SR71 Build

[oneplustwo]

Hey folks! I'm another noob here so just wanted to introduce myself. I'm fairly active over in the head-fi.org DIY forums so shout-out to those of you who also participate over there. And of course, I've now discovered this community of DIY-ers that will surely be a further strain on my wallet.

Speaking of which, I'm looking for help on how to spend my money.

As background, my current setup has a cheapy integrated amp feeding a pair of Boston Acoustics VR900's. These are the ones with powered subs in the bottom of the cabinet and a mid and tweeter on the top. They've been "ok" over the last 9 years or so and I don't really have any complaints as they've been fine for all around TV/movie/music duty in my small living room.

Over the last year or so, I've built a number of high end DAC's and headphone amps for my Sennheiser HD650's and now would like to expand my listening universe to higher end stereo speakers. I don't feel a need for huge low end as my house shares walls with my neighbors. Instead, I'm thinking that something in the family of the Zaph ZRT or ZA5 might be a good first project given the availability of complete kits with or without cabinets. Of course, there are different flavors of both of those at different price points but my first question is whether one of those two kits would be a good first foray into DIY speakers that would satisfy me given my semi-relevant reference of my headphone listening.

I guess when it comes down to it, I'm trying to decide if they extra cost of the ZRT system is worth it compared to the ZA5's. I've tried to do some searches to get people's impression of these both individually and compared to each other but haven't had much luck. My own conclusion (very pedestrian and in no way truly informed) is just that the response curves of both systems seem pretty good except the ZRT "looks" better at the high end without the peaks and valleys that the ZA5 tweeter seems to exhibit. Of course, if there are other kits that would be no brainer much better choices, please let me know. But the ZA route seemed like a good one to me so I'd like to focus on that if that's ok.

Also, I'm pretty adept at wood working so the cabinets shouldn't be a big issue regardless of whether I go pre-fab or not.

Anyway, that's my rambling intoduction/question. Looking forward to starting my speaker DIY career!

[---k---]

The Zaph ZA kits are pretty new. I know they've sold a lot, but I haven't seen anyone here that has purchased them. Kit buyers are typically a quite bunch and not fanatics on these forums.

My guess is that the ZRT are more accurate and reproduce detail better and clearer. But the ZA MTM or TMM will go louder and be more dynamic. Apples and oranges. Both are probably very good, and at normal levels and with simple music might be hard to distinguish.

[evilskillit]

Welcome aboard. I'll see if I can chip in with any helpful info. The Zaph ZA kit should be pretty nice, I know they sold a lot but as K said, nobody built one the came here and said "Man this thing is awesome" but kit builders do sort of seem to keep to themselves.

I have built a similar small speaker, check these out.

http://rjbaudio.com/Microbe%20SE/microbe%20SE.html

They are similar in spirit to the Zaph ZA kit and they sound awesome, they are very clear and articulate but if I rock out very loudly the lack of full low end is a bit of a bummer. I paired them with a sub and high cut them at 80hz and that seems to help a lot, it also makes the lower mids sound a lot less strained, probably due to the small speaker working it's self to death trying to produce full range sound.

The ZRT kit is pretty pricy for your first project but I bet they sound incredible. If you want a kit that sounds great and can probably split the difference you might check out the Zaph SR71 kit. Its a bit more than the ZA 2 way kit but its probably nicer in every way (tho I'm guessing, having not heard either yet). The Seas woofer used in that design is supposed to be incredibly smooth, and as a 6.5 woofer should have plenty of guts without making your neighbor angry.

Me personally, after much consideration I'm taking a stab at his Waveguide TMM design. It has been described as having some "headphone" characteristics, which is interesting, and the crossovers are very simple, especially the minimalist version. Which is intriguing and appealing.

Well I hope I haven't made your decision more difficult but I think the SR71 is a nice half way point between the two designs you're looking at tho I'm sure either of the others would make you very happy too. Just the ZRT is very pricy and, having made a very small speaker like the ZA for my first project I found myself quickly wishing I had gone a bit bigger. I do enjoy a lot of rock and metal tho.

