It takes months of fiddling to get a speaker doing exactly what you want it to, but I think it is good to start with the right concept. 😎
We are looking at series wired D'Appolito here. It has some very strengths, IMO. It is no worse than the regular two way idea, but adds a couple of features.
This is a series wired MTM centre speaker in my possession:
This is the illustrious foamed Gale Gs401A, bit of a legend.
I'd guess we are looking at about 40L of stuffed closed box here. About 9" wide. Don't much care whether it's tower or standmount. It'll work best vertically aligned with a 3kHz crossover.
It's your project, so you've gotta like what you are seeing to go ahead. I'd still do that removable baffle:
http://www.diyaudio.com/forums/multi-way/223174-interesting-read-i-found-lossy-cabinet-designs-harbeth.html#post3234256
We are looking at series wired D'Appolito here. It has some very strengths, IMO. It is no worse than the regular two way idea, but adds a couple of features.
This is a series wired MTM centre speaker in my possession:
An externally hosted image should be here but it was not working when we last tested it.
This is the illustrious foamed Gale Gs401A, bit of a legend.
An externally hosted image should be here but it was not working when we last tested it.
I'd guess we are looking at about 40L of stuffed closed box here. About 9" wide. Don't much care whether it's tower or standmount. It'll work best vertically aligned with a 3kHz crossover.
It's your project, so you've gotta like what you are seeing to go ahead. I'd still do that removable baffle:
http://www.diyaudio.com/forums/multi-way/223174-interesting-read-i-found-lossy-cabinet-designs-harbeth.html#post3234256
Odougbo's post and clarification -
The Ansonica build (vented) with the Anarchy woofers is only an example of a MTM house shaker - and reasonably priced drivers.
However that is a big heavy box; but I see ideas for a 2cf on the table; that also is a large/heavy box.
I spend hours-and-hours this past summer making mtm's with a 6.5 - $29 mid woofer, with a best in class driver. It will easily go past 50hz with a very nice, lay back sound.
They are 9.5"w, 23"t, 12"d - 35lbs (which I think is a good cut off point for weight).
The Ansonica build (vented) with the Anarchy woofers is only an example of a MTM house shaker - and reasonably priced drivers.
However that is a big heavy box; but I see ideas for a 2cf on the table; that also is a large/heavy box.
I spend hours-and-hours this past summer making mtm's with a 6.5 - $29 mid woofer, with a best in class driver. It will easily go past 50hz with a very nice, lay back sound.
They are 9.5"w, 23"t, 12"d - 35lbs (which I think is a good cut off point for weight).
Please all remember an MTM is not automatically a D'Apolitto. (neither picture is) First, they must be in line. Second, the third order crossover is very carefully aligned to manage the phase combination to give the managed dispersion. A D'Apolitto is designed to be vertical as it has reduced vertical dispersion. This is why I suggested a MMT more traditional design. D'Apolitto alignment is not for beginners unless you have a proven design.
Never saw a Gale with the cover off. I remember them less than fondly.
Never saw a Gale with the cover off. I remember them less than fondly.
Well, I'll leave Tony in both of your capable hands then. 😕
MCM Audio Select 6 1/2'' Polypropylene Cone Woofer | 55-1170 (551170) | MCM Audio Select
The Madisound Speaker Store
Because I thought I knew the difference between closed box and reflex drivers. 🙄
MCM Audio Select 6 1/2'' Polypropylene Cone Woofer | 55-1170 (551170) | MCM Audio Select
The Madisound Speaker Store
Because I thought I knew the difference between closed box and reflex drivers. 🙄
Doug is referring to the Silver Flute that for the cost, is quite a performer, but it does have serious issues. One of it's attributes is it does go very low. Making it behave is not a beginners project either.
A free way to get started in design here is to use the published driver specs and punch them into WinISD to do box design. Then use the crossover System7 has so nicely provided . A good start.
LinearTeam
A free way to get started in design here is to use the published driver specs and punch them into WinISD to do box design. Then use the crossover System7 has so nicely provided . A good start.
LinearTeam
tvrgeek, we are getting seriously bogged down here. It's really not that hard to build a speaker! 😀
FWIW, even Joe D'App has abandoned 3rd order butterworth in favour of 4th order L/R. But I digress. I don't make it harder than it is.
Is this forum full of people who only see difficulty in building speakers? Go to the shop then and buy ready made...😕
FWIW, even Joe D'App has abandoned 3rd order butterworth in favour of 4th order L/R. But I digress. I don't make it harder than it is.
