Elac B6 upgrade

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Danny Richie

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Elac B6 upgrade
« on: 9 Nov 2015, 05:12 pm »


The new Elac speakers are quite the buzz, and they were a real hit at RMAF. They appeared to be a solid performer in the lower ranges of the cost spectrum. And they performed much better than other speakers in their price range and then some. At RMAF the Elac room sounded good enough to embarrass a lot of rooms with MUCH more costly speakers. So quite a few people began asking me how far these little speakers can be taken with some internal upgrades. I had enough people ask me about these that I felt it worth looking into. I even called up Andrew Jones and chatted with him about it.

Then I had a customer send me a pair of the B6 model still in the unopened box.

The first thing to do was to set them up and for testing and measuring to see where they were. They measured about as expected based on what I heard from the larger floor standing model at RMAF. Typically various problems and issues tend to stand out like a sore thumb to me. I hear them immediately and can't get past them. The larger ones playing at RMAF had no glaring problems other than the cabinet walls buzzing along with each bass note. Other than that they were smooth and balanced. They didn't standing out in any one way. They just sounded real good (too good) and very balanced for their price point.

Okay, all set up for measuring and here we go....

Here is the on axis response. This was the best response I got out of the two of them (the pair). This was without the grill.



They are real smooth up to about 2.5kHz. These will be pretty easy to listen to. The top end is pretty rolled off though. That will effect the imaging and spacial ques up there in the top octave. Still, overall this is real good. This is without the grill.

There was also good consistency with the pair. Here is the response curve of each speaker.



And here is the effect of the grill. With the grill it makes the blue line.



And here is the spectral decay. This is really the most telling of all measurements if you want to know how something will sound. And the spectral decay of the B6 looks really good. It decays very quickly and stores very little energy. There is a little excess ring in the 3kHz to 6kHz range but not bad at all. This was actually a little woofer cone break up. The crossover pushes it down about 20db. That's not great, but this is much better than a lot of speakers I have tested.



The horizontal off axis looks real good. These are taken on axis and then at 10,20, 30, and 40 degrees off axis.



The vertical off axis looks good too. There is just a little bit of a dipped area that forms in the crossover region as height increases, but that is not bad at all either. These are taken at 1 meter and each additional measure is made moving up four inches.



Next up is the impedance curve. Here we see a couple of issues. The impedance levels from the woofer to the tweeter are a bit of a mis-match. The levels are unusually higher on the tweeter end compared to the woofer. Some amplifiers will react differently to the different loads. For instance would you use the 8 ohm or 16 ohm taps on your tube amp? I think most customers aren't going to be driving them with high end tube amps though.

There were also a couple of resonate peaks in the 23Hz range and the 55Hz range. These are being caused by internal standing waves in the box. These can also excite the cabinet walls adding to the low frequency buzz of thin unbraced panels.



Next up was to remove the beauty rings that are covering the driver mounting. This is a little tricky to take off if you don't know how to do it. I finally figured it out. You have to reach in around the woofer edge and get it to pop up a little. Then slid in a flat head screw driver and twist it carefully to raise up each of the push in tabs. Do the woofer area first then you can move up to the area around the tweeter. Here is the front side.



And here is the back side.



And here is the speaker with it removed.



And here is the new response curve (light blue) without the beauty rings.



So if you want to improve the response just remove the grills and beauty rings.

Next was to have a look at the crossover. It is not bad for this price point. I see a lot worse.



I hate seeing sand caste resistors, but for this price point it is what I expected. All poly caps though. The inductor on the tweeter network is an air core, but the woofer network used a very thin gauge iron core inductor.



Mounting the network externally allowed me to measure the drivers independently. So I took a look at the tweeter curve.

Here is the tweeters response with and without the beauty ring. The blue line is without the beauty ring.



Also the top end was pretty rolled off. So I by-passed the inline resistor with a .47uF Sonicap. The light blue line shows the lifted top end.



This brought the top end up and made it much smoother overall.

