Good Evening, and Happy Thanksgiving to all.
Recently my brother ordered a quantity of these MCM Electronics http://www.mcminone.com (order # 55-1862) a fully shielded, aluminum cone 6-1/2" High-Excursion MCM drivers with rubber surrounds for a decent, dirt cheap quantity price, and they looked interesting, so I agreed to purchase 3 from him, in anticipation of building a voice timbre matched triad for Home Theater use. They also resemble a similiar product sold through Parts Express in thier Dayton line, but in a 7" non-shielded version. He also agreed to furnish to me, free of charge, 3 spare Audax AWO1OE1 3/8 shielded Polymer Dome tweeters he has, to my avail for the asking.
Since I first heard Transmission Line Designs, whether home-built DIY, commercial offerings, such a Vandersteen, KEF as well as others I instantly fell in love with the sound. I began studying on the subject, and became interested in labyrinths, stuffed pipes, Voigt pipes and the like. A few years ago I assisted my brother (an audiophile, as well and an autosound/ car electronics retailer) in building a simple, low-cost, tall, narrow, column tower modeled around a cheap, Pioneer 6-1/2" poly woofer and simple crossover network with a Motorola Radiant Piezo Tweeter. (One feature I did not care for) I liked the tall, narrow, modern contemporary appearance. We decided to try this project in anticipation, based on the promise of unusual bass response from a small 6-1/2" woofer. This design he decided to copy verbatim to stay in keeping with the low cost project's budget and was primarily duplicated for experimental reasons, as we were both curious to see what it would do. It exceeded our expectations. My brother uses these in his home. It can be seen in the publication, "The Great Stereo Sound Speaker Manual with Projects," by David Weems. Another variation of this speaker in a similiar design can be seen at the following link
http://members.tripod.com/oakleyspeakers/MAIN.html
My understanding is, though, that these designs are dated, TL design in the past was more accidental luck, with no clearly defined parameters, and I have recently been informed of recent breakthroughs regarding accurate data for calculated modeling design with absolutes by a person named Martin J King.
Based on various information abound, (both past and present)regarding TL theory, as well as opinions of TL advocates who make powerful claims and arguments regarding the natural, uncolored sound, spatial depth and ability for a woofer to achieve bass down to it's free air frequency. Most feel the sound is less cramped, goes down lower, natural, deeper and they value the purity of the bass, particularly in the upper and middle bass frequencies. I believe this, not only based on thier claims, but on my own experience, which is limited.
I would really like to build a main pair and matching center channel around these magnetically shielded drivers, for home theater use, in a simple, 2-way design similiar to the above mentioned projects. I also have plans to incorporate a "Glass-over" (using ordinary, Dyna-Glass used for fiberglass automotive body repair) into the build any design I am able to come up with to give the sculpted, rounded, aesthetic appearance similiar to the "Rosinante" cabinets sold by Zalytron for a small fortune. This is probably taxing work, but I am far more capable of building any cabinets this elaborate than I am at designing and modeling. (Especially Transmission Lines.) The extent of my DIY experience is calculating Thiele/Small parameters to achieve box volumes to obtain a desired Q for ordinary Acoustic Suspension sealed boxes. (I have always preferred Q's of about 0.6-0.7.)
If anyone out there has any suggestions, or even a proven build design modeled around this woofer, I'd be extremely interested in hearing about it. I would like to build something better than a simple, small sealed or ported bass reflex design. I'd like to build something similiar, in a proven design, in resemblance to the towers I've mentioned here that maximizes the woofer's potential.
I greatly admire those of you with expertise and value your experience and opinions tremendously. Any guidance, direction or designs you might be able to provide would be greatly appreciated.
Recently my brother ordered a quantity of these MCM Electronics http://www.mcminone.com (order # 55-1862) a fully shielded, aluminum cone 6-1/2" High-Excursion MCM drivers with rubber surrounds for a decent, dirt cheap quantity price, and they looked interesting, so I agreed to purchase 3 from him, in anticipation of building a voice timbre matched triad for Home Theater use. They also resemble a similiar product sold through Parts Express in thier Dayton line, but in a 7" non-shielded version. He also agreed to furnish to me, free of charge, 3 spare Audax AWO1OE1 3/8 shielded Polymer Dome tweeters he has, to my avail for the asking.
