Building on the open baffle design I created earlier, quite successful in its own way, once again I started musing about another design, this one with a large bass driver, using low cost components and easy to build.
The current design is a result of many influences: first of all the rising and not inconsiderable cost of speaker drivers compared to a complete used speaker set: as low as $10 per pair for a vintage Sony or other brand. Given these costs it simply does not make sense to build one. The other driver, if I may call it that, is the combination of an equalizer on my music player (Musicolet) and the Sony XB10 Bluetooth speaker pictured. It is only after a some time that I began to appreciate the little speaker's ability to reproduce voices and the mid-range well, and bass, and, with some equalizer adjustments, a balanced clear sound across the audible range, with all the sounds being heard. Could a small speaker really produce such bass? Well hes, due to some passive radiator arrangement within, still it did not change the size of it.
Preferring two speakers, even two left channel speakers hooked up in series to a single mono source, I set out to design another set of speakers, with some new features.
For reference, here are my Desktop Open Baffles (sadly, dismantled) and my Sony BT Speaker.
The current design is a result of many influences: first of all the rising and not inconsiderable cost of speaker drivers compared to a complete used speaker set: as low as $10 per pair for a vintage Sony or other brand. Given these costs it simply does not make sense to build one. The other driver, if I may call it that, is the combination of an equalizer on my music player (Musicolet) and the Sony XB10 Bluetooth speaker pictured. It is only after a some time that I began to appreciate the little speaker's ability to reproduce voices and the mid-range well, and bass, and, with some equalizer adjustments, a balanced clear sound across the audible range, with all the sounds being heard. Could a small speaker really produce such bass? Well hes, due to some passive radiator arrangement within, still it did not change the size of it.
Preferring two speakers, even two left channel speakers hooked up in series to a single mono source, I set out to design another set of speakers, with some new features.
For reference, here are my Desktop Open Baffles (sadly, dismantled) and my Sony BT Speaker.
Attachments
General design :
The speaker consists of the sides needed to house the woofer/midrange, tweeter and the woofer on the upper surface (1 speaker only). The lower side is for support, these speakers can be placed on a desktop or possibly wall mounted. Open baffle speakers are best not mounted directly on the wall: a space of 20 cm or more between the rear of the driver and the wall improves sound considerably.
Next: choosing a mid range, tweeter and woofer.
The speaker consists of the sides needed to house the woofer/midrange, tweeter and the woofer on the upper surface (1 speaker only). The lower side is for support, these speakers can be placed on a desktop or possibly wall mounted. Open baffle speakers are best not mounted directly on the wall: a space of 20 cm or more between the rear of the driver and the wall improves sound considerably.
Next: choosing a mid range, tweeter and woofer.
Attachments
an open baffle/dipole speaker will have a very deep null at 90deg off-axis, usually parallel with the edge of the baffle.
that's the purpose actually, to reduce unwanted reflections from off-axis radiation.
if you mount the woofer horizontally that null will be directed right at your ear.
that's the purpose actually, to reduce unwanted reflections from off-axis radiation.
if you mount the woofer horizontally that null will be directed right at your ear.
Yes thanks. so then where to mount the woofer, and more importantly, is there a mid/woofer plus tweeter combination in an open baffle that will sound great with proper equalization? That is the question here.
It's hard to design a tiny open baffle speaker. The physics of the design push you towards 3+ ways and large bass drivers to overcome the cancellations that increase rapidly with lower frequencies. And 20cm placement from the walls might be acceptable with the mids but will play havoc with the bass response.
If you want desktop small, I would consider a sealed sub-bass module and a separate mid-woof/tweeter on an open baffle. You could look at the Aurasound NSW2 wich is a 2" full-range with a unique magnet that is open to the rear, unlike most "normal" tweeters. And it could cross very low (well under 1000Hz I think) to a 6" or 8" woofer. Are you planning to use active filters with DSP or passive crossovers? Active makes an open baffle design much easier.
