel the need to change the headphone for different types of music. For me that's a real bonus since I listen to anything from speech to classical to rock to electro .... anything. Having a load of headphones for each purpose is a pain so a neutral headphone kind of makes sense. A lot of my other may also be going as well as a result. I am very happy with them both. I think they're a good headphone because nothing glares out at you as 'wrong', but then again, others may find them too bland. To me, they're spot on. I'm also wondering where Mike will get with the T50. It is apparently possible to extend the top without the need of a filter but there's some kind of secret or perhaps a slight 'untruth' in what people say. What is surprising is how much this guy LFF sells the modded version for. As Mike said - time costs money and I think he tunes them via measurements as well. They all seem to be individuals but it's a rather nice project - to be able to tune a headphone in different ways for different results. They do sound different to other headphones though so at first, I think people could find them strange and then they kind of grow on you!!
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Post by PinkFloyd on Mar 16, 2013 20:55:56 GMT
I'm a bit late to this plasticine party Chris but better late than never Give me a couple of weeks extensive tweaking / listening and I'll have the "get the best out of these for under a sixpence" photorial up and running! That's sixpence in old money (BTW!) I cannot BELIEVE that people are selling "kits" of plasticine and cotton for £20 GBP PLUS shipping!...... let's get real here and show people how to get the best out of these for PENNIES. I'll be back ;-)
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Post by Imagemaker18 on Mar 16, 2013 21:05:31 GMT
Wow, Chris! Congratulations! As I said, NEVER GIVE UP! And, you probably thought of it already, but your friend deserves a drink, or two, or three, or.... It goes to show you! When there is a will, there IS a way! Enjoy your phones now! All the Best! Israel
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Post by PinkFloyd on Mar 16, 2013 21:22:47 GMT
x2 Greek Chris..... "result" Keep that hatch glued down! Don't go there again! Quit while you're winning Mike.
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chris1967
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Post by chris1967 on Mar 16, 2013 22:28:21 GMT
Thanks guys!! its past midnight and i still have them on my head... i think the cable and the damping on the ear side of the cup, has given more extension and resolution... very happy!! These are not going to open again, that's for sure... i have good friends...all the boozing was not in vain...
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pagan
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Post by pagan on Mar 17, 2013 7:53:56 GMT
I'm going to treat the cups with a thick coat of bitumen (body schutz) and fill any void in the enclosure with sheep's wool..... I won't be "felting" the drivers but will be using a rubber honeycomb instead.... you know the small rubber stick on feet you get? Well, when you pop them off the backing you are left with a piece of self adhesive rubber which has holes in it, perfect for this I think! I'll show you what I mean when I get round to it. I've had the plasticine running for about 1 hour now and already can say it has made a BIG improvement..... maybe it's the placement of the different "colours" or the fact the plasticine has added damping (more likely) but I can already sense better bass response and more informative mids. It will now be VERY easy to over egg the pudding so every mod I make, from here on in, will be a tiny one.... I am not going to slap things in holus bolus, from here on in it's all about tiny steps..... I don't agree with the felt over the driver mod BUT will try it.... what I am trying to achieve is to tune the enclosure to give "filter" like performance WITHOUT the filter..... the plasticine "alone" has made a very big improvement, it's now a case of much experimentation and a lot of listening. Phase one complete The "bitumen (body schutz)" was something I was thinking about, I've used it in speakers before to deaden panels. Only thing is, it's a bitch to reverse. My thought was, to cover the inside of the plastic cups without loosing too much volume. as to use plasticine would be also to take some of the internal volume away. But to remove the plasticine would be easier than the bitumen. Allan ps Chris Good to see the driver survived..
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Deleted
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Post by Deleted on Mar 17, 2013 9:20:17 GMT
Well... my friend did it!! he managed to scrape a little off the celophane and managed to precision solder some transformer wire on the very small track... Uploaded with ImageShack.usI took it up from there and solder the same on the other side... Also added some extra damping on the ear side of the baffle Uploaded with ImageShack.usSoldered the nasty Mogami on the copper wire Uploaded with ImageShack.usAnd voila... dual entry modded Fostex singing again... Uploaded with ImageShack.us That was a drama with happy ending... never opening these phones again, i tell you... Excellent, Up and running again, if your happy with the result leave well alone now. I think you can over do the modifications on these and get to a stage where its just the "Kings cloths".....it must be "sounding better" because i`ve added or changed this!!! Mick.
