View Full Version : NEW!!! Loudspeaker Design Services

25-02-2015, 16:49
RFC is delighted to announce the launch of a new service intended to help DIYers and people looking to refurb existing speakers themselves.

The problem, as anyone who has tried it, with speaker design is not just where to start (!) but if building a kit or developing your own designs, how to successfully design a crossover which sums correctly, ensures that drivers are phase matched, and that step response is excellent. It is all but impossible to do this "by ear" or by using textbook values because EVERY driver has its own unique set of electro-acoustic parameters and response, not least rising impedance with frequency (hence a nominal 8 Ohm speaker might be 12 Ohms or more at crossover meaning that on-line calculators wont work).

RFC uses advanced measurement systems and software which take the guesswork out of speaker design, including:

Calibrated electrical measurement devices for drivers which determine very accurately (to within 1%) impedance profiles
Rub & Buzz testers which check the health of existing drivers
Calibrated specialist acoustic measurement mic
Signal generators and PC software to generate and measure impulse measurements, check phase response and anechoic frequency response (via gated short burst in room response)
Advanced simulation software which uses driver measured electrical and acoustic data for accurate simulation of filter design
Ability to measure and tweak completed crossovers
Decay Spectrum Waterfall measurements
Polar response measurement ability to check off axis response

For each commission, you will received a detailed measurement report and if crossover design is required, a detailed schematic with a full list of components (plus advice on the most appropriate choice of components).

All you need to do for your DIY kits or new DIY speaker designs is to take one of the cabinets furnished with your drivers (but no crossover) to me and you decide on what measurement or simulation you require for your speakers in order to build the crossovers. Alternatively, RFC can build them for you and present you with completed crossovers and print outs of the acoustic response profile.

Although these services are available elsewhere, the current independent specialists offering these services tend to charge between £40 and £50/hour plus VAT.

The RFC charge for this highly specialised work is £30/hour all in.

A typical straightforward 2 way speaker design might take between 2 to 3 hours work for the measurements and file conversions for the software needed to give you a crossover which works well. It may take upwards of a few days or more for exceptionally accurate crossover design to match anything available commercially (ie the cheaper option lets you arrive at 90% of the performance, whilst advanced design might get you to 99% perfection for that speaker system).

Whilst some contemplating DIY speakers do so because of the budgetary advantages of building your own, consider this: Components are expensive so the usual iterative approach of guesswork or calculation followed by re-designing filters several or more times before you're close to happy with what you hear probably will cost you way more than a few hours well spent with RFC taking all the guess work out. You can then leave confident that what you have will work.

Please contact me if RFC can assist you with your project.

25-02-2015, 17:29
Good luck with this, Paul. Iím sure itíll be a much valued service for AoS members :)


25-02-2015, 17:51
Thanks Marco.

It seemed a no-brainer really as so many on here like to tinker with older speakers or have the DIY bug, so this at least offers a guarantee of great performance from whichever DIY route they go without all the usual months & months worth of tinkering, cost and guesswork, tinkering and more guesswork (and cost!) without really seeming to arrive at that "Eureka!" moment. Not many offer this service (there's only a few in the UK) so I'm hoping that folk take advantage of it, especially at the rates on offer.

25-02-2015, 18:22
Yup, it’s just the type of service I like to see offered here by traders, as it caters for the specific needs of the AoS community, and has the potential of removing lots of headache, especially for those modifying/upgrading the crossovers on vintage Tannoys, etc.

In fact, I have a friend with a pair of 1990s-vintage Canterburys who could well be a potential customer… I’ll give him a nudge for you! ;)


25-02-2015, 20:01
Sounds like a no brainer to me.

13-10-2017, 22:23
very quiet these days at RFC towers , hope are things progressing ? whats the latest developments ?

14-10-2017, 06:29
Hi Phil, Paul stopped posting on here a while back, mainly due to the armchair 'experts' always wanting to disagree with him.

If you've ever met him, as I have, you'll know that he is one of the most talented designers in the country, if not the world.

14-10-2017, 09:18
Paul is an extremely honest guy. My Tannoy XOs are going through their second design and I wouldn't trust them with anyone else. He designed my tannoy cabinets he is indeed very very talented bu also extremely busy. He dosen't need to be on here simply because his work speaks volumes, he has a waiting list several months long. Why have the hassle of having your work slagged off ?

14-10-2017, 09:39
Why have the hassle of having your work slagged off ?

It wasn't so much his work being slagged off as his expertise. Would have pi**ed me off too.

14-10-2017, 17:30
ah thanks guys , yes i have been to pauls twice and use his cables too .

14-10-2017, 20:38
Post removed.