Dual hi-vi mini project

[BionicSniper]

Ok so i'm heading off to college for areospace engineering and airforce ROTC in about a month and i'd like to shrink my stereo a bit. I currently have 4 polk audio r15's, a polk cs1 center, yamaha 10 inch sub and a pioneer reciever.

I've been doing research into speaker building for about 3 weeks now and I think i've finally gotten to the point where i'm ready to try.

My goals are to beat the clarity of the polk r15's in the mid and high area's and allowing my sub to take the low end (sub 200hz range). My neighbor has bassbox pro so i have have access to graphs and box design and the such. I do some audio editing and creation and strongly prefer a completely flat response to anything else.

Each speaker (2 total) are going to be comprised of 2 mids and a tweeter. At this point i'm stuck between the m4n and the m3n. The m4n's seems to be overpowered before 200 ( so it's not a big deal) and then a flatter response out to 5k which is where i'd like to cut them. For the tweeter i'm not really sure. i'm thinking about the hi-vi sd1 right now

I'm totally stumped when it comes to crossover options or desing. I could build my own without a problem (soldering is no problem at all even .05 pitch and smd's) but i don't know how to go about it.

any suggestions? I have 3 weeks to get this done

[gtforme00]

I'm going to make a few assumptions given the information available. One is that you would like something small and inexpensive. Two is that you don't presently have access to or experience with frequency response measurement equipment, though I'm sure you seem willing to learn. Three is that you will be trying to pack a lot of stuff and see a lot of friends in the next three weeks and that you will not be able to spend a large amount of time on this project.

Based on the time limit (3 weeks) and the lead time to get parts which will eat up a minimum of one week, I would highly recommend building an already published design if you want to have a finished pair of speakers by the time you leave for school.

I realize that this suggestion removes some of the romance from the speaker building dream, but the reality of the situation is that even for an experienced speaker designer, 3 weeks would be an insufficient amount of time to properly design and build a speaker, if for no other reason than lead time alone in ordering parts.

A nice design is the bargain mini at zaphaudio.
http://www.zaphaudio.com/ZBM4.html

This design has already been thoroughly tested and was designed by a very reputable source. It has very flat response and is perfect for use with a subwoofer.

You can always build more speakers later if you want to design your own, it can be very rewarding and a great way to get some engineering practice.

Best of luck with the project, which ever way to decide to go; and best of luck with school as well!

Regards,
David

[badman]

He's absolutely right, build a tried 'n true. Speaker design is largely a process of refinement, and the first 'box' usually doesn't 'work'.

[sdclc126]

Here are a couple of Hi Vi designs you might consider:

http://www.partsexpress.com/projects...ct=HiviJuniors

http://www.partsexpress.com/projects...m?project=Sc51

[gtforme00]

I just noticed that the woofer used in Zaph's project is on sale at MCM. Use coupon code WA807 to get it for $9.95 (regularly $12.95). You can also get $4.99 shipping right now for orders over $50 and free shipping for orders over $100.

It is a little known fact that MCM carries Bennic capacitors as well (the brand carried by Madisound and the ones in the bill of materials for the bargain mini), and that they are often cheaper than Parts Express or Madisound.

Bill of Materials for the Bargain Mini as purchased through Madisound.

C0 - 2.7 uF Bennic Poly $1.30 ea
L1 - .25 mH 19 ga Air Core $2.75 ea
C3 - 10 uF Bennic Poly $3.75 ea
R4 - 4 ohms Eagle Metal Oxide Film $1.20 ea
R5 - 5 ohms Eagle Metal Oxide Film $1.20 ea
L7 - 1.50 mH 19 ga Air Core $5.40 ea
C9 - 3.3 uF Bennic Poly $1.60 ea

Prices at MCM (using current 15% coupon code)

C0 - 2.7 uF Bennic Poly $1.15 ea
L1 - .25 mH 19 ga Air Core (Not Available)
C3 - 10 uF Bennic Poly $2.63 ea
R4 - 3.9 ohms 25W Wirewound Resistor $0.74 ea
R5 - 5.1 ohms 25W Wirewound Resistor $0.74 ea
L7 - 1.50 mH 19 ga Air Core $5.64 ea (Cheaper at Madisound)
C9 - 3.3 uF Bennic Poly $1.44 ea

You still have to place an order to Madisound for the tweeters and inductors, but if you order the rest of the parts from MCM you can save another $4.22, on top of the $6 you save for the woofers being on sale.

The total for the components and drivers could be as low as $85 or so including shipping from both MCM and Madisound.

Best Regards,
David

[BionicSniper]

Thanks for that info! I'm going to build a pair of zbm4's. I only wish they were a tad shallower but with that frequency response i'll live. Any thing i should read to get a better understanding of all of this?

Don't worry i'll have some pictures

[gtforme00]

A wise choice, I think you will find the build enjoyable and rewarding.

You should read the whole zbm4 page carefully, and there is at least one other thread on this forum where someone built the zbm4 and documented the build. While you are on Zaph's page, read the design mantras article to get a feel for how Zaph designs and builds his projects.

The biggest challenge on this project will be building the enclosure. You will probably want to go ahead and start on that as soon as possible, which you can do without the drivers since you have detailed drawings on the zbm4 page. Do you have a router and table saw? If not you might consider pre-built enclosures. These can be rather pricey, but are worth every dime if you don't have proper space/time/tools to do woodworking yourself.

Go ahead and start compiling your order(s) for the parts, if you are anything like me you will need a day or two to add on all the extras you might feel compelled to order.

I was wrong earlier about the shipping cost for MCM. It looks like you only have to have a minimum order of $40 to get the discounted $4.99 shipping, which should work out perfectly for you if you order the capacitors, woofers, and the 1.5mH inductor from them.

I found a 20% off code for MCM, which makes the deal even sweeter. The source code is FF020 . You will need to enter both source codes (FF020 and WA807) to get the sale price on the woofers in addition to the 20% off.

Good luck on the project and be sure to ask any questions you have and give us updates!

Regards,
David

[amps]

I hate to butt in but you've given some great advice gtforme00, just the advice I was about to register and ask for.

Big question: Where did you find the Bennic caps and other parts on the MCM site? I've tried searching all over and can't locate any of the components you mentioned other then the speakers. If you still had the part numbers that would be fantastic.

Thanks!

[gtforme00]

Not a problem, try this link: http://www.mcmelectronics.com/browse...ponent/1000296

MCM doesn't list Bennic as the manufacturer, but if you look at the pictures you can tell that they are, and the manufacturer part number is a Bennic part number. More importantly, I have ordered them in the past and can confirm that they are Bennic branded.

MCM isn't the easiest site to browse, so sometimes searching for keywords and using filters is the only way to find what you need.

Most of the crossover components on the MCM site are listed under AMS Enterprises as the manufacturer. You can select to list items by manufacturer to help narrow the list.

Regards,
David

[sreten]

Originally posted by sdclc126
Here are a couple of Hi Vi designs you might consider:

http://www.partsexpress.com/projects...ct=HiviJuniors

http://www.partsexpress.com/projects...m?project=Sc51

Hi,

Not to put too fine a point on it, both those designs are poor designs.

/sreten.