advice on build first speakers?

[smaki]

hello,
after recently looking in to buying some decent speakers, it has been suggested that i try building my own. i put together my own computers, and like the idea of building speakers too, so this idea really appeals to me. i have done a fair bit of research but have joined this forum hoping to tie up some loose ends which i cant seem to figure out just browsing, as well as to get some general good advice and guidance from people with more experience, so that i may learn and eventually help others too, so here goes.

my budget is in the range of about $700-1000, and have been looking at building a set of 2 way speakers with the morel ET 338 and the morel EW 638, crossing over at 3000hz using the dayton XO2W with 12 awg speaker wire. i am planning to build my own cabinets out of 1 1/2" thick mdf measuring 10" across, 12" deep and 15.5" high with a 1" support brace and a 2" flared port tube (though i will research this more - i have read that 1 1/2" mdf is the best thickness and measurements were briefly self calculated- but the cabinet seems slightly large for a 6" woofer and 1 1/8" tweeter, and an 1 1/2" seems awfully thick). all of these parts are available from parts-express, which is handy because i am living in the uk, and their delivery charge isnt too bad when you buy a whole set.

so thats my plan as of now. i have 4 questions which ive been trying to find answers to,
firstly wheather 12 awg speaker wire is the right one to use,
secondly weather a 2" flared port tube is too wide for the setup,
thirdly and weather its worth changing the setup to a 3 way system but with cheaper drivers when spending in this price range
and finally, when it comes to flush mounting drivers, does this refer to cutting an indentation around the driver whole so that it lays perfectly flat with the cabinet?
however, as this is my first time building, if you can spot any flaws in my plan, or have any advice whatsoever on driver choices, cabinet sizing etc then it would be much appreciated. thankyou all in advance for any comments you may have.

[planet10]

Originally Posted by smaki

dayton XO2W with 12 awg speaker wire... cabinets out of 1 1/2" thick mdf ...

however, as this is my first time building, if you can spot any flaws in my plan, or have any advice whatsoever on driver choices, cabinet sizing etc then it would be much appreciated. thankyou all in advance for any comments you may have.

Yes, there is a fatal flaw. An XO needs to be tailored to the system. The likelyhood of the Dayton generic XO actually doing a good job is <1%.

For a 1st time build i would strongly suggest finding a proven design and building that... and start with a more modest budget. A 2-way system (even with only a couple hundred dollars in parts) with a well sorted XO, has a much greater chance of sounding good than what you are proposing. XO integration is critical and the hardest part of a speaker to get right (one of the reasons i tend to avoid them completely).

As more research is done on getting good bass in rooms (Floyd Toole's book (and the Geddes thread here) are the top references on this subject) is best done with bass limited satelittes & multiple poswered woofers, so a good 2-way (or 1-way) is a necessary start. After you have them nailed you add the woofers ending up with a 3-way (or 2-way FAST).

The other point is that i personally would never use MDF for a cabinet, i feel it is a lousy material for the job.

dave

[smokinghot]

Originally Posted by planet10

The other point is that i personally would never use MDF for a cabinet, i feel it is a lousy material for the job.

x2

Forgetting about the argueable ascoustic issues for a moment. The last sheet of MDF I purchased was noticably damp with chemical. Too the point where it's dimensions differed greatly (after drying) from a earlier bought sheet. At best, MDF has been reduced to test baffle status.

[mikje]

Originally Posted by planet10

The other point is that i personally would never use MDF for a cabinet, i feel it is a lousy material for the job.

dave

Originally Posted by smokinghot

x2

Forgetting about the argueable ascoustic issues for a moment. The last sheet of MDF I purchased was noticably damp with chemical. Too the point where it's dimensions differed greatly (after drying) from a earlier bought sheet. At best, MDF has been reduced to test baffle status.

Interesting... what material do you gentlemen recommend?
Mike

[smokinghot]

Not meaning to derail the thread but I'm looking forward to using Dave's personal fav, Baltic Birch. To this point I don't have experience with it though. My frustration with MDF has come to a boil during my current project. I can't say I buy into all the acoustic negativities some claim, but simply working with MDF is just wearing thin on me.

