[mresseguie]

Hello to anyone with experience or interest in this topic. 

I've got too much time on my hands, so I'm about to embark on a kit speaker adventure. The speakers in question are called The Helios - co-designed by the late Jeff Bagby and Javad Shadzi. The speakers are a two-way design using the SBA Satori TW29BNWG and the Satori WO24P-4. The original plans call for using a 10" passive radiator mounted on one side. The designers obviously never met my wife, so I'm going to move the PR to the rear baffle. Unfortunately, the 10" PR will not fit, so I'm going to replace it with two 8" PRs - 8” SB20PFC-00 / Paper. I chose the squarish basket for esthetic reasons. [Before you caution me to make certain this will work, allow me to share that I have discussed this with Javad. He gave me the  on this plan.]

I purchased the kit plans from Mark at Meniscus Audio https://meniscusaudio.com/ I really like the selection of kits on this site. I could have purchased a complete unassembled kit; barebones kit, or just the build plans. Purchasing the plans suited my situation best, so that's what I did. My purchase price went directly to Jeff Bagby's wife as a donation. I think this is a terrific idea.

I chose this particular design for the following reasons: designers, increased bass over my current speakers, higher sensitivity, stand-mount design, and stellar drivers. On the off chance these speakers do not fit my needs, all is not lost. I can discard the cabinets and commission any number of designers to redesign a new speaker by adding a midrange driver into the mix.

Okay, enough preface.

Even though Javad told me poly caps are good enough for these speakers' XO, I can't help but look into upgrading the crossovers with better caps. I'm looking into Miflex KPCU, Jupiter Cu, Mundorf, GR Research Cu caps, and V-cap ODAM capacitors. There's a ton of information available on all of these. There are even some reviews. I'm hoping to get firsthand thoughts from you, reader, with the hope that I can glean more knowledge and make a more informed decision.

I've wondered if using premium caps on the tweeters and poly caps on the woofers is a good way to save money, or if it's a bad idea because the result would be that the woofers would lag behind the tweeters. Thoughts?

I know. Some of these caps are expensive. Don't tell my wife, please!   

Thanks for thinking about this project.

Michael

[mresseguie]

I wonder if I should have placed this in "The Lab". 

[Argoncat]

Humble Homemade HiFi has done an exhaustive capacitor test / review; from basic poly caps to Deulund cost no object cast beasts..

http://www.humblehomemadehifi.com/Cap.html

I went with all copper caps from Danny @ GR Research with 0.01 Deulund Ag bypass caps on both circuits.  The cost of the caps exceeded the NX-Studio monitor kit I got from him, a true buy once cry once strategy..  However, with ~100 hours on the speakers / XO I couldn't be happier.  Holographic, detailed, rich bass, instrumental isolation and separation, and a center image (especially on Nick Caves' new album Idiot Prayer) that has pulp and presence.







 

[morganc]

I'd start with Danny's copper caps or the Mylfex. 

[mresseguie]

Unfortunately, only Danny's 20 uF cap could fit one of my needs if I bypass with another 4.7 uF cap. Miflex caps could fill three spots. After much searching, I'm leaning toward V-cap ODAM caps for the three smaller values and <possibly> a good quality poly cap for the 25 uF cap.

Thanks for the feedback!

Argoncat,

Thanks for reminding me about Humble Homemade Hifi. I'd forgotten about his thorough comparisons.

Michael

[jostber]

Do you have the specifics for the crossover that is part of the original Helios speakers design?

These articles by Troels Gravesen have a useful overview and discussion on the value of using Super caps vs. Polypropylen caps:

http://www.troelsgravesen.dk/super-caps.htm
http://www.troelsgravesen.dk/Response-super-caps.htm
http://www.troelsgravesen.dk/Alumen_Z-Cap.htm

[mresseguie]

Thanks for the links.

I'm still undecided on how to populate the 25 uF cap position, but the other three caps (2.2, 3.3, 4.7) will all be V-Cap ODAM caps unless someone has a really strong argument against them.

[Tyson]

The 25uF could be broken down into 2 caps of 12uf each which gets you to 24uf which is close enough.  Or you could do a set of 3 caps that are 8uF each which also gets you to 24uF total.  Might be cheaper/easier to find audiophile caps at these lower values. 

Only caveat with this approach - the caps must all be of the same value.  So combining 2 caps that are both 12uF is fine.  But it is NOT OK to combine caps of different values.  For example, you should NOT combine a 15uF and a 10uF cap to get the 25uF value. 

[BobM]

It's pretty simple ... you could spent a boatload of $ on a super premium brand or you could get 98% there and buy Sonicaps.

