Again, I'll bug you about a 3-way

[mpmarino]

OK folks,

I’d like to build a 3way as I have indicated in another thread. I will build new cabinets. Like so many others I’d like to use the Dayton RS drivers for their value and quality. I could easily copy another design but then I wouldn’t learn a dang thing besides how to better use my table saw and soldering iron  . I’ve seen some interesting stuff over at the htguide forum but not exactly what I am looking for. Here is what I propose, please tell me if I am off my rocker. My goals are :
- dynamics
- accuracy
- dynamics
- simplicity (when complete)
- dynamics
- full bandwidth
- and, of course it must be dynamic
__________________________________________________ _____________________
I want to reproduce low bass without a sub. And I don’t want 6ft3 speakers either. I am proposing to use a Dayton RSS315HF-4 12" HIGH FIDELITY SUBWOOFER (side mounted). According to Winisd this will have a Qtc of .71 in a 1.9ft3 sealed enclosure, down about 11dB at 20hz.

Specifications: *Power handling: 400 watts RMS/700 watts max *VCdia: 2-1/2" *Le: .95 mH *Impedance: 4 ohms *Re: 3.3 ohms *Frequency range: 23 - 1,000 Hz *Fs: 23 Hz *Magnet weight: 150 oz. *SPL: 89 dB 2.83 V/1m *Vas: 3.00 cu. ft. *Qms: 3.00 *Qes: .52 *Qts: .44 *Xmax: 14mm *Dimensions: A: 12-3/8", B: 11-1/8", C: 5-3/8".
__________________________________________________ ______________________
I would like the midbass to be strong and snappy. How about a pair per speaker, of DAYTON RS180S-8 7" REFERENCE SERIES SHIELDED WOOFER in mtm (or tmm)? They could share a .75ft3 sealed enclosure with a low Qtc and easily perform to 100Hz.

Specifications: *Power handling: 60 watts RMS/90 watts max *VCdia: 1.5" *Le: .90 mH *Znom: 8 ohms *Re: 6.4 ohms *Frequency range: 40-2,200 Hz *Fs: 38 Hz *SPL: 87.6 dB 2.83V/1m *Vas: .88 cu. ft. *Qms: 2.00 *Qes: .47 *Qts: .38 *Xmax: 6 mm *Dimensions: A: 7-1/8", B: 5-3/4", C: 3-5/8".


Tweeter… ?? Has to play low enough for an MTM(possible TMM as I said) and avoid the breakup of the metal cone mids. Also it must be able to stay linear and accurate without blowing up when I kick the crap out of it. A lot to ask. I need suggestions on a tweeter.

My main issue is the crossover. I could easily go active woofer to mids to start, but I would like to be passive ultimately. Mid to tweet - maybe I could build on an established design MTM crossover with same RS 7”mids and Seas or RS tweets?

I know, your thinking I’m a hammerhead. Sometimes I am. When I want to crank it up, it MUST CRANK UP. Usually I’m much more civil and reasonable though.

This is somewhat long range as I would slowly acquire parts. Your suggestions and comments are MOST welcome before I start dropping dollars.


Thanks a lot, Marc


edit: the more I think of it, the more I doubt I will ever match my Tannoys.

[RyanW]

Marc,

I too would be interested in such a project... Unfortunate that there has been no feedback on this thread yet.

[Hezz]

This sounds like a good project. Here are a few tips.

If you want good sounding bass use a regular 12 inch woofer instead of a sub woofer. Subwoofers are not that good at music reproduction. If this is not enough bass for you build a large dedicated subwoofer to supplement the main speakers. It would be better to use two large standard woofers than a subwoofer if you want to have better accuracy.

Dynamics. This is mostly attained by a super high quality cabinet and good high current amplification. Standard speaker cabinet construction is inadequate if you want high dynamics. This means double wall MDF and lots of bracing that ties all four walls together in several places.

THe mids and tweets in a seperate cabinets is preferable in some kind of stackable method.

IF you are using two mid/bass drivers try to design the crossover so it uses one of them for baffle step compensation.

Decide on how big the speakers can be and if possible use two woofers in the bass cabinet if you are going to make a rather large speaker.

Read through this thread to get an idea of what kind of cabinet construction is required for a high end system. Of course it can be simpler than this.

High-end 3-way active Avalon look-alike

[sdclc126]

Here are a couple of suggestions:

http://www.partsexpress.com/projects...mtm/index.html

http://www.zaphaudio.com/BAMTM.html

Now, as for your statement: "I could easily copy another design but then I wouldn’t learn a dang thing besides how to better use my table saw and soldering iron"

No - don't look at it this way at all. There is A LOT to learn from building an established design or kit. You'll learn how to build crossover networks for one, and how they work and how all the components integrate. Building this way is one of the best ways to get started in DIY, and work toward one day designing your own system from scratch, if that's your goal.