Now here is the response of the speaker and individual drivers with the beauty rings off and the by-pass cap across the tweeters resistor. Looking pretty good now. The actual crossover point is at 2.5kHz rather than the advertised 3kHz point.



The by-pass of the inline resistor used on the tweeter will definitely have to be part of a budget upgrade.

Also, with the drivers out we can see the issues with the cabinets. There was very little damping material internally. And the unattenuated standing waves were causing the resonances seen in the impedance curves.



The front baffle is 3/4" thick, but the rest of the cabinet only has 1/2" thick unbraced panels. And it is the soft Chinese type of MDF that you can dig into with your finger nail. So lining the cabinet with No Rez will be a big upgrade. It will tighten up the bass response and clean up the panel resonances and the internal standing wave issues. This will clean the sound up considerably from the bass response up into the vocal region.

And here's a bonus tweak. Take some of the left over No Rez and cut it in small strips. Then peal the foam layer off of it so that you just have the damper only. Now apply those to the back side of the stamped steel woofer frame. This will keep the frame from ringing.

So I am going to offer what I call the level 1 B6 upgrade. This will include a sheet of No Rez. It will include a .47uF Gen. 2 Sonicap for lifting the top octave. It will include a 1.5uF Sonicap to replace the poly cap that's on the board. This will improve detail and clarity in the upper ranges. And it will include a 20 ohm Mills resistor. This will further improve clarity over the stock sand cast resistor and lift the range that the tweeter covers by about 1/2 of a db. This will help balance out the response. The crossover upgrades are easy add on's to the stock crossover board that the average Joe can do himself. The cost for all the parts, the sheet of No Rez, instructions, and support is $76. plus shipping.

Here is some illustrations for you guys to show how easy the Level 1 Mod really is.

You have to un-solder the tweeter cap and pull it off the board. It's the small yellow one that is a 1.5uF value. One side is easy to get to. Un-solder it first. Then use a box cutting knife or an exact-o knife to cut through a little of the adhesive holding it down. Put it up and stand it up on its end and then you can get the other side un-soldered pretty easily.

Next, un-solder the the leads on the 22 ohm resistor and just fold them to the side so that they are out of the way. Don't bother pulling it off the board. It is glued on too well and it doesn't hurt anything to just leave it there.



Now take a very small drill bit and drill out the solder holes so that you have a fresh hole to slide the new parts in through.

Now twist the new .47uF Sonicap onto the new Mills 20 ohm resister as seen here. Solder them together and solder them into the spot where the old resistor was mounted.



Then flip it over and solder in the new 1.5uF Sonicap into the same spot as the old 1.5uF cap. Be careful not to let your soldering gun touch the small inductor next to it.



It should now look like this:



Lastly, run a little line of hot glue across the parts to help hold them all down.



This will lift the tweeter level just a little bit, it will lift up the rolled off top end, and improve clarity all across the tweeters range.

It is a pretty simple upgrade for the average hobbyist. If you are not a hobbyist and aren't interested in un-soldering and soldering on new parts then send me your crossover and I'll put the new parts on for you and send them back ready to go. $10 plus the shipping cost is the least I can charge for dong this. It really doesn't cover my time very well, but I am making a little on the parts cost.

The rest of this mod is installing the No Rez in the cabinets. This will do away with the cabinet resonances, tighten up the bass response, and clean up the vocal region.

Again the level 1 mod is only $76.
« Last Edit: 23 Jan 2017, 10:10 pm by Danny Richie »

Danny Richie

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Re: Elac B6 upgrade
« Reply #1 on: 9 Nov 2015, 05:13 pm »
Next I answer the question as to how far these things can really be taken with a new point to point wired crossover and other upgrades. Well, I've done that too. And I have made several improvements besides just a parts quality upgrade. The work is done. Hang on and I'll post new information with measurements.

Okay fellow. Check this out...

I designed a whole new crossover for the B6 that made improvements in several different areas.

