hehehe as have I!! first started thinking about my MTM's (they weren't MTM's then) back in 2003... started building in 2005, getting close now but not there quite yet. (but as per my sig, there was four years of nothing in there
) Tony.
I think we should look at the PinkFish media "PFM Special" project.It uses this mid & is a open baffle hybrid project. There is one pair built & is a very nice speaker system. Thing is the Vifa M26WR-09-08 is discontinued, but a SEAS CA26RFX can be used with a inductor with higher DCR, there is a BOM for this project & very complete build pictures etc, Chili is the owner of the one pair still in existence, only 2 were actually built, the designer recycled hid for other projects.The tweeter is SEAS SS 9300 aka D2905, a SS 9500 could be used in place of the 9300 with slight XO change as James has stated on PinkFish media site. This design is far,far from cheesy & is easily referance grade speakers IMO. Please take a look at the build, just search for "PFM Special"
I am sure James would be happy this design is bieng revitalized with some XO changes. It is passive XO, which is cool for those who don't have active ablilties. This is probably the best implemetion of SEAS MCA15 RCY I have seen. & I bet the best sounding by far & away.
Joe
I am sure James would be happy this design is bieng revitalized with some XO changes. It is passive XO, which is cool for those who don't have active ablilties. This is probably the best implemetion of SEAS MCA15 RCY I have seen. & I bet the best sounding by far & away.
Joe
I totally understand. I finished by 3-way horns yesterday. I started them back in January of 2006. It was a labor of love, but every second and cent were well worth the final outcome. My system is now sublime.
Any progress to report?
I liked where this tread was going when their was talk about which drivers to use in a "reference" 3-way design. Kind of drifted off into everyones dream 3-way, which was a direction never intended, IMHO.
This design should be a simple to build 3-way with drivers that will be around for at least a few years. No complex shapes to cut. Too hard for a beginner. Just a plain tower or a retro 3-way "monkey coffin". OK maybe the woofer can be in a side firing tower. No MTM - too many drivers to buy and more $$. No transmission line - too complex to stuff and build. No open baffles - too bizarre. No horns. No full range drivers. Nothing that needs any angle other than 90 degrees cut. Simple joints only for the box. Ideally it should be a step up from a serious 2-way. There are many 2-ways that pack a lot of sonic value. The 3-way should get down a bit lower and deliver the lower bass missing from the 2-way. Also should improve the power handling over the 2-way since there are more drivers to spread out the power. Vented? Yes or no - depends on the woofer. A passive crossover with and without BSC will be fine. Of course, if you want to go to active crossovers, it's up to you. But it won't be cheap or simple any more.
Is this the direction that this is heading?? Any body care to define what "reference" means?? Anybody have a list of proposed drivers??
I liked where this tread was going when their was talk about which drivers to use in a "reference" 3-way design. Kind of drifted off into everyones dream 3-way, which was a direction never intended, IMHO.
This design should be a simple to build 3-way with drivers that will be around for at least a few years. No complex shapes to cut. Too hard for a beginner. Just a plain tower or a retro 3-way "monkey coffin". OK maybe the woofer can be in a side firing tower. No MTM - too many drivers to buy and more $$. No transmission line - too complex to stuff and build. No open baffles - too bizarre. No horns. No full range drivers. Nothing that needs any angle other than 90 degrees cut. Simple joints only for the box. Ideally it should be a step up from a serious 2-way. There are many 2-ways that pack a lot of sonic value. The 3-way should get down a bit lower and deliver the lower bass missing from the 2-way. Also should improve the power handling over the 2-way since there are more drivers to spread out the power. Vented? Yes or no - depends on the woofer. A passive crossover with and without BSC will be fine. Of course, if you want to go to active crossovers, it's up to you. But it won't be cheap or simple any more.
Is this the direction that this is heading?? Any body care to define what "reference" means?? Anybody have a list of proposed drivers??
