New DIY project - comments welcomed

[capww8]

Well, this is my first attempt at DIY audio, and I think I may have chosen my project out of haste before I had done quite enough research. In any case, I'm going to attempt to make the best of my investment so far.

I stumbled across this project and purchased all of the indicated crossover components already, though I have not started cabinet construction or purchased the drivers:

http://diyaudioprojects.com/Speakers/Hi-Vi-3-Way-Tower/index3.htm

I'm going to build a rounded cabinet rather than the square, and have started drafting in autocad to verify correct dimensions before I start cutting. I did have a couple of quick questions.

I notice on this forum, the front baffle is frequently constructed as a removable piece. Why is this? I had assumed the following, but I don't know if I'm on the right track:

1) Allows the use of more exotic material or finishes for the front baffle
2) Allows easier replacement or changes of drivers for future upgrades (saves having to reconstruct the entire cabinet if you decide to switch from 6 to 7 midwoofers for example).

Any other comments you may have would be well received. After a bit more research, I kind of regret heading down this particular road, I think the Khanspires are more in tune to my tastes, and seem to have been much more refined over the years.

I will post some in-room response when I'm finished... I have access to a good RTA, microphones, and proper tone generators.

Power for this will come from some monster JBL synthesis amps, preamp tbd.

Next project will be a pair of bookshelf monitors for my office, powered by a parasound hca-750a and an Anthem preamp. I'd gladly accept any rec's for this project (I'd like the x-over and transducers to land around $300).

[---k---]

Removable baffles are for the exact reasons you mention. I've never done it because I don't plan on reusing my boxes.

I wish you wouldn't have purchased the drivers yet either. I haven't heard that speaker before, but the crossover looks like it wasn't designed with real measurements. That doesn't mean it will be bad, but it won't be optimal / perfectionist. I would have pointed you towards Zaph speakers, Paul Carmondy, or the Statements or a few others. But, it is what it is... You'll have fun.

[capww8]

I have only purchased the crossover components, no drivers as of yet. I'm coming really close to deciding to just eat that expense and move forward with something more established.

Either the Khanspires in a modified cabinet, or a near clone of the Dayton RS here http://www.htguide.com/forum/showthr...7&page=2&pp=35

I absolutely love that cabinet design.

[fbov]

Well, one nice thing about caps, coils and resistors - they can be reused. Most of us have a box of currently unused parts as test fixture fodder for new designs.

If you'd like recommendations, give us some idea what you're trying to do, your room size, and some idea of your skill level. Lots of good DIY projects out there, just need to find a good fit for you. The master list of projects is a sticky at PE's site.

http://techtalk.parts-express.com/forumdisplay.php?f=2&order=desc

HAve fun,
Frank

[capww8]

Thanks for the help guys. I wish I had posted something sooner.

My electrical skill level is extremely high. My woodworking skill level is high-moderate but I have ready access to some very highly experienced craftsmen, and just about every tool known to man. I'm certainly not above hiring a cnc shop to cut templates or cabinets for me, but I think I have everything I need to produce a quality finished product on my own.

This may seem a little gauche, but I really really like the sound of Paradigms studio 100's, I sold hifi equipment when I was in college, and that was the speaker I always told myself I would buy before I quit (I didn't). I'm also a big fan of tall curved cabinets a-la B&W's 803. My budget for these two speakers is around 800, and I would like to be able to build a center and surrounds to join them sometime in the future.

Power is not a problem, I have a ton of quality electronics lying around the house that aren't being used, and the thought of putting some of it into service was what spawned this process.

The room for the speakers in this project is 15 wide x 18, and not very live at all (carpet, plush couch and loveseat). First reflection on the right will likely land around a sliding glass patio door, on the left a lot of glassed art. There is only one primary listening position, approximately 12 ft from the stage. It may be worth noting that we are replacing the carpet w/in the next year with hardwood, though that will likely have a rug between the stage and listening position.