Is this forum full of people who only see difficulty in building speakers? Go to the shop then and buy ready made...😕
Oh Well. Just when I thought I was getting somewhere this thread seems to be going south. I did not mean to offend anyone and don't see where I did but if I did I apologize .
tvrgeek you wrote "A free way to get started in design here is to use the published driver specs and punch them into WinISD to do box design. Then use the crossover System7 has so nicely provided . A good start."
A couple of posts back I stated that I was going to do exactly that and use Steve's crossover. Steve mentioned "To series MTM them, double coil and resistor values on bass filter, halve the capacitors. Easy..."
My question is for the crossover diagram Steve presented, is that for a single driver? If yes what would be the difference or benefit of using parallel vs series connected drivers?
Also I have one of these :Vifa BC25SC06-04 1" Textile Dome Tweeter | 264-1028.
Would it be worth getting another for this project or is Steve's crossover for a specific tweeter that I need to buy.
Thanks
Tony
I don't like the look of that tweeter at all. Usual spit and sizzle from soft dome, I'd reckon. Bit of a pig to model too.
Any chance you could get something like this?
TW 70 - 8 Ohm
I've modelled the closed box MTM on 60cmX 20cm baffle here. Deep to suit 40L shared enclosure.
I did think that coil was on the big side. 1.5mH per driver might be better. We'll have to hope the bass does roughly the right thing. That bit is guesswork. 🙂
Any chance you could get something like this?
TW 70 - 8 Ohm
I've modelled the closed box MTM on 60cmX 20cm baffle here. Deep to suit 40L shared enclosure.
I did think that coil was on the big side. 1.5mH per driver might be better. We'll have to hope the bass does roughly the right thing. That bit is guesswork. 🙂
Attachments
That TW70 tweeter seems to be only available on your side of the pond. Anything from Parts Express suitable? Also just curious why you came up with 40 L for the enclosure. The simple online calculator I used comes up with 60L. Are you using a higher Qtc. The reason I ask is I'd like to see these enclosures be about 30 inches high for my wive to put her her fancy lamps and figurines and other crap on top of them.
Tony
I noticed Vas of 30L, on a Qts of 0.5, so that's 30L per driver. But that seems a LOT to me. But hey...at worst it's just a bit overdamped.
Box is up to you, Tony. Just keep the baffle around 20 cms wide.
Many ways to skin a cat. 🙂
Box is up to you, Tony. Just keep the baffle around 20 cms wide.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Many ways to skin a cat. 🙂
OK, Proper Job!
Crossover example:
I am good to you. No-one works harder than me here. 😱
An externally hosted image should be here but it was not working when we last tested it.
Crossover example:
An externally hosted image should be here but it was not working when we last tested it.
I am good to you. No-one works harder than me here. 😱
I think maybe I'm in over my head here. Some suggested that I build a kit. Well I just finished building a single Overnight Sensation MTM for the fun of it and I don't really like it but maybe that's a subject for another post. What can you learn from building a kit? Just about nothing.
I thought by doing something on my own I might learn a lot with some help from the experts here but I don't see myself learning anything from it at this point. I don't expect it all to be handed to me on a silver platter but questions like why is a 20 cm baffle important? Why are series wired drivers better for this project than parallel. Why is it only a specific tweeter or two will work here?
I have a significant knowledge of electronics design and it all came easy to me. With speakers though it seems there is no hard true factual information. Everything I read about speakers seems murky and just leads to further confusion . You can go to 3 different sites about a specific aspect of speaker building and come up with 3 different conflicting explainations of the same topic. Then add all the various different individual opinions on all the various forums and talk that leads up to something only Einstein's could understand . Then you got someone like Steve saying its not hard to build a speaker and others who say its very difficult and critical. I tend to lean towards Steve's opinion because I have learned that almost anything in life boils down to common sense. But in the world of speakers nothing seems to really make sense.😕
Sorry for the long post. I thank all that responded. Maybe I should just go out and buy one of those $49 plastic box home theater speaker systems and be done with it.
Tony
Tony, I can't write an encyclopedia everytime someone knocks up a pair of speakers. 😀
Read Lynn Olson for the lowdown:
The Art of Speaker Design
His MTM Ariel project is nice too.
Ariel Speaker Page
Coupla questions? OK...