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chris1967
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Double dip recession, Humous and taramosalata are off the menu!
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Post by chris1967 on Mar 17, 2013 9:58:30 GMT
Thank you Mick!! I have very good ears, and i am an objectivist ... and i can tell you that these headphones react even to the smallest of alterations... I have double checked and reversed some things... like the damping on the cup, the amount of cotton and now (no one spotted it...) the amount of Plasticine (i reduced it a bit)... They all make a difference... so i would like to point out that anything you do take notes as to return to the better sounding combination... The way i have secured the copper wire is fool proof, and it will take carelessness and foolishness from my part to damage them... so in reality i am not so afraid to re open them... The reason not to reopen though...is that they TRULY sound very good... clarity/transparency is nearly on par with my Sennheiser HD800, and bass extension is better than my Sennheiser HD650... they are more "closed" though the sound stage is smaller than the HD800 and very similar to HD650... yet the phone is much more enjoyable than the 650's... which by the way is always the phone i revert to for reference... So this is a winning headphone and i don't really care to compare it with HiFiMAN HE500 or Audeze LCD2... all i say they are one the best headphones i have ever heard... So my advise is for everyone to go for it, don't be afraid to experiment, and one more thing... the cable does make a significant improvement, try not to pull too hard on the cellophane though...
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Post by Rabbit on Mar 17, 2013 10:24:36 GMT
The reason not to reopen though...is that they TRULY sound very good... clarity/transparency is nearly on par with my Sennheiser HD800, and bass extension is better than my Sennheiser HD650... they are more "closed" though the sound stage is smaller than the HD800 and very similar to HD650... yet the phone is much more enjoyable than the 650's... which by the way is always the phone i revert to for reference... So this is a winning headphone and i don't really care to compare it with HiFiMAN HE500 or Audeze LCD2... all i say they are one the best headphones i have ever heard... So my advise is for everyone to go for it, don't be afraid to experiment, and one more thing... the cable does make a significant improvement, try not to pull too hard on the cellophane though... They are very good Chris. I must admit, they have surprised me how well they respond to manipulation. You wouldn't really guess from hearing the stock headphone what they are actually capable of. I also agree that you have to be a little careful with the modding. Not because of damage, but small tweaks seem to alter things. That's why Frans was intent on measuring mine in order to get it as flat as possible. The curious thing was that each earcup needed different amounts of wadding to get them to match more closely. That is really difficult to do by ear. Frans made a frame with holes and two tiny mics on the holes to measure what was happening. The only thing is, the mics themselves tail off at the extremes so the headphones may be going further than he thought. (In the top end as well) He tends to be quite restrained about claims and he quoted exactly what he was seeing on his mics (particularly with regard to the bass). He was saying that they were going to 10 Hz but slightly tailed off but when a tech guy at work measured them for me, he found they were really good down there and with less tail off less than what Frans was stating. Same up top. The extension is terrific although not obvious. It only seems to play bass when it's there and on some recordings they can sound quite thin. It goes down to 10 Hz. (You can't really hear down there) The 'closed' feeling could be the 6dB dip in the treble and the tail off. That's precisely what the filter matches in order to get it flat to 21 or 22 ish KHz. However, I have been using the T40 quite happily without the filter for a week and don't find it that bad at all. I didn't think the filter would be as expensive with regard to parts but for me, it does lift the 'closed in' feeling and restores air to the sound. I kind of equate it to buying an amp and then buying a decent power supply for it (that should have come with it in the first place!!!) You can easily end up paying just as much for the power supply as the amp and perhaps it's the same with this filter. It works well though tbh in spite of putting another bit of electronics in the signal path. However, the effects aren't that great as far as distortion/noise goes. The guys at work compared measurements with and without. A gnat's whisker. They felt that it was a pretty good solution. Bear in mind though, that they aren't hi fi purists and simply measure what comes out. They have no agenda and couldn't care less whether they are good or bad. They were surprised though and a couple of eyebrows went up! The question of components in the way will always be a difficult one since we have to determine whether the differences are actually audible. There will always be claims that it's a bad thing to put more in the way, but it really depends I think on what the benefits are and it's a balancing act. A lot of tweaking with amps is to do with components and cleaning out things/adding others in order to improve some aspect of an amp and yet, it hasn't really been considered with headphones. (or taken seriously) As Mike brought up, the use of an equaliser in the signal path makes hi fi people see you as a bit daft, but their benefits can outweigh their negatives. The often said thing about studios having loads of electronics in the way before the final signal emerges is true and yet, the end comes down to this 'purist' approach where tbh, the hi fi guys are using better electronics at the end than was in the way originally!! It's worth trying - you might get a surprise!! Don't write it off without even hearing it. It's quite amazing that you got the driver working again too. I'm glad you managed to sort that out.
