Building starting system - Kit281 the best choice? (1 Viewer)

[Michael R Price]

I am a high-school student looking to put together a reasonably good stereo system. Why did I post in the DIY forum? Because I am considering using the Adire Kit281 as the basis of the system. My total system budget is probably between $600-800 total, and I would like to get the best possible performance for my money just like everyone else. What I have tentatively planned at this point is to buy a used integrated amplifier and CD player from a friend/family or Ebay, and build Kit281V speakers. Right now I'm thinking over two things: the cost distribution of the system (~75% for speakers, and relatively small amount for components) and the choice of speakers in the $500 range.
I listen to a variety of music, mostly light-to-medium rock and classical. What I am looking for is a system that provides me with reasonably full-range (say, preferably down to around 40Hz or lower in room) response and realistic reproduction of music with a well-defined, clear sound and good soundstaging. (Sadly, the only decent speakers I've ever had a chance to listen to are the original Large Advent, the JBL S38, Allison AL115, and the Klipsch RB-5. Of those, I like the Klipsch the best for its 'forward' sound and transient impact.) While I don't usually listen at very high (95dB+) volume, I would like to have capability to do so anyway. The room the system will be in (my bedroom) is about 11x14ft, and a convienient location places the speakers about 5 feet apart and 7 feet away from the 'listening position' (bed).
Anyway, what I am asking (and this is why the post is here and not somewhere else) is if the 281s are my best option in the $500 range. I don't have any significant experience in designing my own crossovers and picking drivers that would match well, so at this point I think it is best to go with a kit-style speaker; I do have the sufficient (basic) woodworking skills to take on such a project. (Would it be worth it to learn about crossover and driver design so that I could custom-design a speaker better than the 281?) From the testamonials I've seen so far online, it appears as if the 281 (and other kit style speakers) far outperform 'retail' speakers (even used ones) in comparable price ranges; for example, many have stated that the 281 is comparable to other speakers in the $2000 price range. Are there any other kits in the $300-400 range (like the Kit281) that I should consider? I am not very familiar with other comparable kits, and that's why I'm asking.
I do have a few questions about the Kit281 however.
1. I understand that the t-nuts used to mount the woofers on the baffle extend into the side panel. Is the best way to fix this filing metal off the t-nuts, or cutting a small notch out of the side panel?
2. Should the entire box be built before making baffle cuts, or should each piece be fully prepared (drivers and crossovers mounted) before final assembly? I've seen people build speakers both ways, and am wondering which is easier.
3. Does anyone have a ballpark estimate of what the cost would be for a laminate or veneer finish? I am trying to decide if I should finish whatever I build, as opposed to simply painting them.
4. Is there a significant loss in bass transient response due to the low-tuned port on the 281 and how much would plugging the port help this? (And if I were to add a low-cost subwoofer later, should the port be plugged for that purpose?)
Thanks for your help, and I apologize if this post should be in another area as opposed to the DIY forum.

 

[Mark Hayenga]

