Hi guys, first post so bare with me.
Im a second year undergrad product design student and im going to be designing some portable travel speakers that i will then make and just have a few questions.
First off, my aim is to have the highest quality sound that i can in a small space, probably hoping to have drivers that are at most 60-70mm in diameter. In such a small system is it reasonable to have a subwoofer (whats the smallest subwoofer sizes you know).
if its not plausible to have a subwoofer, how can i achieve better bass in the speakers. (i understand its never going to be possible to have amazing bass with the size constraints, but just the best possible)
I assume that it will need to be an active speaker to achieve better sound but does anyone know any ways to have high quality passive speakers?
lastly, where would be the best place to by high quality drivers that are this small? i live in australia, so somewhere that is based here or ships here is what im aiming for.
thanks guys, excuse the ignorance. if anyone has any good tips for designing travel speakers or anything i may have missed please let me know. If theres interest, i will keep you updated with the design process and end product etc.
Im a second year undergrad product design student and im going to be designing some portable travel speakers that i will then make and just have a few questions.
First off, my aim is to have the highest quality sound that i can in a small space, probably hoping to have drivers that are at most 60-70mm in diameter. In such a small system is it reasonable to have a subwoofer (whats the smallest subwoofer sizes you know).
if its not plausible to have a subwoofer, how can i achieve better bass in the speakers. (i understand its never going to be possible to have amazing bass with the size constraints, but just the best possible)
I assume that it will need to be an active speaker to achieve better sound but does anyone know any ways to have high quality passive speakers?
lastly, where would be the best place to by high quality drivers that are this small? i live in australia, so somewhere that is based here or ships here is what im aiming for.
thanks guys, excuse the ignorance. if anyone has any good tips for designing travel speakers or anything i may have missed please let me know. If theres interest, i will keep you updated with the design process and end product etc.
A subwoofer is just going to add complication. A power amp should allow you to get acceptable volume levels from small inefficient speakers, so it's probably worth the trouble. For passive speakers, you need sensitive drivers; I had a pair of 5" surface mount cheapo car speakers that I used as travel speakers that were reasonably loud. Put alligator clips on an old headphone cable and then you can test speakers in stores using your phone or MP3 player as a source.
How small is the main question. A couple of liters per speaker or a fraction of a liter? Travel speakers could mean that they'll slip into a coat pocket, or into the back of an SUV.
How small is the main question. A couple of liters per speaker or a fraction of a liter? Travel speakers could mean that they'll slip into a coat pocket, or into the back of an SUV.
Thanks dangus,
Sorry, I should've been clearer, they will be quite small. I'm wanting them to be able to fit into a jacket possible or something if possible. Or at the very least into a backpack. The overall dimensions im wanting to keep within 15^3cm. So the 5" car speakers are probably a bit big for my purposes.
im still undecided if i want to have one enclosure with 2 drivers or two seperate enclosures
what type of wattage can/should i be looking for in a speaker around 50-70mm?
Sorry, I should've been clearer, they will be quite small. I'm wanting them to be able to fit into a jacket possible or something if possible. Or at the very least into a backpack. The overall dimensions im wanting to keep within 15^3cm. So the 5" car speakers are probably a bit big for my purposes.
im still undecided if i want to have one enclosure with 2 drivers or two seperate enclosures
what type of wattage can/should i be looking for in a speaker around 50-70mm?
would something like these work well?
Celestion AN2075 2" Full Range Compact Array Driver 294-2044
Celestion AN2075 2" Full Range Compact Array Driver 294-2044
Control your directivity. Be inventive - I have seen blow-up "sub" woofers
You need to better the NXT based units I currently use: no magnets, clip together for travel, 20cm x 20cm x 2cm and about 100gms.
like these (mine were made by Sonic Impact Technologies)
(Currently available on Amazon)
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Make them folding or sliding
Teleshopping boxes. A box that you slide and make it bigger and then make it smaller for transport.
