Hi everybody,
This is going to be my first speaker project however I did not want to build a conventional 2-way design as is normally suggested as a first project. I wanted to build something a little larger, more exotic and with low-end frequency response that that cannot easily be built into a 2-way speaker.
Sorry about the length of the post but I tend to do a lot of research, and learn as much as I can, before I start tossing out questions and ideas. So this is really a very condensed and summarized version of my evolved thoughts on building speakers after the last month of reading. I should also thank all the people on this board for the wealth of knowledge that I have been able to find here. The information gathered here has been one of many invaluable resources on loudspeaker design.
My current thoughts on design:
To build a 3-way tower using 4 drivers per speaker and consisting of a tweeter, midrange and two woofers. I would like to mount the woofers in a sealed push/pull and/or isobarik configuration to reduce driver distortion. I'm not really sure which woofer setup I favor so hopefully you guys can give me some advice on that. I'm looking mostly at 10" drivers as I have a set of speakers with 8" drivers and they don’t quite do it for me with some of my music collection. Although, I assume most of the people are on this forum are similar minded to me in their preference of bass I figure I should throw out my preferences anyways. I'm NOT interested in loud, boomy, rumble your house bass but in tight, undistorted base that has a flat low frequency response, which hopefully is reflected in my design choices.
The midrange and the tweeter I would like to mount in an open baffle configuration. I have read some discussion on baffle size for open baffle setups, however this has always pertained to woofers and increasing low frequency. Is baffle size something I should be considering when dealing with midrange and tweeters? My current plan is to try to keep the baffle small with a rounded profile that shadows the shape of the drivers to hopefully minimize diffraction.
I am trying to keep the cost of drivers low and preferably no larger than $300. This really is the part of the design that is holding me up due to the number of drivers I would like to use (eight).For a tweeter I am planning on using vifa or Peerless as there tweeters are very inexpensive and I've head good things about both. I haven’t looked carefully into specific tweeters as I have the largest choice of tweeters in my price range and therefore am going to pick this after I have chosen my midrange and woofers.
I consider midrange to be very important due the frequencies it must cover, therefore, I don’t want to completely cheap out on midrange drivers. I was hoping to get some suggestions of decent midrange drivers that would perform well in an open baffle configuration. Speaking of, are there any driver parameters that need to be considered when selecting drivers for an open baffle speaker?
The woofers really are the biggest cash sink and since I need 4 of them this is really where I think I need to cut my costs. I've done some messing around with WinISD and most of the inexpensive drivers I've been able to find. But the nicest frequency response I've been able to develop so far has been with the Goldwood GW-1038 10" and it happens to be one of the less expensive drivers I've seen. With a large sealed box and isobarik configuration I am able to generate a pretty nice frequency response with a gradual roll-off slope, an F3 of 25HZ, Qtc of 0.94 and the dB Peak is still under one. I had wanted to get a Qtc close to 0.707 however it seems that this driver is incapable of reaching such a level. I realize the specification game is really only part of the picture so I was wondering if someone has had any experience with this driver. Also, I have not been able to find any specifications more detailed than what is available from PartsExpress and it would be nice to see a frequency response graph of the woofer.
I would love to hear all your thoughts on my current design plans. I am a little concerned that my budget is too small for this project. It would really be a shame if despite my best design efforts I built a mediocre to poor set of speakers mostly due to a lacking of quality drivers. If this seems to be the general consensus I may have to rethink some of my design or try to find a way to increase my project's budget.
Anyways, thanks for all of your help. I look forwards to hearing all of your thoughts and ideas.
-Street
This is going to be my first speaker project however I did not want to build a conventional 2-way design as is normally suggested as a first project. I wanted to build something a little larger, more exotic and with low-end frequency response that that cannot easily be built into a 2-way speaker.
Sorry about the length of the post but I tend to do a lot of research, and learn as much as I can, before I start tossing out questions and ideas. So this is really a very condensed and summarized version of my evolved thoughts on building speakers after the last month of reading. I should also thank all the people on this board for the wealth of knowledge that I have been able to find here. The information gathered here has been one of many invaluable resources on loudspeaker design.
My current thoughts on design:
To build a 3-way tower using 4 drivers per speaker and consisting of a tweeter, midrange and two woofers. I would like to mount the woofers in a sealed push/pull and/or isobarik configuration to reduce driver distortion. I'm not really sure which woofer setup I favor so hopefully you guys can give me some advice on that. I'm looking mostly at 10" drivers as I have a set of speakers with 8" drivers and they don’t quite do it for me with some of my music collection. Although, I assume most of the people are on this forum are similar minded to me in their preference of bass I figure I should throw out my preferences anyways. I'm NOT interested in loud, boomy, rumble your house bass but in tight, undistorted base that has a flat low frequency response, which hopefully is reflected in my design choices.