[Tyson]

It's pretty simple ... you could spent a boatload of $ on a super premium brand or you could get 98% there and buy Sonicaps.

I agree, for the 25uF spot.  Get a 25uF Sonicap, they are excellent.  But for the other smaller value caps I'd do the copper foil caps, either Miflex or Danny's copper foil caps.

[mresseguie]

Bob and Tyson,

Thanks for that wake up. It's too easy to get carried away with this stuff. I have no idea how much difference this or that cap will make.

I can only make judgements based on what I read. For example, Sometime ago, I read that Sonicap II is considerably better than 1st generation. Yet, the 25 uF cap is only available in Gen 1. When I see this, I hesitate. I don't know. Too much hesitation leads to paralysis.

Meniscus has a Clarity Cap, 25uf, CSA, 250V for $33. Seems pretty reasonable.

I'll flip flop for another day. Then, maybe I'll make a decision. 

[jostber]

I just bought  a couple of days ago two Clarify Caps CSA 47uF 250v for my Pureaudio speakers for a crossover caps upgrade. These were what looked like the best value per money based on my research. Waiting to receive them in some days.

[mresseguie]

jostber,

Which Pureaudio speakers did you buy? I'd love to read your impressions once they've broken in.

Big OB or horn speakers will remain a fantasy until I have enough money to build a new wing onto our house. [Never because my wife would absolutely flip!]   

[jostber]

I bought these speakers new a couple of years back and the model is the the Pureaudio Trio10 with a Voxativ AF-2.6 tweeter as a custom upgrade. The speakers have the Leonidas crossover with Mundorf 47uF 250V caps. The speakers are sounding wonderful with enough punch and a lot of sound for my main room.

For the caps I just wanted to try an upgrade as I read at the customer feedback site for Pureaudio that these caps would give great results. The same was said for using Jensen Silver Z-caps. I went with the Clarity CSA caps now as this seems to cover the upgrade need at this time.  . Another upgrade I have done is to replace the original crossover speaker cables with the Verastarr ribbon cables.

[sailor]

Sorry a bit late to the party. First of all let me congratulate you on choosing a Bagby design. I have built using SBAcoustics and they have now become a brand I consider first. Simply great value.

You mention a 25uf cap which I assume is a parallel cap in the woofer circuit. The Clarity cap mentioned is excellent for this position.

Planning the XO layout and assembly is not something you want to do twice. I have been building XOs for a very long time and try and build them right first time. I do not use bits of wire to join components, instead I arrange them so I can join them using their own leads which I twist tightly together with the wire to the speaker and then solder. Trying to unsolder this joint to wire in a different cap basically wrecks a carefully planned and built XO.

A good solder joint should not need any solder. The wires and leads should be cleaned with isopropyl alcohol or acetone and tightly twisted and then soldered. The solder merely provides mechanical integrity and helps exclude oxygen.

My suggestion is to roughly breadboard the XO to make it easy to try different components before doing it properly.

I have now some favourite caps that from experience I know will work so I am now very much past swapping caps and resistors. To that end let me suggest you consider for the smaller value caps a Jantzen Audio Superior Z-Cap.

Humblehomemade hifi was mentioned above which is an excellent article to read. The Jantzen I mentioned is one of his preferred caps amongst others.

Mundorf, Jupiter, Clarity and others are all contenders. I did not hear much from the Sonicaps.

I encourage you to carefully study the cap link because the kit you are building will reward you with better XO parts. Everything matters, the resistors, the wire to the speakers, the terminals and inductors (coils)

The spacing between and how the coils are positioned relative to each other also important.

Good luck.

[mresseguie]

Sailor,

Hello, and thank you for your input.

Believe it or not, this project is on hold until my wife and I decide exactly what sort of TV/audio console is acceptable (to her). There's been quite a lot of largely peaceful back and forth on likely designs, but nothing is certain yet. She favors a long, low cabinet that would extend for something like 9 feet from side to side. Such a cabinet would require that the speakers be mounted on the top shelf of the cabinet. The size of the Helios cabinets is such that the speakers would partially block the <planned for> TV. There is a plan to add a taller cabinet to the right of the TV console which would prevent the speaker from being slid away from the TV.

While I hope to still use the Helios in this space, I'm keeping other options open for narrower speakers. One other possibility is to add a subwoofer (or two!) to my existing monitors.

Back when I began this thread, I had expected to be finished by now.   

[JakeJ]

Could she be conspiring against you and your hobby, Michael?  Just kidding.

If you can't add a wing to the house maybe a detached man-cave, like Greg Fisk's?  Just thinking out loud but not too loud.

Keep us posted when you get the project back on track.

Take care,
Jake