AVS Forum banner
1 - 19 of 19 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·

Hi guys,

 

I've been looking into getting a new audio system for a couple months now and am thinking DIY sounds like the way to go. I've spent quite a bit of time researching products and concepts already and am hoping to get some feedback on my ideas.

 

My goals:

-Excellent stereo sounds for music listening with relatively flat frequency response 20Hz-20kHz.

-Core would be 2.1 system of larger bookshelfs playing down to at least the level where directionality becomes difficult to discern. I'm not ruling out towers but am leaning toward keeping them off the floor.

-12"-15" high-quality sub

-Eventual center and surround speakers for 5.1 setup when desired; not as high quality or priority as stereo system

-Compactness and aesthetics at least to the extent that is tolerable to my fiance. Being able to move them to another location without enormous hassle would be a plus too.

 

The biggest uncertainty for me here is the optimal enclosure size and the related issue of whether or not to port or include passive drivers. Looking at the recommended enclosure sizes from parts-express.com gave me the impression I could keep enclosure size fairly small if I stuck to sealed enclosures. It also seems like porting makes tuning/design enough more complicated that I'd be likely to avoid pitfalls by sticking to the sealed enclosures. Given that I plan to use a pretty large subwoofer, that my main goal is not to maximize bass SPL, and that I plan to provide more than ample amplification wattage to the drivers it would seem that going with small sealed enclosures is the way to go. However, it seems that almost all the commercial and DIY designs I come across are not done as sealed enclosures, or if they are they are relatively large relative to the driver size, so I'm second-guessing myself. Will have trouble getting down to around 100Hz with 6.5" Scanspeak or Morel drivers without ports? Surely a 15" sub would get down to 20Hz fine in a sealed enclosure, right?

 

Thanks for your time and I hope this is the right place to post and that I've not made an excessive wall of text ;)  Any feedback would be very welcome.
 

·
Registered
Joined
·
8 Posts
Hey noahclem,


Check out DIY Sound Group http://www.diysoundgroup.com/ . They have a lot of DIY speaker kits and flat packs, ranging from large to fairly small drivers. I am new to DIY myself so I cannot make any specific recommendations, but you can find a lot of reviews of these designs here in this forum. Most (if not all) of these speakers are designed to play down to at least 80 Hz.


Good Luck,


LP
 

·
Registered
Joined
·
1,399 Posts
You make a good point about the size of the enclosures. I am personally sold on the idea of the SEOS style speakers, and for DIY there a some standard sized flat packs which may help you choose an enclosure size.


I have the Fusion 10 Pures, which I assembled using the recommended 1.0 cuft flat pack, ported.
http://www.diysoundgroup.com/review/product/list/id/295/category/92/


This pic will give you an idea of size. The SEOS 10's are the L/R speakers, 12" SEOS waveguides, and 10" woofer. Compare to the TV stand which is a standard 30" tall, and the 47" HDTV on top of the center channel. This is a large 50 lbs speaker, but manageable for a single person lug up and down steps if needed. It is definitely bigger than bookshelf size.




To get to the 12" Fusion the flat pack is a 2.0 cuft enclosure. I have no experience that size, and if you have any questions about quality, read the reviews listed on the DIY Soundgroup website on any of the models.


BTW, don't get the idea that bigger is always better. The Alpha 8 Minion has gotten rave reviews from owners. It uses the same compression driver as the Fusion 10, just in a different waveguide. Very high quality sound, and it can handle more power for a big sound if you want it.


Some other links:

This is a Fusion 10 Max speaker, slightly different from the Pure: http://www.avsforum.com/t/1481968/fusion-10-max-stereo-integrity-ht-18-d2-build-thread/0_50

+++
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #4 ·

Thanks for the feedback guys!

 

@ lpicchiotti - I should have mentioned I'm living in Europe so have different store/shipping options than North American builders. Nice site though, I've enjoyed looking around it for ideas


 

@ wvu80 - Great looking system and thanks for the ideas! Indeed those are a bit larger than bookshelves but a lot of the same ideas apply I think.

 

The restaurant I manage hasn't been as busy as hoped for today so I've had time to mess around with speaker design ideas. Here's my most recent plan:

 



 

It's scaled 1mm=1px for 160x500mm total. Depth should be around 160mm as well which should get me pretty near the ~7L/.26 cubic foot recommended sealed enclosure size with 5/8" plywood and a bit of internal reinforcement.

