[Olimoronio]

Specifically, I picked up a pair of Realistic Nova 44 quadraphonic headphones at a thrift shop and was thinking about replacing the drivers with more modern ones and wiring them for stereo. Is there any benefit to doing this besides just having fun tinkering?

Here's some pics of inside the cup (please excuse the quality):

I was thinking about using these planar drivers but I read that they need a very small cavity to have any usable bass. Then I thought about filling the cavity somewhat by cutting triangle pieces of self-adhesive vinyl damping sheet to fit the top and bottom of the cup. Then I would cutout progressively smaller pieces and stair-step them up to the back of the enclosure. This would give me two drivers per side in what would effectively be a horn-loaded enclosure. Does this sound workable or would I need to stick with dynamic drivers? If so, what's a good source for them? Could I just use tiny full-range drivers like the ones HiVi and Tang Band make?

Like I said, I enjoy tinkering so any labor involved is not really an issue. I'm just wondering if I could have my fun modding these and the results be worth the $$$ cost of the drivers.

or

 

[ericj]

for the nova 44, sure, have fun, go nuts, learn something about acoustics too. But it's probably mostly educational value, and you'll have to make sure you overcome your excitement at having performed a modification that merely works and be critical of your own success to see if you've made any mistakes.

OTOH if you find yourself an old Realistic Pro 30 (not Nova Pro 30), there's some serious value to tweaking the damping.

 

[Olimoronio]

Thanks for the reply.

So basically what you're saying is that it's worth it just for the fun of it but I shouldn't get my hopes up too high about how well they'll perform... Gotcha.

Any comment on the planar drivers I linked to above?

What about very small full-range drivers? Will 1" full-range drivers like the ones that Tang Band and HiVi make work in this scenario?

 

[ericj]

The 120ohm SFI is a popular planar driver for hobbiests - i once bought almost a hundred of them at once. Very similar in construction to the driver in the Pro 30.

i don't think that tiny fullrange speaker drivers are a good idea for headphones.

 

[Olimoronio]

So in this application, with two drivers per side, would the 120ohm be preferable to the 32ohm version? I'd be running these off a cheap HotAudio USB DAC/HP amp combo unit that I bought off of eBay. Also, are you saying that you believe there would be sufficient bass even with the large cavities on the Nova's?

Really appreciate the help.

 

[ericj]

No i'm saying the tangband drivers would have too low impedance for the average headphone amp and aren't designed for such a small enclosure anyway. Plus it's a lot of money.

The classic problem with SFI retrofits as i see it isn't bass quantity but getting a good mix of bass quantity and bass quality. But it would be better to take this discussion to the orthodynamic roundup thread.

 

[Olimoronio]

Will do... Thanks again.