New project

A while ago I bought an Onkyo 7.1 home theatre amp to replace our ageing sony unit.

The Onkyo worked fine as a 5.1 amp but a friend also had one but was running full 7.1 sound. Boy is there ever a difference :

The rears we were using were small Solid units ( made by B&W England), and these would do fine as surrounds.

This left me with a problem... what to do about the back speakers.While perusing the speakers section on the trade me auction I can across these http://www.kef.com/en/about/museum (click the 1980's link and look for Concord IV)I have always been a Kef fan since the early seventies. Very pricey way back then and I could never afford them. These are circa 1980 -81 and have 2 bass/midrange and one tweeter.

After looking at the specs I got to thinking that these units would perform better in a different style of cabinet and only one woofer would be needed.

I did a google on speaker design and cabinet characteristics and came up with the units shown. Taylored specifically for this particular 8 woofer and sealed rather than ported.

The cabinets are made from recycled 2 x 4 rough sawn New Zealand native "Rimu". The walls are 3/4 of an inch all round and the density is similar to that of MDF. I still have to make the grill covers, but we tested them today as fronts and they blew my 21st century B&W out of the water. By luck or design the sound image is perfect. My son and I auditioned them against the B&W's and no matter what we played the 25 year old Kef speaker were better in every respect. Shows how good a good cabinet and design is when coupled with a good speaker manufacture.

To say I'm pleased with the look and sound of them would be an understatement

Note first photo shows the original Kef and the third photo shows the B&W which are our main front speakers...the re-done Kefs will for now be used as rears until I decide what to do with the B&W's.

NB: The kefs I bought for $180.00 for the pair.

Ralph, if they sound half as good as they look, I'll bet they knock your socks off. great job.

Vaughn McMillan said:

Ralph, if they sound half as good as they look, I'll bet they knock your socks off. great job.

Click to expand...

Lol thanks, yeah they sound great...better than I had hoped actually. Socks are off, full of sawdust

They look a heck of a lot better than anything you could buy in a store, or at least that I could afford, and I do bet they sound very good!

Very neat Ralph. If thats the wood you guys have for 2x4s boy i wish we had it here.

Sounds like you hit a real good luck with the design and the speakers.

You bring up a real good point that many people dont seem to realize. A sound system is only as good as its speakers.

I remember working in a hi fi store back in the day as a student. One of my subjects at the time was audio engineering. Very theorectical but one thing we learnt that stuck with me was the actual efficiency of a basic moving coil speaker when it came to transforming electrical signal to sound. Its under 10% if my memory serves me correct.

It always amazed me in the store how people would come in and spend a fortune at the time on the actual amps and other components and then when it came to the speakers their lack of knowledge became apparent. They would want to see the amps frequency response curve and wattage rating (not knowing the difference between RMS and Peak Wattage) and yet not ask a thing about the speakers or allow sufficient money in the budget for decent speakers.

Enjoy your new system and those speaker cabinets sure look better than the black units.

Thanks for the feedback folks.

I neglected to mention that the speakers are not stained in any way, I just sanded them to 240 for a fine finish. Then apllied to coats of satin finish clear polyurethane, let it cure off for 24hrs, then I did a light rub with 1200 grit paper to take any rough spots of and polished them with a good grade of furniture polish.

The finish is silky smooth and the color of the wood really stands out.

BTW I'm making a second pair for my son so will show you the before and after shots as I process the wood. You wont believe what it looks like to start with..

Cheers....