I lifted the tweeter output a little at the lower end of it's range while still allowing the same roll off and extension. I also pulled the woofers upper range down so that it wasn't allowed to play up into the break up area. So without putting much more of a load on the tweeter I shifted the crossover point down to 1,750Hz. Check the stock crossover verses this one and see how far down the tweeter is at 70db. It is only playing about 150 Hz lower.



I did a little phase shift manipulation as well to get the drivers closer to being in phase on and off axis (vertically). A lower crossover points help that too.

The spectral decay is a little cleaner now.



The horizontal off axis now looks a little better because the top end isn't rolled off to begin with.



The vertical off axis looks a lot better. In fact a vertical off axis response doesn't get much better than this. This little speaker now has an extremely consistent vertical off axis. This is better than 98% of all the speakers that I have ever tested. Have a good look at this one compared to the stock one. This was done with a slight phase shift and a lower crossover point.



And here is the new impedance response. The impedance is much more balanced now. And the resonance peaks in the lower end are gone now. Just adding some fiberglass insulation to them can solve that issue.



Here is the response at 5 degrees off axis. It is even smoother than the on axis. These are +/-1.25db.



Now we're talking about a good little speaker turning into a great little speaker. Want to stun your audiophile buddies? Take a decked out pair of these little speakers over to their place and let them compare them to their expensive whatever speakers. They'll be speechless.

Okay, the cost of taking the Elac B6 speakers to this level.... All inductors are 16 gauge Erse XQ (air core), caps are all Sonicaps, and all resistors are Mills resistors. This includes a sheet of No Rez, 14 feet of high purity Copper internal wire, and a set of tube connectors (and I discounted the tube connectors). The cost of all of these parts is $290 plus shipping.

I know, the upgrades cost more than the speakers, but the speakers didn't cost anything to begin with. You still aren't into them for very much even with the upgrades. And the drivers are pretty good. They are worth added the higher quality parts to them.

Great little speakers now.  :thumb:
« Last Edit: 9 Nov 2015, 09:02 pm by Danny Richie »

kenreau

Re: Elac B6 upgrade
« Reply #2 on: 9 Nov 2015, 07:17 pm »
Uber coolness, Danny.  I'm really  :scratch: surprised at the degradation from the beauty ring.  I wonder if a felt pad/ring on the baffle may improve things further?

Looking forward to you wringing out all its latent potential  :thumb:

Kenreau

Peter J

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Re: Elac B6 upgrade
« Reply #3 on: 9 Nov 2015, 07:55 pm »
Uber coolness, Danny.  I'm really  :scratch: surprised at the degradation from the beauty ring.  I wonder if a felt pad/ring on the baffle may improve things further?

Looking forward to you wringing out all its latent potential  :thumb:

Kenreau

Agreed about trim piece. Looking at it from a novice point of view, it would seem removing it uncovers more "ripple" potential because of hills and valleys it exposes.  I'd be curious to hear hypothesis on what's going on, always on the hunt for better understanding.

P


Danny Richie

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Re: Elac B6 upgrade
« Reply #4 on: 9 Nov 2015, 08:17 pm »
Guys, I tried various felts and foams around the tweeter but it had the smoothest response with nothing around it.

Keep in mind that the upper frequency ranges do not wrap around the cabinet like lower frequency ranges. They play from the driver forward. The baffle step loss will be below 900Hz. So from there up the speaker becomes direction.

persisting1

Re: Elac B6 upgrade
« Reply #5 on: 9 Nov 2015, 09:01 pm »
Would gluing bracing into the cabinets also help? Bracing similar to your X-LS cabinets.

Danny Richie

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Re: Elac B6 upgrade
« Reply #6 on: 9 Nov 2015, 09:03 pm »
Would gluing bracing into the cabinets also help? Bracing similar to your X-LS cabinets.

It would but it will also eat up some air space. I did not model the woofers to see if they needed more or less air space. The No Rez won't take up any air space.

brj

Re: Elac B6 upgrade
« Reply #7 on: 9 Nov 2015, 09:15 pm »
Danny, are you able to grab the phase angles when you make the impedance plots?

