Subwoofer crossovers

jadedavid

I was always using Vandersteen subs with Vandersteen and other brands of speakers when I was using the high pass system so I just used the X1 filters that were sold through Vandersteen dealers. Over the 15+ years I used the subs I went through so many different amps I owned pretty much every value of X1 they sold from 10k to 100k. I still have the subs and the most of the crossovers but they are all SE. They are spec'd for the input impedance value of the amp on the outside but I don't know what values of parts on the inside. When you order from Ayre and Aesthetix the dealer tells them what the spec is for your amp and they add the resistor/capacitor to match to what the Vandersteen subs need before shipping. It is required that you use the high pass system with Vandersteen subs but when I switched to the Rythmik subs I just connected them high level and ran the mains full. One of the speakers I ran with the Vandersteen subs were the Offrande's and both they and them amp seemed to benefit from the high passing. I suspect your final version of the Offrandes would see some benefit too. I found this article and calculator on line for making the parts determination and wiring diagram but the actual calculations I will leave to someone with more EE background than I have. We've got several members here like Ralph(Atmasphere) and others that probably have a better understanding of this than I do as I depended on Richard Vandersteen's expertise.
 
Thanks Jack.
I am using a .o22 cap in series to my line magnetic amp which has an input impedance of 100K. This gives me a 6db roll off starting at 70hz.
Works really well with my Reynauds. This is in a single ended application.
A calculator is available at Learningaboutelectronics.com/articles/high-pass-filter-capacitor-calculator.php#answer1
 
The Offrande's are a great speaker. I actually owned the review pair from Bob's PFO review back in 2003 for about four years. When I bought my Abscisse Jubilee's I was actually calling Bob to buy the last ever pair made of the Offrande Supreme V2 that were sitting in the warehouse of the Canadian distributor. Over the course of a half hour discussion Bob talked me into buying the Acscisse Jubilee instead as he had just sold his Supreme V2's and swapped to the Abscisse. I currently have my eye on the new Grand Voce which would be the replacement for the Offrande as Jean Claude could no longer get the parts necessary to continue with the Offrande and no idea what parts he has in reserve though that should never be an issue. Will have to be after the first of the year though as currently far too many speakers around already.
 
Randy

I think you are probably going to be pretty close with the first try but your ears will tell you in the end. One thing to consider though as from looking at the picture of the balanced Fmods on the Harrison web page they look to be fairly long. So like the balanced Rothwell's they could over time put stress on the amps XLR connectors so best to start looking for something simple to prop them up like a piece of foam, etc. I ran into that issue with the Vandersteen X1's and had to swap out the SE input connectors on a Belle's amp after a couple of years.
 
Jack said:
Randy

I think you are probably going to be pretty close with the first try but your ears will tell you in the end. One thing to consider though as from looking at the picture of the balanced Fmods on the Harrison web page they look to be fairly long. So like the balanced Rothwell's they could over time put stress on the amps XLR connectors so best to start looking for something simple to prop them up like a piece of foam, etc. I ran into that issue with the Vandersteen X1's and had to swap out the SE input connectors on a Belle's amp after a couple of years.
Click to expand...

Good suggestion Jack. The Audioquest cables come through a cutout in the center of the rear metal panel. It is about half way up the height of the shelf. There is also a considerable amount of space behind the Hattor so I am thinking that the cables will get extra support.

The only unit that does not have a lot of space behind is the MBL. That sucker is deep!
 
Do the Fmods go on the amp or preamp end? The Vandersteen units went on the amp end. With the Rothwell's you could order them either way.
 
Harrison Labs appears to be a good company. I left a message just to verify if they received my order. A nice lady called me back to tell me they did get my order and make these to order. Mine will be shipped Monday!
 
So the High Pass filters arrived on Monday. Therefore the lady who called was incorrect :D, they didn't get shipped on Monday they arrived on Monday! I can't remember the last time something actually arrived ahead of schedule. :)

I listened for a little bit last night, only in mood for digital... didn't feel like changing records, etc. Hard to describe the differences and I am sure like most things break-in is going to come into play (the KEF's are probably not totally broken in yet :) ). I definitely liked what I was hearing. I would say everything sounded a bit more relaxed and open. Definitely added to the amazing disappearance act of these Meta's, it was even more so (which I was surprised about). The mid lows and bottom end was more defined with a complete lack of any kind of muddiness.

I have to pull out some of my better vinyl and really put this through its paces, but on first listen I have to say it is nothing but good improvements!

I also cannot say enough about the quality and service from Harrison Labs. I highly recommend their products.
 
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