Hi Michael,
I was in your shoes not too long ago, putting together what would be my first 'real' stereo system during my senior year of high school. I've since gone on to college to study electrical engineering, and taken up loudspeaker and crossover design as an, um, very involved hobby. And I just wanted to assure you that you are very much making the right decision to consider DIY kits for your first system - if you don't mind the sweat equity involved, you can achieve some very surprising results within a given budget, without having to worry about all of the design issues and decisions involved.
Now, on to the speaker questions. Unfortunately, I have never heard a single 'kit' speaker - surprising (arrogant?)when you consider I'm about to start recommending some over others. What I have done is spend the last year and a half working with various drivers attempting to design my own systems and, based on my experience, I feel competent enough to make some cursory criticisms of some kits and their design compromises. So, to get on with it...
Given your listening tastes, room size, normal listening levels, and budget, I believe there are some kit speakers available that may present a better value for you than the Kit 281. (Heresy around these parts I know ). The 281 strikes me as very much geared towards high-output home theater usage - shielded, dual 8" bass drivers, extended bass response, and highly efficient. From others' personal accounts that I've read online, they're also not too shabby at music reproduction (though I have read posts by people who were less enamored of them than others).
With regard to their design, I see several things that I like - namely their high efficiency, deep bass response, and their usage of higher-order crossovers. Such a design is also an excellent compromise to achieve a full-range system without resorting to a full-blown, more expensive, and more complex three-way. And while eight-inch two ways don't exactly qualify as my ideal for midrange reproduction, they can be better than most people usually expect if properly executed.
So why do I think other options might be better for you? First, the Kit 281s are large speakers, and are likely voiced to be used in large rooms - something which might be a cause for concern in a smaller room, as different amounts of baffle step compensation can greatly affect perceived tonal balance to a much greater extent than one might imagine due to its affect on a wide bandwidth of frequencies. You might ask Dan just how much baffle step compensation was incorporated into the design, and ask people who are using them in smaller rooms how they sound. But in an 11x14 foot bedroom, I would be a little hesitant to use a pair of large floorstanding speakers.
Also, unless you really need an eight inch MTM to acheive the level of bass extension and output you need (which from your listening tastes and room size it sounds like you might not use), I think having a smaller driver cover the midrange band would be preferable. You'll push cone breakup farther out of the passband, and get better off-axis response to boot.
Finally, if you go with a smaller two-way system with a single midrange and tweeter (instead of an MTM), your money will go towards buying a fewer number of higher quality drivers (instead of more drivers of the same quality). One of the things I think is important in loudspeaker design is the inherent linearity of the drivers used - I like low Fs tweeters with large excursion and high power handling, and woofers/midranges with advanced motor technologies (Faraday loops, highly optimized gap geometries, etc). While these don't always ensure better performance, I've found such things to be generally good indicators of improved sound quality over similarly priced drivers that don't use them.
So, for a similar amount of money as the Kit 281s cost, I think there are a few less popular options that might work better for your listening requirements. Both the speakers I'm going to recommend are smaller, two-way loudpspeakers, with a single 6.5" midwoofer and a 1" soft dome tweeter. They're both available from a lesser known, non-profit company, with variations on both designs to be found posted on the internet.
The first kit which I'll recommend is the Selah Audio X2. Selah Audio is a small non-profit company run by Rick Craig, a frequent poster at the Madisound discussion forum. He's also been heavily involved in the now-annual Madisound DIY speaker competition. His X2 uses a Vifa P17WJ-08 and Vifa D25AG-35 with a simple second order crossover. I've worked with both these drivers before, and they really are good units for the price (especially the tweeter - I was very impressed with it). Furthermore, this is a VERY popular driver combination among the DIY crowd, and there are at least another half-dozen crossover designs published on the net for it. Perusing the Selah Audio page I don't see the X2 listed anymore, and Rick might have discontinued it. But since all his plans and schematics are free, you might email him and ask if you could get a copy, and just order the parts from Madisound. Another benefit is the exceptionally low price of this kit. Drivers, crossovers, and unfinished cabinets should cost you LESS than $200. Much less than your intended budget I know, but the quality of this driver combination is just exceptional, and not necessarily just because of the price. About the same time as I was designing the crossovers for my friend's P17/D25 system I was working on a much more expensive two-way ($400/pr) for myself and, though I can appreciate my more expensive speakers as technically superior in critical listening tests, I think I could be very happy with my friend's P17/D25 system. Decreasing returns kick in VERY quickly in the DIY market, so don't discount kits simply because they're inexpensive (Indeed, it took me a little while to get out of my 'driver snob' phase and start listening to guys like EdP (who you might see post around here or the Home Theater Talk forum) about the virtues of some less expensive drivers. I still like my faraday loops and exotic cone technology, but I also appreciate for what it is - technical superiority and not necessarily more listening pleasure). Dennis Murphy measured an example of the X2 with Liberty Audiosuite, and posted the measurements here: ttp://www.accumatics.com/dm/measurements/X2oa.gif . There's approximately 3dB of baffle step in the design, which would probably work well in a smaller room.
The second kit I'll recommend is the Selah Audio STS (Scan the Seas). It uses a Seas Excel 1" soft dome tweeter, and a Scan-Speak 8545 woofer. These are exceptionally high-quality components, and are commonly used in high end systems (for example, Wilson Audio, Vienna Acoustics, ProAc, and several other companies use either the same Scan-Speak woofer or a variant of it). The kit cost is $465, which puts it at the high end of your budget, but from all the reports I've read on the Madisound forum it is a very well designed kit. If you have any questions about this kit or want feedback from people who have built it, the discussion forum at www.madisound.com is a great place to ask.
BTW - I've no affiliation with Selah Audio, they're just the only ones I know of producing a kit plan and have previously offered driver/xover parts for a P17/D25 system. Their STS has also gotten rave reviews over at the Madisound board, hence my recommendations.
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Mark Hayenga
www.hayenga.com
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"My standards are so high, most of them are double."
[Edited last by Mark Hayenga on August 26, 2001 at 01:04 PM]