Also, check out the Pluto design from Sigfried Linkwitz. Not an open baffle but an omnidirectional that might give you the open and spacious sound you desire in a desktop friendly package if you make the mid-woofer enclosure small. Lots of DIY builds that use that design principle. BTW, it uses a woofer placed horizontally like you have proposed but it is in a sealed enclosure.
Hopefully another member can chime in here with more suggestions.
If you want desktop small, I would consider a sealed sub-bass module and a separate mid-woof/tweeter on an open baffle. You could look at the Aurasound NSW2 wich is a 2" full-range with a unique magnet that is open to the rear, unlike most "normal" tweeters. And it could cross very low (well under 1000Hz I think) to a 6" or 8" woofer. Are you planning to use active filters with DSP or passive crossovers? Active makes an open baffle design much easier.
Also, check out the Pluto design from Sigfried Linkwitz. Not an open baffle but an omnidirectional that might give you the open and spacious sound you desire in a desktop friendly package if you make the mid-woofer enclosure small. Lots of DIY builds that use that design principle. BTW, it uses a woofer placed horizontally like you have proposed but it is in a sealed enclosure.
Hopefully another member can chime in here with more suggestions.
There is a large volume of relevant information in the thread listed here:
https://www.diyaudio.com/community/...-design-your-own-speaker-from-scratch.332688/
which I will comment on.
https://www.diyaudio.com/community/...-design-your-own-speaker-from-scratch.332688/
which I will comment on.
Thanks tommus
I have already designed and built and tested a small open baffle speaker, with a 5 inch or so driver and a tweeter, pictured above. I have also built and tested an open baffle speaker with the Realistic 40-1011 5 inch woofer, I have since given them away since they are 30 years old. I have purchased a set of Wharfedale Diamond 4s used and they are on their way here, and will act as a reference speaker. I have also compared my speakers - the open baffle ones - against the large Sony ES floor standers and the Sony XBS Bluetooth speaker.
What my open baffle speakers lack is bass. I have briefly turned up the bass on the amplifier for the larger open baffles and they sounded acceptable, meaning I could listen to them forever if not for many years to come. I will be putting together the drivers and testing them in a real setting to check how they sound. What I lacked was not the successful design but the finish of the speakers and the drive to complete them.
The Aurasond looks good, at $22 is a possibility. I am counting on using passive crossovers to keep out unsuitable frequencies, unsuitable for each driver that is, and also software equalization which has proven very successful with by BT speaker. Is this what you mean by active?
Ah the Pluto😱f course. One huge advantage of the Pluto is that the speaker can be built using a rolled sheet of plywood, easy to build, but supported at each end, and takes care of the enclosure in one fell swoop. The bass driver can be mounted horizontally and the enclosure can be ported to obtain be best best, experimentation should be quite interesting. The tweeter of course will go on top, however I have thought of the idea of a horizontally mounted, downward firing tweeter with a cone underneath for 360 degree dispersion. Someone else had come up with the idea though.
I have already designed and built and tested a small open baffle speaker, with a 5 inch or so driver and a tweeter, pictured above. I have also built and tested an open baffle speaker with the Realistic 40-1011 5 inch woofer, I have since given them away since they are 30 years old. I have purchased a set of Wharfedale Diamond 4s used and they are on their way here, and will act as a reference speaker. I have also compared my speakers - the open baffle ones - against the large Sony ES floor standers and the Sony XBS Bluetooth speaker.
What my open baffle speakers lack is bass. I have briefly turned up the bass on the amplifier for the larger open baffles and they sounded acceptable, meaning I could listen to them forever if not for many years to come. I will be putting together the drivers and testing them in a real setting to check how they sound. What I lacked was not the successful design but the finish of the speakers and the drive to complete them.