The midrange and the tweeter I would like to mount in an open baffle configuration. I have read some discussion on baffle size for open baffle setups, however this has always pertained to woofers and increasing low frequency. Is baffle size something I should be considering when dealing with midrange and tweeters? My current plan is to try to keep the baffle small with a rounded profile that shadows the shape of the drivers to hopefully minimize diffraction.
I am trying to keep the cost of drivers low and preferably no larger than $300. This really is the part of the design that is holding me up due to the number of drivers I would like to use (eight).For a tweeter I am planning on using vifa or Peerless as there tweeters are very inexpensive and I've head good things about both. I haven’t looked carefully into specific tweeters as I have the largest choice of tweeters in my price range and therefore am going to pick this after I have chosen my midrange and woofers.
I consider midrange to be very important due the frequencies it must cover, therefore, I don’t want to completely cheap out on midrange drivers. I was hoping to get some suggestions of decent midrange drivers that would perform well in an open baffle configuration. Speaking of, are there any driver parameters that need to be considered when selecting drivers for an open baffle speaker?
The woofers really are the biggest cash sink and since I need 4 of them this is really where I think I need to cut my costs. I've done some messing around with WinISD and most of the inexpensive drivers I've been able to find. But the nicest frequency response I've been able to develop so far has been with the Goldwood GW-1038 10" and it happens to be one of the less expensive drivers I've seen. With a large sealed box and isobarik configuration I am able to generate a pretty nice frequency response with a gradual roll-off slope, an F3 of 25HZ, Qtc of 0.94 and the dB Peak is still under one. I had wanted to get a Qtc close to 0.707 however it seems that this driver is incapable of reaching such a level. I realize the specification game is really only part of the picture so I was wondering if someone has had any experience with this driver. Also, I have not been able to find any specifications more detailed than what is available from PartsExpress and it would be nice to see a frequency response graph of the woofer.
I would love to hear all your thoughts on my current design plans. I am a little concerned that my budget is too small for this project. It would really be a shame if despite my best design efforts I built a mediocre to poor set of speakers mostly due to a lacking of quality drivers. If this seems to be the general consensus I may have to rethink some of my design or try to find a way to increase my project's budget.
Anyways, thanks for all of your help. I look forwards to hearing all of your thoughts and ideas.
-Street
hmm i dont know about goldwood,even if the specs are nice, you never know how it sounds til you buy it.
Notice there is no distortion measurements,but a jBL such as my 15 does have THD measurements at 60wat input.
i would stick with the treid and proven vifas such as 8inch,i wouldnt go any larger,you need the midranger to be non beamy.
even a vifa 6.5inch,perhaps a kit or set of speakers,with crossovers to avoid fiddling for hours + magic lol to get it working nice?/
im a sub guy at moment not main speakers,yet..
im sure il evolve.
if u have a decent sub in the first place,you wont need isobarik.i find its best for cheap crap woofers but thats mainly all.
planet10 has made isobariks i think.
so you want a small sub smooth sub? go for peerless 10inch XLS it is very tiny with a PR,or a shiva in 54L sealed,or similar dont forget efficiency with not much power you need a decent rating.
i would go for a ported box,tuned to say 40hz, with a nice roll off SIMILAR to sealed box,but not quite that bad, i think it will be better sounding and smoother,also it may help incase room gain boosts lower Frequencies,perhaps like a SBB4,-modified <alignment that winisd pro does.>
since no one has replied i thought i would share my 2cents
Notice there is no distortion measurements,but a jBL such as my 15 does have THD measurements at 60wat input.
i would stick with the treid and proven vifas such as 8inch,i wouldnt go any larger,you need the midranger to be non beamy.
even a vifa 6.5inch,perhaps a kit or set of speakers,with crossovers to avoid fiddling for hours + magic lol to get it working nice?/
im a sub guy at moment not main speakers,yet..
im sure il evolve.
if u have a decent sub in the first place,you wont need isobarik.i find its best for cheap crap woofers but thats mainly all.
planet10 has made isobariks i think.
so you want a small sub smooth sub? go for peerless 10inch XLS it is very tiny with a PR,or a shiva in 54L sealed,or similar dont forget efficiency with not much power you need a decent rating.
i would go for a ported box,tuned to say 40hz, with a nice roll off SIMILAR to sealed box,but not quite that bad, i think it will be better sounding and smoother,also it may help incase room gain boosts lower Frequencies,perhaps like a SBB4,-modified <alignment that winisd pro does.>
since no one has replied i thought i would share my 2cents
with $300 to spend on drivers you are going to be challenged. i however would prefer to spend on smaller drivers of higher quality. a sample break u would be....
2 x tweeters $50
2 x 6" midbass $100
4 x 8/10" woofers $150
at these prices we are not considering vifa or peerless. they might be too expensive. dayton might be more affordable.
