Open baffle speaker project.

It's all, but number 4.

Read Linkwitz' site. The whole site.
http://www.linkwitzlab.com/

Then head over to see Jon Marsh, and read this thread. It is a bit long, but key info is strewn throughout.
http://www.htguide.com/forum/showthread.php4?t=7644

Once done you will be ready to forge ahead.
Good luck.

On Linkwitz site the Concepts section has the most info. There are other little bits thrown around, but the bulk is in there.

You can do them simply, and cheaply, but you will have to sacrifice a lot when comparing to the Jamo, Orion, and Arvo.

For dipole baffle layout, and modeling you will need The Edge. http://www.tolvan.com/edge/

Hehe... no you just get out what you put in. It is up to you how picky you want to get with it. Of the total cost of my Arvos well over half went to the xover/EQ.

The real hidden cost is in the EQ. Like everything else, you can cut corners here as well though.

Have you ever designed a speaker before? I ask because this isn't going to be easy.

I've seen some near 'Jamo' clones using a pair of Eminence Alpha15's and a single 3-4" fullranger for simplicity.....which apparantly have been very very successful. The high Q Alphas have a natural response hump and IF the baffle width is chosen properly for a target dipole peak, bass response into the 35hz range is possible. I think your WMTMW approach might be a bit much for a beginners project but a simpler Jamo clone is well within reach and at least you could scavange the woofers if and when you head in a more advanced direction BUT i think the simple WWF might satisfy quite nicely! Check out some of the dipole theory at http://www.quarter-wave.com/

That is plenty of time. First off do you have any experience with measuring a speakers FR and Impedance? This will be the first real hurdle. There are ways to get things pretty good using free software without measuring anything yourself, but it isn't the best way to go.


There are some, but we need to find out what you will be using first. The answer to the previous measurement question will steer this.

I would recommend LspCAD if you can swing it. It can do everything in one program. It ain't free though.

As I recall, lots of people that liked the Jamo's also liked the Hawthorne audio ob's, although the Hawthornes where not my cup of tea, but YMMV...

Oh, i forgot to add a like to this thread at DIYaudio. You may find something you like over there.

http://www.diyaudio.com/forums/multi...b-gallery.html

If you can manage REW correctly you will be fine later on with a better mic.

Yeah, LspCAD isn't cheap. I throw it out there because you never know how much money someone is going to be throwing around on this forum.

Sphynx, have you ever heard a good OB? If so, what?

Lots of people seem to like them, but I am definitely not one of them. Not trying to put you off, but before undertaking a journey, it's best to be sure the path is going to get you to a location you want to end up.


If still interested, as well as Sl and MJK's sites, read John Kreshovsky's Music and Design site, about his NaO designs and theory behind them.

Just wanted to share a few links you could take a look at.

The Lotus Group Granada has made quite a splash in the past year. Many have claimed it to be the best speaker they ever heard. We have had dozens of people ordering Dipole12's and Dipole15's after hearing it.

http://www.lotusgroupusa.com/Granada.htm

Soul Sonic Speakers is also doing an open baffle, but quite different style:

http://www.soulsonicspeakers.com/

The most common open baffles people are making seem to be either 2ways with Dipole12's or 15's and then a fullrange driver like the Feastrex, Lowther, etc. The others are 3way. The kit we came up with uses the Dipole15's, the Dipole6 and then the ESS Heil AMT to keep a full open baffle at all frequencies. Several have done the RAAL for the high end section as well but it is not open baffle.

The minidsp units will be used in our kits. This allows for all the processing in one unit. It also leaves the parametric EQ on the input to be used to EQ the room itself.


John

If you don't mind, can you say what it is you don't like about them? I am curious, and I'm sure the OP would like to know.

The only down side to me is that they need a lot of room to sound their best. The difference between a good sized room with proper placement (and seating,) and a not so perfect room is pretty large. The OB Dipole still sound fine, but the wide presentation, and openness is lost compared to what they can do.

Bass can be a problem if you like to run things a little hot, or "thump." If this is the case you will need a sub section to take over somewhere below 80Hz. This will give you enough wiggle room to play with the EQ down there.

FWIW, I have my stereo pair setup as 4-ways with an active stereo xover at 50Hz, sending the lows to a 15" EBS sub positioned behind each speaker.

I am not a fan of OB line-arrays. I would rather go sealed there.

When I was first toying with the idea of building some OBs I bought the tweeter and two eights(x2) that I would need for the set I wanted to build, and built a test baffle set out of that. I just made up a test baffle out of some 1/2" plywood 24"x48", added a simple 1st order xover between them, and then let the receivers auto EQ tame them a bit. Once I heard what this thrown together set sounded like, it was enough to dive right on into the deep end.

That would be tough. It is a purely subjective thing, that I feel in my case is not helped by the fact that I find the idea of "opening up" a design whose purpose is to have a narrow focused output pattern that is naturally wider in one direction odd.

I have played with OB line arrays, but I always prefer a standard array. I find the artificial image they present is too unfocused. The sound field is wide and deep, but hazy somehow. YMM and will V.

This is all in ones head though. I don't know how many times I have worked on mixing a track, only to return to it the next day to find it sounding awful.

All I was really trying to get across was that I was not an OB fanatic. Everything has it's place.

Artificial and vague soundstage, overly diffuse and generally lightweight sounding. Blech.

I have heard many, many electrostats, ribbons and Maggies over the years and all have had the same feeling. Some were in rooms better than others, and the last pair of dynamic driver OBs were well set up in an excellent room and left me very cold. The owner loved them, but I wouldn't have accepted them as a gift. Well I would, but I'd have sold the parts and invested the money into something I like better.


This is precisely why I strongly suggest you hear something like you're interested in building before you spend dollars. Do not trust other people's experience or opinion on sound preferences online, if you don't know them and their gear, and listening habits and preferences. I have made the mistake several times of reading someone's opinion that something sounds a certain way, and when I actually hear it, it sounds nothing like the description to me.

Be sure the project is really what you want. Go find a store that sells the Jamos and have a listen with a variety of tracks. If you still love them and they meet your needs, look at the designs already out there similar and start from there. If not, look at something else.



Short answer to the above two paragraphs is no.

A9X-308, thanks. I agree that it is something you really need to hear for yourself.

I should add that along with OB linearrays, I do not like OB with a rear facing tweeter. They produce the same artificial hazy sounds.

To me a good set of OBs (dipole only from the mids down) sound like giant headphones when run fullrange. This would be like the Orions(not the +) and Arvos.

If you want more "bawls" than a decent set of headphones will give you, you need a set capable of +100dBs clean fullrange, some EQ, and a good subwoofer to take over between 60-40Hz.

My Arvos can kick you in the chest, and stay audibly compression free until ~108dB (c-weight/slow)at ~13ft in rock mode with a 44Hz xover. It is a big and imposing setup though.

Well i think the OP is a bit overwhelmed by Dipole design so this thread might be a bit in vein. I do think the large woofer/small fullrange option i outlined is a pretty easy implementation shown to have pretty nice results according to the quarter-wave crew. The theory behind the design is sound with the use of high Qts woofers.

Naiant. Slightly more money, but much better sorted out design. Also, do you have a soundcard/box/mic-pre that will do phantom power? Also, whichever mic, consider getting calibration done by Cross-Spectrum.