WAF is also not a factor, she got the bathroom she wanted, so I get the speakers I want :-D. I do have my own ideas for aesthetic goals though (above). I would prefer to let the speaks live within about 18" of the wall, and I will construct a subwoofer at a later time, but if I can grab response down to around 40 hz, I'll be very happy.

[capww8]

I should also mention that I want to stay with a simple monopole design. I'm not interested in open baffle, or dipole at this time. I would prefer a sealed enclosure just to have a little bit looser tolerances in the build, but a ported woofer is not at all out of the question.

[---k---]

If you like Paradigm 100's, do not build the Khans.

I really don't want to slag your initial design, because I haven't heard them. Just my personal preference.

Regardless of what I did, I always recommend building small cheap speakers first to get a feel for things. For example, you could build a pair of CJD RS150 MTM first for a reasonable price. If you like the sound of them, then the Khans would be a great upgrade with a very similar sound. Even cheaper, you could build a pair of the Ochocincos that CJD designed for me. $150 will let you hear how CJD voices his designs. His voicing style, I believe is similar to JonMarsh's and Zaphs. Then you can decide if you like our style or Paradigm's. Big difference. Not right versus wrong. Just different.

[Ed H]

The frequency response attached was "produced by averaging 120 1/3-octave spectra taken for each speaker individually in a grid centered on the position of my ears".

http://www.stereophile.com/floorloudspeakers/105paradigm

The Paradigm's are definitely voiced differently. Not better or worse, just different.

I own Paradigm myself - ready to upgrade to DIY - but don't want something too bright by comparison...

[Hdale85]

Most DIY designs are designed around a FLAT FR, I've heard many people say Paradigm speakers can be bright and sometimes harsh on some materials. I'd be pretty surprised if you found a DIY design bright compared to a commercial speaker though unless the commercial design was incredibly laid back.

[---k---]

Frequency response curves are WAY to simplistic to tell you everything. For example, JonMarsh's last Ardent post was about changes he made recently to the crossover. He said the frequency response looks on paper much the same, but they sound different.

I don't want people to end up unhappy or with regrets. I've had too many people say they can't hear the difference or the difference didn't matter to them between my speakers and commercial speakers costing 1/2. As a result, I'm overly cautious in recommending people spend several hundred dollars building speakers, if they've never heard a DIY design in their life. So take my suggestions with a grain of salt.

I owned Paradigm Titans and Atoms prior to my Khans. We also demoed the Paradigm Studio 40s head to head against CJD's RS150 MTM. I would say at the time, I was very familiar with the Paradigm sound and enjoyed it. But in ares it is very different than the Khans. I can pretty much promise that they won't be as bright/harsh as Paradigms. But, you must remember that it is that brightness/harshness that give them the "pop" and "sizzle" that attracts people. It's been too long and their designs have changed in the last 5 years, so I can't go into specific details.

Not saying you won't like it or whatever - if you spend $800 building it you'll probably think they're better than sex - but I just don't want to be the rah rah cheerleader that you blame if you're not. Go to AVS for those.




Yes, most DIY designs are designed to be flat. In rooms without much absorption (ie no carpet or curtains), some tend to sound bright. Others like Jon design with the top end sloping down. You can't really make that broad of a conclusion.

[Hdale85]

I can agree with that, although I will say if you do find a particular speaker bright, or not bright enough, most of the designers here have tweaks you can do (usually a resistor or something) to change that a bit.


I think the reason a lot of people don't hear the difference between a commercial design and a good DIY design is that 90% of the people out there think that good sound is all in the highs and lows, they don't listen to the midrange which is where I think the biggest difference is on DIY designs.

[fbov]

...I always recommend building small cheap speakers first to get a feel for things....

Or, go to a DIY meet and listen to a bunch of different DIY designs.

