Finally!

It has taken a very long time (over a year), but I finally have my own crossover designs completed for the V-Trac upgraded Khorn and Belle speakers.  The new designs also lend themselves well to the new speakers I'm building that utilize the 2" Volti horns.

I have very high standards when it comes to sonic quality and aesthetic quality.  I like to own things that are very well built and also beautiful to look at.  I like smart design and elegant construction.   So it is with these ideas in mind that I took on the task of designing my own crossovers.

My engineer is always telling me that in the world of audio, it's all been done before.  I'll throw out a new idea to him and he'll say, oh yeah, someone did that back in the 1920's!  So for this new design, I used ideas and designs from those that came before me, as all audio designers do.  I certainly had the Klipsch "A" networks in mind, as I prefer that kind of simplicity in my entire system.   I also took cues from the ALK Universal networks that I have had, and enjoyed in my Khorns for years.  But I'd like to think that these new crossovers that I'm building offer some little bit of new thinking as well; like the use of screws through inserts, connecting components to wiring below the boards, and the use of multiple inductors to provide different mid-bass "voicings".

I decided to use solid hardwood for the boards, finished in clear lacquer.   I currently have Oak, Maple, Cherry, and Mahogany available.  I have a couple of customers who have lengthened their internal wiring so they can mount the crossovers on top of their cabinets where they can be seen and easily adjusted.

By keeping the wiring underneath the boards, the top is very clean looking.

The networks utilize very high quality components; open air 12ga woofer inductors, Litz coil inductors for the tweeter filter and Sonicraft Sonicaps throughout.

Connections are made with the brass screws that connect through to the bottom of the board.  It is intuitively laid out, with the midrange connections right in front of the midrange autoformer, the woofer connections in front of the woofer inductors and the tweeter connections in the back.  Note that there are no push-on connectors to the autoformer, the user simply chooses a combination of two screws to hook to for the midrange attenuation level.

I spent hundreds of hours developing these networks, with over one hundred hours of "seat time" in front of my Khorns, bread-boarding with components while listening to music.  One of the things I discovered while doing this, is that the old thinking, that there is only one ideal combination of caps and inductors for the mid to woofer crossover point, is just simply not so.  It is possible to have several different combinations that work very well.  When speaker manufacturers build new designs, the choice of crossover components is often dictated by an engineer, looking at measurements, but can also be decided during listening sessions done to voice the speaker.

Also, it is commonly held that when you change the woofer inductor of a filter circuit you must also change the midrange caps.   But I found that this just simply is not the case.  I was clearly able to get various mid-bass voicings from my speakers by choosing different sized inductors, without changing the midrange caps.

So for my new networks, I decided it would be nice to provide my customers with the ability to make their own choice for mid-bass voicing, done with the use of two inductors for the woofer filter, instead of the usual single inductor (6db-slope, first order network).  I wired these networks so the user could choose the small inductor alone (1.2mHy), the large inductor alone (2.2mHy), or a combination of both inductors in series (3.4mHy).   I call these the three mid-bass voicings, "most mid-bass", "middle mid-bass", and "least mid-bass".  Being able to choose from these different voicings allows the user to tailor the system to their room, the music they listen to, the volume levels they choose, or to their own personal preference.

In crossover construction, we are taught to never stack inductors in the same orientation.  When a signal passes through an inductor, it creates a magnetic field, and placing another inductor, or any metal object on top will change the mutual inductance of the first inductor.  So why did I decide to stack the two woofer inductors on these networks?  Because my testing has revealed that there is no interaction at all when both inductors are connected and working, they work just as one larger inductor would.  And because when one inductor is connected and the other is idle, the change in mutual inductance of the first inductor is so slight that it is barely visible in the tests, and certainly not audible.  In fact, you could just as easily make the argument that stacking a second inductor on top of another actually makes the sound better, as you could argue the other way.  So this is an examnple of where the rules can be broken and not suffer any loss.  Certainly if we had two inductors, one carrying a midrange signal and the other carrying a bass signal, we would not want to stack those in the same orientation.  But for this filter circuit, it's a non-issue.   Unless you're a competitor of mine trying to discredit me!  LOL, some of you know who I'm talking about.

I decided to have the components mechanically fastened to the boards, rather than rely on glue.  So you'll notice that the inductors are bolted on, and the caps are screwed in place with mounting head ties.  No, that's not a steel rod through the center of the inductors holding it to the board, it's made of nylon, as is the cap nut and the fixed nut on the bottom.