[Not2Evil]

If you've been happy with what you have, why do you want to "upgrade"?

Your current speakers have built in amplified subs. It's going to be hard to top without relativly large speakers (not an MTM) or at least a small sub to go with them.

You didn't mention whether you intended to continue listening/watching in stereo. I would think stereo vs. surround would make a huge difference on your decision making. (Center channel rules)

I would suggest spending your money on a HT reciever first, then come back and talk some more.

Remember, if the women don't find you handy, I hope they find you. Wait, that's not how it goes!

[oneplustwo]

If you've been happy with what you have, why do you want to "upgrade"?

I have this serious disease called "upgraditis." Maybe you've heard of it? :W Seriously, my main motivation is just that I enjoy diy projects. Secondarily, I feel like I'm probably about where I was with headphones a couple years ago and didn't know what I was missing. So I figure some DIY speakers will help "show me the light" at a reasonable price point.

Your current speakers have built in amplified subs. It's going to be hard to top without relativly large speakers (not an MTM) or at least a small sub to go with them.

That's fine. I figure a sub will be a good second project if I feel it necessary.

You didn't mention whether you intended to continue listening/watching in stereo. I would think stereo vs. surround would make a huge difference on your decision making. (Center channel rules)

I plan on sticking with stereo. I don't have the space for surround and most of my serious listening is with 2 channel audio. That may change in the future... but pretty distant future.

I'll check out the SR71 as well. I looked at it briefly, but was looking for a set of floor standing units initially. Maybe I'll start out with the ZA5's since it is my first foray into speaker building and then upgrade later (see... it is a disease). Any quick recos as to which configuration? At the price, I'm tempted to go with the MMTMM kit... but the TMM kit is probably a better fit given my small space and noob status.

Thoughts?

[evilskillit]

hrm, yeah I just assumed you were going with the ZA5 TM. Well Zaph has a long article on his page about each one, what it does and why. I would bet you'd be happy with any of the bigger ones the MTMMM MMTMM or TMM or MTM. In this case more is probably better, he says specifically the difference between the MTMMM and the MMTMM.

http://zaphaudio.com/ZA5/

I guess the MTMMM is just a bit shorter but has less midrange above tweeter level. So if you can, might as well make the MMTMM

[oneplustwo]

hrm, yeah I just assumed you were going with the ZA5 TM. Well Zaph has a long article on his page about each one, what it does and why. I would bet you'd be happy with any of the bigger ones the MTMMM MMTMM or TMM or MTM. In this case more is probably better, he says specifically the difference between the MTMMM and the MMTMM.

http://zaphaudio.com/ZA5/

I guess the MTMMM is just a bit shorter but has less midrange above tweeter level. So if you can, might as well make the MMTMM

The more I read, the less sure I am about what to get. The SR71 seems like it would be a nice compromise between the ZA5 and the ZRT. The price is in the middle and the response curves look to me to be between the two as well. If speakers weren't so big, I would plan on building all three sets. That's what I've done with DIY amps and DAC's... to hear the difference for myself and decide what to keep. But they're nice and small.

Hmm... will have to keep noodling this one for a bit.

[---k---]

I'm thinking about picking up a ZA MTM kit. We'll see. I got a crazy projec that I may or may not go through with. But the Zaph kit fills the bill. Good price. Not to expensive, but enough that the quality is there. Nice size. And, I just want to try a Zaph design. We'll see. My only worry is that it might sound better than the Khans!

Got to get a heater installed in my garage first.

[oneplustwo]

Yah... that might be my second choice. I dunno, I keep changing my mind. I'm also considering making a DIY amp first to drive the speakers. Anyone here dabble in that stuff?

[ClosetSciFiGeek]

DIY Amplifiers

Check out these sites:

Interesting Tripath amps

http://www.41hz.com/shop/

Gainclone kits(all are on a really good sale now too)

http://www.chipamp.com/orders.shtml

[chupalt]

I'm currently building a ZA5 MTM center channel.

My plan was to build the center channel first, then build a pair ZA5.3t (TMM floorstanders). Hopefully I can apply some of the lessons learned on the bigger enclosures.

