Speaker crossover mod. Your advice?

Hi Byron, what was the result of the cap replacement in these speakers? interested to know your results

Thanks
Kris

Hi Bryon,

have some new infos for the 1027 BE fans. Last week I added the Yamaha RX-V2067 AV Receiver to the equipment and used the YPAO calibration function. It complained, that the phase of the 1027 would be wrong connected, but this was not the case. So I asked my self, why does the software report this error. Since I had made fotos of the crossoverboard from front and back sides incl. the wiring I took a look at it. And what surprise, the minus pol of the input terminal is connected to all drivers plus pol except the mid driver. In my opinion, this is the reason, why voices do sound thin and wider than usally experinced.
The YPAO SW is able to calibrate reflection and frequency and so, does equalize this unusual turns in phase.
Since your fotos do show the same crossover board with the same wiring, this is not a factory fault. That is the way focal want let the LS sound, but as reported doesn't satisfy me fully.
I turned the polarity at the input terminals and calibrated again. The error diappeared. Voices are now more in forground and not so thin, the sound not so bright and not unnaturally wide.
The RX-V2067 did neutralize bassmodes of the room and made slight modifications to the frequency response, to have it more linear. With this setup I am now very happy with the focal 1027 BE.
Would be intereseted to here, if anyone experienced the same or could retrace it.

Best Regards

Hifisoundguy... By that you mean a single "full range" driver.

Sorry to rain on your parade, but full range drivers have a mechanical crossover due to cone breakup. The dust cap and innermost portion of the cone are the tweeter. Such a mechanical filter is difficult to design, hard to manufacture consistently, and prone to wear-out change.

Hi Hifisoundguy,
Go ahead and get some Focal 1027's, remove the crossovers and let me know how it goes.

I hate to break the news to you BUT the best crossovers is NO crossovers AT ALL ! Crossovers just degrade the sound !

Hi Bryon, have you got pictures of your finished crossover to share? Thx

Hi Bryon,

thanks for your help. In the meanwhile I could get in contact with someone of the Focal service. He told me, that the mid drives of the S and BE are the same but the casing box construction and the crossover board differs. The S is softer tuned. The S doesn't have the beryllium tweeter.

louk

The other midrange was too faint to read as well. Judging from your picture of the rear of your driver, I'd say our midrange drivers are the same. So I don't know what to attribute the difference to.

bc

Hi Bryon,

yes, midrange driver. Here is a photo of mine: http://img855.imageshack.us/img855/4416/mid6w4361back1.jpg.
If you like, you may look on the second mid driver, whether the label is there better readable.
I would assume, that your 1027 BE was later produced an may have been improved a bit. On the crossover C1 changed from 3.9uF to 3.6 on your board.

louk

Louk - The serial number is 10E005493.

Which midrange chassis is built in your BE (my is as stated 6 W 4361)?

By "midrange chassis," do you mean the midrange driver? If so, I'm not sure what its designation is. I looked at the back of the driver and the information was so faint that it was unreadable. Here is a photo of the midrange driver:

midrange driver.

bc

Hi Bryon,

before I got the 1027 BE I did have the Trent II from Castle, a wonderful sounding little loudspeaker combined with an Infinity subwoofer. Not that perfect as the Focal but not so far of it. For the price, absolute high value. If I compare the 1027 BE with the Trent II and with other loudspeaker, the midrange is to thin. Also my ear is missing some pressure in the mid (voices and some instruments). Clearly it may also be a matter of taste, but I don't beleave, that it is only that. Maybe they changed something in the series. Which midrange chassis is built in your BE (my is as stated 6 W 4361)? The serial number of my BE is 10A 000 115, but there is nowhere a date of production.
One point but very unlikely could be, that the mid chassis has a lost of efficiency. Electrically I could not find a problem. I did wobble the voltage at the mid with a tone generator and checked the wave with an oscilloscope. Below 2kHz it gets a maximum of 80% amplitude of the crossover input. The impedance of the mid is 7 Ohm, I expected 8 Ohm, but I have to verify that with a better multimeter.

louk

Louk - The "s" in the first sentence of my post was simply meant to be plural, as in "my Focal ten twenty sevens." I had forgotten that Focal made a speaker designated 1027S. Sorry for the confusion.

In any case, I do indeed have the 1027be, and I can say that I don't have the same problem in the midrange that you are describing. I don't doubt what you are hearing, but I wonder if there's an issue elsewhere in the system. I have found that the 1027be is rather revealing of issues in upstream components.

