Pass xvr -1 problem in the setup

[tdh888]

Hi to all,

I was helping a friend of mine in his bi amp setup. He recently acquired a pair of JL Fathom F212 powered sub woofer. According to JL audio they strongly recommend that a high quality active x over should be used if these subwoofers will be used in 2 channel audio systems. This is because this subwoofers have only low pass filters and no high pass filters to prevent low frequencies from entering the main speakers or satellites. JLaudio recommended 80hz 12db/octace for both high and low pass filters. This we did to the XVR-1's. We followed both users manual but since 80hz was not available in the XVR's we set them at 75hz. When we listened the sound was very sharp, no body, no midrange frequency. Bass was present. It sounded horrible. We tried 88hz and it was worst.
To owners of the XVR's maybe you can point out what we forgot in the setup, suggestions, etc. Did you get it at once the 1st time.

This is his setup

VPI HRX w/ Clearaudio Statement

SME Model 30 w/ Lyra Kleos

Audio Research Ref Phono 2 SE

Audio Research Ref 40 Anniversary linestage

Audio Research Ref 750 monoblocks

B&W800 Nautilus Signatures

A pair of JL Fathom F212 powered subwoofers

Thanks in advance,

tdh888

 

[Steve Williams]

Why crossed so high

Mine are crossed at 43 Hz

 

[microstrip]

The B&W has a very extended bass response (anechoic 20Hz at - 6B). Considering your friend has the REF 750's you should use the subs mainly to compensate for room interaction. IMHO, the frequency settings will depend mainly on room size and placement. Steve advice of 43 Hz seems a reasonable first approach, but you also must be prepared to play with the subwoofer positions. Anyway you should get some measuring equipment - it can save a long of time of hard experimentation.

BTW, having experience with REF40 and REF250 I would never insert any active crossover in series between them, but perhaps others will thing differently.

 

[tdh888]

Why crossed so high

Mine are crossed at 43 Hz

We set it at 75hz because the the subwoofers manufacturer manual stated that if using an active x over 80 hz should be the setting for the low/high pass filters @ 12db/octave. Since 80hz is not available to the XVR-1s the closest was 75hz

 

[tdh888]

The B&W has a very extended bass response (anechoic 20Hz at - 6B). Considering your friend has the REF 750's you should use the subs mainly to compensate for room interaction. IMHO, the frequency settings will depend mainly on room size and placement. Anyway you should get some measuring equipment - it can save a long of time of hard experimentation

The subs were acquired to compensate for room interaction. The room ever since seems to be lean in the midbass(My friend has done a lot of upgrades w/ his electronics & front end's and the speakers are the only one's that has not been upgradeD) The plan now is to borrow another xvr-1 because were thinking that the 1st unit we tried was a defective unit.

 

[KBK]

The subs were acquired to compensate for room interaction. The room ever since seems to be lean in the midbass(My friend has done a lot of upgrades w/ his electronics & front end's and the speakers are the only one's that has not been upgradeD) The plan now is to borrow another xvr-1 because were thinking that the 1st unit we tried was a defective unit.

Pretty low odds of defect issues.


I suspect that you are getting a masking interference. largely, a phase alignment issue. move the subs, if the problem changes, then that is probably prt of the issue.

I have to ask, as it is pertinent: familiarity with the crossover? have the settings for slope and q been properly set?

This, as a pair of potential problems will get to sounding much like what you seem to be hearing.

Acoustics are major component of the audio system. No matter how much we think we know about audio, that is a primary point.

the sad part is that with no proper acoustics we are moving into being the equivalent of Ferrari owners who have no driving experience, and put dump trick tires on them.

back to the subject at hand. Lower the frequency on the sub end of the crossover. I believe that the Pass crossover allows for this. Move it to ~60 hz. if not, leave it at 75hz, and change the slope on the sub to 18db per octave.

This should give you some indications about interference, which is what your problem sounds like, on paper.

 

[microstrip]

We set it at 75hz because the the subwoofers manufacturer manual stated that if using an active x over 80 hz should be the setting for the low/high pass filters @ 12db/octave. Since 80hz is not available to the XVR-1s the closest was 75hz

As I was recently considering the JL212 I have the manuals. IMHO, you are misreading them - they do not say that 80 Hz should be the setting. They only say that 80 Hz is a commonly used setting . I quote the manual:

The Low Pass (LP) Frequency selector knob allows the user to choose the rolloff frequency of the Fathom’s internal low pass filter. The frequency is variable between 30 Hz (full counter-clockwise) to 130 Hz (full clockwise). This knob does not affect the input signal in any way if the LP Filter switch is set to “Off ”. 80 Hz is a commonly used filter frequency and usually serves as a good starting point for adjustments.

