The modular approach is a valid way of developing the prototype. It allows us to evaluate multiple woofer/mid/tweeter concepts. The final design need not be modular (although it could be).
I believe that Andy should have final decision authority. I don't see how a project like this can evolve without a lead decision maker, and Andy had the initiative and interest to start the thread.
I believe that Andy should have final decision authority. I don't see how a project like this can evolve without a lead decision maker, and Andy had the initiative and interest to start the thread.
So, what is the reason for a group designing a speaker? Is it an effort to offer a design to others who can't, but might want a monkey coffin.? I always thought that DIY speakers were ideal, because you design for your needs, and room, but it sounds like your group wants to make all the decisions for someone else. Over the years I've seen people want to build, but want something cheap. They are often told to build an established design. Is this a project simply to create a design to recommend? Although designing anything is fun, I just wonder about the reasons involved. Are there already people wanting to build such a design, or is the thinking that they will want to after they see the design? Why does a group need to design it, as opposed to one designer? I'm sure many posting already could design it without help. We do need more threads to entertain ourselves though. So, I'm all for reading whatever is posted.
@waxx
I am late to the party... but I live in EU too, and it is hard for me to find anything 300EUR per side for three drivers. Ok, that means we have only like 150-180EUR for 12 inch woofer from some reputable company, like the one which at least has publicly stated their driver T-S parameters.
Aren't we in the range where the speaker is kinda party type, what was mentioned above - like stamped steel and PA stuff?
What could be your quick-n-dirty driver suggestions, waxx?
Last edited:
If i'm allowed to quote myself from earlier in this tread. But i would opt for a 10"
But if you want to go on with this, maybe start a seperate tread. It seems that Andy, the OP wants to go in a different direction...
For a 12" maybe look at the Faital 12FE300 or the Beyma 12BR70. That both will need a big (75l netto) cabinet altough, and a for the Beyma you need it loose filled with stuffing cabinet to avoid a one note bass. Fitting a 12" in a small cabinet is mostly a problem with modern woofers, therefor i would opt for a 10", that is still big enough for a monkey coffin type speaker. You can make the cabinet smaller if you make it aperiodic (like the Dynaco A25), but that is not so easy to do it right.
But if you want to go on with this, maybe start a seperate tread. It seems that Andy, the OP wants to go in a different direction...
Last edited:
As said AllenB, you can design a good loudspeaker with normals drivers to rephrase him shortly.
https://en.toutlehautparleur.com/fullrange-speaker-peerless-fsl-0512r01-08-8-ohm-5-9-inch.html
https://en.toutlehautparleur.com/do...-c000-4-impedance-4-ohm-voice-coil-26-mm.html
All high efficienty (almost). At those prices you qualitivly (S)can peak a Sb34RNXL and pay yourself a little linkwitz transform... or not according the size room perhaps !
So less than 300 euros of drivers/channel if you have an account at TLHP. All reliable drivers;; cut off expected 350/400 12 dB ; 3000 hz 12 dB (to be checked). SB34RNXL, 50 L sealed stuffed with Ikea pillow. Bafle step ruled in the mid serie low pass coil (helped by the width of the front bafle and an offset for the difraction control)
It is just an illlustration to show it is feasible.
https://en.toutlehautparleur.com/fullrange-speaker-peerless-fsl-0512r01-08-8-ohm-5-9-inch.html
https://en.toutlehautparleur.com/do...-c000-4-impedance-4-ohm-voice-coil-26-mm.html
All high efficienty (almost). At those prices you qualitivly (S)can peak a Sb34RNXL and pay yourself a little linkwitz transform... or not according the size room perhaps !
So less than 300 euros of drivers/channel if you have an account at TLHP. All reliable drivers;; cut off expected 350/400 12 dB ; 3000 hz 12 dB (to be checked). SB34RNXL, 50 L sealed stuffed with Ikea pillow. Bafle step ruled in the mid serie low pass coil (helped by the width of the front bafle and an offset for the difraction control)
It is just an illlustration to show it is feasible.
Last edited:
It combines the expertise of different persons. Xover designs, measurement tools, electroacoustic models, woodworking, etc. Very different skills and knowledge. It's hard to combine deep knowledge in all fields into a single person.
It provides for an automatic review of design choices along the way. Someone has a wild idea and gets lost in a rabbit hole. The others will get things back on track.
It makes the design more attractive to the DIY community. Picking up a DIY build of a design developed by experts in a public discussion is likely going to work out well, and there's usually someone around to provide support.
Not sure about principle and there is no difference in woofer box volume if the upper half of the front baffle is removable in the manner of, for example, a Neumann KH420, JBL LSR6300, Genelec 1237A, etc... There may be a modest reduction if we opt to improve the performance of the cabinet with respect to vibration by isolating the upper half baffle but it will depend on how signficant the issue of movement may be on the woofer and how it might be addressed without losing the benefits of passive isolation. The quantitative pros and cons of this type of thing is very much what I hope this group project will study as we iterate towards a set of designs.