Inputs are through heavy-duty five-way binding posts, which is a whole lot better than using the small screws on the barrier strips.  They are still bi-wireable by removing the jumpers between the inputs.

I have also made a split version for use in some of the new speakers I'm building.   These fit nicely around the midrange driver and allow easy access at the back of the speaker.

On the VTK400 networks, which are made specifically for the V-Trac upgraded Khorn, the choice of components effectively lowers the crossover point between the midrange horn and bass horn, taking low-mid frequencies out of the bass horn and putting them into the midrange horn.  This cleans up and controls what is a difficult region of the Klipsch Khorn, the mid-bass.  Providing the user with control over this region is one important reason why the VTK400 is the perfect match for the Volti Audio Khorn upgrades.  My own personal Khorn system was already spectacular sounding with the ALK Universal networks, but with the VTK400's, I was able to tune out a bit of mid-bass "drone" that I was detecting on some recordings, and the system has never sounded better.

If you've purchased V-Trac horns from me to upgrade your speakers, and you're using ALK Universal networks, I am NOT recommending that you change to the Volti networks.  Not necessarily anyway, it depends on your budget.   The Universals work very well with the Volti upgrades, and changing to the Volti networks would only provide a slight improvement in sound quality, along with the ability to better tailor the sound to your liking.  I do have a tweak that you can do to your Universal networks that I think cleans up the slight mid-bass "drone" that you might be hearing on certain recordings.  If you're interested please send me an email.

I'm very proud of these new networks, and from the first feedback I got, I guess I should be!   Here's an email from a customer after his first evening with the Volti Audio upgrades and the new Volti crossover networks:

Holy Moley Great Kooga Mooga!

Greg, you are a genius.

What a FANTASTIC IDEA to give the user the opportunity to tune his crossover network to his room, speakers, and (alas!) age.  I tried a number of hookups with your remarkable new network, and with your equally remarkable upgrades to my Klipschorns.   Credit where credit is due.   You have chosen to offer excellent upgrades to bring the Khorns to new sonic possibilities.   But the new crossover network is your baby, and Daddy, your baby rocks!

For the record, I've chosen 4(+) Y(-) on my 3636 for the BMS 4592ND, for 14.74 dB attenuation.   I chose the least mid bass from the woofers, jumper 2-3 and leads C(-) and 4(+).   This provides me with a slightly enhanced high end for my 55 year-old ears, so I can hear the tizzz of cymbals without the use of a digital add-on in the signal path.   And the bass is rock solid down to below 40 Hz.   I have subwoofer enhancement for 20-40 if needed, and that is rarely.

The sound is slightly beyond my ability to describe.   First of all, the soundstage is definitely more 3D than I have heard before.   Also, the speakers provide more of a window into my other components.   For example, while I can localize instruments in a symphony with much less effort, I suspect the nuances of each instrument can be brought out by cap, tube, and cable upgrades (which are all ordered and being shipped).   But, compared to my previous system consisting of an Art Audio Jota BX (currently retailing at $13000) and Fidelity Parsifal speakers ($20,000 and up), I am frankly blown away by the ability of my Almarro amp and 1979/2011 Klipschorns to outdo the previous system at a fraction of the (retail, which I would never pay) cost of my former audio icons.

Bottom line question: is there an end to tweaks, upgrades, trades, or outright overhauls?

I can't answer until I'm no longer buying, trading, or upgrading.   But I can say that there are definitely special times in ones life where the level of satisfaction with what one already owns is blissful.  I think you have brought me there with your offerings.

Viva Volti!

Michael

Ciare 1.26Nd TW

I finally found a tweeter that is on par with the Beyma CP25!  This is big news, because while I like the Beyma very much, I needed a tweeter that was easier to install.  The Beyma tweeters have horns that stick out in front of the flange that they mount with, which makes for very difficult mounting.   They can't simply be mounted on a motorboard that is the front of the speaker, behind grill cloth.   They need to be recessed to allow room for the horn, which obviously creates problems with dispersion and complicates the construction of the speakers.  The Beyma tweeters are also quite large, which is fine for big horn speakers, but it limits new design possibilities.