Another idea, Use the table top or whatever surfave the speakr sits on as part of the speaker enclosure. For example the suportting surafce might be one side of a horn
The face of the drivers are protected when folder up for transport but exposed when in use. The connecting plug is also hidden when folded, forcing the use to actually unfold and set up the speakers
thanks guys, excuse the ignorance. if anyone has any good tips for designing travel speakers or anything i may have missed please let me know. If theres interest, i will keep you updated with the design process and end product etc.
Teleshopping boxes. A box that you slide and make it bigger and then make it smaller for transport.
Another idea, Use the table top or whatever surfave the speakr sits on as part of the speaker enclosure. For example the suportting surafce might be one side of a horn
The face of the drivers are protected when folder up for transport but exposed when in use. The connecting plug is also hidden when folded, forcing the use to actually unfold and set up the speakers
thanks for the responses guys
theres some great ideas here that i will need to further look into. The NXT based speakers seem quite a good approach however the availability of them could be an issue, ill be looking into that further.
i also like the idea of a volume changing enclosure and i will be researching how a horn works so i can see how i could adapt that tabletop idea.
ill be beggining my concept generation in the coming days so hopefully i will have a firmer direction of where i want to go after that.
im sure ill be back soon with more questions
theres some great ideas here that i will need to further look into. The NXT based speakers seem quite a good approach however the availability of them could be an issue, ill be looking into that further.
i also like the idea of a volume changing enclosure and i will be researching how a horn works so i can see how i could adapt that tabletop idea.
ill be beggining my concept generation in the coming days so hopefully i will have a firmer direction of where i want to go after that.
im sure ill be back soon with more questions
okay so ive had an idea to make a semi portable speaker. In the sense that when plugged into a wall i will have a 2.1 system and then when i want to take the speakers travelling i can leave the subwoofer, plugged in and take out the 2 smaller drivers (which i am hoping to run off batteries) thus making them portable.
is this possible? how would i go about connecting them in a 2.1 system with 3 (or 2) different amplifiers powering the speakers?
is this possible? how would i go about connecting them in a 2.1 system with 3 (or 2) different amplifiers powering the speakers?
Hi,
You cannot become an instant loudspeaker designer. The various
tradeoffs for small battery speakers are particularly tricky. Most
of the skill required is in the electronics and understanding the
acoustics you are trying to get the electronics to make work.
If you come up with a good packaging idea, your best bet
is to cannibalise existing portable speakers for the parts.
rgds, sreten.
You cannot become an instant loudspeaker designer. The various
tradeoffs for small battery speakers are particularly tricky. Most
of the skill required is in the electronics and understanding the
acoustics you are trying to get the electronics to make work.
If you come up with a good packaging idea, your best bet
is to cannibalise existing portable speakers for the parts.
rgds, sreten.
everyone has to start somewhere though no? why just settle for the minimum? obviously there is alot to speaker design and im not going to get every little detail that i may need from this forum,im just looking for a rough direction, thats why there are many other resources on the internet that i can also use.
designing only a package is a pretty cynical view when i can try to understand how a speaker works and incorporate that too.
In a real life application with the time i have i have no doubt that there will be problems with the design (it is afterall just a concept/prototype) but if i want to continue the assignment, I could further refine it where needed.
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Hi,
You won't even scratch the surface of the knowledge needed nevermind
"get every little detail" asking asking for guidance here. I assume your
course is "design", not "engineering" and loudspeaker design is mainly
"engineering". You are way out of your depth.
Come up with a concept like "expanding" portable speakers :
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You would be quids in as a "product" designer. It addresses a
fundamental basic limitation of small speakers, the box volume.
Nobody would care if you ripped the gubbins out of a larger speaker
to build your prototype, that is not the point at all of the design.
rgds, sreten.
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i think you've misunderstood my aim for this project, im not trying to make the perfect sounding speaker for an audiophile. Im trying to get a basic understanding of speakers so i can have some background knowledge of what is plausible and what is not when making speakers.
I dont have anything against reusing another speaker i just feel that it would limit me to a certain format.
This is a design course however i do have engineering units and I will be in contact with engineers and other people that can help me with the electronics of it. As for acoustics, this is no a major concern for this design, however i would like to try and get an understanding of basic principles where possible.
I dont have anything against reusing another speaker i just feel that it would limit me to a certain format.