Moondog55's intention was to have a 3-way speaker that was available to all at a reasonable building cost as well as ease of build (correct me if I'm wrong Ted). That seems to line up with your thoughts as an exotic build would have limited appeal due to budget restraints, room placement. It's not to say that it cannot evolve into something like that in the future.
Reference only means a reference point and the goal was a provide a very good sounding design that can be used to judge others or as a yardstick to beat as the builder progressed in the hobby. The 2-way ref was just that and was a modest speaker that was economical to build but held it's own well and was a datum point for any new speakers that followed (a check if they were better or worse).
I thought we were close to the final drivers:
27TFFC (alt 27TDFC) + MCA15RCY + CA26RFX.
Direction of 3-way ref
To get this off the ground takes a lot of commitment from several parties. With the 2-way ref, the concept came from a comment in other threads from planet10 about a good starting point speaker in this hobby. I did a design based on this comment and x. onasis built the design. From there different crossovers were designed and tried by x. onasis who gave feedback on the direction. I then built the speaker and trialled various crossover designs and box sizes. In the end 2 box sizes and 3 crossover variations were finalised and there has been several built around the globe. Some have measured the final speaker, moved on to other tweeters, tried other crossovers and generally had a good play. What it had going for it was an economical build price as the drivers were cheap, box was simple and most of the crossovers had only 3 components.
The 3-way ref is another story as the build price would be around 3x-4x more so requires much more commitment.
What we need now is some volunteers to get this off the ground. I thought we were close to the final drivers which are 27TFFC (alt 27TDFC) + MCA15RCY + CA26RFX.... am I correct?
From here we need bodies to do:
1. Woofer box design (single woofer BR or TL and 2 woofer sealed)
2. Mid enclosure design
3. Overall integration of box designs into the final enclosure configuration
4. Box drawings including damping arrangement
5. Crossover design
These processes should be documented in the thread as forms a good guide for those interested in 3-ways and their design.
Now for the big one.... we need someone to put their money and time on the line to buy the parts, build and tweak to achieve the final design.
This final design then has to be documented I imagine in the wiki as well as this thread.
A lot of work.... what do you guys reckon? Any show of hands?
To get this off the ground takes a lot of commitment from several parties. With the 2-way ref, the concept came from a comment in other threads from planet10 about a good starting point speaker in this hobby. I did a design based on this comment and x. onasis built the design. From there different crossovers were designed and tried by x. onasis who gave feedback on the direction. I then built the speaker and trialled various crossover designs and box sizes. In the end 2 box sizes and 3 crossover variations were finalised and there has been several built around the globe. Some have measured the final speaker, moved on to other tweeters, tried other crossovers and generally had a good play. What it had going for it was an economical build price as the drivers were cheap, box was simple and most of the crossovers had only 3 components.
The 3-way ref is another story as the build price would be around 3x-4x more so requires much more commitment.
What we need now is some volunteers to get this off the ground. I thought we were close to the final drivers which are 27TFFC (alt 27TDFC) + MCA15RCY + CA26RFX.... am I correct?
From here we need bodies to do:
1. Woofer box design (single woofer BR or TL and 2 woofer sealed)
2. Mid enclosure design
3. Overall integration of box designs into the final enclosure configuration
4. Box drawings including damping arrangement
5. Crossover design
These processes should be documented in the thread as forms a good guide for those interested in 3-ways and their design.
Now for the big one.... we need someone to put their money and time on the line to buy the parts, build and tweak to achieve the final design.
This final design then has to be documented I imagine in the wiki as well as this thread.
A lot of work.... what do you guys reckon? Any show of hands?
Rabbitz is 100% correct.
I'm not great on the design front but i will comitt $$ to a a build in Feb. My preference is the TL however there is no reason why the drivers couldn't be recycled into different enclosures.
How about some of the TL gurus Scottmoose et al take on board the TL design. For clarity it may be a good idea for each configuration to have its own thread. What do you think?
I'm not great on the design front but i will comitt $$ to a a build in Feb. My preference is the TL however there is no reason why the drivers couldn't be recycled into different enclosures.
How about some of the TL gurus Scottmoose et al take on board the TL design. For clarity it may be a good idea for each configuration to have its own thread. What do you think?