Bryon

I haven't read all the posts, so- someone may have already mentioned the sonic benefits of observing the directionality of film caps. Most of the better ones are marked, in some way, as to which lead is connected to the outer foil. Good tips, especially(in your case) point three, here: (http://www.audience-av.com/capacitors/a_applications.php)

Hi Bryon,

in your first post on top you wrote in the first sentense: "I'm considering modding the crossovers of my Focal 1027s".
So I thought you have the 1027 S version. Then this is a misunderstanding of me. I was questioning for the differences of both (BE and S version) to adapt the midrange design of the 1027 S to the BE. This is supposed to be more present than on the BE and results in a more round and warm sound. But since you have also the BE, you can't answer my question. What a pity.

louk

Hi Louk - I have the same speakers that you have, the 1027be.

I'm not sure I understand your question. Are you asking about the crossover, the drivers, or the enclosure?

Bryon

Hello Bryon,

I have a Focal 1027 BE spreaker, which is simular to your 1027 S. I like the detailed sound very much, but what I am dissatisfied with, is the midrange. Its to thin and lightweight.
So I am thinking of a modification and found this thread.
I analysed the crossover circuit. It has as your 1027 S, the same layout, board and parts except C1 for the beryllium tweeter section, which has 3.9uF instead of 3.6. The inductors (winding, size) looks very much the same.

Since it is reported by other users, that the sound of the 1027 S is warmer and more filling especially in the midrange, I would like to check, wether the sound can be adapted to the 1027 BE.

Mid and tweeter have on both speakers the same crossover frequency, which is about 2.2 kHz. So this can not be the difference. The used mid chassis in the BE version is Focal 6 W 4361. Can you tell me, which one is build in the 1027 S (top chassis of the speaker)?

Either they used different mid chassis or they modified the inside of the box. Maybe there is no path through below the mid or tweeter to the woofers (closed chamber). Did you make photos from the inside or do you remember how it looks like?

Sorry for my poor english, hope you understand it.

louk

Jeff/John - I will get a meter to measure the capacitance of the midrange caps before replacing them.

Timlub - Thanks for the recommendations. I will take a look.

And thanks again to everyone for your input. I will report back after I have ordered and installed the parts to let you know how things turn out.

Bryon

Also, Byron, I just went up and read Jeff's recommendations for sonic craft, he is right on. He is recommending some expensive parts. I am a really cheap mug. I would recommend that you go on flea bay. Do a search for Polystyrene capacitor... you will find some 1.0 mfd russians come up, these are great caps, use a good polyprop 1.0 mfd shy and then use the polystyrene as a bypass, you won't find a better bang for the buck. Like wise do a search for Teflon Capacitor. These two russian caps compete with caps 10x their price. Be aware, these are BIG parts. You might even find some larger value Polystyrenes or Teflons, they do exist, just hard to find.
Good luck, Tim

Byron, Just by looks, I'd say your parts are correctly labeled. A 10mfd Polypropylene is in general about the same size as a 100mfd electrolytic... In general only, different configurations are all different. I have a couple of .47mfd Teflons, they are larger than a 200mfd Electrolytic. The small cap values that you quoted look to be polypropylene, the larger value caps are definately electrolytics. Your coils all look to be reasonable quality, I would not mess with those, it could cause more problems than helping, replacing the electrolytics will make the biggest difference. After that, you will need to spend some money on replacing the Polyprops to make much of a difference. When you make the change, don't be immediately upset if there isn't a huge improvement, caps take time to burn in just like electronics do. Good Luck, Tim

Bryon,

The size of the capacitor does not indicate its capacitance. You can get a meter from Sears for about $25 that will let you measure capacitance. That way you can be confident when you place your order.

I made a big post about 'parts ain't parts' and it never made it.

without elaboration:
no part is pure anything. Inductors? have DCR and capacitance.
Caps? ESR and inductance. Caps are even microphonic.:: Clarity link available upon request.

It is possible and not THAT tough to replace a saturable small ga. iron core inductor with an aircore of similar (within say......5%) DCR. My Maggies have an iron core inductor. .4ohms, 16ga. wire. Online calculators? Designed a new inductor of 0.38ohm, using 14ga wire.
IF the minor effect of a change in DCR is of importance than surely the configuration of the inductor must be important, too.

The OP of this thread? The crossover had 7 inductors and they were not optimally placed....mutual inductance, and all.
I'd take this opportunity to go to an external crossover.