 

[Robert_J]

There are some less expensive designs at Wayne J's web site. They are not sold as kits but they do have a parts list for Parts Express . There are a lot of reviews at the PE Tech Talk board.
-Robert
[Edited last by Robert_J on August 25, 2001 at 03:40 PM]

 

[Michael R Price]

Thanks Mark. The Vifa P17/D25 looks very good, and I still haven't decided if I want to go a bit cheaper (than the 281). At this point I am still leaning towards the 281; mainly because so many people on the 'Home Theater Talk' forum have had such great experiences with them.
I understand how the 281s in my room would possibly produce too much bass. I guess it's hard to find kits that are designed for full-range output in a small room... Can this be corrected by lowering the tuning point? (And also, I still am not familiar with 'voicing' - what is the difference between a 'nearfield' monitor and a far-field one?)
I also looked at Wayne J's designs at speakerbuilder.net. Unfortunately they all seem to be either above or below my price range! While I shouldn't doubt the capability of a kit using only, say, $150 worth in drivers, I wonder if there are any other kits in the $300 range that would compete with the 281s.
Does anyone know what the costs for real-wood veneer to cover a pair of speakers is like? I'm leaning towards finishing my speakers, mainly to increase their value if I ever decide to sell them. (And also to help with my 'parent acceptance factor'.)
Edit - Any thoughts on the GR Research AV-3? http://www.gr-research.com/performer/av3.html
Another edit - I just realized that there's a mistake in my first post, I have also listened to the Martin Logan Prodigy hooked up to a Krell KPS-25s CD player and Full Power Balanced monoblocks. So I do have an idea what near-perfect sound is... I would also like to say that the three main things I am looking for in a speaker, in no particular order are bass depth, soundstaging, and transient response. I like to be able to hear and feel the underlying bass notes along with the harmonics (many smaller bookshelf speakers can't do this). I also enjoy the forward presence and 'impact' of Klipsch-style speakers in particular. I assume this is because of the horn-loaded tweeter and excellent transient response of their speakers (the best one I have heard is the RB-5, which I really liked except it was a bit harsh at high volumes sometimes, and that it didn't quite reach deep enough in the bass region, though it was auditioned in a large room.) And also, while I don't listen at insane houseshaking levels I do often like to turn the volume up to a comfortably loud level, where you start to feel the sound a little bit; I'm guessing that's between 80 and 90dB continuous. Also since I will be using a cheap lowpowered amplifier, I think that rules out the Selah STS, but am not sure. Again I am still leaning towards the Kit281, and tower-style kits in general because I don't mind the extra size, don't want to pay for stands and would like the extra bass extension they provide. I may send an e-mail to Dan Wiggins or other kit producers for some input.
Sorry about the long rant.
[Edited last by Michael R Price on August 27, 2001 at 03:34 PM]

 

[Brian Fellmeth]

ACI has a similar 2 way tower called the opal thats about $350/pr. I have purchased from both ACI and Adire and they are both great. http://www.subwoofers.com/HomeAud/Kits/opal/opal.asp
As for veneer, the easy route is to get a 4x8 foot sheet of backed veneer which runs about $60. If you are willing to work with raw strips, enough can be purchased on ebay for $20-$50 depending on the grade and species.
I wouldn't put much effort into "increasing resale value" because DIY has horrible resale at best. Assume anything you build will be yours forever.