I'm just starting to apply sanding sealer to the enclosure, so I'm probably still a week out from listening to it. I'll let you know how it sounds.

[oneplustwo]

CSFGeek - I've heard of the gainclones. Seems like a fun simple project. I'll have to build one at some point. At moment, I'm going to other direction with a Beta 24. (http://www.head-fi.org/forums/f6/24-...lifier-287953/ if you're interested.)

chupalt - sounds good! what will you be comparing against?

[cjd]

My only worry is that it might sound better than the Khans!

Heh. Different it will sound. Better? Probably. You'll just need a high-end version of the Khans using Scan drivers... let me know, I've been wanting to try that... :B

[chupalt]

My current primary system is a set of b&w 600 series (S3). The fronts are the DM602 S3 and the center is an LCR600 S3. So those are the only speakers I can compare these to.

The current plan is to use the ZA5s for the master bedroom. However, I'm afraid that the ZA5s may blow the B&Ws away and they'll end up in the primary spot.

[---k---]

Likely.

[Dave Bullet]

Do you like refined, loud or both? If refined - a quality TM is what you want. Get a sep. powered sub for low end (but as you say, that's not a priority given your neighbours). In this case I'd go the ZRT. Do it once and do it right (if you were happy for 9 years with your current pair, then another 9 is quite feasible with the ZRT). If you go the ZRT - invest in better upstream electronics. The ZRT will definitely reveal a quality power source. Without it, you will have wasted your money or feel the ZRT haven't delivered.

If you want loud and refined - you'll probably need to consider a larger TMW or WMTMW. There are designs here in missions accomplished.

Scanspeak drivers are the crown jewel when it comes to very low distortion. Given Zaph knows how to work these babies - I think you'll love a pair of ZRTs. (just spend more money on your electronics - ok?)

[oneplustwo]

Dave... thanks for picking the most expensive route for me! Refined is what I'm looking for and I typically like the idea of do it right the first time, so ZRT's may be where I end up. As for electronics... I've got a high end DAC built already (Buffalo 32S from www.twistedpearaudio.com) and am in the process of building a fully differential balanced amp as well (Beta24 from www.amb.org/audio/beta24/). So I think I have my work cut out for me for probably 6-9 months! The only thing I'm nervous about is that this will be my first speaker build. But I guess I can always redo cabinets if I screw them up. MDF isn't that expensive.

[Licinius]

The Zaph ZA kit should be pretty nice, I know they sold a lot but as K said, nobody built one the came here and said "Man this thing is awesome" but kit builders do sort of seem to keep to themselves.

I've built the 5.2's, and man, they are awesome. Impressively clean and accurate - the ZA14 is a killer driver - and the imaging is amazing. I try not to thread crap since I really dislike fanboi-ism, but the ZA kits are of exceptional quality, and for the price, with pre-built crossovers and all the needed parts, are a killer value to boot, especially for the first-time builder (and even veterans who need something quick and clean without any fussing).

https://www.htguide.com/forum/showpost.php?p=475530&postcount=38

[Licinius]

The current plan is to use the ZA5s for the master bedroom. However, I'm afraid that the ZA5s may blow the B&Ws away and they'll end up in the primary spot.

I wouldn't doubt it.

[oneplustwo]

Licinius - thx for the perspective. I just can't get over the tweeter response. I know it probably isn't that noticeable in listening, but it bothers me anyway. That being said, for the price, it's hard to go wrong. Why did you go with the PE cabs vs the madisound ones?

[oneplustwo]

Well, I think I'm going to go with the SR71 kit. The 7" woofer will provide more bass response than the ZA5 which I hope will be enough to allow me to run sans sub-woofer. And I'm thinking this might be a good project as my first DIY speaker since it's so much cheaper than the ZRT kit. Plus, I'm betting the sound quality will be "good enough." And if it's not, then I can always build the ZRT later!

[evilskillit]

The SR71 will be a fantastic speaker. Should have plenty of bass for a small bookshelf. If you want more bass you can always add a really nice sub later for only a few hundred. Until you get the itch that should get you by for as long as you care to listen to them.