Since I first heard Transmission Line Designs, whether home-built DIY, commercial offerings, such a Vandersteen, KEF as well as others I instantly fell in love with the sound. I began studying on the subject, and became interested in labyrinths, stuffed pipes, Voigt pipes and the like. A few years ago I assisted my brother (an audiophile, as well and an autosound/ car electronics retailer) in building a simple, low-cost, tall, narrow, column tower modeled around a cheap, Pioneer 6-1/2" poly woofer and simple crossover network with a Motorola Radiant Piezo Tweeter. (One feature I did not care for) I liked the tall, narrow, modern contemporary appearance. We decided to try this project in anticipation, based on the promise of unusual bass response from a small 6-1/2" woofer. This design he decided to copy verbatim to stay in keeping with the low cost project's budget and was primarily duplicated for experimental reasons, as we were both curious to see what it would do. It exceeded our expectations. My brother uses these in his home. It can be seen in the publication, "The Great Stereo Sound Speaker Manual with Projects," by David Weems. Another variation of this speaker in a similiar design can be seen at the following link
http://members.tripod.com/oakleyspeakers/MAIN.html
My understanding is, though, that these designs are dated, TL design in the past was more accidental luck, with no clearly defined parameters, and I have recently been informed of recent breakthroughs regarding accurate data for calculated modeling design with absolutes by a person named Martin J King.
Based on various information abound, (both past and present)regarding TL theory, as well as opinions of TL advocates who make powerful claims and arguments regarding the natural, uncolored sound, spatial depth and ability for a woofer to achieve bass down to it's free air frequency. Most feel the sound is less cramped, goes down lower, natural, deeper and they value the purity of the bass, particularly in the upper and middle bass frequencies. I believe this, not only based on thier claims, but on my own experience, which is limited.
I would really like to build a main pair and matching center channel around these magnetically shielded drivers, for home theater use, in a simple, 2-way design similiar to the above mentioned projects. I also have plans to incorporate a "Glass-over" (using ordinary, Dyna-Glass used for fiberglass automotive body repair) into the build any design I am able to come up with to give the sculpted, rounded, aesthetic appearance similiar to the "Rosinante" cabinets sold by Zalytron for a small fortune. This is probably taxing work, but I am far more capable of building any cabinets this elaborate than I am at designing and modeling. (Especially Transmission Lines.) The extent of my DIY experience is calculating Thiele/Small parameters to achieve box volumes to obtain a desired Q for ordinary Acoustic Suspension sealed boxes. (I have always preferred Q's of about 0.6-0.7.)
If anyone out there has any suggestions, or even a proven build design modeled around this woofer, I'd be extremely interested in hearing about it. I would like to build something better than a simple, small sealed or ported bass reflex design. I'd like to build something similiar, in a proven design, in resemblance to the towers I've mentioned here that maximizes the woofer's potential.
I greatly admire those of you with expertise and value your experience and opinions tremendously. Any guidance, direction or designs you might be able to provide would be greatly appreciated.
http://www.mcminone.com/content/ProductData/Spec Sheets/55-1862.pdf
Hi,
I'd suggest the 88dB/W sensitivity figure is pure BS.
You will need two for decent sensitivity albeit at 4 ohms.
If you use one driver sensitivity will be very low, but good bass.
Low Vas also suggests 2 drivers for a floorstander.
See http://www.zaphaudio.com/6.5test/
for info on similar Dayton and MCM drivers.
3/8" poly domes are a complete non-starter.
See http://www.zaphaudio.com/BAMTM.html
for how to use the Dayton drivers.
TBH you could do a lot worse than using this as your starting point.
Something similar to :
http://www.seas.no/images/stories/diykits/pdfdataheet/thor_cab.pdf
Should work OK using info from :
http://www.quarter-wave.com/Theory/Alignment_Tables.pdf
🙂/sreten.
http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spkrbldg/
http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm
http://www.humblehomemadehifi.com/
http://www.rjbaudio.com/projects.html
http://www.zaphaudio.com/
Hi,
I'd suggest the 88dB/W sensitivity figure is pure BS.
You will need two for decent sensitivity albeit at 4 ohms.
If you use one driver sensitivity will be very low, but good bass.
Low Vas also suggests 2 drivers for a floorstander.
See http://www.zaphaudio.com/6.5test/
for info on similar Dayton and MCM drivers.
3/8" poly domes are a complete non-starter.
See http://www.zaphaudio.com/BAMTM.html
for how to use the Dayton drivers.
TBH you could do a lot worse than using this as your starting point.