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Hi Rabbitz, I've been holding off a bit on contributing more than "theory", as I don't feel that I have any proven designs under my belt, at least not until I finish my current speakers, and maybe have someone else (experienced) listen to them and give them the thumbs up
I've been thinking about getting up to speed with akabak to have a crack at a design for a bass reflex enclosure (possibly dual chamber), but I'm not going to commit to anything at this stage, as I know time has been a scarce resourse for me lately. barely making progress on my own diy stuff without spending time on something else...
Having said that the final two pieces of veneer went onto my second MTM box on the weekend (unfortunately it was a bit hot and I might not have a great bond), so it is getting closer to being completed (at least up to the point where I need to start doing the crossover).. so maybe in another few months I might be in a better position
Tony.
I've been thinking about getting up to speed with akabak to have a crack at a design for a bass reflex enclosure (possibly dual chamber), but I'm not going to commit to anything at this stage, as I know time has been a scarce resourse for me lately. barely making progress on my own diy stuff without spending time on something else...
Having said that the final two pieces of veneer went onto my second MTM box on the weekend (unfortunately it was a bit hot and I might not have a great bond), so it is getting closer to being completed (at least up to the point where I need to start doing the crossover).. so maybe in another few months I might be in a better position
Tony.
I havent got alot of spare time these days unfortunately, hence why I have contributed very little to this thread. However, I am willing to build a reference speaker for this build to get things underway. Or to atleast be able to give some listening impressions.
Regards
Cameron
Home Audio Solutions
Regards
Cameron
Home Audio Solutions
I'm working on a starting point design for this speaker. To keep it simple it's going to be a single woofer BR that should be easy to build. Should have an F3=35Hz and F6 just under 30Hz which should be plenty of extension.
I'll put up a simple 1st order starting point crossover (will need tweaking for sure) that may work in a series xo as well as a parallel xo. There is an alternative crossover that has been mentioned previously and based on Troel's 3W but with the MCA15RCY crossover section.
This will take a little time but I hope to have it up in a month or so. This should kick off the design and allow scope for variations by others to follow.
I'll put up a simple 1st order starting point crossover (will need tweaking for sure) that may work in a series xo as well as a parallel xo. There is an alternative crossover that has been mentioned previously and based on Troel's 3W but with the MCA15RCY crossover section.
This will take a little time but I hope to have it up in a month or so. This should kick off the design and allow scope for variations by others to follow.
For Aussies, Rockby has cheap caps for PSU
http://www.diyaudio.com/forums/parts/156129-rockby-oz-weekend-sale.html#post2001205
http://www.diyaudio.com/forums/parts/156129-rockby-oz-weekend-sale.html#post2001205
That W26 Classic project by Troels looks nice , but the Seas drivers would still be quite expensive
Sorry for going AWOL guys. As mentioned earlier family issues have been keeping me busy and might well do till mid 2010 (Ouch!).
Still I do intend to someday build the 2 woofer (sealed) version. I assume the drivers chosen are the 27TFFC (alt 27TDFC) + MCA15RCY + CA26RFX.
The reason for choosing this is (a) I intend to go active so driver sensitivities is not an issue (b) sealed boxes are much easier to build and I have found to my delight they tend to integrate well into my room (my speakers are near the rear wall and get quite a bit of boundary reinforcement) (c) part of the cost of the second woofer would be offset by the reduced complexity of the sealed cabinet (as compared to a TL).
The mid enclosure, I humbly propose, could be a short transmission line built on the lines of the mid encloure Troels built for his Cyclops or maybe even an OB!
Good luck guys.
PS. Here is a link that might prove useful
http://www.hometheatershack.com/forums/diy-speakers/8355-re-creating-revel-f50a-speakers.html
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We could just use the manufacturers T/S specs and designing a "book" filter all second order and then lots of tweaking to get it right, what I have found in my experiments is the woofer almost always needs a second order roll-off but often the midrange and tweeter need third order slopes on the high-pass for best integration.