I cant believe its a year...since I last made something. A speaker project.

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57
Location
Hamilton, New Zealand
Well actually I can :)I have been concentrating of my other love , Photography and working on my website that goes with it. Your all invited to say high of course, just follow the link in my signature.Anywho's heres what I have been up to over the Xmas break.

My B&W 309's finally started to surrender to 12 years of home theater use as did my Mission centre which blew both of the 4.5 inch woofers.Money being a little tight this year and having 4 weeks off for the first time in years got me out in the shed.

The design is a prototype, so I choose off the shelf componentry from Jaycar, including matching crossovers. As a means of testing I also have a very nice set of Kef Concord IV's.After much deliberation and a great deal of time using the online design tools at DIY Audio & Video - FAQs, Tutorials, and Calculators for Speaker Boxes, Crossovers, Filters, Wiring and more, I finally settled on the design. Some of the cabinet design was inspired by the Kef KEF International - Showroom - Imagesrange. using a semi trapezoidal shape for dampening reflected sound waves in the enclosure. Much the same as you see when ripples in water disperse when contacting non uniform surfaces. These are to be sealed enclosures. I prefer the more accurate precision from this type of enclosure.

So we have Response 6.5 inch mid coupled with Response 8inch woofer and as I had a spare pair of Kef t33 tweeters, matched this to 1200/5000 three-way crossover.So a reasonably inexpensive setup, now all that was needed was the enclosures. The design worked out at an overall size of 1170mm h X 260mm w X 325mm D for the enclosure. Constructed from 18mm mdf with 4 mm recycled heart Rimu veneer, which I machined from 100 x 50 rough-sawn studs. This meant that the wood had good color & character including weather stain and nail holes. I didn't quite do enough and had to run some extra so matching thickness was a bit of a pain :(

The first pic shows the basic enclosure with some of the bracing and dividers assembled

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A front view showing the speaker positioning

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First cabinet veneered with cutouts and one coat of sealer. Note the weather staining

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Applying 2nd and 3rd coat

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Top coat done, ready to mount the drivers

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Drivers mounted and speakers put into service.

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And how do they sound? Well truth to tell I wasnt expecting too much as I didn't know a lot about the Response drivers, but I have to say they blow my old B & W's away and then some. The Kef's dont beat them either which was a surprise. Initially I felt the mid range was a little bright but after 20 or so hours of reasonably hard running in they are settling very nicely. I have them coupled to a Onkyo SR576 home theater amp.The base is excellent and the mid nice a crisp with the tweeters topping out without shouting. The crossover I bought for these is recommended for these speakers and I'm glad I choose them as they seem a very good fit for the Response units. Frequency response is 30Hz to 22Khz. My sub has been retired, its entirely superfluous with the new speakers. The movie Transformers - The Dark of the Moon has a lot of very low base sound during action sequences especially in the explosions and these bad boys make the floor jump big time, which makes for a very nice change.My son works for Heathcotes ( think NZ version of Harvey Norman or similar audio hi-fi shop).He feels that while they are not as refined as B&W's and the new Kefs, once they burn in more they will give then a run for the money. I'm upgrading the amp soon so the speakers will be going into the sound lounge and we will test them against some of the high end gear. Should be fun.Total build cost approx $400.00 NZ give or take a dollar.Now I know how the speaker enclosure performs, the next set will have either Seas or Morel drivers.
 
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Very cool project Ralph!

I like the idea of not needing a subwoofer. And those look fantastic to boot!
 
Hey, good show. You sound like I did in the 40's through the 80's.

I was on the air a few times at KPRO Riverside, CA, USA. The reason I brought that up is that there were no two parallel surfaces in the main studio (Can't remember if there were other studios). Even the floor was not quite straight. It curved from side to side and from end to end. The ceiling did the same thing, only with greater change between high and low areas (you don't have to try to walk on the ceiling). The walls had continuous gentle curves horizontally and the "vertical" was not vertical---it varied also.

They had great acoustics for broadcasting plays and music.

Have fun with your speakers and enjoy that great sound.

JimB

Oh yes, I have some Onkyo stuff too.
 
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