Voltage is as much a determinant of size as is capacitance. Also, film caps occupy lots more volume per Farad than 'lytics.

Just make sure you read them carefully. 56uF is not unusual in a MR filter; mine had a 33uF 'lytic.
.

I have one lingering question regarding the values of the caps for the midrange. Here is how they are labelled on the caps themselves:

MIDRANGE CAPS
C3 = 56µF 63V, bottom right of this pic
C4 = 12µF 63V, bottom left of this pic
C5 = 4.7J 250V, top left of this pic

Notice that C3 and C4 are both SMALLER than C5, yet according to their labels, they are much LARGER values.

I am now wondering if C3, which is marked 56uF, is really a 5.6uF cap. Likewise, I am wondering if C4, which is marked 12uF, is really a 1.2uF cap.

Could C3 and C4 really be 56uF and 12uF and still be much smaller than C5 which is 4.7uF? Or can I infer from their small size that they are really 5.6uF and 1.2uF, even though there are no decimal points on the caps' labels?

I just don't want to order the wrong midrange parts.

Bryon

Magfan, of the 3 types of passive components in hi-cuurrent filters, coils have the least sound. Also, their resistance helps determine the Q of the filters. So one could spend a lot of money and time buying new coils with matching inductance and resistance and produce NO audible difference in sonic quality. 'Tis much better to spend that money on higher-quality caps.

He gave me the same advice (but for specifics on tweeter caps) on the filters in my Avanti x-overs, I heeded it, and I'm thrilled with the results.

Bryon, I believe you'll be very happy with your results.
.

Correct.

NO inductor change recommendations? hmmmmmmm.

Just spoke with Jeff from Sonic Craft. Very knowledgable and very helpful. Here is what he recommended:

1. Tweeter cap C1. Replace with (2) Mundorf s/o in parallel (1.8uF + 1.8uF)

2. Tweeter cap C2. Replace with (1) Mundorf s/o.

3. Tweeter Resistor R1. Replace with Mills MRA-12.

4. Midrange cap C3. Replace with Jupiter Vintage Flatstack + Black Gate AC series in parallel (exact values TBD).

5. Midrange caps C4 & C5. Replace with Sonicaps Gen 1.

6. Bass caps C6 & C7. Replace with Axon or Solen caps.

Will do.

E-mail Jeffrey Glowacki of Sonic Craft for advice. He knows more about crossover parts than ALL of us put together.

mail@soniccraft.com
.

I have read a large fraction of the Mundorf s/o thread, the entire humblehomemadehifi shootout, and several others threads devoted to caps and crossover mods. I now have a plan...

1. Tweeter cap C1. Replace with a single 3.6uF ClarityCap MR.
2. Tweeter cap C2. Replace with a single 6.8uf Mundorf silver/oil.
3. Tweeter resistor R1. Replace with a Duelund CAST resistor.

My reasoning, FWIW...

--I would like to begin with the tweeter only. I very well may replace other crossover components in the future, but as a beginner, I would like to approach this in steps. Hence I will not be replacing any inductors at this time.

--I wanted to avoid bypassing caps, since several people warn about possible smearing effects. Hence each cap will be replaced with a single cap of identical value.

--I want to try to make the treble smoother and more liquid. Hence the choice of the Mundorf s/o for the 6.8uF cap. But the Mundorf s/o is not available in 3.6uF. Hence the choice of the ClarityCap MR for that position. I know that some folks discourage mixing caps from different manufacturers, but others report good results with that approach. So I will give it a try. My hope is that the liquidity of the Mundorf s/o and the transparency of the Clarity MR will combine to give me a pleasing balance of both characteristics.

--I cannot afford Duelund caps at the moment.

--I cannot go external.

That's the plan.

Bryon

Listen to Al.

The advantage of multiple caps in parallel? Lower ESR.

The DIS advantage? Lots of space. And, since caps are not 'pure' capacitance, they also have an inductive AND resistive component. Careful consideration must be given such changes.

Changing the caps without addressing the inductor is only 1/2 the job. if that.

Caps are also considered microphonic, which is a good reason to get the crossover OUT of the enclosure, not to mention the increased volume taken up the the caps could conceivably change the bass tuning.

Get an integrated plan together.

Thanks for the warning, Al. That's just the kind of rookie mistake I was hoping to avoid.

RE: The lack of room on the circuit board for the new caps...