For an example : I did a trial run of a translam build using MDF. Being my first translam, I wanted to gauge build time, difficulty, with a cheaper material. I left the assembled cabinet (without baffle) in the trunk of my car over night. The temperature dropped below freezing and a small handful of laminents split. Not the glued surfaces, but the width of the laminent sheet. This is after the layers were left to dry for well over a month in an arid enviroment, without assembly. Yes I know, most people won't leave their speakers in areas that will fall below freezing mark. However, I'll be damned if I'll go through all the effort of finishing a project just to have blow apart because I had to drive somewhere during the winter months.

Will Baltic Birch elminate this concern...?...I don't know. However I do know based on experience that it will happen with MDF. That's enough for me.

[planet10]

Originally Posted by smokinghot

Dave's personal fav, Baltic Birch

A relatively inexpensive, practical material with great properties for building really good enclosures without going to extreme efforts.

Discussion on what materials to build speakers out of

dave

[Brett]

advice on build first speakers?

Two options, but first you'll need to work out what size physically you want them, how low you want them to go, how much you're willing to spend, how loud you want them to be capable of playing and any other aspects of the design such as aesthetics that matter to you.

1: Find a design that is already developed that meets the criteria you have selected and build it. This will be far quicker and cheaper and by far the preferred option for a first time build.

2: Spend a lot of time reading, simulating, measuring and building test enclosures and refine your designs. Expect it to take a long time (years) and cost a lot more than option 1, but it can be a fun hobby.

Compared to assembling a computer, designing and building a good speaker is a lot harder.

[planet10]

And even if you go with Brett's #2, starting with 1 teaches you lots that makes #2 easier, shorter & more effective

dave

[head_unit]

Originally Posted by smaki

hello,
after recently looking in to buying some decent speakers, it has been suggested that i try building my own.

Ha ha, we got you, SUCKER!

Originally Posted by smaki

...looking at building a set of 2 way speakers with the morel ET 338 and the morel EW 638, crossing over at 3000hz using the dayton XO2W with 12 awg speaker wire. ...firstly wheather 12 awg speaker wire is the right one to use,
secondly weather a 2" flared port tube is too wide for the setup,
thirdly and weather its worth changing the setup to a 3 way system but with cheaper drivers

12AWG is fine, 2" port sounds too small offhand (settle on your cabinet size and start another thread about that), and don't go 3-way with cheaper drivers. Cheaper will sound cheaper, and 3-way is a LOT more complicated especially for a first project.

Originally Posted by smaki

i am planning to build my own cabinets out of 1 1/2" thick mdf...

Back in the day, the Alpine guys swore by Baltic Birch as strong and dimensionally stable. A lot of MDF can be junk. 1/2" seems quite thin. Multiple strong braces if possible, coat the inside with vibration absorbing goop, line the inside with fiberglass or absorptive foam, but not around the port end. The lining will perhaps lower the port tuning a bit.

Originally Posted by smaki

...and finally, when it comes to flush mounting drivers, does this refer to cutting an indentation around the driver whole so that it lays perfectly flat with the cabinet?

Yes

[smaki]

wow, thanks alot guys - some great advice there. my main priority was to get some really good quality speakers, and had been looking at a pair of adam active a7s or a preowned pair of genelec 8040a's, which both sounded absolutely phenomenal to me, and as an added bonus both sets were self amplified to make things that little bit simpler. when looking into building speakers i was hoping to create something similar, maybe accepting a loss in sound accuracy in exchange for gaining some charecter and general fun learning.

from reading your replies, i am under the impression that this is not realistic on a first time attempt and that maybe i would be better off getting some decent prebuild speakers now and building a cheap pair in a few months to come to terms with the process.

however, i would still like to build a pair... the two hardest taasks seem to be building the cabinet, and finding a crossover. the cabinet designs ive seen seem to recommend mdf ( and i was planning on using 1-1/2" thick, not 1/2"), and i have already found a descent supplier for this, but will research more thoroughly, finding 2-way cabinet designs doesnt seem to hard. as for the crossovers... it seems i would have to build those myself. does anybody have any recommendations on where to search for help on this? or have any basic advice on what to look out for/ avoid? much appreciated to everyone who responded, thats really helped alot.