[Madgravity34]

So, I come to you guys in need of some aid. First off, however, I should inform you that the object of these repairs/modifications is none other than the Bose Triport (the super-comfy kind). My dog chewed through the cable, so instead of just repairing it, I decided to to a full re-cable. I used solid copper 24AWG wiring.


I have already done the full modification and the phones are currently working just fine, but I have run into some changes in sound that require some answers.

Differences:

1. Bass response is lower (its not as boomy and there isnt as much)
2. The treble sounds much clearer and extends farther
3. Mids are around the same or a little less

So here is my question, I thought copper would increase the bass response, but instead I am getting results I would have expected from silver. Could these have been caused by soldering the wires in reverse? (each side has a signal and ground) or is it just a characteristic of the cable and I should wait for it to burn in?


PS. Please let me know if you would be interested in a guide showing how to dismantle and mod these phones. Maybe we can make them a little bit of a better value.

 

[Madgravity34]

no one?

 

[adamus]

if the bass sounds light and a bit distorted they may be out of phase. If its just a bit lighter could just be cable differences.

 

[beerguy0]

Quote:

Originally Posted by adamus /img/forum/go_quote.gif if the bass sounds light and a bit distorted they may be out of phase. If its just a bit lighter could just be cable differences.

I'm thinking the same thing, the relative phase is off between the two channels. I really don't think a piece of wire would make that much difference in the sound quality.

 

[-=Germania=-]

Quote:

Originally Posted by beerguy0 /img/forum/go_quote.gif I really don't think a piece of wire would make that much difference in the sound quality.

Sorry, but I have to call you out on that one. I have done direct testing of different materials, even putting them to the scopes. Differences are distinct even using medium gear.

I have one question for you.

Does the headphone require less volume than when you first heard the new cable?

That is a sign of the cable "breaking in".

With solid core cables that use a single conductor, this kind of spikeyness is pretty common in my mind. I say that if you use solid core conductors, YOU ALWAYS USE MORE THAN ONE if you are doing a distance more than 0.5m.

What you might have is a "skinning" issue and certain emphasis placed based on the guage used (good for treble and mids in solid core). Silver has far less of this issue due to the properties inherant (like the larger internal resisitance and better transmit of signals in the audio range).

Quality of the cable used has a large part to do with it as well.
OFC solid core is going to be more spikey than OCC solid core.
the grade of silver used in conductors has a large part to do with bass response (yes, silver can have great bass - just needs to be the right kind and the right setup *my current LOD has no such issue*).

Material experimentation lead to a lot of discovery for me.

IMO - headphone cables should use stranded. Otherwise, you get signal phasing causing uneven response curves.

 

[threEchelon]

IIRC, the bass would be less because of the large gauge. Try some 28 or 30AWG.

 

[Madgravity34]

Thankyou guys for your replies, it really helped give me some insight.

Is there a way to get the cables back in phase or is that just with cable quality alone?

Also, I have spent some time listening to the phones, and they really do sound a lot better in terms of treble and mid response. The bass is only slightly reduced after further listening so it might just be a tonal change because of the different cabling.

Are there any other places that sell good copper cabling than HGA? Ill probably pick up 24AWG copper and 30AWG copper stranded and similar silver cables to test them out just to see the difference.

 

[threEchelon]

Quote:

Originally Posted by Madgravity34 /img/forum/go_quote.gif Thankyou guys for your replies, it really helped give me some insight. Is there a way to get the cables back in phase or is that just with cable quality alone? Also, I have spent some time listening to the phones, and they really do sound a lot better in terms of treble and mid response. The bass is only slightly reduced after further listening so it might just be a tonal change because of the different cabling. Are there any other places that sell good copper cabling than HGA? Ill probably pick up 24AWG copper and 30AWG copper stranded and similar silver cables to test them out just to see the difference.

If the wires are out of phase, it means that on one or more of the drivers, you have the + lead from the plug connected to the Ground terminal on the driver and the Ground lead from the plug connected to the + terminal on the driver. If you have a multimeter and you know which solder point is which on the driver, you can be absolutely sure if the driver is in phase.

 

[dsavitsk]

Quote:

Originally Posted by -=Germania=- /img/forum/go_quote.gif I have done direct testing of different materials, even putting them to the scopes. Differences are distinct even using medium gear.

You have some measurements that show these differences? Cause you'd be the first.

 

[-=Germania=-]

Yeah, when I get back to school I will try and get back into the labs and bring some materials with me.

I used a Freq generator to do a sweep of 20-20k.
Then used a scope to get a graph.

I need to get access to one of the nicer labs (which I will have for next year because of a course I am taking that is a circuit and machine design) that have the computer graphing hook-ups to the scope systems.

It looks much like the graphs that Headroom posts.

 

[beerguy0]

Quote:

Originally Posted by -=Germania=- /img/forum/go_quote.gif Yeah, when I get back to school I will try and get back into the labs and bring some materials with me. I used a Freq generator to do a sweep of 20-20k. Then used a scope to get a graph. I need to get access to one of the nicer labs (which I will have for next year because of a course I am taking that is a circuit and machine design) that have the computer graphing hook-ups to the scope systems. It looks much like the graphs that Headroom posts.

I have a spectrum analyzer on my lab bench that starts at 100 Hz, and a function generator that goes from DC to 15 MHz. The spectrum analyzer is a much better instrument for amplitude vs. frequency measurements than an oscilloscope. What exactly are you measuring? The response of the headphone with different wires?

 

[dsavitsk]

Quote:

Originally Posted by -=Germania=- /img/forum/go_quote.gif It looks much like the graphs that Headroom posts.

I don't find any graphs of cable performance on Headroom's site (am I looking in the wrong place?) But, I look forward to yours.

 

[Madgravity34]

@Echelon

Hey, I do have a radioshack multimeter and (luckily from computer voltmods

) I know how to use it lol. How would I go about checking if I have these hooked up? I already soldered the mini connector on and would like to leave that alone, but desoldering from the drivers is no biggie for me, so how would I measure it from there with the ipod running?