 

Woofer: 6" Morel Classic advanced http://www.europe-audio.com/Product.asp?Product_ID=7053

Mid: 2" Morel Elite Textile Dome http://www.europe-audio.com/Product.asp?Product_ID=7028

Tweeter: Gradient Axis Ribbon http://www.europe-audio.com/Product.asp?Product_ID=11378

 

Amplification:

They're fairly power-hungry drivers with RMSs of 150w, 200w, and 30w respectively. I'm thinking maybe 150w each from internal class AB amplifiers to the mid and woofer and 30-50w internal class AB to the ribbon. I don't have a lot of knowledge of products and prices in this area so I may have to scale back my ambitions if this gets excessively pricey or possibly go with external amplification.

 

Crossovers:

I want to do active crossovers supplemented with a passive crossover for the ribbon to prevent damage to it from the amplifier.

I'm thinking of crossovers around 1kHz and 4kHz and around 80Hz once a subwoofer joins the system. I don't know much about crossovers but this keeps all the drivers fairly far away from the borders of their useful playing ranges. Perhaps very gradual crossovers would help the drivers compliment each other and avoid individual week points in their frequency response or directionality, etc?

 

Once again, feedback is very welcome as I don't know much about what I'm doing ;)   And to reiterate, excellent music playback is the main goal here and these speakers are planned to be used with a 12-15" sub.
 

·
Registered
Joined
·
1,399 Posts
Have you found any proven kits from other projects yet? When you are doing your first DIY you can avoid lots of problems by not "re-inventing the wheel."


Here's a three-way design I found on Parts Express:
http://techtalk.parts-express.com/showthread.php?238425-Construction-info-on-my-winning-MWAF-speakers-the-Amaroso-%28long%29


And a Madisound 3-way. The cross over on this kit is very high quality:
http://www.madisoundspeakerstore.com/3-way-speaker-kits/zaph|audio-sb12.3-sb-acoustics-12-dual-midrange-3-way/
 

·
Registered
Joined
·
53 Posts
 http://speakerdesignworks.com/index_page_2.html


Look into the statement series(statements, mini-statements, statement monitors, and center channel).


The picture you posted reminded me of the statement monitor. If you end up loving them(don't think I've read anything negative about them from at least four different forums), you can easily upgrade to a 5.1 with another set of monitors and the timbre matched center channel, or go full out and build the towers for much more sound.


It's been said many times that for music listening the full sized statement towers don't need the help of a sub.


Many build threads and impressions at www.htguide.com , as well as having the speaker designers as active members.
 

·
Registered
Joined
·
1,399 Posts
Good post, Starquester. The Statements link is the one I couldn't think of, which would be most helpful to what Noah is looking to do.
 

·
Registered
Joined
·
509 Posts
The cabinet volume is almost a trivial decision/calculation compared to the rest of the speaker design. Crossover design is really the most important part of the design process and will make or break a speaker. Unless you have the tools and skills to measure driver frequency response and impedance, then use that data to design proper crossovers, you are better off building a pre-existing design like the Statements. You will end up with far better sound and if you decide to pursue speaker building as a hobby, you can use that proven design a a benchmark for your own designs later.


Regards!
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #9 ·

Thanks again for the much-appreciated advice guys :)

 

@ wvu80 - Thanks again for your feedback. Your suggestion is still quite a bit bigger than what I'm after but I'm learning from everything you're posting. I know I'm putting myself through a lot more difficulty than I'd have to by going it my own but "reinventing" seems like a fascinating and enjoyable challenge for the time being ;)

 

@ Starquester - The statement monitors are definitely getting closer to what I'm after--but I'm still hoping for something a little smaller, or at least narrower, and have been leaning pretty strongly towards non-ported since I'm more worried about size and aesthetics than power and money (not that I have a lot of money but I see these mains as a very worthy cause). I'm also not in a hurry at all and have no problem thoroughly researching and planning everything....

 

@ djarchow - Iowa?! I've lived most of my life in Sioux Falls, SD though I'm much further away now :D  My questions at the end are aimed in part your way.

 

You've all been pointing me in the direction of pre-designed systems and while the opportunity to design my own speakers was one of the biggest attractions to me of DIY I'm not the kind of person that ignores consistent advice from multiple people that are much more experienced and knowledgeable than me. If it's the case that my project isn't feasible than it isn't and I'll accept it and look for a different way to go but I would want to be very sure of it before abandoning it. I have a few questions about the difficulties I'd be likely to encounter:

 

-Is the manufacturer data wrt impedance and frequency response not enough for design due to differences in enclosure, etc? If so are the tools to measure such things independently unreasonably expensive or difficult to learn?