 

[Michael R Price]

I apologize for 'bumping' this post but I am looking for all the help I can get. If anyone has any experience with the GR AV-3, ACI Opal or the 281 their comments would be greatly appreciated. Again I am looking for transient response, soundstaging and bass depth. Also I would like suggestions on finishing the speakers, whichever kit I choose; I'm considering going with a real wood veneer finish, though that is costly. Thanks for your help.

 

[Rich Kraus]

youve probably already seen it, but but i have a kit 281 construction page in my sig file.
im pleased as punch with my kit281/kit81 project. id do it again, exactly the same way.
my room is 15x17 with a high celing, and i believe thay sound great. (havent heard many others in my room i will admit, but the adires have more than met my expectations.)
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'Till next time,
Rich (the kite guy)
My DIY audio page!
Use your ashtray please, dont throw um on the street. thanks

 

[Brian Bunge]

Michael,
I built the ACI Opals almost two years ago and I think they are excellent speakers. This is a sealed design which works like an aperiodic enclosure or "pressure release." The enclosure is separated into chambers by the bracing so the woofer is in a small chamber which releases pressure into the rest of the enclosure using acoustic foam and dacron batting. Because of this design the Opal has excellent transient response and depth. I'd have to model the Vifa 8" driver to get an idea of the Qtc but I imagine it's in the .6 range. Also soundstage and imagining are excellent. Put on some Sarah McLachlan and you're in heaven!
They've also done quite well with all types of music and with movie soundtracks. I'm talking Metallica, Rage Against the Machine, etc. I had them in a huge room and an open floor plan and they never seemed to sound strained.
I haven't heard the Kit281's so I cannot compare the two but I did listen to PSB Stratus Silver's (around $1700 retail) before buying the Opal kits. I'd say the Opals can hold their own quite well.
Let me know if you have any other questions.
Brian
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[Michael R Price]

Just a few questions for Mark, Brian and Rich:
Mark - what exactly is baffle step, and how does it affect the tonal balance of a speaker at different listening distances? If you actually had a chance to hear the P17/D25 system, how did it sound? I'm just a bit concerned of the ability of a 6.5" driver to produce low bass without strain. Dan Wiggins has said that higher cone excursion raises intermodulation distortion at higher frequencies, and that was one of the reasons for the 8" driver in the 281. Have you actually noticed this effect, and what is your preference (8" vs 6.5")? [I haven't yet, in my very limited chances at listening. The reason I can't listen much is that the local high-end audio store doesn't exactly invite people in to casually listen to things. The salesmen seemed to be a bit ticked off when they realized we weren't going to buy anything at their insane prices.]
Brian - What drivers does the Opal use? Can you describe any strong/weak points in the sound of the Opals, and in general what they sound like?
Rich - Though many people have spoken their thoughts in bits and pieces, I would also like your opinion on the 281s sound. A few people have complained about the 281's lack of midrange clarity, have you noticed anything like this? (Though one of them hadn't broken them in and was comparing to Magnepans...)
Brian and Rich - What method did you use to construct your speakers and did you run into any difficulties? From your web page, Rich, it appears as if you constructed a box with no holes in it, applied the veneer, then routed/cut out all the holes, installed components and then ifnished veneer. Is it possible to completely prepare each panel [veneer, drivers and all] before assembling the speaker, or is this not a good idea? Also, what veneer, finish, and application method did you use and how much did it cost? [I'm trying to get a good idea of my costs involved, it looks like the unfinished cost will run about $450. My total system budget is $800, that's more than my entire income for the summer and I'd like to still have some cash left. Still trying to decide if finishing is worth it.]
Well, that was a lot of questions. Thanks very much for your help everyone. Hopefully I'll be able to make a decision about this matter and get started in a few weeks.

