Biamping Everest II

[wolfgang]

I want to drive my Everest II in biamping mode with an active corssover.
What are the settings for the XVR1 from Nelson Pass ?
Who can help me

[rs237]

Hallo Wolfgang ,

willkommen im Forum. Zu deiner Frage : Das kann man nur bei einem persönlichen Besuch bei dir feststellen.

Welcome to the Forum. To your question: That can only be a personal visit with you to determine.


regards
juergen

[Robh3606]

Heres the manual

http://www.passlabs.com/downloads/xvr1_om.pdf

Looks straight forward just match the voltage drive to one of the curve and Q families to start out. You may not get a perfect match or may need to actually measure the voltage drive from the network to confirm it's correct.

That should be enough to get you started

Rob

[wolfgang]

Hallo Wolfgang ,

willkommen im Forum. Zu deiner Frage : Das kann man nur bei einem persönlichen Besuch bei dir feststellen.

Welcome to the Forum. To your question: That can only be a personal visit with you to determine.


regards
juergen

Hallo Juergen

toll, wann und wo ?

ich komme aus Burgstädt bei Chemnitz

Gruss

Wolfgang

[wolfgang]

Heres the manual

http://www.passlabs.com/downloads/xvr1_om.pdf

Looks straight forward just match the voltage drive to one of the curve and Q families to start out. You may not get a perfect match or may need to actually measure the voltage drive from the network to confirm it's correct.

It's really all there.

Rob

thanks Rob


i have used this voltage drive

first I used following settings

high pass 12 dB 750 Hz Q = high
low pass 24 dB 590 Hz Q = middle

a measure with the soundcard of my laptop and kirchner software was near equal these curves

but the sound was sometimes not so good
than I tried

low pass 24 dB 530 hz Q = low

now it was better

it is not so easy to get the best settings, because I have no measure equipment

in the XVR1 manual there are over 1 million choices to get the right settings

regards

wolfgang

[Robh3606]

Have you tried contacting Pass Labs?? You may be able to adjust/tweek both the Q and one of the set crossover points with some part value changes. The way you are now you can't hit the exact recomended crossover frequencies with the stock choices available in the network. Also don't know if the stock filter Q's are correct.

Figure you have points at 480,530,590,750,880Hz You need 550Hz 600Hz and 770Hz

Try sending Ian an email/PM. He was building a crossover based on this and he may have contact information at Pass Labs he can share with you.

http://www.audioheritage.org/vbulletin/member.php?u=10

Hell of a set-up!!!

Good Luck

Rob

[bigyank]

Wolfgang, welcome!



Please, I would love to see them!

Yank

[Ian Mackenzie]

I would suggest you email Passlabs.

They offer very good technical support.

Make sure you have phase continuity with the amps...that can cause a lot of confusion with your crossover settings

Okay, I skimmed through the manual and look at the network schamatic.

While the overall target slopes are acoustically 24/24 db for the 1501AL and the 0476Be (Gee I wish I had pair of them from K.K) the electrical networks for the woofer appear to be a tailored 24db slope and the compression driver 12 db.

The Q of the filters is the key. What happens is when the characteristics of the woofer and the horn combine you get an overall 24 db acoustic slopes and a smooth transition in the crossover region.

So I would keep it simple to start with and set the XVR1 Low pass filter set for 24 db by using two medium Q settings in each 12 db filters @590 hz and the High pass filter set for 12 db high Q @ 750hz and see how that goes. Make sure the passive crossover bar are set correctly for biamp mode. (refer to the manual)

Then try modifying the XVR1 Low pass filter with the first 12 db slope set for 530 hz with Medium Q and the 2nd 12 db filter set for 590hz with a high Q setting and see how that goes. The higher Q setting results in higher phase shift.Try different Q settings and see how it goes

The product of the Q is the Q of each filter (x) each other. The filter Q JBL have chosen has spread crossover points and different Q settings but the overall Q is 0.595. The a standard LR filter has a Q of 0.49. The higher Q offers a tighter knee in the crossover point and a greater phase shift.

What this is all about is getting a nice smooth transition on that 700hz region with the combined horn characteristics and the high pass filter. Any adjustment in this frequency range will be quite audible and should be carefully reviewed with a known program content.

I dont know specifically what Low, Medium and High Q is in terms of a specific value of Q for the XVR1. Low Q is usualy 0.49, high Q is 1 and medium is 0.707 .

Passlabs will be able to offer more specific information on the Q settings.

To avoid confusion and going completely cross eyed with the settings have your digital camera handy and take a close up image of the settings with the lid removed of the XVR1

Follow the procedure carefully in the manual for setting up the rear bars and in the XVR1 manual. This is really important



Ian

[edgewound]

With all due respect to Wolfgang....

I've heard the Everest II and met with Greg Timbers at the CES '07.

I wouldn't see...or hear... the benefits of biamping such a phenomenal system when so much effort was put into the passive networks and drivers to make this system so pristine to begin with.

Load up on plenty of great dual mono power and then sit back and enjoy the music.

[merlin]

Having heard the Everest a good few times now in a variety of systems, my feeling is that one really needs to isolate that lower 1501al and actively drive that, leaving the rest of the speaker passive. I don't know if the jumpers make this possible.

I'm of the (probably unpopular ) opinion that active biamping in this manner is the likely cure for the bass issues I personally have heard in each of the setups I've been lucky enough to listen to.

[Ian Mackenzie]

Edgewound,

I agree its a bit fiddly and so on but this is often the case in the quest for the ultimate.

Wolfgang is indeed fortunate to have such fine equipment.

A set of X600.5 mono blocks would be quite something.

Wolfgang, I have sent to a pm with Pass Lab contact details.

Ian

[Rolf]

wolfgang ...

Can we have some pictures of your system??

[timc]

wolfgang ...

Can we have some pictures of your system??

I second that question




-Tim

[Mr. Widget]

I would suggest you email Passlabs.

They offer very good technical support.

I would also contact your JBL dealer... if they are selling a system of this caliber, and making the profit from the sale, I would expect excellent support. I would have them contact Pass Labs and work out the best angle of attack.

Merlin brings up another issue... he has been disappointed with the bass of the system... so he is suggesting a possible solution for that. I have only heard the system in one location, but I thought the bass was quite good stock.

Wolfgang, how does the system sound in your home in fully passive mode? Are you going with the biamp alternative because you are disappointed with some aspect of the sound of the system or are you doing it because you have the XVR1 and want to play around with it?

Unless you have years of experience using active crossovers and or experience designing passive networks, the likelihood of making a really top notch system like the Everest II sound worse than stock is quite high. Of course there is no harm in trying as long as you take precautions not to blow up any drivers. (Read the safety notes in the Pass Labs manual!!!)


Oh, and welcome to the forum, and congratulations on your purchase!


Widget

[Robh3606]

Unless you have years of experience using active crossovers and or experience designing passive networks, the liklihood of making a really top notch system like the Everest II sound worse than stock is quite high.

He really needs to verify the final Voltage Drives are correct on the active network.

Rob