Something similar to :
http://www.seas.no/images/stories/diykits/pdfdataheet/thor_cab.pdf
Should work OK using info from :
http://www.quarter-wave.com/Theory/Alignment_Tables.pdf
🙂/sreten.
http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spkrbldg/
http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm
http://www.humblehomemadehifi.com/
http://www.rjbaudio.com/projects.html
http://www.zaphaudio.com/
Hi. Thanks for your reply. I have already seen the info on Zaphaudio.com regarding this woofer. I also was in quarter-wave.com and found it confusing. Supposedly, there's a worksheet that you use by entering a woofer's given specifications, that calculates a box volume and length for a long, tapered line, a short fat box, etc. I had a friend, whjo is more familiar with the website run a model of this woofer, and he seems to think there are better choices for a woofer. He modeled the MCM woofer in different configurations, using MathCad, the program of Martin J King, and did not seem to think it looked promising. Although, he also modeled the very similiar Dayton 7" aluminum cone woofer, which he seemed to really like the results.
I am considering the possibility of purchasing 2 of the Dayton drivers, which he feels match a profile for a more promising candidate for a TL driver. Then, using the 3 remaining MCM drivers for a timbre voice matched acoustic suspension center channel and surround pair.
Any thoughts or opinions ? Thank You.
I am considering the possibility of purchasing 2 of the Dayton drivers, which he feels match a profile for a more promising candidate for a TL driver. Then, using the 3 remaining MCM drivers for a timbre voice matched acoustic suspension center channel and surround pair.
Any thoughts or opinions ? Thank You.
these woofers are cheap, but need to be crossed over low, they require expensive tweeters and crossovers. IMO not worth it.
you can try to use full range drivers if you have limited budget.
you can try to use full range drivers if you have limited budget.
Which Drivers?- The MCM or the Dayton ones?
Which drivers are we suggesting are cheap, too in low Xmax to be utilized in a TL application? The MCM 6.5" shielded units, or the Dayton 7" woofers? The woofers I am currently working with, are the Dayton DA 175-8. My friend, who is working the MathCad program seems to think these drivers are very promising in a mass loaded TL design he is working on. Here are the specs for this driver:
Voice coil diameter: 1-3/8" Le: 1.15mH
Impedance: Re 5.9 ohms Freq Range: 35Hz-10KHz
Fs: 36Hz SPL: 85dB Vas: 0.75 cu ft
Qms: 2.15 Qes: 0.53 Qts: 0.42 Xmax: 4.25mm
We recently had a discussion, and arrived at the decision to try the Dayton driver, which he felt modeled well with MathCad, So I decided to purchase a pair of those to build a main pair to match the MCM drivers, which I will use for both a center channel and pair of surrounds.
Opinions ? Other input on this project ? Please tell me what you think.
Thank You, Eric
Which drivers are we suggesting are cheap, too in low Xmax to be utilized in a TL application? The MCM 6.5" shielded units, or the Dayton 7" woofers? The woofers I am currently working with, are the Dayton DA 175-8. My friend, who is working the MathCad program seems to think these drivers are very promising in a mass loaded TL design he is working on. Here are the specs for this driver:
Voice coil diameter: 1-3/8" Le: 1.15mH
Impedance: Re 5.9 ohms Freq Range: 35Hz-10KHz
Fs: 36Hz SPL: 85dB Vas: 0.75 cu ft
Qms: 2.15 Qes: 0.53 Qts: 0.42 Xmax: 4.25mm
We recently had a discussion, and arrived at the decision to try the Dayton driver, which he felt modeled well with MathCad, So I decided to purchase a pair of those to build a main pair to match the MCM drivers, which I will use for both a center channel and pair of surrounds.
Opinions ? Other input on this project ? Please tell me what you think.
Thank You, Eric
both, mcm and da175 are cheap, they don't play loud, begin distort too early. it's just my opinion(I have da175's), maybe you'll like these drivers. I liked them at first 🙂
Cheap Drivers ???
Do we mean "Cheap," as in inexpensive, or "cheap," as in poor quality. I know zaphaudio says otherwise. http://www.zaphaudio.com
Do we mean "Cheap," as in inexpensive, or "cheap," as in poor quality. I know zaphaudio says otherwise. http://www.zaphaudio.com
Zaph uses them in a MTM where you have two of them to help with the DA-175's limitations. But I'm pretty confident that it's better then the MCM.
Re: Cheap Drivers ???
Cheap as in inexpensive. MCM has been selling tons of these Aluminum drivers for more than a decade. I don't know too many experienced speaker builders that haven't done a speaker design using them sometime in the past. They aren't the ultimate driver, but they look nice and are fairly forgiving for metal cone drivers. In the real world their power handling ability is fine for most home environments. Remember, that for most people, including me, they're a good driver start out with and can give very satisfactory results.
