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View Full Version : FOCAL Speakers! X-over and cable mods



UV101
27-01-2010, 22:50
Hi guys,

I think it was Andre who asked about my mods to my Focal 716v'a.

Just for background, I've had these speakers for 15 months and I was a right pain in the arse for Audio-T in Swindon when I was trying to make my mind up!

I tried several speakers at home over 3 or 4 weeks! I had a set of Kefs (don't recall the model) which were about the same price and they were just plain awfull! I ran them for about 30 seconds and they sounded like they were still in the boxes!!!

I um'd and ar'd over floor standers (which I have always had) and standmounts. Although i know that there are plenty of standmounters that would put my current choice to shame, I can't seem to get my head around the physics. To me (and I'm not suggesting this theory is right) Stand mounters can't go down low enough (open flood gates for abuse!). I know they do, but for some reason I am completely turned off the idea!

I also tried the next model up the 816V. These are slightly bigger, and have an additional downward firiing bass port. I've also auditioned the WSE versions wich have the 'W' cones (found in their megga expensive range) but tbh at the time, the rest of my system wasn't up to the difference.

My choice was made purely on the fact that I didn't hear masses of difference between all the Focals i listened too!

As my System has got better i've made a few changes to the speakers too.

My experience with Mundorf Supreme caps, lead me to look at the x-overs! I'd been using them as DC blocking on the output of my CDP for several months and was very impressed with the transparency. The CDP became more open and dynamic upon installation.

Based on the theory that the best cap is no cap, any inferior quality caps in the audio path must be bad?!?! X-Overs have several caps that ususally fall into this catagory!

Time to open the 4 month old cabs! :lolsign:

Upon inspection, I found a crappy little elco bp6.8uF on the low pass filter and a small MKP on the mid. I decided to spend the considerable amount required to replace them both.

The 6.8uF went on to the LPF and I mistakenly ordered 2.7uF for the mids instead of the 3.9uF I needed. I ordered additional 1uF ampohms to bypass the 2.7's giving me a total of 3.7uF where the original 3.9uF's were!

What did this do for me? Pretty much exactly what I expected. The sound stage opened up. There was more punch and overall character became more aggresive, faster with more attack and most importantly no unruleness under louder volumes.

The attached pics were taken during phase 2! I aquired some odd lenghts of Kimber 4TC (same as I use for speaker cable). I used these to rewire the whole speaker. I made several other system changes at the same time so I cannot comment on the effectiveness of the rewire. It could be that it made no audable difference at all. However, I know its there and it makes me smile! lol

A couple of pics for you. I do recommend having look at your own x-overs. In future, the 1st thing i'd do with any speaker is to throw away and electrolytic caps lurking in there!!!

edit:- how do you upload larger pictures? I'm limited to about 97k which is a resize of 12% :-(

Kris
27-01-2010, 23:47
Well done that man!

It never ceases to amaze me how they can sleep at night knowing they've put cheep components in gear, yet charge an arm and leg for it.

I'll hopefully be rebuilding my X-overs this year and have chosen Mundorf as well :)

Of course it must be said that any component substitution will invalidate the guarantee, but you already knew that :lolsign:

UV101
28-01-2010, 08:10
Why Thank you!!!!! :cool:

Indeed the manufacturers componenet choice does leave a lot to be desired! Previously I did manage to blow up one of the elco's in my Mission's. Very impressive!!! Smoke and smell from the reflex port! Seemed a bit strange that i'd blow the x-overs and not the cones?!

I'm sure as the price goes up, so do the -x-over component quality but i'm not sure many would go of the extent of Supreme's! Even this considered, i'd use mundorf MKP's at least in every x-over (would have cost about £8 per speaker here).

It was pointed out over on the diyaudio forum that it was a bad idea, and that the whole balance of sound created by the originally carefully selected x-overs would be lost! My response "rubbish!". Are you telling me that the components within the x-overs were chosen by hand following listening tests? I suspect that they were chosen based on cost using the output of some computer program!!!

One thing to note here is the change in value. I think i did work out that this would raise the x-over freq on the tweeter. As these are considered fairly bright sounding so I was not worried at all about this albeit I will have effected the output characteristics. I'm pretty sure to my ears, having tried on freq sweeps that i've really not created any significant dips or holes in the freq response!

One other thing to note here, the 7xx and the 8xx series speakers appear to use the same internals!;)

If you were thinking about it, personally i'd give it a go (if you're not worried about the warrantee of course!)

Kris
28-01-2010, 13:17
I'm no expert. But here's my thinking on this:


It was pointed out over on the diyaudio forum that it was a bad idea, and that the whole balance of sound created by the originally carefully selected x-overs would be lost!

I've read this a lot as well, and it does make sense. If a manufacturer has used quality caps such as Mundorf or Auricap etc then these have obviously been specially chosen, and any 'upgrade' would actually be just a side-grade and could well negatively affect the sound.

However:


My response "rubbish!". Are you telling me that the components within the x-overs were chosen by hand following listening tests? I suspect that they were chosen based on cost using the output of some computer program!!!

I agree with you. These caps are bog standard cheapies, To think that someone has sat down and compared the sound of these Vs other cheapeies stretches credibility too far, especially when you consider the 5% (at best) tolerance rating. 5% tolerance means that two identical caps could vary electrically by as much as 10%, so the only way these could have been chosen for their sound quality is if they've been graded and matched. Can we really believe that the company is going to spend money grading and matching cheap caps, especially considering the high reject ratio that goes with it? Nah, I suggest it would be cheaper for them to use better quality close tolerance caps in the first place.

As you say, the elco caps in your Focals were chosen "based on cost using the output of some computer program". It's the only sensible answer. And because they were not graded and matched, your speakers were most likely running below spec in the first place!

Upgrading the caps to Mundorf 2% tolerance can only improve the sound quality and dramatically increase the likelyhood of the speakers running to spec. It's a no brainer. . . .