This is a design course however i do have engineering units and I will be in contact with engineers and other people that can help me with the electronics of it. As for acoustics, this is no a major concern for this design, however i would like to try and get an understanding of basic principles where possible.
Look up Hoffman's Iron Law (after J.A. Hoffman ) for starters.
Roughly, Hoffman's Iron Law states that the efficiency of a woofer system is directly proportional to its cabinet volume and the cube of its cutoff frequency. *
Which will bring you quickly to Thiele and Small
(*Tom Danley side stepped this once with the "servo drive" which bent some of the physics.)
Start by reading all the books you can find on the subject. Then hunt down forum, mailing list, and newsgroup postings by real speaker designers.
Play with loudspeaker modelling software to get a feel for what Hoffman's Iron Law feels like using real drivers that you could actually buy. If possible, model some commercial speakers and see how the advertised specs compare with the modelled performance.
Really, for a job like this you should hire a speaker designer first, then have a "product designer" work under them. There are an awful lot of real world products that have been designed by people with inadequate engineering knowledge, particularly when it comes to heat management. Not a consideration with low-powered speakers, but speakers do involve a slew of technical compromises plus knowledge of human hearing and the program material.
Play with loudspeaker modelling software to get a feel for what Hoffman's Iron Law feels like using real drivers that you could actually buy. If possible, model some commercial speakers and see how the advertised specs compare with the modelled performance.
Really, for a job like this you should hire a speaker designer first, then have a "product designer" work under them. There are an awful lot of real world products that have been designed by people with inadequate engineering knowledge, particularly when it comes to heat management. Not a consideration with low-powered speakers, but speakers do involve a slew of technical compromises plus knowledge of human hearing and the program material.
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Ok...the last two comments would lead to another level ( I recently looked at the PE techtalk and there's a nice diagram as a sticky thread about speaker families)
OP question is similar to what I had explained in a email exchange, a year ago. This friend of a friend is a student in Design, and after one or two mails I captured what he had in mind: the system for attaching the cable to the box...no binding posts but magnetic. I had a Monacor SPX-30 in mind. Researching further...and later , through this site I saw a project (cheap trick) for a 2.1 system employing such kind of speaker
PLUS two woofers in an enclosure....working in stereo ?? with included passive crossover AND a pair of tweeters...so a simple fullrange isn't quite adeguate for certain kind of listenings...and I would add: I agree !
OP question is similar to what I had explained in a email exchange, a year ago. This friend of a friend is a student in Design, and after one or two mails I captured what he had in mind: the system for attaching the cable to the box...no binding posts but magnetic. I had a Monacor SPX-30 in mind. Researching further...and later , through this site I saw a project (cheap trick) for a 2.1 system employing such kind of speaker
PLUS two woofers in an enclosure....working in stereo ?? with included passive crossover AND a pair of tweeters...so a simple fullrange isn't quite adeguate for certain kind of listenings...and I would add: I agree !
Hi,
Well you have to very good at joining the dots and for most that takes
a lot longer than you might think given all the misinformation out their.
FWIW electonics experts who know nothing about acoustics make
terrible speaker designers, they do "right", and completely wrong.
rgds, sreten.
http://sites.google.com/site/undefinition/diy
(see if nothing else, the excellent FAQs)
The Speaker Building Bible
Zaph|Audio
Zaph|Audio - ZA5 Speaker Designs with ZA14W08 woofer and Vifa DQ25SC16-04 tweeter
http://audio.claub.net/Simple Loudspeaker Design ver2.pdf
FRD Consortium tools guide
Designing Crossovers with Software Only
RJB Audio Projects
Jay's DIY Loudspeaker Projects
Speaker Design Works
http://www.htguide.com/forum/showthread.php4?t=28655
A Speaker project
DIY Loudspeakers
Humble Homemade Hifi
Quarter Wavelength Loudspeaker Design
The Frugal-Horns Site -- High Performance, Low Cost DIY Horn Designs
Linkwitz Lab - Loudspeaker Design
Music and Design
Great free SPICE Emulator : SPICE-Based Analog Simulation Program - TINA-TI - TI Software Folder
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