[caminoguy]

I built the sr71 about a year ago using parts express curved cabinets. It was my first diy project and i was very happy with the results. The sound is full of detail and the bass is decent and responsive for a small book shelf but could use a sub if you like alot of bass. I just bought the za5.3c center channel kit but havent had a chance to put together so i can't comment on the za5.3 yet. There's lots of designs around the web but in my opinion alot of zaph designs are very budget friendly and he makes things easy for a noobie especially with detailed write ups.

Also, you can make a floorstanding cabinet for the sr71's...i believe zaph briefly details it on his website.

[oneplustwo]

I considered floor standing, but decided to start small. Maybe I'll build the ZRT's if these go well and I feel like an upgrade. I'm a little nervous about the holes for the woofer and tweeter, but I bought the jasper jig so it should be pretty straight forward... I hope. Also, I haven't figured out how I'm going to finish the outside. I'm going to try for cheap and easy but good... maybe just prime and paint and be done with it? Any suggestions for a first go at this would be appreciated.

I built the sr71 about a year ago using parts express curved cabinets. It was my first diy project and i was very happy with the results. The sound is full of detail and the bass is decent and responsive for a small book shelf but could use a sub if you like alot of bass. I just bought the za5.3c center channel kit but havent had a chance to put together so i can't comment on the za5.3 yet. There's lots of designs around the web but in my opinion alot of zaph designs are very budget friendly and he makes things easy for a noobie especially with detailed write ups.

Also, you can make a floorstanding cabinet for the sr71's...i believe zaph briefly details it on his website.

[evilskillit]

If you just want to try something simple and cheap that can look good go down to the local home store and buy a good can of primer and a good can of house paint in a color of your choice and brush or roll it on after applying a few layers of sanding sealer.

I tried to spray on a black finish on my first project, 2 small bookshelves, it came out nice enough till one of the spray cans sputtered, then I tried to wipe the bubbles, then I got cloth stuck in the paint. I would have had to start over on that speaker and I was already behind schedule and between one can of primer, 1 of paint and 1 of clear coat I had $15+ in spray paint and I didn't want to sand that down and start over.

Read up on finishing, if you use MDF you need to use a high solids sealer or primer to fill the grain, something like sanding sealer, or just a bunch of wood glue cut with a bit of something to thin it. Then prime and paint. With house paint it should go on pretty easy, and if you do mess up you've got plenty in case you need to sand and repaint.

[ClosetSciFiGeek]

Not to change the topic, but I am so sick of sanding and refinishing MDF that in future I will continue to veneer the main enclosures on all future speakers(that's pretty easy to get right with a router and a flush trim bearing bit), but trying to get baffles of mdf to turn out right has driven me over the edge. Maybe I am a painting leper, but trying to shoot gloss black over auto primer/then multiple coats of 400 grit sanded auto primer got maddening. The machined edge of the MDF kept showing through. I finally got a marginally acceptable(to me) baffle that I put on my last speakers. I am going to woodcraft shortly and buying some actual wood(not mdf) for new baffles. I think this would have been cheaper after all the paint, primer and sandpaper I went through(not to mention the elbow grease). I'll tell you how the real wood baffle goes when I finally get there. Gotta be easier than mdf. When making furniture I just sand 100-150-220-400/blow surface with compressed air/tack cloth/stain and-or clearcoat. Should be the same for speaker baffles.

[evilskillit]

Yeah I haven't even gone through that much in the way of finishing woes. For my first few builds I think raw MDF looks ok but I'm getting tired of the dust and the weight. I bought some birch ply and I'm thinking of seeing if I can find a solid birch plank big enough to be my front baffle and doing that. Tho I'm afraid over time it may warp and/or crack. We'll see how it goes, if it goes.