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Post by Deleted on Mar 17, 2013 10:33:48 GMT
Thank you Mick!! I have very good ears, and i am an objectivist ... and i can tell you that these headphones react even to the smallest of alterations... I have double checked and reversed some things... like the damping on the cup, the amount of cotton and now (no one spotted it...) the amount of Plasticine (i reduced it a bit)... They all make a difference... so i would like to point out that anything you do take notes as to return to the better sounding combination... The way i have secured the copper wire is fool proof, and it will take carelessness and foolishness from my part to damage them... so in reality i am not so afraid to re open them... The reason not to reopen though...is that they TRULY sound very good... clarity/transparency is nearly on par with my Sennheiser HD800, and bass extension is better than my Sennheiser HD650... they are more "closed" though the sound stage is smaller than the HD800 and very similar to HD650... yet the phone is much more enjoyable than the 650's... which by the way is always the phone i revert to for reference... So this is a winning headphone and i don't really care to compare it with HiFiMAN HE500 or Audeze LCD2... all i say they are one the best headphones i have ever heard... So my advise is for everyone to go for it, don't be afraid to experiment, and one more thing... the cable does make a significant improvement, try not to pull too hard on the cellophane though... Yes, if you feel that the differences obtained by constantly tweaking are giving positive results for you, then fair enough. I consider my ears to be very good also, i think that just the basic additions that i have carried out on mine, have made a slight difference, but its not "day and night", as they sound good to me straight out the box. Even if i made "notes" on the before and after SQ at different modes of tuning, unless i had a standard pr for A-B comparison, i would find it difficult to say yes! that sounds MUCH better now, as i cant find much wrong with the standard HP. Perhaps if i were prepared to open them up after every few hours of listening to make adjustments,i might also find the "holy grail" of HP`s. But for me, at the price paid and time spent so far these are just fine. Mick.
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Post by gommer on Mar 17, 2013 10:40:20 GMT
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pagan
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Post by pagan on Mar 17, 2013 10:41:16 GMT
Thank you Mick!! I have double checked and reversed some things... like the damping on the cup, the amount of cotton and now (no one spotted it...) the amount of Plasticine (i reduced it a bit)... About the plasticine, how much did you remove Or leave in there?
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chris1967
Been here a while!
Double dip recession, Humous and taramosalata are off the menu!