-Is the software that people use to research their speaker designs relatively accessible or impractically expensive? If the software is inaccessible are there people willing to lend their expertise?

-If this project turns out to be too much for me would a small, non-ported, satellite speaker project also be too difficult? My most likely project to cut my teeth on will be a smaller pair of speakers, 2-way, sealed enclosure.
 

·
Registered
Joined
·
1,399 Posts

Quote:
Originally Posted by noahclem  /t/1519972/advice-on-diy-speaker-system-particularly-enclosures/0_50#post_24418827


Thanks again for the much-appreciated advice guys



(respectful SNIP)


-Is the manufacturer data wrt impedance and frequency response not enough for design due to differences in enclosure, etc? If so are the tools to measure such things independently unreasonably expensive or difficult to learn?

-Is the software that people use to research their speaker designs relatively accessible or impractically expensive? If the software is inaccessible are there people willing to lend their expertise?

-If this project turns out to be too much for me would a small, non-ported, satellite speaker project also be too difficult? My most likely project to cut my teeth on will be a smaller pair of speakers, 2-way, sealed enclosure.
I think that is an excellent idea. I think of it like singing, first you start out singing, then mastering singing on someone else' songs, THEN you write and sing your own songs. It is a learning curve, and I can see you want to get it right, and you want to keep these speakers for a long time.


There was a recent thread where a poster did something similar to what you want to do, which is design a speaker from scratch. He was a complete novice at speaker design (but had GREAT woodworking skills!) and he put together a speaker which was, well, not sonically correct. This might be a good thread for you to read, to learn from someone else's mistakes so you can avoid those same mistakes. Of particular relevance, starting around post #7, read the other poster's comments on driver implementation.

http://www.avsforum.com/t/1507413/80-speaker-towers-kerfed-out-of-one-mdf-sheet-9-spkr-setup/0_50


The two best links I read from that thread were these:

https://sites.google.com/site/undefinition/diy-faqs-provendesigns

The Speaker Builder's Bible
 

·
Registered
Joined
·
509 Posts

Quote:
Originally Posted by noahclem  /t/1519972/advice-on-diy-speaker-system-particularly-enclosures#post_24418827


Thanks again for the much-appreciated advice guys



@ djarchow - Iowa?! I've lived most of my life in Sioux Falls, SD though I'm much further away now
  My questions at the end are aimed in part your way.


You've all been pointing me in the direction of pre-designed systems and while the opportunity to design my own speakers was one of the biggest attractions to me of DIY I'm not the kind of person that ignores consistent advice from multiple people that are much more experienced and knowledgeable than me. If it's the case that my project isn't feasible than it isn't and I'll accept it and look for a different way to go but I would want to be very sure of it before abandoning it. I have a few questions about the difficulties I'd be likely to encounter:


-Is the manufacturer data wrt impedance and frequency response not enough for design due to differences in enclosure, etc? If so are the tools to measure such things independently unreasonably expensive or difficult to learn?

-Is the software that people use to research their speaker designs relatively accessible or impractically expensive? If the software is inaccessible are there people willing to lend their expertise?

-If this project turns out to be too much for me would a small, non-ported, satellite speaker project also be too difficult? My most likely project to cut my teeth on will be a smaller pair of speakers, 2-way, sealed enclosure.

No you need frequency response and impedance measurements of your drivers mounted in your enclosure. The dimensions of the cabinet baffle, the driver spacing all impact the frequency response. There is fairly cheap and free software that can be used. You would still need a calibrated microphone, and depending on the type of mic a preamp. To measure impedance can be done with some basic/cheap parts and software but the best choice is something like the Dayton Woofer Tester.


The software is fairly easy to use, the challenge is to know what to do with it. The crossover circuit design to get the right response out of all the drivers and to get them to integrate properly is the hardest part. A three way speaker is at least twice as hard to design as a 2 way. My current project is a 3 way coaxial design and I probably have at least 100 hours in the crossover design to get it where I am satisfied with it.


Speaker design is a great hobby. But if you just want to make one pair of speakers and want them to sound as good as possible, build a pre-existing design by a well respected designer. If you want to take up the hobby and design your own, that is great; but don't expect that first (or even third) pair of speakers to sound all that great.
 

