GR Research Super-V

[Tickwomp]

Had the pleasure to hear a pair of these last night and I think I'm in love.  DiY, 97db, and incredible bass (driven by 700 watt monoblocks kind of overkill).  Anyone else listened to these?  Speakers are my weakest link now, and I need to do something about it. 

Comments?

[Paul Joppa]

Any info on impedance vs. frequency?

[Tickwomp]

Any info on impedance vs. frequency?

8 Ohms, and supposedly flat down to 20hz. Extremely solid down low with twin servo driven 12" woofers. Not tons of specs on the website, but I've got an email into the owner.

The top end was interesting as well with a coaxial mid and tweeter.

[corndog71]

The coax is made to be an easy 8 ohm load for an amp.  The subs take over from I think 200Hz down and are servo controlled by a 370 watt amp per channel.  The subs are no joke as I built a single sealed version myself.  

I haven't heard the Super Vs but I've heard many of Danny's other designs and own several of them.  The man has a talent for speaker design.  I admit I'm biased.  

http://gr-research.com/super-v.aspx

A fellow bottlehead drives a pair with his Stereomour if I remember correctly.

[Grainger49]

I think Paul was asking for a graph of impedance vs frequency to see if it is a tube friendly load.  Rob mentions a tweeter, I'm guessing there is a midrange too, and a crossover.  All affect the impedance curve.   

The input impedance of the sub's amp(s) is most likely resistive.  

I think Paul's point was that there are high sensitivity speakers that have peaks and dips that make them perform poorly on SET amps.

Oh, I have to agree, 700WPC on a 97dBW speaker, that is the definition of overkill.

[corndog71]

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwww.gr-research.com%2Fmis%2FsuperVimpedance.jpg&hash=c4e3f938b9e36c0885d1a12ea77f3b4206373f8e)

It took me a bit to find it but here's the impedance graph of the coax.  It's designed to be an easy 8 ohm load.  Danny was able to get 105 dB peaks with just a 15 watt tube amp.

Here's a shot of the back.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwww.gr-research.com%2Fmis%2Fopenbackside.jpg&hash=5a4f00a027eaa3892d818c37ac2af374c80c544d)

The kit comes with one servo amp per pair of 12 open baffle subs.

[Paul Joppa]

The impedance above the LF resonance looks fairly well controlled. The open-baffle woofer is a surprise - no wonder there are two 12" drivers! I just note that 105dB with 15 watts translates to 93dB sensitivity - I suppose there are measurement details that explain it, like whether it is sine wave, whether it is at 1m distance, and whether it is anechoic. Richie certainly has a great reputation.

[Tickwomp]

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwww.gr-research.com%2Fmis%2FsuperVimpedance.jpg&hash=c4e3f938b9e36c0885d1a12ea77f3b4206373f8e)

It took me a bit to find it but here's the impedance graph of the coax.  It's designed to be an easy 8 ohm load.  Danny was able to get 105 dB peaks with just a 15 watt tube amp.

Here's a shot of the back.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwww.gr-research.com%2Fmis%2Fopenbackside.jpg&hash=5a4f00a027eaa3892d818c37ac2af374c80c544d)

The kit comes with one servo amp per pair of 12 open baffle subs.

WANT!

[corndog71]

WANT!

Me too!  I just wish I had the money and the space for them.

[Jim R.]

ebag4 on this forum has the V1s, which have the same coax driver but different subs, and he's driving them with a stereomour quite well.

I spent a lot of time listening to these at RMAF in 2010 and they do an awful lot right, but for me personally, the tone was just not as I would like it.  Dynamics ad transparency galore tho9ugh.

I was going to build the smaller brother, the V2s, but I simply don't have the room to pull them out far enough from the front wall -- even the minimum 3 feet did not meet with approval :-).

I think the V2s made of something like plyboo instead of MDF would be a more tonally satisfying design to my ears, but that's just me.

HTH,

Jim

[corndog71]

Actually the V1 has a cheaper coax by the same manufacturer and the same subs/servo amps.  It was also designed with a rear firing tweeter vs. the open backed tweeter of the Super V.  The coax of the Super V is a lot better but it also costs more.