The Aurasond looks good, at $22 is a possibility. I am counting on using passive crossovers to keep out unsuitable frequencies, unsuitable for each driver that is, and also software equalization which has proven very successful with by BT speaker. Is this what you mean by active?
Ah the Pluto😱f course. One huge advantage of the Pluto is that the speaker can be built using a rolled sheet of plywood, easy to build, but supported at each end, and takes care of the enclosure in one fell swoop. The bass driver can be mounted horizontally and the enclosure can be ported to obtain be best best, experimentation should be quite interesting. The tweeter of course will go on top, however I have thought of the idea of a horizontally mounted, downward firing tweeter with a cone underneath for 360 degree dispersion. Someone else had come up with the idea though.
So Wintermute has a list of suggestions which are useful and will help finalize the design:
Step 1. Determine your basic needs.
This may sound easy enough but it can be quite a difficult task. There are many things that you need to consider here.
Things to think about:
Is SAF (Spouse Appreciation Factor) something you need to consider?
Yes. Open baffles will be covered with grille cloth to make a box
What are your space constraints (may not be relevant if SAF above is a strong factor). Hoffman’s Iron law says you can only have 2 out of the following three things: 1) Bass Extension, 2) Efficiency, 3) A small enclosure. If space is a constraint then you are going to have to sacrifice Bass
2 and 3
How loud do they need to play?
75 to 85 db
How will I use them (this should maybe have come before the above point).
Music: soft rock, pop, EDM, Jazz
What sort of amplification are you planning to use? Low power valve amps will tend to dictate that you go for high sensitivity, but if you have high powered solid state amplification then sensitivity will be less of an issue, but power handling might be more important.
300 mW to 2 Watts
What sort of Box (or lack thereof) do you want? This may seem like a simple question at first,
No Box
What sort of polar pattern do I want?
I will take my chances
Will I build the cabinets (assuming you have cabinets!) myself or pay someone else to do it? This will have an impact on the overall cost of building the speakers.
Build myself or purchase a "wooden BT speaker " from Ali express and modify these. Drivers included.
Do I have all of the tools necessary to design and build these speakers?
On line MS excel is an option and it is free. No other tools
Do you plan to do a passive crossover or an active crossover? Don't fall into the trap of thinking that an active crossover will be much easier. If you want to do the crossover right it is going to be a lot of work whether you go passive or active.
Passive crossover consisting or a capacitor and an inductor. That is it. The rest will be software equalization.
Perhaps most importantly. What is your budget?
$40 per pair. Even then it is extremely difficult to compete with used speaker market prices.
If you put a driver on an open baffle, the sound emitted from the front of the cone is opposite in polarity to the sound from the back. the lower and longer the wavelength is, the more anti-phase energy will wrap around the sides and cancel itself out. so it's an unfortunate fact that the low end of a dipole driver will roll off at 18db per octave, consigning you to an ever escalating arms race of baffle size, cone diameter and Xmax to get incrementally more low end SPL.
But that roll off zone is the most linear region of frequency and phase response in the drivers passband so you need to use all of it until you run out of excursion. DSP filtering and EQ on each driver with a dedicated amplifier channel (but not global system EQ) can compensate for the low end roll off of each drive unit (and also create perfect high order crossover filters) So a truly active system with separate amplifier channels and DSP will let you get the maximum bandwith and output from each driver. IMO it's masochistic to do this with passive crossovers. But you can do it if you choose the parameters wisely and use large, sensitive drivers. The design below is an example but it's not a desktop speaker. This points again to using a monopole woofer. And I doubt 2 watts per channel is going to give you the output needed, after you account for the dipole loss compensation and other EQ.
https://www.diyaudio.com/community/...nsive-ob-project.110583/page-125#post-6507949
However, open baffle bass is a unique listening experience and well suited for the music you listen to. I don't know if anyone here has done it, but you could mount the woofers horizontally in the desktop and the desk would act as a quasi-infinite baffle, giving you enough low end support to get full-range bass extension at decent volumes. Make a frame and small baffle to fly the tweeter above the woofer, Pluto style, directed at your listening position.