·
Registered
Joined
·
53 Posts

Quote:
Originally Posted by noahclem  /t/1519972/advice-on-diy-speaker-system-particularly-enclosures#post_24418827



@ Starquester - The statement monitors are definitely getting closer to what I'm after--but I'm still hoping for something a little smaller, or at least narrower, and have been leaning pretty strongly towards non-ported since I'm more worried about size and aesthetics than power and money (not that I have a lot of money but I see these mains as a very worthy cause). I'm also not in a hurry at all and have no problem thoroughly researching and planning everything


I'd have to check if this applies to the statement monitor, but the statement towers can also be built as a sealed enclosures. The neat thing about the monitors is that there's an option to build them with a switchable crossover for "near wall" placement, as the entire line has placement requirements(18" from the wall) due to the open back midrange speaker design.


I hear ya on the size aspects of them, but altering the baffle widths will require the crossovers to be reworked.


Have a look into the DIY section of htguide, there's a whole lot of speaker options and plenty of assistance if you do decide to tackle designing your own crossovers.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #13 ·

Thanks again guys!  I've had more time to go through the links and other information presented here and feel like I've now got a fairly good understanding of what the difficulties of design are. Starting with a 3-way system designed from scratch is now safely out of the question ;)  I'm not sure for the smaller speakers if I'll do a kit or own design but if I do go with an own design it'll be based on or at least heavily influenced by a kit(s). Speaking of which, I did a quick mock up of what a little 2-way with 4" & 1" morel drivers would look like based on PE's recommended sealed enclosure size.



 

I did find quite a few interesting designs looking around the different sites, including those statement monitors. A non-ported version of them could be nice but since my main reasons for wanting to go sealed were to avoid another potential area of design to mess up (not relevant here as design has already been done by experts) and lack of need due to high power drivers (maybe the lower-powered drivers here, relative to Morels at least, could really benefit from the port), a sealed enclosure might not be necessary. If the sealed version had a narrower baffle it'd definitely be a plus though.

 

I'm going to continue looking into other people's designs and researching DIY speaker design in general but in the mean time I had a couple more questions:

 

-I've noticed just about all these designs are for passive speakers. Is there a reason for this? Can passive designs be adapted to active ones with active crossovers or does that conversion wreak havoc with crossover design? Is there somewhere I can learn more about active designs?

-Is there a practical reason for why baffles are usually much wider than the width of the drivers other than achieving desired enclosure size?
 

·
Registered
Joined
·
1,399 Posts

Quote:
Originally Posted by noahclem  /t/1519972/advice-on-diy-speaker-system-particularly-enclosures/0_50#post_24421084



I'm going to continue looking into other people's designs and researching DIY speaker design in general but in the mean time I had a couple more questions:


-I've noticed just about all these designs are for passive speakers. Is there a reason for this? Can passive designs be adapted to active ones with active crossovers or does that conversion wreak havoc with crossover design? Is there somewhere I can learn more about active designs?
-Is there a practical reason for why baffles are usually much wider than the width of the drivers other than achieving desired enclosure size?

May I check your use of the term "baffle?" The baffle is the wood thing that covers the entire face of the speaker and has holes in it for drivers.



Are you by any chance referring to the "ports," the plastic slot pieces which have some depth to them, which in this picture are wider than the drivers? It has been routed so the drivers in this kit can be flush mounted.

+++


If you are referring to the baffle, it must by necessarily be larger than the drivers so there is material to drive screws into for the drivers. In the case of the above picture the baffle has roundovers on the edges for sonic reasons, and it provides an extra-thick (double baffle) frame which can better support heavy drivers and compression drivers which are bolted to the SEOS horn frame.


If you are referring to the 3 plastic slot pieces (in this particular kit, in the picture above) which end-to-end stretch wider than the drivers? They provide enough port length and flow enough air, which is very specifically matched to properly tune the enclosure which very specifically matches the design of the XO. Due to the oblong, wide design they keep the height of the enclosure lower than if they were large round ports.

+++


If you've got the proper names correct for those things, then I apologize for questioning you. If you got it wrong, then you would not be the first to do so, you would be the second; I would be the first.
 