2 x tweeters $50
2 x 6" midbass $100
4 x 8/10" woofers $150
at these prices we are not considering vifa or peerless. they might be too expensive. dayton might be more affordable.
um.... if you have never designed a speaker before, a 3-way, and especially one with an open baffle will not be successfull. Will Not.
Build Wayne J's Veritas, and you will be happy.
I cant get to the link right now, but you can find it at www.speakerbuilder.net
I can assure you that it is an outstanding design, with outstanding sound quality.
I can also assure you that you will not succeed in making a nice sounding speaker, much less one with a flat frequency response (there are many speakers with flat frequency responses that sound bad).
-Paul Hilgeman
Build Wayne J's Veritas, and you will be happy.
I cant get to the link right now, but you can find it at www.speakerbuilder.net
I can assure you that it is an outstanding design, with outstanding sound quality.
I can also assure you that you will not succeed in making a nice sounding speaker, much less one with a flat frequency response (there are many speakers with flat frequency responses that sound bad).
-Paul Hilgeman
Street: I´m sorry, but I´d also strongly suggest you to cancel or to choose yourself a project on another level.
It´s fully possible to build a set of speakers with a very decent performance on your budget, but they won´t even resemble the project you described.
If I were you I would build a couple of nice 2w monitors with provisions for extension, at a later date, with 2 active, tower shaped subs witch would also act as stands.
It´s fully possible to build a set of speakers with a very decent performance on your budget, but they won´t even resemble the project you described.
If I were you I would build a couple of nice 2w monitors with provisions for extension, at a later date, with 2 active, tower shaped subs witch would also act as stands.
I can only 2nd navin's and Paul's comments.
Try to see through the allure of cheap drivers. If you look at the better designs using cheap drivers, they often use complex crossovers to tame the beasts, sometimes even negating the cost savings.
Also, don't be suckered in by PE's prices. Your in-your-hands cost will be much higher in The City of Champions (muhaha; sorry, couldn't hold back ). I bought 4 12" Goldwood's for my dipoles, but regret I did when I saw the final cost.
Try to see through the allure of cheap drivers. If you look at the better designs using cheap drivers, they often use complex crossovers to tame the beasts, sometimes even negating the cost savings.
Also, don't be suckered in by PE's prices. Your in-your-hands cost will be much higher in The City of Champions (muhaha; sorry, couldn't hold back
). I bought 4 12" Goldwood's for my dipoles, but regret I did when I saw the final cost.As i am really into horns and TLs i can state that a poineerB20 run full range in a TL (no crossovers) with a helper tweet rolled in at around 8Khz(takes a cap and an l-pad) will give you a near flat response and very powerful bass for the least investment.However a properly designed TL is very hard to do for a first timer.
ron
ron
Thanks for all the input. I was kinda suspecting/fearing to hear what you all have told me. So, I'm scrapping my 3-way project and looking at a 2-way design. I may try to build something similar to the design I described above once I have a little more experience under my belt and when my budget is not so constrained by things such as tuition.
I'm currently trying to decide between a MTM driver configuration and spending less money per driver or having 2 drivers per speaker and buying more expensive drivers. Anyways, I'll post my re-thought out design to make sure there are no big holes in my thinking.
Thanks again for the help and happy speaker building.
-Street
I'm currently trying to decide between a MTM driver configuration and spending less money per driver or having 2 drivers per speaker and buying more expensive drivers. Anyways, I'll post my re-thought out design to make sure there are no big holes in my thinking.
Thanks again for the help and happy speaker building.
-Street
I think that with your budget, you should look @ Vifa and Peerless for the tweeter/midbass combo, and look towards Dayton for the woofers. (I have been using some 8" Daytons for project woofers, and for $15 each they have been great, clean with deep extension) Anyway, that's my two cents, I hope it has helped. Oh, and before you start to build, make sure that you do plenty of reading and get a firm grasp of what you are wanting to do (on paper) before you turn a single screw. LATER!!!!!!!
Drewman
Drewman
i don't think there is anything wrong with a 3-way on that budget. is that $300US? doesn't sound like too little.
what i wouldn't do is bother with 2 woofers per cabinet, one will probably be enough. say per speaker:
1 dome tweeter
1 midrange, cross relatively high (200hz or more) - maybe even a dome midrange crossed higher
1 woofer (an 8" or 10")
that shouldn't break the bank. and if u get reasonable drivers, and have a sub in the system, i would go for 8"s for the woofers, no larger. there shouldn't be a need.
but this isn't coming from an expert, just someone used to being on a tight budget.
what i wouldn't do is bother with 2 woofers per cabinet, one will probably be enough. say per speaker:
1 dome tweeter
1 midrange, cross relatively high (200hz or more) - maybe even a dome midrange crossed higher
1 woofer (an 8" or 10")
that shouldn't break the bank. and if u get reasonable drivers, and have a sub in the system, i would go for 8"s for the woofers, no larger. there shouldn't be a need.
but this isn't coming from an expert, just someone used to being on a tight budget.
navin said:
I like this idea too...