But that roll off zone is the most linear region of frequency and phase response in the drivers passband so you need to use all of it until you run out of excursion. DSP filtering and EQ on each driver with a dedicated amplifier channel (but not global system EQ) can compensate for the low end roll off of each drive unit (and also create perfect high order crossover filters) So a truly active system with separate amplifier channels and DSP will let you get the maximum bandwith and output from each driver. IMO it's masochistic to do this with passive crossovers. But you can do it if you choose the parameters wisely and use large, sensitive drivers. The design below is an example but it's not a desktop speaker. This points again to using a monopole woofer. And I doubt 2 watts per channel is going to give you the output needed, after you account for the dipole loss compensation and other EQ.
https://www.diyaudio.com/community/...nsive-ob-project.110583/page-125#post-6507949
However, open baffle bass is a unique listening experience and well suited for the music you listen to. I don't know if anyone here has done it, but you could mount the woofers horizontally in the desktop and the desk would act as a quasi-infinite baffle, giving you enough low end support to get full-range bass extension at decent volumes. Make a frame and small baffle to fly the tweeter above the woofer, Pluto style, directed at your listening position.
This is not possible at the moment, but the quick open baffle with a large driver is an interesting future option.
Anyone used a grille cloth open baffle to make it look like a box speaker without affecting sound? WAF is the driver here.
The search for the woofer has begun...
https://www.parts-express.com/GRS-5PF-8-5-1-4-Paper-Cone-Foam-Surround-Woofer-292-405
OR
https://www.parts-express.com/6-1-2-Poly-Cone-Woofer-4-Ohm-299-609
https://www.parts-express.com/GRS-5PF-8-5-1-4-Paper-Cone-Foam-Surround-Woofer-292-405
OR
https://www.parts-express.com/6-1-2-Poly-Cone-Woofer-4-Ohm-299-609
I need to get upto speed on DSP. Analog and digital equalization I am familiar with. Is digital equalization DSP?
OK so this makes it clearer: DSP
Allows for changing the phase of your audio signal between speakers
Allows you to equalize each channel
Allows you to create a digital crossover for each channel
Sounds very useful.
Anything else?
Allows for changing the phase of your audio signal between speakers
Allows you to equalize each channel
Allows you to create a digital crossover for each channel
Sounds very useful.
Anything else?
The problem with satellite sub-woofer systems - I was listening to one in the store the other day - is that it is inconvenient to place the woofer on the floor. Two speakers will work out fine, each mounted on a wall with the correct height and angle, but where to place the sub-woofer - in between?
I came up with the idea of two speakers - the satellites speakers - mounted on the walls - these could be full range or mid-range + tweeter, and the sub-woofer mounted directly below, also on the wall, as it was a part of the main speaker, connected by a sort of invisible tower. The weight of the satellite speakers is a concern, by separating them from the heavy woofer cone, they can be mounted easily higher up.
One sub-woofer box could be used, the other one a dummy - a space for storing CDs or DVDs or other things.
I came up with the idea of two speakers - the satellites speakers - mounted on the walls - these could be full range or mid-range + tweeter, and the sub-woofer mounted directly below, also on the wall, as it was a part of the main speaker, connected by a sort of invisible tower. The weight of the satellite speakers is a concern, by separating them from the heavy woofer cone, they can be mounted easily higher up.
One sub-woofer box could be used, the other one a dummy - a space for storing CDs or DVDs or other things.