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Post by chris1967 on Mar 17, 2013 11:26:52 GMT
Thank you Mick!! I have very good ears, and i am an objectivist ... and i can tell you that these headphones react even to the smallest of alterations... I have double checked and reversed some things... like the damping on the cup, the amount of cotton and now (no one spotted it...) the amount of Plasticine (i reduced it a bit)... They all make a difference... so i would like to point out that anything you do take notes as to return to the better sounding combination... The way i have secured the copper wire is fool proof, and it will take carelessness and foolishness from my part to damage them... so in reality i am not so afraid to re open them... The reason not to reopen though...is that they TRULY sound very good... clarity/transparency is nearly on par with my Sennheiser HD800, and bass extension is better than my Sennheiser HD650... they are more "closed" though the sound stage is smaller than the HD800 and very similar to HD650... yet the phone is much more enjoyable than the 650's... which by the way is always the phone i revert to for reference... So this is a winning headphone and i don't really care to compare it with HiFiMAN HE500 or Audeze LCD2... all i say they are one the best headphones i have ever heard... So my advise is for everyone to go for it, don't be afraid to experiment, and one more thing... the cable does make a significant improvement, try not to pull too hard on the cellophane though... Yes, if you feel that the differences obtained by constantly tweaking are giving positive results for you, then fair enough. I consider my ears to be very good also, i think that just the basic additions that i have carried out on mine, have made a slight difference, but its not "day and night", as they sound good to me straight out the box. Even if i made "notes" on the before and after SQ at different modes of tuning, unless i had a standard pr for A-B comparison, i would find it difficult to say yes! that sounds MUCH better now, as i cant find much wrong with the standard HP. Perhaps if i were prepared to open them up after every few hours of listening to make adjustments,i might also find the "holy grail" of HP`s. But for me, at the price paid and time spent so far these are just fine. Mick. Mick, what tweaks have you done? because in my case the difference IS night and day... the standard phone is midsentric... and now i have full range... i am just wondering about your findings... talking about "holy grail" of headphones... there is no such thing... it is a matter of which headphone your hand reaches for more frequently... and this is different for different people... flat frequancy response is or may be not the answer, for different people... i would think proffesionals should use flat... i am not so sure about myself, on the contrary... I have been tweaking these for one and a half year... Thank you Mick!! I have double checked and reversed some things... like the damping on the cup, the amount of cotton and now (no one spotted it...) the amount of Plasticine (i reduced it a bit)... About the plasticine, how much did you remove Or leave in there? I removed so much as to be flush with the plastic compartments/webbing... just like Mike has done with his multicolored job...
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Post by Rabbit on Mar 17, 2013 11:49:27 GMT
You're right Chris - Ideally flat to work with. (although often really not the case) Extension isn't such a problem. In fact, limiting it into the middle helps to focus on what is happening much easier.
However for entertainment, as you say, flat may well not be liked by many. That's why headphones are tailored to give (very often) a mid bass hump.
Interestingly, the HD580 was regarded as a top notch headphone, followed by the HD600 and imo, the not quite so good HD650 with its top end being slightly more laid back.
However, they have always remained in the background really. They kind of represented a 'standard' that started to get overshadowed by much 'brighter top end' alternatives like the AT's and Beyers.
Recently, I've noticed a trend back to bass response - so the selling of things like Dre's. None of them neutral - they're basically trying to sound different so they get noticed in the market.
However, I still think that the HD600 is a kind of bargain (or was at the old price) since it is still a good standard headphone as far as FR goes. To me, that's always been the standard for others to be set against. Trouble is, they've become so damned expensive so I never bothered to replace my old one.
The orthos offer less distortion and the potential for a fantastic sound.
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Post by PinkFloyd on Mar 17, 2013 20:12:40 GMT
I'm going to treat the cups with a thick coat of bitumen (body schutz) and fill any void in the enclosure with sheep's wool..... I won't be "felting" the drivers but will be using a rubber honeycomb instead.... you know the small rubber stick on feet you get? Well, when you pop them off the backing you are left with a piece of self adhesive rubber which has holes in it, perfect for this I think! I'll show you what I mean when I get round to it. I've had the plasticine running for about 1 hour now and already can say it has made a BIG improvement..... maybe it's the placement of the different "colours" or the fact the plasticine has added damping (more likely) but I can already sense better bass response and more informative mids. It will now be VERY easy to over egg the pudding so every mod I make, from here on in, will be a tiny one.... I am not going to slap things in holus bolus, from here on in it's all about tiny steps..... I don't agree with the felt over the driver mod BUT will try it.... what I am trying to achieve is to tune the enclosure to give "filter" like performance WITHOUT the filter..... the plasticine "alone" has made a very big improvement, it's now a case of much experimentation and a lot of listening. Phase one complete The "bitumen (body schutz)" was something I was thinking about, I've used it in speakers before to deaden panels. Only thing is, it's a bitch to reverse. My thought was, to cover the inside of the plastic cups without loosing too much volume. as