Unless you are going with a proven design, try to find drivers with the flattest possible response (easier to work with).
If you like the idea of a 3 way system, maybe the way to go would be what I think of as an extended full range design: find a nice full range driver for the mid with an extended and flat response. Cross over to a tweeter at the highest frequency possible (usually where the mid starts to beam, or a little before) and cross over to a more efficient woofer on the bottom where the baffle step would normally be (kind of a built-in baffle step compensation). It seems like this type of design would be easy to tune by ear to get what you want.
BSC starts around 100hz and extend out to 1.5k these are very approx number but will suffice as a guide for narrow baffle towers using 6" drivers.
if are hoping to use the woofer for baffle step you would need a bit of approximation as the second woofer will probably kick in in the range of 300Hz.
so your mid should be able to handle a range from 100Hz out to 3k. this is where most 5 or 6" mid abss drivers excel.
given the above (I know I am not being detailed here) you are back to a 2.5 way using a 8" 6" and 1".
if are hoping to use the woofer for baffle step you would need a bit of approximation as the second woofer will probably kick in in the range of 300Hz.
so your mid should be able to handle a range from 100Hz out to 3k. this is where most 5 or 6" mid abss drivers excel.
given the above (I know I am not being detailed here) you are back to a 2.5 way using a 8" 6" and 1".
let me bit more specific.
lets assume you got a M22 and M18 and D27 from Vifa. (total cost of these 3 will be about $150 I think.)
The M18 will start to expereince BS loss around 100Hz the slope for BS is quite slow so that by 1500Hz or so the loss is only 6db. Since the slope is so slow noticeable / audible loss is around 300hz.
Hence many 2.5 way systems have the second driver operate from 300 Hz up. This is an emperical number. if you make a big inductor you can simply unwind a few rounds at a time till you feel it sounds right. At these freqs. the room is also prominent for 2 reasons (1) floor bounce - Roy Allison wrote a few papers on this and (2) the ear starts getting more sensitive at 300Hz or so.
Hence it makes a lot of sense to tune by ear. A carpeted room will be different from a marble floor.
Also if the front baffle is sloped back to time align the speakers the sound changes. You can tilt the speaker before you finish it to see what sounds best to you.
We'd all like to think (and hope) speaker building was a science unfortunately there is a bit of art in it as well. The BIGGEST advantage we DIYers have is that we can customise the speaker to our taste, room, requirements, etc... this cannot be done by most manufacturers.
A few manufacturers have realised this and offer tunable bass sectionsas this is the region where rooms tend to dominate most. mass loading (the most creative I saw was on a rear mounted Passive Radiator on an ALR Factor 2), electronic compensation (KLH, AR, Infinity etc...), tunable bass ports, etc...
BTW the more i think about it the more I like Dave's idea of a push push. The only disadvantage of this is that you can build a cabinet with curved side panels like 7V, Rob wells and a few others have done.
lets assume you got a M22 and M18 and D27 from Vifa. (total cost of these 3 will be about $150 I think.)
The M18 will start to expereince BS loss around 100Hz the slope for BS is quite slow so that by 1500Hz or so the loss is only 6db. Since the slope is so slow noticeable / audible loss is around 300hz.
Hence many 2.5 way systems have the second driver operate from 300 Hz up. This is an emperical number. if you make a big inductor you can simply unwind a few rounds at a time till you feel it sounds right. At these freqs. the room is also prominent for 2 reasons (1) floor bounce - Roy Allison wrote a few papers on this and (2) the ear starts getting more sensitive at 300Hz or so.
Hence it makes a lot of sense to tune by ear. A carpeted room will be different from a marble floor.
Also if the front baffle is sloped back to time align the speakers the sound changes. You can tilt the speaker before you finish it to see what sounds best to you.
We'd all like to think (and hope) speaker building was a science unfortunately there is a bit of art in it as well. The BIGGEST advantage we DIYers have is that we can customise the speaker to our taste, room, requirements, etc... this cannot be done by most manufacturers.
A few manufacturers have realised this and offer tunable bass sectionsas this is the region where rooms tend to dominate most. mass loading (the most creative I saw was on a rear mounted Passive Radiator on an ALR Factor 2), electronic compensation (KLH, AR, Infinity etc...), tunable bass ports, etc...
BTW the more i think about it the more I like Dave's idea of a push push. The only disadvantage of this is that you can build a cabinet with curved side panels like 7V, Rob wells and a few others have done.
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