Selecting drivers: should be interesting to try these out:
https://www.parts-express.com/YDT613-68-2-1-4-x-5-Paper-Cone-Full-Range-Speaker-8-Ohm-77-289-2314
https://www.parts-express.com/BN83-...-Cone-Full-Range-Speaker-8-Ohm-11-16-289-2222
https://www.parts-express.com/BN83-...-Cone-Full-Range-Speaker-8-Ohm-11-16-289-2222
https://www.parts-express.com/YDT04...Cone-Full-Range-Speaker-16-Ohm-50-57-289-2266
https://www.amazon.com/Visaton-R10S-Full-Range-Speaker/product-reviews/B003A66SSE
https://www.parts-express.com/YDT613-68-2-1-4-x-5-Paper-Cone-Full-Range-Speaker-8-Ohm-77-289-2314
https://www.parts-express.com/BN83-...-Cone-Full-Range-Speaker-8-Ohm-11-16-289-2222
https://www.parts-express.com/BN83-...-Cone-Full-Range-Speaker-8-Ohm-11-16-289-2222
https://www.parts-express.com/YDT04...Cone-Full-Range-Speaker-16-Ohm-50-57-289-2266
https://www.amazon.com/Visaton-R10S-Full-Range-Speaker/product-reviews/B003A66SSE
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A 5" woofer combined with the tweeters I already have would be the best design for my purposes. I looked at full range speakers, however a dedicated woofer with a tweeter will give me the best chance of approaching the performance of the bookshelf speakers I have. PC speakers by themselves are capable of producing good music but not bass, so this is where the woofer will improve the range and performance of the system.
So we go on to Parts Express > woofers and sort by price: Shipping is the same cost for 1 or more items so better order more stuff...
https://www.parts-express.com/speak...anges-tweeters/woofers?order=pricelevel12:asc
4" Treated Paper Cone Woofer 16 Ohm
22 Reviews
BUYOUT$5.80
In Stock
Part# 299-320
6-1/2" Poly Cone Midbass Woofer 4 Ohm
248 Reviews
$6.98
In Stock
Part# 299-609
SHIPPING $8.95
Additional Shipping Options & Tax Calculated At Checkout
So we go on to Parts Express > woofers and sort by price: Shipping is the same cost for 1 or more items so better order more stuff...
https://www.parts-express.com/speak...anges-tweeters/woofers?order=pricelevel12:asc
4" Treated Paper Cone Woofer 16 Ohm
22 Reviews
BUYOUT$5.80
In Stock
Part# 299-320
6-1/2" Poly Cone Midbass Woofer 4 Ohm
248 Reviews
$6.98
In Stock
Part# 299-609
SHIPPING $8.95
Additional Shipping Options & Tax Calculated At Checkout
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Options. I may have settled on a small 3" woofer coupled with a tweeter. Those woofers have some capacity for bass that can be boosted with EQ.
https://www.diyaudio.com/community/threads/cheap-and-fast-ob-literally.249984/
OR
New 1PCS origin Germany Nubert 6.5'' Super Bass Woofer Speaker Driver Unit Double Magnet Casting Aluminum Frame 8ohms
Ships From:China
US $3.40
https://www.diyaudio.com/community/threads/cheap-and-fast-ob-literally.249984/
OR
New 1PCS origin Germany Nubert 6.5'' Super Bass Woofer Speaker Driver Unit Double Magnet Casting Aluminum Frame 8ohms
Ships From:China
US $3.40
Placing tiny open baffle satelites on the wall is a mistake. Too many reflections interacting with front signal. Small closed bookshelf would be better, but still with lots of compromises.
Not sure what you are after.
You obviously do not understand the concept of satelites and subwoofer. Once proper crossover for subwoofer is selected and its high pass filter is proper slope, you will not be able to localize, or hear, where the sub is.
Theoretically you can place it anywhere, but each placement will have different response. Mainly due to wall reinforcement.
Neat trick is to place the sub in your listening chair and then crawl around the room and find the most natural sounding bass, and place the sub there. Reciprocity.
Theoretically you can place it anywhere, but each placement will have different response. Mainly due to wall reinforcement.
Neat trick is to place the sub in your listening chair and then crawl around the room and find the most natural sounding bass, and place the sub there. Reciprocity.