Another poster suggested (in private email) that I build a small platform to go above the existing crossover board and attach the platform to the circuit board with wood blocks that are glued to the spaces created by the removal of the old caps. Then I can mount the new caps to the second platform, which would provide plenty of room for some of these big boys. I'm planning on using this approach.

RE: Which caps to use...

Obviously, folks have strong feelings about caps. I don't want to start a war, but I do want to elicit one last piece of advice about which caps to go with. Here is what I'm hoping to achieve: SMOOTHER treble. I would like to try to remove the last bit of grain and glare from the top end. In light of that...

-After reading about caps in other threads, the Duelunds sound perfect. But they are too much of a budget buster. :-(

-I have seen the Mundorf silver/oil caps described several times as "smooth." Hence my interest in them.

-I have seen the Clarity MR caps described as "neutral" and "transparent." Those characteristics are great, but may or may not involve greater "smoothness," which is the principal reason why I am changing the caps.

Thanks for any guidance.

Bryon

Bryon, judging by the photos you linked to in your first post dated 2-12-11, it appears that the circuit connections are on a layer or layers internal to the board. Unless you can see exactly where they are by shining a light through the board, drilling holes would therefore be a no-no.

Best regards,
-- Al

You might want to consider an all-new layout with point-2-point and terminal strip wiring.
You should change those nasty iron core inductors, too.....at least for the bass and possibly the midrange.

How many layers of conductor does the board have? IF a single layer on only 1 side, just drill and AVOID any traces. IF conductors on both sides, you'd best be REAL careful.

Did you go to the Humble Hi-Fi site? The site 'owner' DOES mix caps with claimed good results. This guy has tested multiple dozens of caps and has a fair grip on the subject matter.

Just an example, the caps in my crossovers have 4 in parallel to get the required value.
mag16-2.gif

...use a half-inch-square chunk of wood on the board as a spacer, cap on the wood, 3M foam tape holding all layers together, and a plastic ziptie thru the board.

Thanks, Jeffrey. I was thinking of doing something like this.

Last rookie question for you: To create the holes for the zip ties to pass through the board, is it ok to drill through the board with a regular drill bit?

Bryon

I too wouldn't mix brands of caps between the 2 positions, and I wouldn't use Clarity caps if they were free.

Mundorf SOs are fine. If the caps are too large in diameter to reach the board, use a half-inch-square chunk of wood on the board as a spacer, cap on the wood, 3M foam tape holding all layers together, and a plastic ziptie thru the board.

But I'd still use SoniCap G1s and Platinums. :-)
.

Bryon,

I just want to add that I respect Face's experience and would heed his advice.

John

Face - Sorry, my last post wasn't that clear. The tweeter has 2 caps associated with it - C1 and C2 - that are 3.6uF and 6.8uF. What I was trying to say in my last post is that I'm currently leaning toward doing this:

1. Replacing the stock 3.6uF cap with a SINGLE 3.6uF ClarityCap MR.
2. Replacing the stock 6.8uF cap with a single 6.8uF Mundorf, (possibly silver/oil)

What do you think of that idea?

Bryon

Bryon, why split a mediocre cap and high end cap instead of just using a single high end cap? The combination of bypasses mentioned above can add artificial artifacts and can also sound very detailed, not something I would want with a metal dome tweeter. Besides, a single cap in series will have better spacial information than unequal split values or bypasses. YMMV.

Thanks Jeffrey. Not trying to make things difficult. Trying not to make a mistake I will regret. To a pro, a rookie's caution may seem silly. But we are all rookies at one time or another.

Speaking of not making a mistake...

As Magfan pointed out, it's going to be difficult to mount the new caps to the crossover board, as they are MUCH bigger than the stock caps. Can anyone make a suggestion as to how the new caps can be secured to the board, which is mounted vertically inside the speaker cabinet. No, I can't go external.

BTW, I did discover that ClarityCaps MR will be available in March from Parts Connexion in the value I need - 3.6uF. I'm now leaning toward a combination of ClarityCap MR and Mundorf (not sure which one). Both have their proponents, so I may just split the difference.

Bryon

Byron, the approximate voltage-rating minimum for x-over caps is about FIFTY. 250VDC caps are used by manufacturers because they're available. 100s and 200s will work perfectly.

One can always use higher-power-rated resistors to replace lower-rated ones.

In paralleling caps, one uses the SoniCap Gen.1 for most of the value and the RTX or Platinum as the 'filler'. The higher proportion of higher-quality cap, the better-overall the sound is. And remember, ending up within c. 5% of the rated values is JUST FINE.