to use plasticine would be also to take some of the internal volume away. But to remove the plasticine would be easier than the bitumen. Allan ps Chris Good to see the driver survived.. Hi Allan, I was thinking of brushing the body schutz "sparingly" onto the cups and not the driver housing..... it's messy, smelly stuff, but I've got a gallon of it in the garage so may as well use what you have The plasticine, alone, has made a nice improvement.... I think it's going to be a case of less is more with these 'phones.... stuffing them full of "material" may not be the best way to go..... the plasticine has added a bit of mass to the baffle and it appears to have payed dividends without affecting the LF performance. It would be EASY to "mask" the LF performance, which would give perceived "better mids / highs" performance, but I want to retain every ounce of bass that is currently on offer. I tend to agree with Mick..... I'm actually quite happy with the stock sound and only want to tune it slightly. The soundstage / headstage is good and I'd like to keep that as wide as possible too..... the minute you start stuffing at random / holus bolus you lose the personality that first drew you to the T50RP sonic signature and end up with something vaguely resembling that sonic character. I've looked at a few of the "mods" on Head-Fi and some of them must be strangling the sound beyond belief...... I've also noted that quite a lot of these mods are appearing as "kits" and the more that's on offer "stuffing wise" the more expensive the "kit"...... It's typical Head-Fi, each going with more and more "stuffing" and all trying to outdo each other..... it will turn full circle and the "less is more" mod will be the in thing..... those that have bought into the stuffing mods will be well and truly stuffed
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Post by PinkFloyd on Mar 17, 2013 20:16:02 GMT
Totally unrelated to this thread but a few notes on sound dampening / acoustic materials courtesy of QTA systems:
A Brief Overview of Loudspeaker cabinet Damping. The selective use of foams and damping materials within a loudspeaker cabinet can significantly alter / enhance it's acoustic performance.
These materials fall into two basic types, those that can selectively absorb energy over a limited range and those that can shift / move the energy elsewhere. All vibrating objects produce sound pressure waves. These can act as a form of airborne interference and spoil the overall listening experience. For best cabinet acoustics we require a speaker cabinet to be acoustically dead and a number of designs exist to meet this criteria with varying degrees of success. These range from using very heavy panelling materials, e.g. concrete or marble slabs to sand-filled double-walled panels. A variety of materials attached to the interior of the cabinet can also modify it's response. The fact that there are so many options suggests no one approach is optimum for all occasions, disregarding the cost considerations of course.
Vibrating panels effectively act as large speaker cones with a small peak amplitude. These have selective modes of vibration, (resonances), and can be of sufficient amplitude to colour the overall sound. In addition the rear radiation from the speaker cone may be reflected around the inside of the cabinet and then back out through the speaker cone. This all contributes to a background noise which tends to distort the listener's sound experience and give rise to what's known as a 'box sound'. Low priced manufactured items are more prone to this problem as it's an easy area in which to make economies. Increasing the signal volume does little to help as the cabinet noise is increased also. So ----- what to do?
At this stage, it is important to realise that light weight materials can only be effective at high frequencies and that the heavier damping materials progressively take effect at the lower end of the frequency spectrum. So, lets look at the options.
Sheep's Wool. Traditionally used to stuff transmission lines, at a density of around 450gms wool per 28L of enclosure volume, the wool is used as a moderator to the line velocity and thereby tune the line to some desired end result. Historically it was based on Dr Baileys processing prescription and was called Dr Baileys Long Haired Wool. Also used to stuff loudspeaker cabinets in which the acoustic properties are applied to provide a small dampening effect on medium frequency output, (HF Tweeters often sit in their own enclosure and are therefore unaffected). In addition, the propagation delay through the material is used, to some effect, in closed box designs to acoustically increase the box volume and hence change the characteristics of the box. The mathematics of this is complicated and is not investigated here. Because of the relatively small usage for this application it is now difficult to obtain such material and consequently has to a large extent, been replaced by BAF, (Bonded Acetate Fibre), although the performance of this material is not as good.
The loose wool fibres settle in volume after a period and a number of ways have been invented by DIYer's to keep it suspended within the cabinet and hence maintain performance. These range from using wooden dowel rods as a suspension medium, small stuffed parcels of modified fine denier tights and trapping the wool using plastic mesh. See picture below. QTA can supply wool from Herdwick Sheep which has been both scoured and mothproofed. This is a close equivalent to the original, although the fibres are not quite as long. See damping materials.
Bonded Acetate Fibre (BAF). A white, man-made synthetic material commonly known as 'BAF' , Bonded Acetate Fibre, and now often used as a replacement for wool-based acoustic applications. The fibres are all of a similar diameter and therefore have a different sonic performance to the more randomly distributed fibre diameters of wool. In this respect it is inferior to sheep's wool. Available in a number of weights, gms per sq metre and fibre thickness, (denier), the material is easy to cut, self supporting and moderately cheap. Available from good quality stores where it is often used as stuffing (insulation), for outdoor clothing. However, from most outlets there is no choice in specification.