Usually, expensive drivers use exotic materials, have excellent power handling ability, cast baskets, greater x-max, blah, blah blah....
The question is, do they sound better? That tends to be a sticky question, as it really depends on what you're looking for. There are many "cheap" drivers that sound just fine within their design limits, and in fact may sound just as good or better than the exotics, if used in a "normal" situation. Lots of experienced designers like paper cones, for instance, and cost has absolutely nothing to do with that preference.
My advice is to just use them and enjoy the results, this is supposed to be fun, not a form of self inflicted neurosis.
Best Regards,
TerryO
NepaEric said:
Cheap as in inexpensive. MCM has been selling tons of these Aluminum drivers for more than a decade. I don't know too many experienced speaker builders that haven't done a speaker design using them sometime in the past. They aren't the ultimate driver, but they look nice and are fairly forgiving for metal cone drivers. In the real world their power handling ability is fine for most home environments. Remember, that for most people, including me, they're a good driver start out with and can give very satisfactory results.
Usually, expensive drivers use exotic materials, have excellent power handling ability, cast baskets, greater x-max, blah, blah blah....
The question is, do they sound better? That tends to be a sticky question, as it really depends on what you're looking for. There are many "cheap" drivers that sound just fine within their design limits, and in fact may sound just as good or better than the exotics, if used in a "normal" situation. Lots of experienced designers like paper cones, for instance, and cost has absolutely nothing to do with that preference.
My advice is to just use them and enjoy the results, this is supposed to be fun, not a form of self inflicted neurosis.
Best Regards,
TerryO
I meant "cheap" both ways (price and quality) 
if I had to chose between two, I would definitely chose da175, mcm's are just unacceptably ugly 🙂
if I had to chose between two, I would definitely chose da175, mcm's are just unacceptably ugly 🙂
MisterTwister said:I meant "cheap" both ways (price and quality)
if I had to chose between two, I would definitely chose da175, mcm's are just unacceptably ugly 🙂
MT,
I personally don't think the MCM's are ugly, although they'll certainly never win a contest in industrial design.
As for quality... Well, there's a reason that they're inexpensive, but I usually do enough mods to almost any driver I use that most of any perceived shortcomings are addressed. I suppose that if the time taken for this were factored in, then it's more of a toss-up.
One very "real" reason that these inexpensive drivers aren't used commercially is that there can be unit to unit variability that would be unacceptable for mass production. I might note that many of the more expensive drivers fall down in this area as well, at least as far as their advertised T/S vs. measured specs are concerned.
It's all about which compromises we're willing to accept. I currently have a box (or two) of magnesium mid ranges, as well as woofers, and they're fine, custom built drivers that aren't available to the public, but they aren't "that" much better, that I'd turn up my nose to the MCM drivers.
However YMMV...😉
Best Regards,
TerryO
I'm going to build these- drivers en route
As I mentioned previously, I already have the MCM drivers. The Daytons are on the way. I'm not going to waste these drivers. Nor am I going to sweat this. Like Terry said, this is not supposed to be a form of self-inflicted neurosis. Terry has been very helpful on this subject, here, and in another forum. As was Wolf, Paul K, Paul S, John Stockman, as well as a handful of others. Many Thanks! I've done enough study on this topic. It's time for me to get busy on the cabinets.
I've seen enough information on the web suggesting these drivers are not bad for the price. I don't doubt one bit of what Terry says about these drivers. Time and again I have had experience buying lower priced products, both speakers and otherwise, and gotten excellent results. Often I have bought higher priced ones only to be sadly disappointed in finding them to be inferior to lower priced alternatives. You don't necessarily always, "get what you pay for, " I've found.
My brother seems to like the MCM's in his own personal HT, and he is a custom autosound professional, who buys many products of different price tiers regularly. He knows the market and makes wise choices, often times for cost/benefit ratio reasons. If I'd had signifigantly more in my discretionary, monetary budget for such a project, perhaps I might have opted for Focals, ScanSpeak, Morel, Seas, or something, "more exotic." Keep in mind: I got everything except the Dayton drivers for a minimal cost or free. The Daytons only cost $18 a piece + shipping. So I call this smart. These MCM units were leftover stock my brother had laying around from an A/V job. Most of the material I have read suggest these will do well for my application. I am only looking to power these with a Marantz HT receiver. My other, main system, which is primarily Carver separates might be another story.
My main questions were primarily as to whether these units modeled well in a TL, and to see if anyone knew of any proven TL designs around either of these woofers. I also was inquiring in reference to other opinions about TL designs in general.
