RFC Reference Rubicon

I love the look of those..

They'd work fine in medium sized rooms tbh. The photo's a bit misleading as the room is about 12ft wide from where the photo was taken to the speakers which are on the long wall. They do shift a bit of air too...I've sized the port generously to ensure no "chuffing" can be heard and you don't get any mid leakage as the mid and tweeter sit in their own internal enclosures.

You'd be welcome to but the only ones on permanent demo are the big RFC Canterburys and I have a resto project in the wings for some Mk1 Cheviots which I had to buy...it would have been rude not to. The Rubicons were the result of a 12 month development with a client who specifically wanted a 3 way which didn't take up much real estate but he wanted his final speakers and didn't want to have to shell out £15K for the quality he was after. We discussed his needs and music tastes, chewed over various drive units and I provided him guidance to do the legwork principally that he learnt from the experience about driver matching and the importance of matching things like polar response at crossover. Those are some decent quality drive units he ended up with. I advised on cabinet volume and shape, persuaded him to drop the woofer close to the deck to avoid bass slap issues and advised on time alignment and internal construction.

He went off to cad up the sketches and as he works in a specialist factory dealing in quality cabinetry, he had the panels CNC's for the final versions although we had a prototype in MDF here so that I could measure, model and test crossover prototypes before development of the final versions. They're extremely refined sounding and at a rough guess were these from a major retailer, £15k per pair wouldn't be out of the way bearing in mind the cost of components, crossovers and final fit and finish. The project cost him significantly less than that as in less than a 3rd of that cost all in.  They are much heavier than they might look at about 85lbs per cabinet.

They look mighty fine.

Frequency response.  Target for distortion was a majority of the response to be -45dB under program...marginally better performance achieved :



System impedance (note bass peaks are equal for bass section but this looks imbalanced when rest of system is in.  The port is optimally tuned):

normally instinct dictates the grain on the sides going from top to bottom but i like the effect,it works very well.

Mystery solved regarding the tonal balance. These incorporate a separate internal damped chamber for the mids and HF units which is acoustically dead but should not be more than critically damped. The client had added too much BAFF stuffing to the already foam lined internals, forgetting that this has to be carefully balanced to get the QTC to about 0.701 (critical damping which can only be properly measured using impedance sweeps). When I worked on the prototype they were not as heavily stuffed. It transpires as a result of the BAFF, it had killed the natural presentation by overdamping. Baff removed and magic restored! One very happy camper who now describes the sound as "awesome, refined and extremely musical with no missing details!". Job's a good 'n.

No changes required to the crossover which it turns out was spot on. These, thankfully have turned out to be a superb sounding set of loudspeakers. He reports that the bass was easily good enough for the biggest thunderous crashed on AV duties and they can be placed close to a screen as all drive units are properly shielded. For hifi duties, he says that his older 753's were "utterly destroyed" in all departments but especially in the bass. It's great to have a happy client!

He's a great guy Oli and has been so helpful in giving me such free reign over the design as he started out with some good strong intentions. Once he realised how much more there was too it at each step, he virtually left me free reign to shape things from driver selection to cabinet design and it was important at each step to explain how each decision was arrived at instead of just taking the commission and handing back something at the end.

In this way, he felt far more involved and an important part of the design process in terms of input, which indeed he was. The outcome is now he has some speakers that he loves the looks of, loves the quality and most important, loves how they sound!

These were some of his comments after removing the offending BAFF and he's happy for this to be shared:

"wow this has already made a big difference, i had put a little more in than [was] in the prototype, not intended"...

"hard to understand how these small changes can free up the drive unit"

"[The] Tweeter back as original ie your positive to positive on speakers equals one very happy boy and a wife who is humming along and tapping her foot. ( lol she has 2 but just one is tapping)

I don’t intend making any crossover adjustments


Weird but removing the damping [as suggested] seems to have also increased hf. Bloody amazing 👍🏼👍🏼🎵

Delicate smooth detailed and oh so Musical

Huge thanks!"

For anyone interested, I may offer this as a kit of plans with a set of crossovers.  The rough estimate of build cost for materials, drivers and components excluding any other sub contract or external services work (ie you buy everything needed) is £2k to £2.5K plus any veneer costs.

The cost of the complex 3 way crossovers to have built would require externalised enclosures and in addition to the above would be an extra £1000.

The cost of buying them as ready made, matched and tuned with a professional finish would be close on £6.5K

That would compare with most commercial offerings of similar quality and performance very well.  You'd be paying a minimum of a 5 figure sum for these once distributors and dealerships took their cut.

So ending up with your final destination speakers..the cheapest way into the so-called "High end" for something like these is to buy the crossovers and plans and build them yourself (or have someone do it) or come to someone like myself and cut out all the middle men plus get exactly what you want rather than just pick from what is on the shelf.

I'm sure that it will Oli. The Traffos haven't been wound just yet...checked and thankfully my bungling of the actual spec was rescued just in the nick of time so we will have exactly what is needed when the skeleton crew can get the order done.