Baffle width determines the slope of the speaker FR curve. Big baffles have more bass. Pulling a speaker away from the wall loses 6dB of wall gain at the low end.
Series MTM has nicer impedance, and a few other things that make it my weapon of choice over Parallel wired MTM.
Cone tweeters are sweeter than soft domes for very good technical reasons. Er, that's it.
Don't give up, chum. Once you've got a good box, you can keep playing with different drivers. I often buy old speakers with good cabinets and rebuild them completely! Woodwork bores me a bit. But I do it.
Don't forget Troels:
DIY Loudspeakers
Read Lynn Olson for the lowdown:
The Art of Speaker Design
That's what I did here, I listened to Lynn...😉
His MTM Ariel project is nice too.
Ariel Speaker Page
Coupla questions? OK...
Baffle width determines the slope of the speaker FR curve. Big baffles have more bass. Pulling a speaker away from the wall loses 6dB of wall gain at the low end.
Series MTM has nicer impedance, and a few other things that make it my weapon of choice over Parallel wired MTM.
Cone tweeters are sweeter than soft domes for very good technical reasons. Er, that's it.
Don't give up, chum. Once you've got a good box, you can keep playing with different drivers. I often buy old speakers with good cabinets and rebuild them completely! Woodwork bores me a bit. But I do it.
Don't forget Troels:
DIY Loudspeakers
Download WinISD and play with it.
Download The EDGE and play with it
Download HOLM and read the entire users guide. Same for SoundEasy, ARTA.
Download PSD-Lite and play with it.
Read the entire set of pages on TrueAudio
Read the Linkwitz site and see how to build a decent instrument mic for about $10.
Build a sound card interface to measure T/S parameters ( also really cheap) like is says in Sound Easy, HOLM, or LIMP.
Several threads mention many more sites and books to get you started.
Building a kit or established design lets you reverse engineer something that will probably work. If the goal is just a DIY speaker, that is the way to go. If you wish to learn the various engineering necessary to design a speaker, that is a totally different question you had not asked.
Basically:
Concept: You have one, so good start
Pick the drivers for the concept. You are half way there.
MEASURE the parameters of the drivers. (You can use the T/S fro the woofer, but yo must MEASURE the acoustic response in the prototype box of woofer and tweeter.
Model several possible solutions )
Build a prototype box
Measure the drivers in the prototype
Start over
Now design a crossover for the adjusted box
Prototype again, and again, and again.
In about 6 months, you come up with a finished project if all goes well. Speaker design is engineering, not handyman.
Speaker building has a lot of common sense. Many beginners forget to apply common sense when selecting drivers or have unreal expectations on what a system will do. Common sense does have to have a foundation in knowledge. Speaker design requires electrical engineering, acoustics, psychoacoustics, lab practices, mechanical engineering and fabrication. You then have to blend in industrial design and WAF. It is pretty well understood after about 70 years. Most of what was written in AES papers in the 50's and 60's is still true. The advances are in modern materials where we can now make drivers closer to what was specified 60 years ago.
Speaker building is EXPENCIVE. If you just want good speakers, buy them.
Baffle width is one of the parameters that effects the crossover design due to baffle step. (Read about that on TrueAudio) Steve provided a crossover design with the specification of a 20cm baffle. If you change the dimensions, it changes the crossover design. Play with The Edge modeling program to see what we mean.
Download The EDGE and play with it
Download HOLM and read the entire users guide. Same for SoundEasy, ARTA.
Download PSD-Lite and play with it.
Read the entire set of pages on TrueAudio
Read the Linkwitz site and see how to build a decent instrument mic for about $10.
Build a sound card interface to measure T/S parameters ( also really cheap) like is says in Sound Easy, HOLM, or LIMP.
Several threads mention many more sites and books to get you started.
Building a kit or established design lets you reverse engineer something that will probably work. If the goal is just a DIY speaker, that is the way to go. If you wish to learn the various engineering necessary to design a speaker, that is a totally different question you had not asked.
Basically:
Concept: You have one, so good start
Pick the drivers for the concept. You are half way there.
MEASURE the parameters of the drivers. (You can use the T/S fro the woofer, but yo must MEASURE the acoustic response in the prototype box of woofer and tweeter.
Model several possible solutions )
Build a prototype box
Measure the drivers in the prototype
Start over
Now design a crossover for the adjusted box
Prototype again, and again, and again.
In about 6 months, you come up with a finished project if all goes well. Speaker design is engineering, not handyman.