I've purchased and listened to at least a dozen different compression tweeters over the last year, and most have been good or fair, and a couple have been poor.  Almost all have had a characteristic "PA" type of sound, which is edgy and a bit harsh.  The only two that stood out for me as being "hi fi", or worthy of being used in a high-end type of speaker, were the Beyma CP25 and the Ciare 1.26Nd.  Both of these tweeters just sound more like what you would expect a high-end tweeter to sound like.  Others that I've tried just don't.

Check out the frequency response curve and how it rises as the frequencies go up.

My own testing reveals that the frequency response doesn't rise at the high end nearly as much, but they do look very good.  More importantly, they sound very good.

The Ciare is made in Italy.  It is much smaller than the Beyma, and the tweeter horn is nearly flush with the mounting flange, which gives me a lot of flexibility in the design of new speakers.

I'm currently using them in the new Voltiscala and the Volti Cornscala speakers that I'm building.  I'm recommending them as an option for the Belle upgrades, to compliment the V-Trac horns.  I am, however, stopping short of recommending them for the Khorn.  At least for now, until I'm able to do more testing.  There is a question about the efficiency of the tweeter and how it will balance with the greater output of the Khorn.  I think it will work fine, but until I know for sure, I don't want to recommend it.

Which do I prefer?  Geez I don't know.  The Ciare tests better than the Beyma, with a beautiful curve that actually rises a bit at the top end, while the Beyma is peaky and drops at the high end.  But there's just something about the Beyma tweeter that I like.  A lot!  So I don't know.  It's close; very, very close.

Voltiscala

When I was fourteen years old, I sold everything I owned; my bike, my dirtbike, my football card collection, and my Soundesign stereo, to buy a used pair of Klipsch La Scalas.  The big black boxes were dragged down into my basement bedroom and I lovingly cared for them.  I didn't have a stereo and couldn't play any music through them!  But that didn't matter to me!

My mom finally felt sorry for me and bought an integrated amp and a turntable for me.  Since then I've probably owned at least twenty other pairs of La Scalas.   It's a speaker that I'm very familiar with!

Now that I've learned about the shortcomings of the design, and I've developed my own horn system that beats the heck out of a stock La Scala with ease, I no longer have the same feelings for the design that I did when I was younger.

The Voltiscala is the next step for me.  I started with the restoration of old Klipsch speakers, added the development and building of upgrades for Klipsch speakers, and now I'm moving towards building new speakers from scratch.   The Voltiscala is mostly Volti, with a little Klipsch thrown in.

For this design, I stuck with the Klipsch La Scala bass horn dimensions, but I built the cabinets better than Klipsch did, to provide a tighter bass and better defined mid-bass.  From there, the rest becomes all Volti Audio, with the Fc280 midrange horns with integral tweeters, and the new Volti Audio crossover networks.

The sound quality is superb.  Much, much better than a stock La Scala.

In the last issue of the newsletter, I showed construction pictures.  I still do not have them 100% completed, but they are close enough to show some glamour shots!

The Bosse Cedar veneer is fantastic!  The grain shimmers as you walk by, and if you're not careful, you feel like you might fall into the grain!   It also has a beautiful dark red color.

I am now spraying catalyzed lacquer instead of nitro-cellulose, and the resulting finish is far superior.  I'm getting a very hard, smooth finish that looks and feels like a million bucks.

These particular ones are for sale.  For more information and pictures, please visit the Voltiscala webpage by clicking here.

Another Restoration Page

Switching over from the old "Gregs Audio" website to the new one has taken some time, especially with the work involved in re-doing the rather large restoration pages.  The last one is finally switched over, the "Three Pairs Of La Scalas" restoration webpage.

You can view that page by clicking here.

Interesting Picture

Courtesy of Iain at itishifi.blogspot.com

Just For Fun

Live From Daryl's House is an online monthly show that is produced by Daryl Hall.  Each show features a different musical guest, who is invited to come to Daryl's home in upstate New York to play music, be interviewed, eat food, and just have a great time.  Daryl's band is great, and his production crew might be even better.  The sound, video, and overall production are top notch.  New episodes air on the 15th of every month, and all the old shows are archived so you can view them anytime.

Live From Daryl's House

Well I guess that's it for this issue of the Volti Audio Email Newsletter.

Please tell others about Volti Audio, about our email newsletter, and about the Volti Facebook page.  We're really trying to spread the word about Volti through the Audio community.

Thank you for your support, and until next time, I hope it all sounds good!

Greg Roberts
www.voltiaudio.com