Has anyone completed a Zaph SR71?

[jkoll42]

Hi all

I was going to build a NatP until I realized that my receiver would only handle down to 6ohm so...... no NatP for me

I was looking around for a similarly priced speaker and came across the Zaph SR71 which looks good. Problem is, I cant seem to find anyone who has built one.

Also, if anyone has other suggestions for a good build I would love to hear!

Thanks

[Brian Bunge]

There's always the Modula MT, which uses just a single RS180. I don't know of anyone on this board who has built the SR71.

[Dennis H]

http://www.htguide.com/forum/showthread.php4?t=28179

Modula MT is a little cheaper but you can buy a kit for the Zaph design with preassembled crossovers and precut baffles (if they ever get them back in stock). Both look like excellent 8-ohm speakers.

[AlanH]

I haven't built or heard the SR71. I have built Zaph's Seas L15RLYP / 27TFFC System, which comes in at about the same price but with a 5" woofer. It was a great first project that is very well documented. I liked having all of the information in one place rather than having to dig through a thread.

I'm still very pleased with the L15RLYP / 27TFFC performance. I've compared them directly and indirectly to the Modula MTs and I'm very happy that I chose to build Zaph's design. The midrange and top end of the L15RLYP / 27TFFC seems much cleaner and more listenable to me. There is a little less low end in the L15RLYP / 27TFFC System (the L15 is a 5" driver vs a 7" driver in the Modulas), but the difference wasn't as big as I expected at normal listening levels and if you're going to use a sub the low end is a moot point. The Modula's are more efficient though.

Since finishing the L15RLYP / 27TFFC System, I built Zaphs' Vifa XG18 / Seas 27TDFC MTM. While they've only been finished since this weekend I can say I am also very happy with the result there too. By extrapolation I expect that the SR71s will be a good build too. :T

[jeff_free69]

Yes, I did - its up and running and sounding very fine!

The kit sounded very good from the get go, but for my application (studio nearfield), I found the stock crossover to have a slightly recessed soundstage (e.g vocals didn't have quite enough presence). So I tried some of the tweaks mentioned in the article. John alluded to the possibilty of a slight "warmth or heavyness".

Your mileage may vary; I have a small but extremely well treated room and usually work at about a 4 ft from the speakers, but here's what I tried:

- Reduced Baffle step tweak (L7 = 2.5 R0 = 3) : this I found it slightly too forward and present in the vocals and somewhat "busy" in the midrange (if I used this in my studio, the recordings would tend to be inversely muted)

-Trying to get somewhere in the middle, I now have about L7 ~2.8, R0 ~3.5 (not sure if this is a theoretically optimal combination of L & R; but while tweaking R's is cheap and easy; its not for the L's.)

Actually I still have a Pot wired in, and after a couple of weeks of serious listening on a very wide range of CDs I'm very pleased with this voicing; so I'm ready to measure it and hard-wire in a fixed R.

Just for kicks I may try putting the original L7=3.3mH back in, because I think the R0 (i.e the Tweeter Level tweak ) is much more critical. In which case I might recommend that at the very least you simply buy a couple of extra resistors (3.3, 3.5) to play with. When listening to a single speaker the differences may seem subtle, as you might infer by looking at the graphs, but the effect on the stereo imaging is VERY dramatic, so its worth a try.

Bottom line: The SR71 is as clean and smooth as advertised ; the imaging is spectacular and I'd buy it again.
(but i won't cut anymore MDF till I can do it outside I built my own cabs (~16L), but bought the front baffle (and gave it a 1/2" roundover)

The only picky criticism that I can think of is visual. You have to resist the urge to dust off the woofer when you unpack it. Mini-threads of "pulp" can protrude out slightly. They are not black and might look like shreds of cardboard sitting on the surface, but they are firmly embedded.

[jkoll42]

Thanks for the reply! Nice to see someone has built one.

I was wondering about the visual of it. It seemed from the picture like there were cardboard colored sections in the cone. It it that obvious or does it just look a bit odd up close?

Seems like they are definitely some good sounding speakers. I will be using them for about 80%HT/20%music with the music mainly being rock, alt, etc. I am running a 15" Tc-2000 Sub on the system. The room is a medium sized living room - no special HT sound treatments to walls, etc.

having built these, does this all sound like a decent application for the speakers? Will they play loud enough that if I am in a different room I can at least hear the music (cleaning around the house, etc?)

Thanks

[jeff_free69]

Thanks for the reply! Nice to see someone has built one.
I was wondering about the visual of it. ..

Yes , you can see the fiber specs in the photo (once you know about them), and from several feet away in person. Not as cool looking as an aluminum driver, but then you'd have to deal with a more complex crossover. I usually work in low - medium lighting so its not an issue for me.

I am running a 15" Tc-2000 Sub on the system. The room is a medium sized living room - no special HT sound treatments to walls, etc.
having built these, does this all sound like a decent application for the speakers? Will they play loud enough ...

They are fairly neutral so I don't see why the wouldn't be; You can screw with the EQ on your receiver if you prefer some boom and sizzle.

I use a 100W/ch NAD amp (no EQ) and have cranked them, so they can get moderately loud, but i don't like to work like that for extended periods.
They're as efficient as most.

I also have a madisound 12" sub / plate amp in 3.5cuft. I added an additional passive XO 12db / 100Hz to prevent too much overlap. The builtin active XO was clearly audible up to 200Hz. With the active sub, the SR71 goes lower than it really has to, but at this point I'm satisfied enough to not worry about modifying its bass response. That could increase the power handling if you need to. (IF there were a suggested tweak I'd try it, but aside from stuffing a sock in it, I'm not up on things enough to mess around with tuning the port).

I now think I'll try one last tweak to balance changes in L's vs R's. It always takes me a couple of days of listening to be sure my observations are consistent. Check back next week if you're interested.

[JonP]

I also have a madisound 12" sub / plate amp in 3.5cuft. I added an additional passive XO 12db / 100Hz to prevent too much overlap. The builtin active XO was clearly audible up to 200Hz. With the active sub, the SR71 goes lower than it really has to, but at this point I'm satisfied enough to not worry about modifying its bass response. That could increase the power handling if you need to. (IF there were a suggested tweak I'd try it, but aside from stuffing a sock in it, I'm not up on things enough to mess around with tuning the port).

Those spongy Nerf footballs, of appropriate size, work really well as port pluggers... They're kind of the "official" sock replacement of the DIY community. :T