Speaker building has a lot of common sense. Many beginners forget to apply common sense when selecting drivers or have unreal expectations on what a system will do. Common sense does have to have a foundation in knowledge. Speaker design requires electrical engineering, acoustics, psychoacoustics, lab practices, mechanical engineering and fabrication. You then have to blend in industrial design and WAF. It is pretty well understood after about 70 years. Most of what was written in AES papers in the 50's and 60's is still true. The advances are in modern materials where we can now make drivers closer to what was specified 60 years ago.
Speaker building is EXPENCIVE. If you just want good speakers, buy them.
Baffle width is one of the parameters that effects the crossover design due to baffle step. (Read about that on TrueAudio) Steve provided a crossover design with the specification of a 20cm baffle. If you change the dimensions, it changes the crossover design. Play with The Edge modeling program to see what we mean.
You probably don't want another opinion but here's mine.
As you have stated that you have a hearing loss at low frequencies ( I'm glad mine is above 5k) I'd be advising to not go MTM but WWT ( those drivers are NOT midrangers IMO) and make the box a 2.5 system.
2.5 merely means that one of the drivers is rolled off early with a large coil to boost low frequencies. Yes it adds another component but it has benefits; can be used to compensate for the baffle step loss and you can approximate its value by using the -3dB baffle step frequency
As you have stated that you have a hearing loss at low frequencies ( I'm glad mine is above 5k) I'd be advising to not go MTM but WWT ( those drivers are NOT midrangers IMO) and make the box a 2.5 system.
2.5 merely means that one of the drivers is rolled off early with a large coil to boost low frequencies. Yes it adds another component but it has benefits; can be used to compensate for the baffle step loss and you can approximate its value by using the -3dB baffle step frequency
Hi,
MTM or TMM doesn't matter, you have no idea what the drivers
are doing in the midrange and without that you are lost, period.
It is hard to build a speaker properly and S7's opinions on the
subject are simply wrong, they get you ~ close, but no cigar.
Lazy analysis and simplistic misinformation is not working hard.
rgds, sreten.
MTM or TMM doesn't matter, you have no idea what the drivers
are doing in the midrange and without that you are lost, period.
It is hard to build a speaker properly and S7's opinions on the
subject are simply wrong, they get you ~ close, but no cigar.
Lazy analysis and simplistic misinformation is not working hard.
rgds, sreten.
I did say I dont expect it all to be handed to me on a silver platter. I guess the point of my last post is I have never in my life had so much difficulty understanding something electronic or technical as I'm having right now with speakers. I going to go ahead and build this system as you have suggested with your crossover. I feel myself getting sucked into all this as what will probably be an ongoing hobby.
I going to start another post about the Overnight Sensation that I built just for something to do and see if there's a reason I don't like the sound of it.
Thanks for everything
Tony
I didn't say why I like series MTM so much. It's this stunning fact: You can take ANY two way design and convert it to series MTM by doubling the bass coils and resistors and halving the capacitors. How easy is that. It just works! There's something else too, but that's MY business...😉
Here's my current bit of fun. This Sony E44 had a simple 3.3uF capacitor on the treble and nothing else and sounded cheap and cheerful. Lovely classic high efficiency 8" bass and cone mylar tweeter. It now has one of my adjustable crossover specials:
That 10R resistor is the adjust for that great unknown bass voicecoil inductance. It's select on test. I like doing filters that way. The one I did for you has a 9R on the tweeter input (and a 7.5R + 1.5uF Zobel, to be exact, I'd use 1uF with most tweeters) that adjusts for different tweeters. 😎
FWIW, I would not get on with those Overnight Sensations. Metal cones, soft domes, no thanks.
Here's my current bit of fun. This Sony E44 had a simple 3.3uF capacitor on the treble and nothing else and sounded cheap and cheerful. Lovely classic high efficiency 8" bass and cone mylar tweeter. It now has one of my adjustable crossover specials:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
That 10R resistor is the adjust for that great unknown bass voicecoil inductance. It's select on test. I like doing filters that way. The one I did for you has a 9R on the tweeter input (and a 7.5R + 1.5uF Zobel, to be exact, I'd use 1uF with most tweeters) that adjusts for different tweeters. 😎
FWIW, I would not get on with those Overnight Sensations. Metal cones, soft domes, no thanks.
I will take your advice and do all of that. I do already have WINISD but it crashes a lot on my Vista system.
Tony
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