You're making this project WAY too difficult. :-)
.

More capacitor tests than you'd have thought possible.....
http://www.humblehomemadehifi.com/Cap.html

conclusion? Try for yourself.

Eld is correct. L6 is a roadblock inductor.

See my thread on B&W 802 Xover mods. Just changed all the caps

Jeffreybehr, have you tried Clarity's MR caps? The rest of Clarity's lines are mediocre in comparison. And as much as I like Sonic Caps, there is absolutely no comparison between Sonic Cap Gen I's and MR's.

Bryon, floating caps is fine as long as the leads are protected with shrink wrap, etc... The leads on MR's are generally pretty long.

Hi Jeffrey - Your advice is greatly appreciated.

RE: SoniCaps Gen 1 caps. They have a 3.6uF cap and a 6.8uF cap, but both are only 200V, whereas the stock Focal caps are 250V. So I assume that's not going to work.

RE: SoniCap Platinum caps. They don't come in the correct uF values, nor do I see any combination of 2 caps that sum to the correct values. Not to mention, they are, to use your phrase, more than I choose to afford. :-) I was hoping to do the whole project for $300-$500, so I need to find caps in the $100 range or so.

RE: MultiCaps RTX caps. Again, I don't see the correct values, nor do I see any combinations of 2 caps that sum to the correct values. Also, they tend to be 200V like the SoniCaps.

Hence the search for caps continues...

RE: Mills MRA-12 resistors. This is a stupid question, but I assume that replacing the stock 7 watt resistor with a 12 watt resistor is fine, provided that they have the same ohms rating (of 5.6). Is that correct?

Bryon

Rx...

In order of importance...

Change L6 to aircore inductor $$$$$$$$$$
Change L3 to aircore inductor $$$$
Change L1 to aircore inductor $$
Change C3 to whatever suits your fancy
Change C1 to whatever suits your fancy

Bryon--of course you're free to take this advice--or not--as you wish, but--
1. Stay away from Clarity Caps. That's what I removed from my Avanti tweeter filters. 'Clarity' my a...er...eye. I've been playing with caps for about 40 years. The SoniCap Gen.1 is the overall-best-sounding affordable cap there is.
2. Build the correct values with 2 caps. I believe you'll be thrilled with the results of using SoniCap Gen.1s paralleled with MultiCap RTXs, or, if you choose to afford them, SoniCap Platinums. The higher proportion of higher-quality cap, the cleaner/quicker/smoother the sound will be; I learned that dramatically in my TWO upgrades of tweeter caps.
3. Piggyback the 2 caps. If the larger of the 2 caps won't fit on the board, put the smaller on the board with the larger above it. I use 3M double-side self-adhesive foam tape. That plus the leads will hold the caps in place forever.
4. Replace the resistors in series with Mills MRA-12s, noninductive wirewounds.
5. Unless it takes hours to get to the x-over boards, do your upgrades in stages, with the tweeter section first.

The new caps in my x-overs made the treble so much better sounding that I now listen at around 5dB higher treble levels. You can tweek your treble balance by changing the value of R1.
.

Thanks to all for the valuable input.

John - No sweat. I was about to send them to you when I saw your last post.

RE: Outboard crossover. Unfortunately, that's not in the cards. The room is not dedicated. Plus wife, pets, kids, etc.

RE: The size of the new caps. I was hoping to have the new caps "float" off the board a little, as in the following sketch:

FLOATING CAP

At least two problems that would need to be overcome in order to make this work:

1. Finding a cap with leads that are long enough to reach the board.
2. Finding a way to stabilize the cap.

Thoughts?

Bryon

Bryon,

I had missed your crossover pictures and apologize for my oversight. Magfan is absolutely right, there's certainly not going to be room on that board for any of the caps I've been discussing, and most likely not in the speaker enclosure either as he also mentioned.

If you do go outboard with your crossover, Google "inductor-coil-crosstalk-basics". There's also a good picture on the Parts-Express board showing good and bad inductor orientations.

John

I believe custom MR's will have to be purchased in bulk, 10 or more. On the other hand, I don't believe Duelund requires a minimum.

Having tried bypasses and mixing values of caps(MR's, Duelund, Mundorf, etc...) to attain a specific value, I would not recommend it for the HF pass. Either use the correct value(within tolerance) or split the value in half as advised earlier.

Best of luck with your upgrade, sounds like a fun project!