Not to change the topic, but I am so sick of sanding and refinishing MDF that in future I will continue to veneer the main enclosures on all future speakers(that's pretty easy to get right with a router and a flush trim bearing bit), but trying to get baffles of mdf to turn out right has driven me over the edge. Maybe I am a painting leper, but trying to shoot gloss black over auto primer/then multiple coats of 400 grit sanded auto primer got maddening. The machined edge of the MDF kept showing through. I finally got a marginally acceptable(to me) baffle that I put on my last speakers. I am going to woodcraft shortly and buying some actual wood(not mdf) for new baffles. I think this would have been cheaper after all the paint, primer and sandpaper I went through(not to mention the elbow grease). I'll tell you how the real wood baffle goes when I finally get there. Gotta be easier than mdf. When making furniture I just sand 100-150-220-400/blow surface with compressed air/tack cloth/stain and-or clearcoat. Should be the same for speaker baffles.

[impulse]

Zaph himself once rated the ZD5 as the best sounding speaker he has done (hi commented this himself in a forum somewhere - can't rembember where). This is a relative small bookshelf speaker, but if you are going to build a sub, then why not go for it?

The filter is not the easyiest to build....

[caminoguy]

The easiest cabinet for a newbie is to buy two 0.5cu.ft cabs from parts express or madisound and mill out the baffle. I'm building a subwoofer right now and I'm having a nightmare with the primer...for some reason it's not curing. Anyways, sometimes a simple foam brush paint job turns out to be a sanding nightmare.

My sr-71's in the PE piano black curved cabinets look great...so for <$500 you could have a great first project with minimal finishing headaches of mdf. Add another ~$400 - $500 for a sub (exodus audio, css, dayton, etc.) and you'll have a great combo for less than zaphs scan speak design.

[oneplustwo]

Yes... I too am not a huge fan of the finishing process. Veneer seemed like it might be a good alternative but not exactly cheap. I've done some furniture with birch ply and liked the relatively simple process as well as the results. But from my reading, it sounds like MDF is a better material given it's physical properties as well as the fact that it's relatively and consistently flat! Also, I can get 2x4 pieces which is easier than schlepping a 4x8 piece on top of the SUV. Is that about right or is 3/4" ply just as good (performance-wise) as MDF?

I might just prime and paint and be done with it. Maybe use one of those fancy auto finishes in a can type things.

If one does use plywood, is there a common methodology to finishing the ply edges? I was thinking of just using solid trim pieces but that seems like a non-elegant solution. I've seem some laminate type executions which were pretty cool, but probably out of my scope for my first project.

[---k---]

Yep. Don't finish them.

[oneplustwo]

Another idea is to go with plywood everywhere except the front and top where you could do a solid piece of poplar or maple or something. That would require a 9" wide piece which I think is easy enough to find. The bottom and rear edges wouldn't be pretty, but who looks there anyway? Then you could just sand, stain, polyurethane and be done with it.

[fbov]

...
If one does use plywood, is there a common methodology to finishing the ply edges? ...

Edge veneer is one common method for hardwood-faced ply.

[evilskillit]

As far as acoustics goes it seems like anything works as long as you brace it up well. 3/4" birch ply should be as good as 3/4" mdf. Pine is ok but its really kind of soft.

If I don't do a hardwood front baffle on my birch cabinets I'm just going to let the ply edge show and use it as a sort of frame for the face.

[oneplustwo]

Hmm... thanks for the input. I'll go to Home Depot this weekend and see what they have. Maybe I can get away with a solid wood cabinet!

[numberoneoppa]

Hmm... thanks for the input. I'll go to Home Depot this weekend and see what they have. Maybe I can get away with a solid wood cabinet!

Not with the woods that are sold at Home Depot. You'll have to look around your neighborhood for hardwood shops if you want to do wood cabinets. Alternatively, you can order hardwoods online.

[evilskillit]

Yeah go see my thread on PE boards called OT: KC hardwood selection sucks.

I went to Home Depot (where I used to work) to pick up a sheet of birch, I've seen some ok looking stuff there. Tonight there were only 2 sheets, obviously the ones no one wanted so I had them get me down a bunk. I couldn't find anything that didn't have a few plugs on the good side and none of it was as bright or as white as I wanted, it was all a bit dull and brown. I wanted some shimmer. Well I made them get it down, so I found the best looking piece, with no orange smears on it from brushing up against the railing, and no dents and only a few plugs and asked them to cut it. Well the blades there get replaced... never so it got some minor tearout on the good side. Definitely not something you want on lumber you haven't even bought yet, but I remember what it was like to deal with those customers who put you through hell and then leave without buying anything. I'm too nice, I bought the sheet. Honestly tho, its use as a piece of finished work is suspect at best. It would be ok for veneering over, or puttying and painting, but I don't think I'll use it for my natural finish speakers. I'll go somewhere else for the lumber for that.

