Townsend Labs Sphere Hacking

[kingkorg]

After seeing a video on YouTube, and couple more images i am 99% sure Sphere uses regular 797audio k67 like Behringer B2 for example. Red/Yellow wire combo is another giveaway. Saddle looks like 797audio as well. Capsule graphics in the manual look exactly like 797audio capsule. So i changed the capsule in my dual output mic for 797 audio one.

My Quick Dual Output Mic:
https://groupdiy.com/index.php?topic=69193.0

Sphere mic closeup:

By measuring the Sphere plugin and all the emulations against expected curves, and some of the mics i have measured in the past i came to conclusion that the original Sphere mic has high end attenuation circuit built in. It is similar to the u87, but a bit more aggressive.  Their Sphere Diffuse model  actually compensates for this roll off. It probably serves as a safety feature if someone tries to use 3rd party mic, and for some off axis modeling explained in the manual. The curve is easy to extract from the plugin.

Long story short, if you use dual output mic with k67 from 797audio and apply this kind of eq curve before the plugin you get the Sphere mic for cheap. The plugin is still free for download

This setup matched two vintage u87s i have measured within 0.5db in every pattern for example.  Their flat model in cardioid matches my ECM8000 response, less low end in omni naturally, sm57 is very close as well. my c12 and u47 replicas are scary close.

Again, even without any emulation with a DIY stereo out mic free Sphere plugin is extremely useful tool.

 

[Wordsushi]

Nice detective work! Bravo.

I've been contemplating this very same topic. Please continue to update this thread with your discoveries.

 

[kingkorg]

Well i hope ill get my hands on one, and measure it to be sure.

Until then i have fine tuned HF attenuation curve, and got some crazy results.
Here are few examples. Right click, open in a new tab.

Real vintage u87 against my Sphere. Blue is Sphere.

My u47 clone against Sphere. Green is Sphere model

My c12 clone with Tim Campbells capsule against Sphere.  Magenta is Sphere model. Slightly darker, but the curve is there.

 

[Wordsushi]

Pretty slick, Slick.

Did you wire the output to a 5 pin XLR or just direct wire a couple of mic cables to the PCB's? 

Next weekend, for laughs I may try to throw together a dual output mic like this with a couple of pimped alice boards. I think I still have an old 32mm K67 taken out of an Apex 460 to try it with for the time being.

 

[kingkorg]

I just used dual cable from pcbs to two xlrs.

I can send you this high end deemphasis curve i've fine tuned. I used Voxengo CurveEQ. It is CSV file, so it can be converted to impulse response, or loaded in some other VST.

 

[kingkorg]

Can't give away the source, but i got confirmed that the capsule is indeed 797 audio capsule.

 

[bremusound]

Nice project!!
Do you know if it's the 3 or 6 micron 797 capsule?
Thanks

 

[kingkorg]

Unforyunately not, but they dont differ much. It's mostly tiny transient response difference, noise, and max spl.  Frequency response should be the same.

 

[rmaier]

I can send you this high end deemphasis curve i've fine tuned. I used Voxengo CurveEQ. It is CSV file, so it can be converted to impulse response, or loaded in some other VST.

Hey Kingkorg, thanks for this information. I just made up a dual output mic around a pair of pimped alice boards and a 67-style capsule I had lying around. I think it's going to be a very useful mic, especially with the Townsend plugin. I have a copy of CurveEQ as well. Would you mind sending me your CSV file?

Ralph

 

[kingkorg]

Sure, let me just get to my pc. And by the way, Austrian Audio just posted their pattern control software on their site. It's free, and it lets you control pattern response for individual bands. It can be use with any dual out mic.  It's in beta, they appreciate reporting bugs if any.

https://austrian.audio/produkt/polardesigner-2/

 

[kingkorg]

Here it is. This is the latest, and most precise tuning for k67 from 797 i use. Just use it with CurveEQ as an insert before Sphere plugin.

https://app.box.com/s/nq2a3rsi961z8dimr6rra0t5fpm88by8

 

[Icantthinkofaname]

So the sphere is a dual output mic using the 797 version of the K67, and by using 797 capsule, and you can use the mic modeling plug in after rolling off the high end to achieve the same results as Sphere?

So could you do something single output mic if you just want to emulate the frequency response? If you used something like 3U Audio's flat K67 capsules or a properly attenuated capsule you should just be able to use the modelling plug in right? Or does the plug in require you use a dual output mic?

 

[cyrano]

Very, very interesting!

Thanks for your efforts. I always look forward to your posts.

 

[kingkorg]

So the sphere is a dual output mic using the 797 version of the K67, and by using 797 capsule, and you can use the mic modeling plug in after rolling off the high end to achieve the same results as Sphere?

So could you do something single output mic if you just want to emulate the frequency response? If you used something like 3U Audio's flat K67 capsules or a properly attenuated capsule you should just be able to use the modelling plug in right? Or does the plug in require you use a dual output mic?

Dual out mic has to be used. Plug in has different type of curve for back and front diaphragm. High end roloff has to be used with any kind of capsule as it is steep, this is important for off axis response. If you look at csv file i provided you'll see that kind of response is not typical for any kind of capsule.

 

[rmaier]

Here it is. This is the latest, and most precise tuning for k67 from 797 i use. Just use it with CurveEQ as an insert before Sphere plugin.

https://app.box.com/s/nq2a3rsi961z8dimr6rra0t5fpm88by8

Thanks very much - greatly appreciated. I've just been playing with this a bit. Thickens things up nicely, doesn't it?

 

[rmaier]

Sure, let me just get to my pc. And by the way, Austrian Audio just posted their pattern control software on their site. It's free, and it lets you control pattern response for individual bands. It can be use with any dual out mic.  It's in beta, they appreciate reporting bugs if any.

https://austrian.audio/produkt/polardesigner-2/

Played with this one a bit, too. Not sure just yet how I'll use it, but I have a feeling it will come in handy. Pretty mind-blowing potential, and I think it could take a bit to learn how to get the most out of it. Have you used it much?

 

[kingkorg]

Well, i have approach that i have a great k67 dual output mic with amazing control without any emulation. You can just use it stock, and play with pattern controll. If any emulation turns to be usefull from time to time it's a great bonus.

However i use it all the time as a room mic paired with a u47 type mic i have built in M/S configuration.

True tube u47 type mic is used as cardioid, and my Sphere version is set to f8 u47 emulation. I get incredible stereo image control with Sphere plugin in that combo.

And it sounds pretty much the same as my u47 mic replica.

 

[kingkorg]

Here's the pic.

 

[rmaier]

Cool, I totally get it. What I meant to say is, I'm not quite sure how I'll end up using the Austrian Audio plugin. I'll need to play with it a bit more.

I've only tested the Townsend with spoken voice, but it's usefulness is immediately evident, so much so that I'll build a second mic to pair with it.

Cheers,

Ralph

 

[rmaier]

Here's the pic.

Nice mic ****. What kind of capsule is in your U47 build?