diyAudio reference speaker project

[rxc]

I've hung around here for a couple weeks and hadn't even noticed that Wiki existed, much less the usefulness of it and it seems like I'm not the only one. Making it a bit more obvious would encourage people to check it out and get more activity and a more useful area there.

[Variac]

Go here:
http://www.partsexpress.com/projects...homeaudio.html

Check out:

The "Nebula" which uses the XT25 tweeter, and PL 18 woofer.

The "Eros" which uses the same woofer and the
SS 2905/9500 tweeter

If these are going to be "reference" enough to catch the interest of the "experts" here then they need high quality drivers.

I nominate the Vifa PL 18 woofer. It seems to be really highly regarded and not as long in the tooth as the P13 WH, and a bit bigger to handle bass better.

I am also very intrigued by the XT25:
1. It's new so needs work to learn how to use it best
2. It is reputed to sound very good in the Audio Physik and Krell speakers
3. It is difficult to get right.
4. For potential quality, it is a reasonable price- around $50 ea.
5. It can cross over pretty low.

The fact that it isn't just another tweeter and that it's tricky to get right will appeal to the gurus.

Total cost of drivers for a pair: $230

First thing to do is build a "Nebula" and everyone critiques it..

Another XT25 speaker. He doesn't seem completely thrilled by the outcome.
http://www.quadesl.com/okara.shtml

[aggielaw]

The Nebula looks ideal due to not having to cut your own wood. The Eros would be a neat design, although I've read alot of criticism about the MTM design over the years. Nevertheless, I've been happy with my MTM center channel for HT use. It does not perform well on music, but my particular MTM was not designed for music.

I don't want to start a major war here, but is there a feeling that a speker using the MTM design can be a good audiophile-quality speaker for music?

[tktran]

One of the difficulties is that all of the speaker gurus have moved above and beyond the simple 2 way box loudspeaker. It will be very difficult to get experienced loudspeaker designers interested, unless perhaps we are using new or excellent drivers.

Besides I'm sure many of our speaker building friends have a handful of 2 way designs, albeit undocumented, and they've rather not start all over again.

For instance, after the Proac 2.5 clone my next speaker project will be multidriver, and will be bi/triamped.

For me the ultimate reference speaker would be something along the lines of the Linkwitz Orion, (open baffle, active XO and bi/triamped) or Dynaudio Evidence (multidriver WMTMW array) - ie. cost no object, do whatever-it-takes to create an accurate loudspeaker for all musical styles.

This is the kind of loudspeaker that will get loudspeaker gurus interested about building...

[Variac]

There IS a lot of suspicion around here about MTM speakers, It's trendy not to trust them, and I understand this. At the same time, most of the very high end commercial speakers are MTM variants it seeems to me.

My point was to show 2 designs that use the same woofer.
If you first built a 2 way MT then later you could buy a second mid woof to play with the MTM concept using the same tweeter. Different cabinet size of course..The idea would be a continuous stream of crossover ideas.

The same way that there are constant varients on the gainclone.

At the end, we would have versions that are MT and MTM and actually might have a real opinion on the subject.

You require only one crossover on a 2 way so it isn't too expensive to whip out the soldering iron to try a new crossover variation, then excoriate the designer. Lots of opinions, attacks,
the resident golden ears could make one and weigh in -good fun.

TKTRAN:
As I mentioned before, the XT 25 is a tough nut to crack- plenty of challenge to the advanced designers if they really know their stuff. You are right , the same old 2 way ain't gonna excite them.

No matter what, the new speaker has to use the size of one of the Parts Express fancy new cabinets: http://www.partsexpress.com/pe/pshow...-722&DID=7That way the newbies can whip a good looking pair together quickly and it will look great.

Others can make their own. Also people can get together for group orders and get better prices on drivers and components.

If we can mount the 2 way tweeter very near the top of the cabinet, then if you want to try MTM, you can just buy or make a second box of the same size, just put a woofer in it and stack them to create the MTM. Of course you need a different crossover- but since the crossover is external of course, it's not hard to change either

Wanna try push push? put the cabinets back to back and a new crossover. Iguess we'd better put ports if any , on the front!!

[aggielaw]

Now that I'm thinking about building, I realize it will likely take me more projects than absolutely necessary to find a set I'll keep forever.

Which leads me to the question: what do you guys DO with the projects you've completed and moved away from? If I start by building some nice bookshelves, they'll replace my current towers (Infinity Overture 2's) in the HT setup, and given that they will just be front surrounds, I'll be happy as long as they sound decent.

I'll have to keep the Infinities until I build or buy much nicer speakers to bring out the full potential of my McCormack gear. So in a couple months I'll try building towers. But it's almost a given that the first iteration won't be exactly what I'm looking for, so that first set of towers will have to go. What do I do with that set? I've read DIY speakers have no resale value, but what a waste to just destroy them.

So what do you guys (and gals) do with speakers you don't use anymore?

Thanks!

[Variac]

So we need module suggestions to experiment with:

Here is Kuei's take on the subject:

System Pictures & Description

The only version of this Seas driver I see at Madisound is the video shielded one at about $225 a pair, so it isn't cheaper than high quality separate woofs and tweets, but the coax arrangement can be superior-price isn't the only point. Also, a single cap xover is sure cheap!! You can get a high end one.