Part of the fun in all of this is anticipation of the result and enjoyment that comes from the satisfaction of building it myself.
Thank You,
Eric
I appreciate your replies. Thank you, Terry, once again for your wisdom and guidance.
As I mentioned previously, I already have the MCM drivers. The Daytons are on the way. I'm not going to waste these drivers. Nor am I going to sweat this. Like Terry said, this is not supposed to be a form of self-inflicted neurosis. Terry has been very helpful on this subject, here, and in another forum. As was Wolf, Paul K, Paul S, John Stockman, as well as a handful of others. Many Thanks! I've done enough study on this topic. It's time for me to get busy on the cabinets.
I've seen enough information on the web suggesting these drivers are not bad for the price. I don't doubt one bit of what Terry says about these drivers. Time and again I have had experience buying lower priced products, both speakers and otherwise, and gotten excellent results. Often I have bought higher priced ones only to be sadly disappointed in finding them to be inferior to lower priced alternatives. You don't necessarily always, "get what you pay for, " I've found.
My brother seems to like the MCM's in his own personal HT, and he is a custom autosound professional, who buys many products of different price tiers regularly. He knows the market and makes wise choices, often times for cost/benefit ratio reasons. If I'd had signifigantly more in my discretionary, monetary budget for such a project, perhaps I might have opted for Focals, ScanSpeak, Morel, Seas, or something, "more exotic." Keep in mind: I got everything except the Dayton drivers for a minimal cost or free. The Daytons only cost $18 a piece + shipping. So I call this smart. These MCM units were leftover stock my brother had laying around from an A/V job. Most of the material I have read suggest these will do well for my application. I am only looking to power these with a Marantz HT receiver. My other, main system, which is primarily Carver separates might be another story.
My main questions were primarily as to whether these units modeled well in a TL, and to see if anyone knew of any proven TL designs around either of these woofers. I also was inquiring in reference to other opinions about TL designs in general.
Part of the fun in all of this is anticipation of the result and enjoyment that comes from the satisfaction of building it myself.
Thank You,
Eric
I appreciate your replies. Thank you, Terry, once again for your wisdom and guidance.
Great Things! Terry and friends
Hi to all. Great things are happening as this project goes forward! Just wanted to keep you all abreast of the tremendous progress being made with this TL project. Thanks to all. Cabinets nearly complete. Design is coming together nicely. Many thanks to TerryO, Paul K and Pete S
Best Regards,
Eric
Hi to all. Great things are happening as this project goes forward! Just wanted to keep you all abreast of the tremendous progress being made with this TL project. Thanks to all. Cabinets nearly complete. Design is coming together nicely. Many thanks to TerryO, Paul K and Pete S
Best Regards,
Eric
Re: Great Things! Terry and friends
Eric,
You sure don't let the grass grow under your feet. How about a sneak preview of what you're doing? The nearly completed cabinets are for the MCM's? What are the projected dimensions and bass frequency cut-off? Are you planning on paint, veneer or ????
I'll bet that they'll not only turn out well, but that they'll amaze everyone that listens to them.
I've never built a speaker that sounded bad, although some were much better that others 😉
Keep us posted on your progress.
Best Regards,
TerryO
NepaEric said:
Eric,
You sure don't let the grass grow under your feet. How about a sneak preview of what you're doing? The nearly completed cabinets are for the MCM's? What are the projected dimensions and bass frequency cut-off? Are you planning on paint, veneer or ????
I'll bet that they'll not only turn out well, but that they'll amaze everyone that listens to them.
I've never built a speaker that sounded bad, although some were much better that others 😉
Keep us posted on your progress.
Best Regards,
TerryO
You got it, Terry!
Sent it out in your e-mail, Terry. They are 1st phase construction pics. Hope you enjoy.
Eric
Sent it out in your e-mail, Terry. They are 1st phase construction pics. Hope you enjoy.
Eric
Eric, is it possible to post your progress for the rest of us to see? I think other people would be interested too, including myself. I have looked at the same drivers and yes wondered what kind of possibilites they could initiate. Cheap TL, sounds wonderful. Please keep us posted.
Yes, I'd be happy to post results and pics.
As soon as I can get my photobucket here working. I'm having trouble with my computer downloading Adobe Flash player, which allows you to upload pictures.
Anyway, the project is going well. Will post more information as soon as possible.
Cheers,
Eric
As soon as I can get my photobucket here working. I'm having trouble with my computer downloading Adobe Flash player, which allows you to upload pictures.
Anyway, the project is going well. Will post more information as soon as possible.
Cheers,
Eric
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