·
Banned
Joined
·
15,491 Posts

Quote:
Originally Posted by noahclem  /t/1519972/advice-on-diy-speaker-system-particularly-enclosures#post_24421084


-Is there a practical reason for why baffles are usually much wider than the width of the drivers other than achieving desired enclosure size?
Google 'diffraction' and 'baffle step' . I think you meant to say 'not much wider', which is generally the case.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #16 ·

I meant the wood thing that covers the front but a couple days ago I would not have known that term so thanks for what could very easily have been a useful heads up ;)  I know it has to be at least as wide as the driver's total width but it seems they are often much wider. I'm wanting a speaker barely wider than the widest driver, primarily for aesthetics (it will contribute towards spouse-acceptance factor and also prevent my month-old 47" TV from appearing relatively small) but also because the space I'm working with is relatively small and narrower should make it easier to fit into any future room they may end up in. I've heard that the shape of enclosures can have significant impacts, such as if the depth is too small relative to the driver, and I was wondering if the width could be similarly problematic.

 

EDIT: Thanks Bill, I'll do that right now :)  And yeah, I meant "not much wider", preferably a centimeter or less per side.

 

EDIT 2: Sorry, I did mean "much wider" :(  Very few of the designs I've seen have had a total width less than 150% of the driver's total width.

 

I've been reading through this http://sound.westhost.com/bafflestep.htm wrt baffle step. Haven't absorbed everything yet but after reading that spheres are ideal speaker enclosures I've decided I need a Death Star for one side (driver positioned where main laser is) and either Earth (driver @ Arctic Circle) or Mars (driver @ Hellas crater)
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #17 ·

Sorry for the double-post :(

 

So basically what I've got from the community here so far is that it's not wise to go it your own on speaker design--but I've been unable to find almost anything regarding active crossovers and speakers and very little that approaches what I'm looking for with regard to speaker width/aesthetics. Should I give up on the idea of a DIY active speaker?
 

·
Registered
Joined
·
1,399 Posts

Quote:
Originally Posted by noahclem  /t/1519972/advice-on-diy-speaker-system-particularly-enclosures/0_50#post_24430578


Sorry for the double-post



So basically what I've got from the community here so far is that it's not wise to go it your own on speaker design--but I've been unable to find almost anything regarding active crossovers and speakers and very little that approaches what I'm looking for with regard to speaker width/aesthetics. Should I give up on the idea of a DIY active speaker?
Please take my advice for what it's worth. There are some experts on such things, but I'm not one of them.



I don't think you should give up on active cross overs. I say that because if it's something you want to do, someone else has surely tried the same thing before, so there are certainly things you could do to avoid the problems someone else has made. If the expertise is not available on this board, maybe someone can refer you to another discussion board where there is more interest in that area.


In terms of width, it seems like there are plenty of designs which have enclosure widths very close to driver widths. I'm not quite sure why you are having trouble finding the solution to that problem. Everything I've read says (in general) that for any particular speaker, a certain volume is needed to achieve the optimum sound quality, SPL, etc that one is looking for. If your woofer driver is (for instance) 8" then the speaker width will be about 9" and the volume is made up with height and depth. That problem seems like it is very solvable with some posters on this AVS DIY discussion board. If you post what the specific driver is that you want to use, I bet somebody could model a good enclosure for it.


Summary: Don't give up yet.


+++


I'll tell you who I think could give you some really good expert advice, LTD02:
http://www.avsforum.com/u/7426121/ltd02


He hasn't weighed in on this yet, so try sending him a PM, refer him to this thread, and see if he will give you his opinion. He's been great on everything I've ever seen him comment on.
 

·
Registered
Joined
·
509 Posts

Quote:
Originally Posted by noahclem  /t/1519972/advice-on-diy-speaker-system-particularly-enclosures#post_24430578


Sorry for the double-post



So basically what I've got from the community here so far is that it's not wise to go it your own on speaker design--but I've been unable to find almost anything regarding active crossovers and speakers and very little that approaches what I'm looking for with regard to speaker width/aesthetics. Should I give up on the idea of a DIY active speaker?

Regarding the width, one thing to take into account is how close the actual cone will be to the inside panels of the enclosure. For example, a relatively popular midwoofer, the Usher 8945 has a 19mm wide mounting flange. With a normal 20mm thick enclosure panel thickness, if you inset the driver only 1cm from the cabinet edge, you only have 1cm between the edge of the cone and the inside cabinet wall which will probably result in reflections which can color the sound. The other thing to consider is if you want to use a grill and only have 1cm between the driver and cabinet edge you will need either a
 
1 - 19 of 19 Posts
Top