Thanks!

Danny Richie

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Re: Elac B6 upgrade
« Reply #8 on: 9 Nov 2015, 09:25 pm »
Danny, are you able to grab the phase angles when you make the impedance plots?

Thanks!

Yeah, I can take the electrical phase too.

Jon L

Re: Elac B6 upgrade
« Reply #9 on: 9 Nov 2015, 10:04 pm »




A couple of non-audiophile people I know ordered these to use in their home theater setup, and I think the rolled top end will likely serve better for these folks using the lowish budget Japanese 5.1 home theater receivers. 

I AM disappointed to see such thin cabinets with low-grade soft MDF, but I guess what else can you expect at these prices  :scratch:

slefley

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Re: Elac B6 upgrade
« Reply #10 on: 9 Nov 2015, 11:11 pm »
is the major mod a easy DIY project or are special skills needed? 

Danny Richie

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Re: Elac B6 upgrade
« Reply #11 on: 9 Nov 2015, 11:23 pm »
is the major mod a easy DIY project or are special skills needed?

For the all out upgrade you will have to assemble the crossovers and you will need basic tools and soldering ability. I'd say it would be a novice level upgrade.

OzarkTom

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Re: Elac B6 upgrade
« Reply #12 on: 9 Nov 2015, 11:30 pm »
Danny, does the mod improve efficiency any?

Danny Richie

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Re: Elac B6 upgrade
« Reply #13 on: 9 Nov 2015, 11:35 pm »
Danny, does the mod improve efficiency any?

No, the sensitivity remains at 87db. It does maintain that sensitivity all the way across now though as the top end no longer drops off.

Panelhead

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Re: Elac B6 upgrade
« Reply #14 on: 10 Nov 2015, 12:44 am »
Would gluing bracing into the cabinets also help? Bracing similar to your X-LS cabinets.

  I worked on a pair of Celestion SL-6 that way one time. Cut 3/4" dowel rod a little shorter than the inside. Then drilled holes though the cabinet and threaded brass stews and washers to tension the cabinet.
  Looking here the hole between the tweeter and woofer is perfect for front to back. The next owner was not too impressed though.

Odal3

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Re: Elac B6 upgrade
« Reply #15 on: 10 Nov 2015, 02:59 am »
Nice! How does the <200hz look like?

luckyguy

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Re: Elac B6 upgrade
« Reply #16 on: 10 Nov 2015, 05:14 am »
Hi Danny.  Would your mods work for the B5?  I read where the only difference was the woofer size.  Hopefully, though I know you haven't taken a 5 apart, the crossovers are identical.  Thanks,  Ron

Chops

Re: Elac B6 upgrade
« Reply #17 on: 10 Nov 2015, 05:26 am »
Hi Danny.  Would your mods work for the B5?  I read where the only difference was the woofer size.  Hopefully, though I know you haven't taken a 5 apart, the crossovers are identical.  Thanks,  Ron

With the use of a different, larger driver and enclosure, I'm sure the crossover is a lot different. The larger driver will require different values for the crossover point (inductors, caps, resistors, zobel, etc, etc), any compensation that may be involved, possible different crossover point and roll-off, meaning probably the same holds true for the tweeter section.

Ultralight

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Re: Elac B6 upgrade
« Reply #18 on: 10 Nov 2015, 07:28 am »
Danny, I've chat with you a couple of times and though I've not purchased anything from you (yet), I'll say that you are amazing.  Just remarkable work. Bravo.

UL

Danny Richie

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Re: Elac B6 upgrade
« Reply #19 on: 10 Nov 2015, 05:25 pm »
Hi Danny.  Would your mods work for the B5?  I read where the only difference was the woofer size.  Hopefully, though I know you haven't taken a 5 apart, the crossovers are identical.  Thanks,  Ron

I'd really rather measure and test a pair before making any claims. I bet similar upgrades would be pretty easy though.