 

[Patrick Sun]

Here's a nice article on the baffle step compensation .
Personally, I would never "finish" the panels before I'm done with putting the enclosure together, and sure that the crossover is performing well.
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PatCave; HT Pix; Gear; DIY Mains; DIY CC; Sunosub I + II + III; DVDs; Link Removed

 

[Pete Mazz]

Michael,
I built the 281v also. If you want to take a road trip to listen to them, I'm about 3 hours away in Bucks County, PA, about 10 minutes off I-95 exit. Let me know.
As far as sound quality, I would describe them as toward the brighter side, very detailed and up-front, with great imaging. They do most music very well on their own, but I generally run them with a sealed Tempest sub, crossed over at 90hz.
I also prefer to cut out the drivers last, using a template.
Pete
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[MikeAcc]

Michael,
The Opal also has a different crossover you can use. Dennis Murphy over on Madisound designed a different xover for the same drivers as the Opal. If you decide to build that kit, you have two options to listen to and see what you like.
If you go to the Madisound Discussion board...www.madisound.com yuo can currently find some discussion on the Opal and Dennis Murphy's alternate xover.
i would also look into what Mark recommended, the STS or SSTS from Dennis Murphy/Rick Craig. Dennis Murphy also just put together a Seas W18/Hiquphon combo for Dave Ellis. Dennis likes the Seas, his Opal version and SSTS in that order.
If Seas drivers are up your alley, check out the Seas web site, they just posted three or four new designs for DIYers. The Thor looks very interesting.
Of course, had I read your post closer, some of these kits may be out of your range. I think one of the Dennis Murphy kits would do the trick.
[Edited last by MikeAcc on August 30, 2001 at 07:00 PM]

 

[Rich Kraus]

"What method did you use to construct your speakers and did you run into any difficulties?"
the boxes were built using wood glue (tightbond II) and a finish nailer and compressor. very smooth, and id do it that way again.
"From your web page, Rich, it appears as if you constructed a box with no holes in it, applied the veneer, then routed/cut out all the holes, installed components and then ifnished veneer. "
thats correct.
"Is it possible to completely prepare each panel [veneer, drivers and all] before assembling the speaker, or is this not a good idea?"
its possible, but i believe it would be dificult to hide the seams that way. this way the mica/veneer coveres up the mdf seams. also i used a jasper jig with a router to cut both the cutouts and the driver recesses, and its easiest to do this accuratly AFTER the veneer/mica is on. (just be carful, as the further you go before you cut, the more that is at stake.)
"Also, what veneer, finish, and application method did you use and how much did it cost?"
i used two finishes on my 281's, the bulk of the unit is covered in curly red oak veneer (10 mil, paper backed) which was applied using the "wood glue/let dry/iron on" method. the face of each speaker is covered with gloss black mica (vertical grade/ color through). the mica was attached using contact cement. i had to buy full sheets (4x8 on the wood, 4X10 on the mica). the wood veneer i "stole" for 30 bucks. the mica cost me 65. both were bought localy. i believe you could cover a pair of 281's completly with one sheet of either (it would be close), but i wanted the gloss black baffels.
so far my 281's have about 20 hours of material through them, so i dont consider them fully broken in yet. as for now, they seem very bright and detailed, with a nice midrange and solid bass. my only dislike is the shrill upper midrange, which has tamed down CONSIDERABLY as more material is played through them.
i listened to many other speakers, but only a few in my room. we have a fairly active HT group here in tampa bay, so i got to hear some nice systems. of the two i liked best, one (jerry pease's) runs some wonderful lynn gear, the other is mike knapps, and he uses 281's. given my budget, it was a no brainer.
i think the 281's are hard to beat for the money. if you chose a painted finish, these could be built well under your budget (depending on what tools you already have.)
dont dismiss the tools part. i got to use some great tools over at brian s's place (thanks again brian, btw your silo II looks great!), and that made it far easier/cheaper than if i would have done it here with my meager tools. if you have or have access to tools, great. if not, youll need to budget to buy/rent/borrow some.
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'Till next time,
Rich (the kite guy)
My DIY audio page!
Use your ashtray please, dont throw um on the street. thanks

 

[Brian Bunge]

