Some just-for-fun speakers

[Shonver]

How many unfinished speaker projects do I have?

Well, there's the Introducing the M1. This one's serious, and will get done someday.
Then there's Shaun's Translam HT uhmmm... that one's way on the back-burner.
And then there's Tripoly. There's no hope for that one. Not until I find an 8" woofer that actually works in that size box...

Oh, and the Meridians (hehe). Them ones I need to triamp, with active crosssover. Lots of work gonna go into developing the amps and the crossover. Measure this one in years(!).

But I still want to build loudspeakers, in spite of my excuse of not getting enough time to build boxes. It seems this time I have run out of excuses. I'm always on the lookout for boxes to recycle. To launch my exploration into building the Meridian crossovers I wanted to build a speaker with heads. The Heads is what Meridian calls the pyramid-shaped enclosure for the midrange and tweeter drivers (see the Meridian thread for photos). I have a pair of KEF C15 satellites that uses their famous B110-series driver but the enclosure is poorly built and sounds way too boxy. A few weeks ago I stumbled upon a pair of 8-sided Tannoy enclosures at the Milnerton flea market. These looked like they would do the job. In spite of their construction (check the pics that will follow later) they appeared to be well damped. They did not have their original drivers any more; these had been replaced by cheap paper tweeters and 3" Sakyno car speakers. But none of that mattered. I had my own plans.

[to be continued...]

[Mervin]

I concur... started by Focal project with a bang.. been out the country twice since then and does not seem if it is easing on the workload side.. but hey, I am not complaining.

[JimGore]

There are people willing to help you with building boxes - you only need to ask 

[Timber_MG]

These just for fun projects are a very evil phenomenon, however there is just so much fun involved working with the lower cost components as the risk is low and it is rewarding to come up with something that "has no right" to sound half alright.

The biggest problem seems to be affordable tweeters that don't suck, but thankfully if one has something with a reasonably behaved mid range one can blend in something higher up. Thankfully us tinkerers have enough stuff to stick in there just to see what a 27TDFC does when mated to cheap drivers...and then stay there.

[Shonver]

I felt the irregular shape would help overcome some of that boxy sound.


It doesn't look too solid, but it does the job.


I jigged the router to take off probably half the thickness of the front baffle.


Glued on a new front baffle.


Bevelled the edges and routed the driver recesses.


My first attempt at vinyl cladding.


Not too bad (vinyl is very forgiving of inaccuracies).


I shortened the port and stuffed it.

[Shonver]

The tweeters are budget Far Eastern units similar to the Dayton Silkie. Bought them from ApexJr.com.
The mids are some McKintosh drivers I got from Anton. Just running these with just a 4.7uF cap on the tweeter yielded a promising sound. I believe these will image very well.

More later.

[chris]

Looks great Shaun, is that a Kef driver? Looks very similar than what I used in my trans lam project, by the way it took less time than I thought to finish, so just do it !

[Shonver]

Looks great Shaun, is that a Kef driver?

Thanks. Nah. Apparently Anton got it from a McKintosh speaker.

[Prince]

 

Looks good..

[GearSlave]

It did come out nice, especially the pleather you used.

[ghostinthemachine]

They look great Shaun!!

[antonsa]

wow shaun, looks good.
i thought i recognised those speakers 

those midwoofers are great, and they do image great, however i used to run them with the tweeters from the kef coda 7's..

these woofers actually sounded similiar to the kef coda7 woofers....

[Shonver]

I am trying to integrate them into a 3-way, but the 8" woofer is not playing along. I also tried these as a 2-way, and they sound  rather good on their own, but missing some bass, as I have sealed the boxes.

[SeanS]

Very very nice and a very neat vinyl finish, what is it, it looks almost like leather?

Those recesses routed for the speakers are pretty exact given the complex shape.. a simpler shape had me swearing and took about 3 templates to get right, whats the secret?

[Shonver]

whats the secret?

Hehe. A  bit of luck, that's wot! LOL!

I found this unused piece of vinyl lying around. I'm sure it was bought for a similar purpose a long time ago. It is rather cushiony, being 1.5mm thick and easily compressible. I had to oversize the recesses accordingly.

I started by routing two circles: the final recess for the tweeter and the central circular shape of the mid. Then the cut-out (i.e., the through hole). Next I lay the mid upside down, centring it on the circular recess. I then traced the pincushion shape, maintaining the same distance by which the circle is larger than the frame. The last bit of routing is done freehand. It is not easy to do this accurately due to the saw dust and burr obscuring the line. The vinyl does cover up the irregularities nicely, though.

Contact adhesive was applied to both surfaces. The MDF absorbs much of the glue, so it required two applications on the wood. When the glue was tacky I applied the vinyl progressively, one facet at a time. At some places the vinyl had to be stretched, at others it had to be gathered (compacted) and smoothed as it was pressed down. For stretching, applying some heat (I used a heat gun) to the vinyl does help, but can make the vinyl layer a bit thin. At the driver recesses the vinyl had to be massaged a bit, after trimming away some of the waste material (the excess material makes the vinyl less workable).