If you're new at this, trying to start by designing from scratch is really putting the cart before the horse - you need enormous knowledge and experience to do this successfully, and the results could be disappointing. It could take quite some time before you work all the bugs out, and during all that frustration you won't have those great speakers that you want to listen to.

You want a great sounding pair of loudspeakers - then build some that will be just that - an established design will get you right there right now, with a minimum of fuss and no trial-and-error.

[ttan98]

I am also building my own system, my requirements are very different from yours, as a novice like myself it would be very difficult to build a pair of speakers from scratch to compete with the commercial ones or even those built by experienced designer like Zaph. One can learn as we get along. Don't expect too much.

One site which may give you some ideas is shown below:

http://www.audiocircle.com/circles/i...?topic=37959.0

GR reasearch drivers are quite cheap and they perform quite well for the price paid.

I just bought a few drivers for testing, and have no affiliations with the company.

[TurboFC3S]

Glad I noticed this ...

I'm the guy who built the MTMWW using all GR woofers that ttan98 linked to right above. It sounds like my goals were quite similar to yours prior to starting, and the project is a complete success I'd say.

Read through that audiocircle thread for all the info you need, and if interested I'll can tell you more

What really blows me away about these is they image better and bring out more detail than my RS180/RS28a MTM's. I really expected the metal cone drivers to sound more 'detailed', but to my complete surprise these soft paper GR cones do. Even the GR tweeter sounds fantastic in these towers.

[ttan98]

Commercial speakers I mean the expensive(high-end) speakers.

The lower end market uses cheap drivers and any drivers such as DaytonRs or GR will beat this segment of the market hands down.

I suppose ones needs a benchmark to measure the speakers one build, and compare them against commercial speakers of similar price range if not more expensive ones. In most cases DIYers get very good results, speakers they make compared very favourably with commercial speakers that cost 2- 3 times more.

[TurboFC3S]

You know, I did about 4-5 months ago have a pair of B&W 802D's in my house. They belong to a friend who let me listen to them for about 2 weeks while he was out of the country.

At the time I thought they were phenominal, but now I'm not so sure they're any better than these speakers I've built. I don't want to say without doing side by side testing, but I wouldn't be surprised if these towers of mine hold their own.

[jupiterjune]

I have built several pairs of speakers and have a couple (actually volumes) of tips and observations:

1) Metal cone drivers can sound horrible, especially if you listen to a lot of female vocalists. I built a pair of SEAS Odins, because I wanted something that I was sure was going to sound good, and they were horrible. Zaph has a detailed explanation for this on his website, and I agree with it 100% (but lacking any distortion analyzing equipment, I drew my conclusions through listening, looking at datasheets, and applying dampening materials to the magnesium cone drivers). The problem is with the harmonic distortion that occurs at 1/3 the resonant peak. I don't know if the RS180-8S's will have the same amount of nastiness, but I know I get significant ringing at app 5-6 kHz from the RS150-4's I used for the bass in last pair of speakers I built.

2) I always design for flat 4pi response. You will need two woofers in parallel to achieve this, and only one midrange. Using two RS-180's in parallel, will give you probably 92dB @2.8Volts@1meter. (the sensitivity of the 150's is lower than indicated on the data sheet). Check out the Zaphaudio website--he has done a tremendous job of demonstrating relative output levels of various woofers. Using that one sub (listed at 89 dB 2.83 V/1m ) will give you app. 83 dB 2.83 V/1m radiating into 4pi space. You would really want to bi-amp if you use those drivers. (which is really a great way to go) You would need a lot of attenuation in front of the mids and tweeters to get the levels to match.

3) I do really like metal cone drivers. I used some 4" drivers made by infinity in a 3 way speaker MTMWW and the midbass was outstanding. But they are still a bit resonant, and I had to put 2ohms of resistance in front of the mids to get the level to match the woofers. I haven't put any damping material on the 4 inch drivers yet -- that may make them the best sounding speakers I have ever built.

4) I used the Tang Band W3-1335SB 3" TI driver in the next 3-way I built. Awesome non-resonant midrange, but the midbass doesn't have quite the same snap compared the the 4" midranges, but then, that could just be a response peak and not really desirable if your looking for flat response.

I guess my recommendations would be:

Go with 4" mids, or maybe the 5" dayton reference speakers. (although I've built with the 5" RS....) Cross them over low, 2K or so.

Plan on at least two woofers, 8ohms in parallel, at least 8" in diameter. If they come in 4ohm versions, you can use 4 in series-parallel configuration to get +3 dB and still 4ohms impedence. I really prefer sealed boxes, too.

The Dayton RS tweeter is good. I like the TB inverted TI tweeter even better, but it requires a higher crossover.
Consider getting a good crossover design program. I love Xover Pro.

I will try to answer any questions I can--just ask! Like I said, I could write volumes.....

Some inspiration:

[Hezz]

I can also offer this tip. IF you are not an expert in crossover design, stay away from metal cone drivers.