 

[GaryProtein]

tdh888

I use an XVR1 three way set-up on my IRS-V and it is WONDERFUL!

The XVR1 is by far the best analog crossover on the market. You bought the right one!

You are crossing over an octave too high. 80 Hz may be fine for the rumble of a HT, but clearly not NOT for two channel audio. You should be using 36 or 48 Hz points on the XVR1. Make sure the multiplier jumpers are OUT. The 12 dB/octave slope is what you should most likely be using.

VERY IMPORTANT: do you have the high pass and low pass jumpers set the same on the XVR1? They must be the same for a bi-amp system like yours.

The XVR1 is a complex instrument. Make sure you read the INTRODUCTION in the manual. They mean what they say, "some audio products are designed for anyone who can put batteries in a flashlight, this is not like that....." You MUST understand this crossover.

Lastly, when others who are not using an active crossover say they are crossed over at "x Hz" what is happening is the sub starts at "x Hz" and goes down, but their mains simply do what they have always done without the sub. YOU on the other hand, with an active crossover have set a point where your mains roll off and the sub "rolls on". It is two different situations. You want your sub to roll on low, especially if you have an otherwise powerful system.

The LP filter on the JL f212 should be set to "OFF". There is no sense running that filter also, since the XVR1 will be doing all the filtering and crossover points.

see my next post--soon for exactly what you should use...

 

[GaryProtein]

XVR1 Settings

Low pass: goes to the sub

Pole 1
36 or 48 Hz
X1

Pole 2
36 or 48 Hz
X1

Pole 3
OUT
OUT

Pole 4
OUT
OUT

High Pass: goes to your mains power amp

Pole 1
36 or 48 Hz
X1

Pole 2
36 or 48 Hz
X1

Pole 3
OUT
OUT

Pole 4
OUT
OUT

The use of Pole 1 and 2 gives a 12 dB/octave slope

Make sure you have the LEFT and RIGHT channels set the same!

Make sure the "SLOPE" JUMPERS are both set on the 6/12 setting on the low pass and high pass sections and the "FILTER Q" are set on "M"--the center setting. (usually the default setting when shipped)

Make sure for your set-up that on the circuit board where is says "OUTPUT BUFFER", under the second "F" in buffer, there are jumpers for "2" and for "B". YOU MUST SET YOURS ON "2". That is the default when it is shipped, so just make sure it is set on that. (The "B" setting is bandpass--you do NOT want that.)

You may find the 36 Hz pole settings to be better.

Another alternative might be to use only Pole 1 for all setting with Pole 2 OUT and use the resulting 6 dB/octave slope. I would definitely use the 12 dB settings first and see how it sounds.

Re-check the earlier post since I added to that too.



I think that about does it. If you have any question, you can post it (I'll read the XVR1 thread--there's not a lot of us users) or you can PM me.

Just as an aside, on my system, the volume settings are mostly between 11:00 and 1:30 o'clock, but that's just my system. Start out with the controls pretty centered and work from there.

 

[tdh888]

As I was recently considering the JL212 I have the manuals. IMHO, you are misreading them - they do not say that 80 Hz should be the setting. They only say that 80 Hz is a commonly used setting . I quote the manual:

The Low Pass (LP) Frequency selector knob allows the user to choose the rolloff frequency of the Fathom’s internal low pass filter. The frequency is variable between 30 Hz (full counter-clockwise) to 130 Hz (full clockwise). This knob does not affect the input signal in any way if the LP Filter switch is set to “Off ”. 80 Hz is a commonly used filter frequency and usually serves as a good starting point for adjustments.

Please read page 26-27 of the JL F212 owners manual. I followed the recommended set up procedure when using active crossover or bass managment processor.

 

[tdh888]

Pretty low odds of defect issues.

With the build quality of the Pass I doubt there's a defect.


I suspect that you are getting a masking interference. largely, a phase alignment issue. move the subs, if the problem changes, then that is probably prt of the issue.

I have to ask, as it is pertinent: familiarity with the crossover? have the settings for slope and q been properly set?back to the subject at hand. Lower the frequency on the sub end of the crossover. I believe that the Pass crossover allows for this. Move it to ~60 hz. if not, leave it at 75hz, and change the slope on the sub to 18db per octave.