Just wanted to give you a heads up. If you're going to veneer or paint Home Depot or Lowes birch ply is probably fine, but don't expect to be able to just finish the stuff.

[---k---]

Did you try Liberty Hardwood in Kansas City?

[oneplustwo]

There's a Home Depot "Pro" near me that has a pretty good selection of solid birch, oak, maple, and poplar. I might be able to make something work there. Poplar is cheap... and will take a stain nicely. I've made some stuff with the birch there that I was pretty happy with. I don't know if they have pieces 9" wide though. Anyway, I'll take a look and see. There are a few other option around that I can check out too, but HD is convenient.

[evilskillit]

Did you try Liberty Hardwood in Kansas City?

That is one of the places I learned about in my thread. I'll have to give them a call and see what their hours are. Their web site is listed as an attack site by both Google and Mozilla, which is freaking me out. I hope they have better hours than Paxton and Schute which basically preclude me from shopping there unless I take vacation time.

[oneplustwo]

I found a local place that has good wood... so I'm going to stop by on the way home and maybe make these things out of solid maple. Excited to start cutting and gluing!

Quick question for you. Do most people go ahead and glue the baffles in? It looks like Zaph's drawing shows 4 places to screw them in to MDF triangular supports. Are those supports themselves just glued in? And I guess I would seal the interface with some sort of foam rubber?

[evilskillit]

Zaph is using a removable baffle on that front, some people like to do that. I never have. It's nice if you need to get back into the box later, or for that matter use the same box for a whole other design. Of course you would want to put some rubber gasket or weather stripping or something behind the front to make sure it seals air tight.

Personally I've never messed with that and find the idea of a removable front baffle to be a bit funny. I do want to try to do a removable back baffle on my next project. It'll be more work but it'll allow me to easily expirament with varying amounts of stuffing and sound dampening material.

[schnottus]

Zaph ZA5 mtm bookshelves and center were my first speaker builds and they sound awesome. I don't have much to compare them to since I am new to speaker building although I can say they are slightly less warm than my Polk LSi speakers, although the clarity is just as good if not better. I made them out of 3/4 inch mdf and finished with high gloss automotive paint polished to a mirror finish. I wouldn't recommend finishing in this way though, it looks beautiful but I probably spent close to 30 hours per speaker between painting, sanding, and polishing. Still, I wouldn't hesitate to recommend the ZA5 kits to anybody.

[moab_dan]

Zaph ZA5 mtm bookshelves and center were my first speaker builds and they sound awesome. I don't have much to compare them to since I am new to speaker building although I can say they are slightly less warm than my Polk LSi speakers, although the clarity is just as good if not better. I made them out of 3/4 inch mdf and finished with high gloss automotive paint polished to a mirror finish. I wouldn't recommend finishing in this way though, it looks beautiful but I probably spent close to 30 hours per speaker between painting, sanding, and polishing. Still, I wouldn't hesitate to recommend the ZA5 kits to anybody.

Pics please!

[oneplustwo]

Just got back from the lumber yard. They didn't have maple in the width I needed and I wasn't willing to spend the money on the mahogany that was wide enough. So I decided to make a compromise... I bought enough African mahogany for the front, top, and rear. The rest of the sides will be birch ply. This way, I hope to get some interesting contrasting colors (I'm going to just finish with some sanding and a few applications of tung oil) and I can cover up the ply edges except for the bottom edge which won't be visible anyway. I might make the rear side ply too and maybe just trim the edges with some scrap mahogany.

Another question... it seems like people just glue the edges without any sort of rabbeting (except for the front baffle). I would like to rabbet all the joints just to have some extra glue surface area... any comments on that?