Since so many of us are into high efficiency drivers and most newbies will be using gainclones or small tube amps, what would be an appropriate choice? Are the the Fostex 206's happy in a ported box? Open baffle? less than 200 pr.

Remember, the idea is that the clever guys here are supposed to be doing the heavy lifting, and a single full ranger doesn't allow much tweaking.

A Jordan JX92S is a final module suggestion. Over $200/pr and not too efficient in most designs. Crossed over to a decent woofer might be pretty interesting, and sounds like a lot of fun to play with. Lots of projects with this around here including Nelson's J-Low horn.

what would make any of the multi driver ideas shine would be a biamped gainclone/crossover spelled out to the nth degree.

[rabbitz]

x.onasis

So let's begin, I'll have a stab at the starting point (haven't built this combination).

Woofer: Vifa P13WH-00-08
Tweeter: Vifa D27TG-45-06
Crossover: 5uF capacitor on tweeter as suggested
L-Pad: required?????......... 2db variation
Vb=5.2 litres plus 0.3 litres for driver and port, internal volume 5.5 litres, Fb=73.7 Hz, F3=78.8 Hz
Box: 175mm wide x 280mm high x 187mm deep?????? (5.5 litres)
Port: 39mm dia x 96mm (easy to get PVC pipe)
Port at front so can be placed against a wall if desired
16mm MDF
Driver location on baffle???????

OK, time for those who have built this combination or the Gurus to step in.

x.onasis, as far a comparison to the Peerless 850488 woofer, IMO the Peerless goes deeper (F3=59Hz) and has very low distortion figures (see tests on Linkwitz Lab site). Was quite a pleasant surprise and only tried this woofer after having success with a 6 1/2" CSX. The Vifa P13WH is probably better in the midrange and excellent roll-offs and I believe very easy to work with. Might be an older driver, but a good driver is a good driver and it doesn't matter when it was designed. Not fair to do a comparison of the tweeter as the Peerless 810653 is a special design only available in Australia to suit the HDS drivers. I needed a lower F3 as this is used a second system without a sub. The Vifa combination would work great with a sub and be spot on when set to small in a HT setup with the sub taking over from 90Hz down.

I think to the title of this thread has mislead some to think it's to build a supersonic you beaut reference speaker instead of a excellent speaker for the Newbie that can be used as a reference for other projects. Maybe further down the line there might a you beaut reference but lets get this one on the Wiki first.

[x. onasis]

Variac-

I like the way you're thinking in terms of a higher end kit that might be a _real_ reference speaker, and trying to challenge the experts with using the XT 25, or other newer, better drivers. I would kinda like using an Aurum Cantus Ribbon tweeter and a mid/woof that goes lower than the P13. But....?

The SEAS (Say-aahs) is a sweet looking driver. Can you post more specs?

I especially like the suggestion of multi-amping and the idea of the gainclone/crossover "spelled out to the nth degree"

This is a system/thread many of us would get very exited about. In fact, if you hang out here, and are not thinking about it, you're not paying attention.

The problem I see, is that most newbies are not, as you say,"using gainclones or small tube amps", but rather just wanting to build their first set of speakers powered by perhaps, a hand-me-down or otherwise less than a high end amp (or maybe a new surround receiver), and they just want to get their feet wet, and do the best they can with their first cash outlay in this hobby.

If the newbie starts reading in the electronics sections of this site, and begins to understands as you do, the benefits of active crossovers, the sharing of amp designs that's going on, not only will the task of learning all this stuff be daunting, but the DIY system they might build, will be months, if not years away.... and the cost$ will be quite high. This may be the _best_ way to go, but not why this thread was started.

Truth is, if you want very good sounding system, and you factor in the cost of your time researching, modeling, the cost of tools to do measuring, building, tweaking, and finishing, etc, you'd be better off just buying it. Just like when the newbie asks,"what speaker should I build?" you say "a well tweaked 2-way kit." (I have heard the Proac suggested, if they've got real money)

I think Mr. 10 (he he) has given us some good links (thank you very much). If the small bookshelf isn't the most desired, maybe the TLb might be. Most who've built them haved raved. But then our Reference (RS?) gets pricier. Your suggestions are indeed good ones, lets explore them.

Here's another kit using the P13 but with Scan Speak D2905/9500 North Creek ....no knocks, just not in the spirit of this site.

Maybe when the experts get back from Vegas, we might get suggestions on the "Better DIYA Reference", I'll wait patiently for them too, to contribute.

rabbitz, sounds good.

Very good...straight forward and simple.... sloped front baffle for time allignment?

The Vifa combination would work great with a sub and be spot on when set to small in a HT setup with the sub taking over from 90Hz down.

I believe you are exactly right. I've found that activeX is the way to go and the first step in that direction is a sub, but please remember I'm a builder, not a designer, I'm seeking as much input on this design as the newbie.

I think to the title of this thread has mislead some to think it's to build a supersonic you beaut reference speaker instead of a excellent speaker for the Newbie that can be used as a reference for other projects.

Right again, maybe Planet 10 wll change the title of this thread to "Reference speaker for the newbie"... I'm quite surprised at the interest generated.

[planet10]

Originally posted by Variac
Are the the Fostex 206's happy in a ported box? Open baffle? less than 200 pr.

There have been reports of successful BR ststems, but the 207 is probably happier in a BR

Originally posted by rabbitz
L-Pad: required?????......... 2db variation

TLb & monopole version FR (note the baffle-step in the monopole)



dave