The proposal to include it is in order to admit to the project the alternative configurations people have expressed an interest in. For a solo project I would agree it makes less sense but for a group project it will hopefully allow more people to get involved. Whether this happens ot not remains to be seen. I also want to assess alternative mid/tweeter configurations and a removable half baffle allows this so I would be doing it with my build.
Count me in.
Yuck.
Last night I had a couple of SB34s in my cart with my finger poised but I have some much more pressing non-hobby jobs. A build will have to wait for summer but a leisurely design study can start in a few days with luck. Got some drivers on the shelves waiting to be mounted on half baffles though what I really want to mess about with are waveguides.
I cannot see how to post a poll to the OP? Do we need to start a new thread? If so, in the spirit of a group project I think it might be a good idea if someone else comes up with a set of questions and posts it.
I could create a poll to attach to this thread, however another thread is also an option if you feel the poll would be an interruption to this thread. In that case I could bring any relevant posts from there back to this thread and eventually close the poll.
Whatever you decide.
Whatever you decide.
Choose the questions to the poll wisely! You need to derive your design targets from these questions/results.
Also try to figure out what people really want to build vs. what they want to read in the discussion thread for their entertainment.
Also try to figure out what people really want to build vs. what they want to read in the discussion thread for their entertainment.
Yup, I beleive the budget and shape, more os so volume being choosed already, we have already a path.
I would try to budget an average cost for the rest : wood, holes in the wood, 2 or 3 coils, one being a little in the range of a 200 hz cut-off low pass for a 8 ohms driver. few Jantzen standar caps (mkp) or DC blocking caps for the industry, or MKT, binding posts.
At least if no a personal helped project, but more something to be wanted by severals. And really think it should be sized for an average size room, which is not so easy as being subjective . What is average : 25 square meters ? 20 ? 35 ? >45 ? It certainly matters for a group project on choosing the size of bass driver and its load.
I suppose we need some idea of who is going to build this and test it. @andy19191 - It sounds like you are planning to purchase a set of drivers for this project, yes? Obviously the person(s) putting up the cash for the first build are going to have a substantial say in how the project proceeds. This is why I don't think a poll has much to offer...
I am rather busy with another project right now, but I expect that by May or June I will have some time. I don't want to be the sole constructor/tester, but I am willing to share the duties with a few others. Assemblies can be shipped to/from Europe/North-America/Asia/Australia and anywhere else.
I am assuming we will soon work out whatever disagreements/ambiguities about cost targets, and how we might vote/decide/collaborate... So I am moving on to the next step.
It is my opinion that the first major decision point is selecting the woofer and its loading. Until the woofer is selected, we do not know the minimum baffle width, and so we cannot start simulating baffle diffraction to optimize driver arrangements. We also do not know the woofer internal volume, so we cannot start the process of selecting box dimensions.
I believe the best way to collaborate is for people to post their suggestions for woofer combined with a loading/alignment. We can all discuss the various suggestions. If we cannot reach a consensus, then Andy has the final decision.
Once we have decided upon a woofer, a box volume, and (if bass reflex) a vent design or passive radiator, then the next phase can begin.
@andy19191 - Do you already have a woofer in mind?
I am rather busy with another project right now, but I expect that by May or June I will have some time. I don't want to be the sole constructor/tester, but I am willing to share the duties with a few others. Assemblies can be shipped to/from Europe/North-America/Asia/Australia and anywhere else.
I am assuming we will soon work out whatever disagreements/ambiguities about cost targets, and how we might vote/decide/collaborate... So I am moving on to the next step.
It is my opinion that the first major decision point is selecting the woofer and its loading. Until the woofer is selected, we do not know the minimum baffle width, and so we cannot start simulating baffle diffraction to optimize driver arrangements. We also do not know the woofer internal volume, so we cannot start the process of selecting box dimensions.
I believe the best way to collaborate is for people to post their suggestions for woofer combined with a loading/alignment. We can all discuss the various suggestions. If we cannot reach a consensus, then Andy has the final decision.
Once we have decided upon a woofer, a box volume, and (if bass reflex) a vent design or passive radiator, then the next phase can begin.
@andy19191 - Do you already have a woofer in mind?
Thanks. What I would like to do is wait a day to see if someone else is willing to do the poll. If not I will come up with one but given (the proposed) modular nature there is no longer a need to zero in on a single option but a configuration that can capture a reasonable amount of what people may be interested in working on.
It's more that I am trying to stop myself buying drivers given I have other more pressing non-hobby tasks to address.
I am not sure there is a need within a group project with a modular speaker for there to be final decisions. If people are keen on something and willing to do it then go for it and keep the group informed on progress.
I am aware of a woofer that is within budget and will do the job well and was tempted to get on with things. I resisted the temptation. There are almost certainly other suitable woofers and which are the better choices ought to be determined later.
My preference is a 12" woofer in order to get the space for reasonable sized midrange waveguides. It would also provide space for those with an interest in larger 6.5" midranges. A smaller 10" woofer has also been proposed and I see no reason not to include both in the initial study phases if there is interest. I certainly lack the information at the moment to have a clear idea of the pros and cons and what is going to fit in well with other choices.