Sound Absorbent Foam. Generally available in two shapes / profiles, flat and egg box, the foam family are usually opaque in colour and have a closed cell construction, The foam cells are chosen to be a specific size / diameter in order to provide a bulk material characteristic suitable for acoustic damping, i.e. the cells are mostly airtight and provide resistance to the passage of air if you try to blow through the material. This closed cell structure absorbs energy when the cell content, air, is compressed and rarefied due to the sound pressure wave. This type of damping is used to alter the high frequency response of cabinets and transmission lines. It does not work well for low frequencies as the amount of damping / energy absorption which the foam can support is relatively small.
Felts. Felts have similar absorption characteristics to foam but, due to their heavier structure, alter the sound quality at lower frequencies. There are no closed cells present but the felt fibres adsorb energy, raising their temperature. The technical study of this is complicated but the degree of effect, is dependant on the fibre thickness, material and the felt density. Usually specified in weight oz per sq yard e.g. 35oz or 50oz etc. Some felts are manufactured to a dual density whereby the inner section has a lower density than the outer walls. This material is however hard to source.
High Mass Materials. The second variety of damping uses high mass materials e.g. Bitumastic sheet, (self adhesive), to physically alter the mass of a panel. Other materials such as laminated hardboard panels are also effective. The volume of these materials should be considered when constructing cabinets as they will modify the free volume box calculations. Heavier panels vibrate at lower frequencies and hence their noise spectrum is shifted. In this they do a good job but such damping will not be effective at high frequencies. A mixture of the two types of approach (high mass and low mass), is often used in the more expensive cabinets along with strategically placed bracing struts. One should note however, it is possible to move Bass Bin out-band resonances, which occur by way of their design, into their 'working' sound spectrum, hence making the problem worse so.......some care is needed.
Cabinet Stuffings. In order to further moderate / tune a cabinet's response, loose volume stuffing may be used. For a closed box design the design often relies on the stuffing to moderate the cabinet volume to produce a specific acoustic response. The cabinet volume is effectively altered / increased by some (5 -10)%.
Stuffing's generally fall into two types, man-made and natural fibres. They have different characteristics but the most commonly used is man made, of which Bonded Acetate Fibre, BAF Wadding for short is the front runner. Polyamide fibre as used in jacket stuffing's is also practical. The second type is Sheep's wool. This has superior characteristics but is more difficult to use.
The application of....Foams and Felts. Unwanted sounds are generally called colorations and these should be minimised to an acceptable level. There is no specific definition of coloration limits so... Different cabinet designs and shapes, have differing colorations, some leading to what is well known as 'the box sound'. In this respect small cabinets can be worse. Its actually more difficult to make a 'good', small, speaker than a larger one. To prevent / reduce internal cabinet reflections from emerging out through the speaker cone, creating coloration, a thick wad of felt, say (20 - 25) mm, may be placed on the rear cabinet wall, behind the drivers. In addition, a similar thickness may be glued to the rear of the driver magnet assembly. This reduces internal reflections. If you have vented rear pole assemblies don't forget to cut a hole in the material to allow the vent to breathe. This should be augmented by foam damping on the other interior cabinet walls of say (10 - 16)mm. Small cabinet boxes may need to be slightly larger in volume to offset the lost volume due to the damping materials. There is no easy way to guess or measure the actual felt / foam volume, some experimentation and listening trials are required The use of Bitumastic damping in small cabinets is not often required, as small boxes are very stiff and hence flex much less than larger panels The picture shows a typical assembly with part peeled backing paper and fixing tacks.
Grille Foam. Grille foams are, by nature, acoustically transparent. Also known as reticulated foam, the cell-like structure is of an open weave arrangement and easily permits the passage of air. Each cell is around 0.7mm in diameter and the number of cells per linear inch specifies the structure. For this application 35ppi, (particles per inch). Usually black in colour the open cell structure has little intrinsic strength and the material has to be supported on some type of frame. The material will not take to stretching as the restoring force is minimal and once stretched the original dimensions cannot be recovered. The minimum usable thickness is around 10mm. At 20 / 25mm the material becomes self supporting, (depending on area and hence avoids the effects of grille frames). Susceptible to UV light, sunlight, the material slowly crumbles and has a usable lifetime of 10 / 15 years before requiring replacement. Often used on designs of the 70's and 80's.