Ryan's made an important point. I didn't make InDIYana this year, but several folks noted that all the designs sounded really good, but not identical... a natural result of 30+ individual preferences coming through despite similar goals of flat response, low distortion and pleasant sound. The key message that DIY designs may sound very different, as a class of speakers, from those you may be accustomed to hearing.

You see, my perception is that there's a lot more variation in SPL capability among DIY designs than in sound quality. "Small and cheap" may not play loud, but it can sound great at 90dB (loud enough to cause hearing loss), and give you an idea what to expect from larger, more expensive designs.

Maybe build your office speakers first?

You appear to have both the mechanical and electrical skills, so keep in mind that you aren't required to build someone else's design without modification. You can learn speaker design principles yourself, and at the very least, should not feel bashful about tweaking someone else's design to your personal tastes or application, with very few exceptions. Perhaps plan on an outboard crossover mounting, as many designers do when voicing a design.

Where do you want to start?

HAve fun,
Frank

[Hdale85]

Yeah definitely if you can make it to an event go!

[capww8]

A huge part of me wishes that I had never talked myself into tackling a DIY speaker... I should have just gone down to the hifi shop and bought something... **kidding**

I have so many different projects and ideas kicking around in my head now, that I simply don't know where to start... but I guess since I've got to start somewhere, it will be with a simple pair of Ochocincos. I love the idea of evaluating how CJD voices his designs with a simple and inexpensive project, and it certainly won't hurt to have a pair of inexpensive MTM monitors laying around.

---k---, you mentioned you had owned Titan's and Atom's prior to your Khans, I would expect that the Ochocincos TM should perform similarly to the Atom's. Can you comment to this? I had always thought that a great deal of the price in 'mid-fi' commercial speakers like the Studio Paradigms, Upper end Energies (before Klipsche bought them), and 800 series B&W's was in the cabinet finish and design. This leads to the conclusion that you could recover a lot of the cost of those speakers by building your own sweat equity into the speaker rather than letting the factory keep that $. Of course you can't really help but purchase better quality x-over components than are used in most mass-market speakers, but I've never really been able to get a handle on how the DiY transducers compare to commercial drivers. If a B&W replacement mid-woofer is $160, do you get similar performance from a $80 Dayton driver, or are they completely incomparable?

I'm really just rambling about some of the ideas bouncing around in my head right now, feel free to comment or not. I'll continue to post my ramblings and extemporaneous craziness as this develops.

[jliedeka]

A lot of commercial speakers use bespoke drivers. Bigger companies like Harman and Paradigm will probably work backwards from what type of speaker they want to market at what price point. From there they know what types of drivers they need.

DIYers don't have that luxury unless you are Zaph and can design your own midwoofer. However, there are enough choices out there that you build to just about any spec and price point. It really helps that there are a few guys out there that measure DIY drivers so you'll know going in what the distortion profile looks like and what frequency response you can expect.

I've learned a lot by reading design writeups from people like Zaph, Jon Marsh, Roman Bednarek, Curt C and Paul Carmody. I don't want to say any one of them is better than anyone else but I appreciate Zaph's crossover designs that don't go too crazy with the parts count. However, I'm actually building Modula MTs and Natalie Ps.

[---k---]

I felt CJD's $250 RS150 MTM was superior to the $1200 Paradigm Studio 40s when I had them both in my room at the same time 5 years ago. The Paradigm and sizzling highs and a little sloppy bass. The $550 internet direct Ascend 340SE came closest to CJD's RS150 MTM, but at volume or complexity, CJD's RS150 MTM bested them. Like you said, a lot of sweat equity.

Build the Ochocinco MTM. CJD got to hear those and approve of the voicing. The TM was modeled, but I built them and didn't like them and adjusted the crossover. All is documented in the build. So, you could do it either way. I just don't trust my ears as times.... I think I documented that the first time I heard the Ocho's at CJD's place I thought the tweeter was too low. So, we increased it. Listened some more made more changes. Listened some more and then made changes to end up back where we started. I think that is how it always goes. Boom and sizzle sounds good at first but gets old.