Good suggestion we might as well try other frequencies and bends/slopes. Its just the XVR 1 is so flexible that its somewhat complicated for as audiophiles. I remember when I was using my ARC EC21 I did not have difficulties in using it. You solder the capacitors specified for your speakers and your on your way.

 

[tdh888]

tdh888

I use an XVR1 three way set-up on my IRS-V and it is WONDERFUL!

The XVR1 is by far the best analog crossover on the market. You bought the right one! We were choosing between the Marchand XM126 and the Pass XVR -1. We chose the Pass because it was available in our country and we can try it in my friend's system before buying it.

You are crossing over an octave too high. 80 Hz may be fine for the rumble of a HT, but clearly not NOT for two channel audio. You should be using 36 or 48 Hz points on the XVR1. Make sure the multiplier jumpers are OUT. The 12 dB/octave slope is what you should most likely be using.

We just followed what was in the owners manual of the JL audio set at 80hz both low/high pass filters @ 12db /octave. We will try other frequency from now on.

VERY IMPORTANT: do you have the high pass and low pass jumpers set the same on the XVR1? They must be the same for a bi-amp system like yours.

yes 80hz for both low/high pass filters @ 12db/octave.

The XVR1 is a complex instrument. Make sure you read the INTRODUCTION in the manual. They mean what they say, "some audio products are designed for....." You must understand the crossover.

Its very complex and thats why its so flexible. How I miss using my ARC EC21 and the Symmetry x over designed by John Curl

Lastly, when others who are not using an active crossover say they are crossed over at "x Hz" what is happening is the sub starts at "x Hz" and goes down, but their mains simply do what they have always done without the sub. YOU on the other hand, with an active crossover have set a point where your mains roll off and the sub "rolls on". It is two different situations. You want your sub to roll on low, especially if you have an otherwise powerful system.

This I will always comprehend & remember.
see my next post--soon for exactly what you should use...

Please post it asap so we can try it.

 

[GaryProtein]

see post #9 "XVR1 settings" posted at 11:46

To say the XVR1 is "somewhat" complicated is an understatement! It is the most complex component in your entire system.

Use a magnifying glass if you have to when checking the jumpers!

When setting the f212 volume, DON'T set it too high. It is supposed to supplement the mains, not hit you in the head and say, "hear me rumble." A pair of f212's is capable of serious house shaking. You won't be aware of its presence on all types of music.

 

[tdh888]

Thanks Gary will try this out.

 

[GaryProtein]

I'm happy to help.

I remember setting up mine.

 

[tdh888]

Thanks very much Gary, my friend is very happy w/ the current setting of 36 hz @12db/octave both the low/high pass filters. I would like to ask you what to expect if we use the 48hz setting. Its nice that you were able to determine the proper frequencies cutoff needed in his system. (Is there a computation / formula to determine the proper cut off or did you check out the specs of the B&W800) Your help is very much appreciated.

Thanks again,

tdh888

 

[JackD201]

I'll be back in a week. I can help out Papa P. if he'd like.

 

[GaryProtein]

Thanks very much Gary, my friend is very happy w/ the current setting of 36 hz @12db/octave both the low/high pass filters. I would like to ask you what to expect if we use the 48hz setting. Its nice that you were able to determine the proper frequencies cutoff needed in his system. (Is there a computation / formula to determine the proper cut off or did you check out the specs of the B&W800) Your help is very much appreciated.

Thanks again,

tdh888

I can't say what to expect with the 48 Hz setting. I based the crossover frequency suggestions on the specs and capabilities of your speakers and my experience "playing" with my XVR1 crossover. There is no formula. That's what makes it so much fun=frustrating and time consuming. You have to test it out!

The 48 Hz setting may give you more or less bass, depending on how you set the volume on the f212. You may or may not like it better, you have to try it out. DON'T make changes quickly unless you hate what you hear. If you are close, you should listen and live with it for a while. Once you are close, which it sounds like you are, make SMALL changes in the volume levels of the subwoofer. Again, as Nelson wrote in the XVR1 manual, you will be tweaking it for a long time before you achieve exactly what you want. I would tend to keep the crossover point on the lower side and let your mains do most of the work, but that ISN'T a rule. EXPERIMENT and see what you like.

Write down your settings each time because you might find your changes start to go down hill, and you need a record of what you had that you really liked. so you can go back to them.

 

[tdh888]

You're the Man, Gary w/ regards to this XVR-1s. Thanks for sharing you're knowledge and experience.

 

[tdh888]

I'll be back in a week. I can help out Papa P. if he'd like.

That would be great!