Michael,
The Opals use Vifa drivers. I think the 8" is the M21WO-09-08 if I'm not mistaken. It's a treated paper cone. The tweeter is one of the D27 silk dome models. I know it's the one that Parts Express sells for about $20.
The biggest strength to me was transient response. I love drums! If a speaker can't handle a drum solo well then I am usually disappointed. So transient response is a biggy for me. That's why from a music standpoint sealed enclosures are my preference. Next would have to be imagining. My room setup is less than ideal but I still got great imagining from the Opals.
As far as weaknesses, the only thing I can think of is that midrange clarity isn't as good as my Emeralds which use a 5.25" mid. But I really wouldn't expect an 8" driver to compete with a 5.25" driver in this respect. I don't think you'd really notice the difference unless you had mini-monitor right next to it or had a CD that you were very familiar with that you had listened to on speakers with smaller midrange drivers.
The Opals were my first speakers that I built (other than a few subs) and I used wood glue and screws. Since then I've moved on to just glue or biscuits and glue. This works much better than screws for me. No matter how careful I was predrilling pilot holes I always ended up splitting the MDF.
I routed out the holes and rebates for the drivers before building the enclosures. It was the first time I'd ever used a router and the Jasper Circle Jig so I didn't want to risk screwing them up. The Jasper Jig is a must, IMHO.
I used a sheet of NBL Maple veneer from http://www.TapeEase.com.
Brian
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[Michael R Price]

Thanks for your comments Rich and Brian, it seems as if the Opal and 281 are very similar speakers...though it appears as if the Opal would have tighter bass due to the low-Q sealed enclosure but the 281 would extend deeper. I'll see if I can model the Opal's woofer to get a basic idea of its response. Rich - how do the 281s handle something like a drum solo? If the 281s deliver bass almost as tight and clean as the Opal but extend 8-10Hz deeper I will probably go with them.
My $450 figure is for the 281s: $340 for the kit, $40 for two flared ports, $20 for shipping coast to coast, and $50 for MDF and polyfill. Veneer from a site like TapeEase would probably be around $50, plus $20 for glue and finish. That would bring my total for the 281 to around $520, which is acceptable. For the Opals my cost would be $350+shipping, $50 for MDF/polyfill, and $70 to finish, or around $500 (these are both slightly liberal estimates). Does anyone know of where I can get a 3" ID flared port for less than $19? (Or where I could find a good deal on a sheet of cherry or mahogany veneer?)
Pete, I appreciate your offer but I would not be able to come over and audition until I have basically everything nailed down. Plus I don't think my parents would like to drive 6 hours for something like that. (I don't drive yet, but some of my friends will soon, though I doubt my parents will allow that either.)
Also I am starting to look for an amplifier and CD player to match with the Opals/281s (whichever I choose; I've pretty much narrowed it down to that choice by now). I am debating whether to get an integrated amplifier as opposed to a plain power amplifier; I would like to have my computer (in the next room) also connected to the system so I can use it to listen to the MP3 material I have, without having to burn a CD. I'm leaning towards a plain amp because reason tells me I'd get better sound for less money. I'm looking at the Audiosource Amp Two and the NAD 214. As for CD player I have no clue but if anyone can suggest one in the $100 (used) range I would appreciate it. Thanks for the help.
Edit - Is it advisable to construct a plain MDF box with all holes cut (but not the driver recesses or anything), then apply the veneer sheets and route out the driver cutouts/recesses in the veneer? (Or even route out the driver cutout/recess in the veneer before applying it, but not before finishing it?) I want to prevent wasting expensive veneer. Also, what type of wood would you recommend? I am considering white birch and African mahogany (from tapeease.com). And after reading a bit more information around the Internet I'm leaning back towards the 281s. Deeper bass, higher output capability, still have great imaging and midrange realism. Plus I've heard comments like 'the Opals don't have any real competition under $1500' versus 'I liked [the 281s] better than the top of the line Paradigms [which are supposedly some of the best $2k speakers you can get]'. Also from testamonials it appears as if the 281 have a more forward sound [which I like] whereas the Opals are 'warmer'... well, I still would like more input before I make a final decision. Plus that last summer paycheck. Anyway, thanks for the help.
[Edited last by Michael R Price on September 02, 2001 at 05:55 PM]