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Post by PinkFloyd on Mar 17, 2013 20:29:44 GMT
That's where the BAF / Sheep's wool comes into play..... it actually INCREASES the internal volume of a cabinet
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Post by PinkFloyd on Mar 17, 2013 20:39:37 GMT
The internal volume "loss" by the plasticine will be about 10%...... you can get that 10% (or more) back by using sheeps' wool / BAF wadding / Fibre glass etc....... if we can calculate the internal volume of the T50RP accurately we can also calculate the amount of wadding required to alter the volume / balance the internal volume / increase the internal volume..... this is starting to become fun
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Post by Deleted on Mar 17, 2013 22:25:13 GMT
Hi Boys............a term loosely used.
I've been following this thread as I'm considering an upgrade to the only HPs in my "Stash" namely HD681.
Would £113 plus a fiver postage be a good UK price.
Alan
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Deleted
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Post by Deleted on Mar 17, 2013 23:17:52 GMT
Would £113 plus a fiver postage be a good UK price. Alan Hi Alan Sounds like Juno? That's what I paid on two separate purchases. I couldn't find any cheaper UK supplier and they are a fast shipper. The Shure 940 pads are recommended by most people, it'll save an extra shipping charge as they sell them too. Syd
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Deleted
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Post by Deleted on Mar 17, 2013 23:55:17 GMT
Hi Syd, that's our man, I'll probably make the purchase soon, thanks for the tip on the pads. The sheep's wool like Mike hangs on fences all around here whilst the plasticine is in the grand-kids toy box next door.
Regards,
Alan
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Deleted
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Post by Deleted on Mar 18, 2013 12:29:37 GMT
Mick, what tweaks have you done? because in my case the difference IS night and day... the standard phone is midsentric... and now i have full range... i am just wondering about your findings... talking about "holy grail" of headphones... there is no such thing... it is a matter of which headphone your hand reaches for more frequently... and this is different for different people... flat frequancy response is or may be not the answer, for different people... i would think proffesionals should use flat... i am not so sure about myself, on the contrary... I have been tweaking these for one and a half year... Hi Chris, I have added modeling clay to the inner cup, the same as Mike has done and to the same depth, but just one colour. Foam strips (6mm thick) similar layout as yours have been added to the outer cups. That`s it for now, waiting for a filter which is where i expect the biggest improvement to be found, before, or indeed if, i make anymore changes. A filter for my HE6`s is now complete and on its way back to me, this should give some indication of the effect a filter will have on the T50`s. I`m sure after 18mths of tuning your T50`s, you now have them perfectly set up for your needs, very commendable, well done. Yup, you are right, no such thing, but we still find new HP`s that perform well for our own tastes and different hearing levels. Personally , i can listen and enjoy all my HP`s as the mood or preference in music takes me, however, i do reach for the Ortho`s more often than not. ATB. Mick.
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chris1967
Been here a while!
Double dip recession, Humous and taramosalata are off the menu!
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Post by chris1967 on Mar 18, 2013 13:34:20 GMT
Thanks Mick,
also try to open the outer cup, and add cotton inside... by adding or subtracting cotton and closing gradually the opening you can tune them to your liking... another thing is the velour pads, make such a difference...
the felt behind the driver helps the driver to be more "punchy" but it is irreversible...
re cabling also makes a small but definitive difference.
or just wait for the filter... its use might make the above mentioned modding unnecessary...
Filter for the He6? what is your complaint? too bright?
Cheers!!
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Deleted
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Post by Deleted on Mar 18, 2013 13:53:06 GMT
Hi Chris,
Yes i forgot to mention the pads, they are the Shure 940`s as recommended on here, and i`m happy with those.
Nothing wrong with the HE6`s, in fact i think they are superb.
Israel has a filter for his 500`s, and is very pleased with the result, takes them to a higher level. So thought i would try the same filter, or very similar (Frans has made the internals) for mine.
Mick.
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