6.5" ReSponse Kevlar Woofers

[f4ier]

I'm currently building the following pair for my bedroom. Gluing is slow 'cause I only have a few clamps; short ones too





The MTM enclosures are vented with hand-routed flares. Disassembled, with drivers and all, each box weighs almost 20kg! I used 18mm MDF. Should've doubled the baffle thickness though


The drivers are:





6.5" ReSponse Kevlar woofers and Vifa D26NC-15-06 (D26NC-55-06) 1" tweeters. At AU$79 a pop, the woofers aren't exactly cheap! But I didn't pay much for the drivers 'cause I casually work at JE in between classes at the University.


I'd be interested to see if anyone has taken measurements of these woofers. The screenshot linked from the woofer's website is only of a BB6 simulation The FRD files would help in designing the crossovers. Liberty Instruments is taking an awfully long time to reply with pricing and ordering details about their (Kim Girardin) calibrated microphones


Isaac

[ShinOBIWAN]

Looking good m8.

The Vifa D26 is a great treble unit and the build on the mid/bass looks spot on too.

The only problem that I can see is the fact that the baffle is only a measly 18mm thick. If I were you I'd stick another layer of 18mm on the front and then redo the driver cutouts and recesses. Not what you want to hear but from past experience the difference will be audible in the form of a more 'sorted' sound.

[martinlo]

Can I have a look of your wooden boxes?

[bigwill]

Nice looking speakers

[David Gatti]

You can get around the baffle thickness problem by glueing in 18mmx18mm hardwood strips on the inner seams of the baffle and around all the cutouts. Use PVA or even better 2-part epoxy.

I've actually saw those drivers today at my local Jaycar. The quality looks really nice but you definitely need to get some sort of measurements. Cheapest option for now could be a Tandy SPL meter taking measurements every 3rd octave or so.

Your woodwork looks very professional by the way.

Cheers
David


www.gattiweb.com

[f4ier]

Thanks for the kind words!

I had decided to double the baffle thickness, but I thought these new sheets of MDF I bought could be used for another project. I've 5 Vifa M22WR-09-06 woofers just waiting to be used Boy this hobby is really addictive! So I just decided to finish up the whole thing as is.

I managed to glue up one of the pair last night, so I fired up the midbass drivers to see if there were any air leaks. The port is quiet thanks to the flares shown below.



The tweeters aren't connected yet, but vocals come out quite well. I'll wait 'til the other one is glued up, and both are fitted with crossovers, before I make a side-by-side comparison to my B&W 601-III -- my only pair of speakers.

Martinlo, I'll be building a site detailing design and construction. I'll bump this thread up when the site is done.

David, your speakers are impressive (!!) and they must have taken a lot of time to build! These are actually my 2nd pair of DIY speakers. I built the 1st pair, which I gave away, 10 years ago when I first learned of vented-box resonance

I skimmed through a recent issue of Silicon Chip, and it looks like Altronics has a very good SPL meter, measures very flat right up to about 16kHz if memory serves me well. Not eactly cheap, and I'd rather spend the money on a Girardin mic. Won't be long now 'til I get a response from libinst regarding shipping cost and payment options. I'll just have to do a temp crossover by ear for now


Cheers!

[bowdown]

Hey f4ier, Any progress on this project yet? How did they sound? Any new pics?


Cheers

Bowdown

[f4ier]

Hey there bowdown. They've been playing for weeks now. The crossovers were adjusted using trial-and-error because my measurement microphone hasn't yet been calibrated. Given this, and the fact that the woofers aren't of the branded type, the resultant sound quality is impressive!

Liberty Instruments didn't reply to my last email so I decided to build my own mic instead. I just gotta find some free time to go to our University's acoustics lab; to have my microphone calibrated against their lab mics. (This is way practical compared to forking out over $200 for a KG mic.)

The MDF enclosures are probably going to stay oh naturale. I bought a long length of Consolidated Edgings-brand walnut veneer, which I had planned to use on this particular project, but I decided to use the veneer on another project in the very near future.

This site already has construction pictures. It will be updated with more pictures and some design/simulation details when my microphone is finally calibrated.

Cheers

Isaac

[tade]

i am excited to see how they compare to B&Ws those are very nice speakers.

[Al.M]

Looking very nice. Could not seem to find any woofer measurements at Jaycar but looked like nice drivers. I think they were down to $45 each in my local store on sale a few weeks back. Very interested to see your listening impressions.