Again in the early study phase I see little need to choose between sealed and ported although I think we can likely dismiss other loadings. Look at the implications and move forward with what looks good. My preference is ported given the large size but supporting both seems viable if others are keen on sealed.
@Juhazi suggestion of the SB Acoustics Gema is fair.
The GEMA ticks the boxes of a "not an expensive speaker using prestige/premium/boutique drivers. A speaker using good standard range drivers"
Anyone can build this kit for 1400 $/€, by building your own cabinet or get your own flat pack cabinet.
As an open source kit, people are free to modify/adjust/change improve as they feel fit. For those who want to build the original Open Source Monkey Coffin, with it's own goals and targets.
If you just want to own a pair of classic 3 ways- it seems that the manufacturers are re-releasing them, Wharfedale, JBL etc.
For some, these big box speakers never went away eg. Harbeth. On my recent trip to Taiwan, I spotted locally made/branded 3-way speakers ported speakers in a rectangular box, hanging in restaurants, on the floor of electronics stores. Audition one you like, buy new or second on a local trader. The world is filled with these speakers looking another home- There are times when you want to DIY, at other times you just want to enjoy the music.
If we're going to design/build yet another 3-way box, I think there should be good reasons for it, rather than re-inventing the wheel...
The GEMA ticks the boxes of a "not an expensive speaker using prestige/premium/boutique drivers. A speaker using good standard range drivers"
Anyone can build this kit for 1400 $/€, by building your own cabinet or get your own flat pack cabinet.
As an open source kit, people are free to modify/adjust/change improve as they feel fit. For those who want to build the original Open Source Monkey Coffin, with it's own goals and targets.
If you just want to own a pair of classic 3 ways- it seems that the manufacturers are re-releasing them, Wharfedale, JBL etc.
For some, these big box speakers never went away eg. Harbeth. On my recent trip to Taiwan, I spotted locally made/branded 3-way speakers ported speakers in a rectangular box, hanging in restaurants, on the floor of electronics stores. Audition one you like, buy new or second on a local trader. The world is filled with these speakers looking another home- There are times when you want to DIY, at other times you just want to enjoy the music.
If we're going to design/build yet another 3-way box, I think there should be good reasons for it, rather than re-inventing the wheel...
Last edited:
That is a perfectly valid reason for specifying a 12" woofer. I have often started a project by establishing an initial design constraint that it shall utilize a particular driver.
I rarely disagree with you, but I am on this point. Designing and building speakers is the whole point of DIY. Not every new design must be innovative or cutting edge in order to justify its purpose. Andy wants to do this project, and he wants some collaboration on it. I know that I have greatly benefitted from the sharing of ideas on my several threads. My recent project was a rather pedestrian 8" 3-way with a passive radiator, using well known drivers that have been around for a long time. It was nothing new or ground breaking, but I had fun designing it, and building it... and my friend loves it. A couple of years ago I made a 2-way using an SB17NBAC and SB26CDC, a combination that has been done many times before... but I still saw value in doing my own.
I am sure the Gema is a nice speaker, but it was designed with the obvious constraint that it must use SBA drivers. I bet we can do better. I notice that SBA does not offer any plots of measured performance..? or maybe I did not see them?
I understand that we're not trying to break new ground here. You can't do that with a rectangular box with square edges. 😛
But in all seriousness, perhaps the group's goal is to get 85% of the performance of the OSMC at 50% of the cost. Whatever the goal, it should be authentic.
Or is it to utilize existing resources (drivers and/or cabinets) and adjust/design them eg. "Jemma" eg. same SB34RNXL, but different mid and/or tweeter.
I didn't make my own drivers from scratch, and even if I did, I don't do it on my own. I certainly didn't mine the ore used to create the magnet or oil used to create the adhesives. We all help each other. DIY doesn't mean we have to do everything from scratch...
If the OP wants a journey to discover the joys (and sorrows) of learning to design and build a "3-way vented speaker for stereo use in the home with a room ~4x6m" that's also a goal, and of course his prerogative. I'm saying the goals need to be clarified... otherwise if people just want to BUILD, why not just build the excellent OSMC, or (probably good enough) GEMA...
I'm sure there are many lurkers that would like to go on that journey...
But in all seriousness, perhaps the group's goal is to get 85% of the performance of the OSMC at 50% of the cost. Whatever the goal, it should be authentic.
Or is it to utilize existing resources (drivers and/or cabinets) and adjust/design them eg. "Jemma" eg. same SB34RNXL, but different mid and/or tweeter.
I didn't make my own drivers from scratch, and even if I did, I don't do it on my own. I certainly didn't mine the ore used to create the magnet or oil used to create the adhesives. We all help each other. DIY doesn't mean we have to do everything from scratch...
If the OP wants a journey to discover the joys (and sorrows) of learning to design and build a "3-way vented speaker for stereo use in the home with a room ~4x6m" that's also a goal, and of course his prerogative. I'm saying the goals need to be clarified... otherwise if people just want to BUILD, why not just build the excellent OSMC, or (probably good enough) GEMA...
I'm sure there are many lurkers that would like to go on that journey...
Last edited: