Zaph SR71, better late than never!

[LonePine]

I'm a long time reader, and a first time poster. I appreciate the wealth of information on this site; it's very inspiring! My most recent build is the Zaph SR71; I'd been hoping to build these for quite some time and I finally got around to it. Here are some pics:

The boxes



Bondo-ed up



Block Mottled Makore veneer



Wipe-on Poly is amazing!



Time to listen

[impala454]

Looks great! I like that you dated and initialed the inside of the cabinet.

[LonePine]

Thanks! It was amazing to see the pattern in the veneer pop out when the polyurethane went on.

[wkhanna]

Very Nice!

[JonMarsh]

Good looking build! :T. Bet they sound fine, too!

[tommarra]

Great looking build! Looking forward to reading your listening impression as well.

[LonePine]

Thanks guys! I appreciate the compliments.

Now that I’ve spent some time listening, I feel I can give a fairly decent description of how my SR71 build is sounding.

These speakers sound very clean, and they stay very clean even when playing loud. The high frequencies sound accurate and natural. I like hearing the stick sound on ride cymbals and I feel these reproduce it very nicely. The midrange doesn’t sound as effortless as I’d hoped for, but is still neutral in terms of tone. I think I’ll stuff the boxes a bit more and listen to what that does for the sound. I’m hoping this will help to improve the depth of the image as well. Now for the low frequencies; this is where the SR71’s really shine for me. Of the other designs I’ve built, none have been so well controlled, tight and dynamic in the low end. The response very even (no dead notes or suddenly loud notes in bass lines); and I’m able to leave the sub turned off without feeling like I’m missing anything.

I’d like to give a big THANKS to John "Zaph" Krutke for posting his SR71 design and everything else that’s on his website. I’ve had my eye on this design for a while and it’s finally here!

[LonePine]

I got my SR71’s sounding much better in terms of midrange clarity and soundstage by bringing the total amount of poly-fill to 6oz. per cabinet. The cabinets seem really stuffed now, is this anything to be worried about? They sound fine, but is it possible to have too much poly-fill?

The improvement in sound quality from just adding some more poly-fill is surprising to me. Before I did this, I spent quite a bit of time experimenting with the options on Zaph’s website and with suggestions I've read in other SR71 builds. I changed the woofer inductor value, padded the tweeter, experimented with room placement and moved the speakers around to a few different sized rooms, but none of this gave any obvious improvement to the midrange clarity or the sound stage. So I thought I’d better try adding more poly-fill like I said I was going to.

I removed both woofers and took all of the poly-fill from one cabinet and stuffed it all in the other, then I put both of the woofers back in and I realized I had no idea which box was stuffed and which one wasn't. This was actually great, since I’d be able to listen and compare without bias. So, I put the speakers back up on the stands and listened to a track. Right away I noticed that the left side sounded more transparent, so I moved the left speaker to the right side and vice versa; then listened again. The clarity followed the speaker; so I swapped a few more times and listened to a few more tracks to verify that I was really hearing a difference. When I was done, I opened up the clear sounding speaker and it was the one containing all of the poly-fill.

Next, I stuffed the empty cabinet with 6oz and listened to how more fill changed the sound as a pair. This was a definite improvement in sound compared to what I first heard from these speakers a few weeks ago. The soundstage was much more transparent and the mids no longer sounded strained. Now I’m able to focus on the sound of the music, rather than on the sound of the speakers.

One thing I haven’t tried yet is replacing the 15AWG iron core inductor with a 14 AWG air core. I know that Zaph feels the iron core is sufficient, but I’ve also read different opinions from others. This is something I still might try, just so I can get my own take on it, but I think I’ll sit back and listen a while before I do.

[elessar]

Wow what a difference from filling. Great looking speakers glad to see they also are sounding great. Did you have any lining on the cabinet walls or are you just using the fill?

[LonePine]

Thanks elessar! I have 1" foam lining the sides and top and 2" on the back wall of the cabinet.