crossover help

[maxx103]

I have read a lot of manuals and they didn't help soooo. I have designed some speakers via parts express and need to make a crossover. I know what frequencies but what i want to do is bi-amp it. The large woofer will have its own connection on my receiver and my tweeter and mid ranges will share so basically i need to make a high-pass and base pass crossover for my top binding post and a low-pass for my bottom this ensures maximum power to my woofer. this is all 8 ohms impedance and if you wanted to take an extra step an design one for me much appreciated. Anyway here is what my speaker might be but i also might change parts but heres the list. Thaks to all that help :

Tweeter-Hi Vi TN28 Fabric Dome Tweeter
Mid range-Dayton RS100T-8 4" Reference Woofer Truncated Frame x2
Woofer-HiVi D8G 8" Kevlar/Paper Woofer
Case-Dayton MTMC-1.0BK 1.0 ft³ MTM Curved Cabinet Gloss Black

Also suggested cross over freq. and recommended changes.

 

[TLS Guy]

I have read a lot of manuals and they didn't help soooo. I have designed some speakers via parts express and need to make a crossover. I know what frequencies but what i want to do is bi-amp it. The large woofer will have its own connection on my receiver and my tweeter and mid ranges will share so basically i need to make a high-pass and base pass crossover for my top binding post and a low-pass for my bottom this ensures maximum power to my woofer. this is all 8 ohms impedance and if you wanted to take an extra step an design one for me much appreciated. Anyway here is what my speaker might be but i also might change parts but heres the list. Thaks to all that help :

Tweeter-Hi Vi TN28 Fabric Dome Tweeter
Mid range-Dayton RS100T-8 4" Reference Woofer Truncated Frame x2
Woofer-HiVi D8G 8" Kevlar/Paper Woofer
Case-Dayton MTMC-1.0BK 1.0 ft³ MTM Curved Cabinet Gloss Black

Also suggested cross over freq. and recommended changes.

That is a huge amount of work. Doing three way crossovers at long range is very difficult a fraught with problems.

Passive biamping is a waste of time. If you want what you are looking for you need to triamp with an electronic crossover and three two channel amps.

I will check and see if acoustic response data is available for those drivers my be tomorrow. Accurate T/S parameters and accurate acoustic data for all drivers is essential. If not you will have to measure it before crossover design.

The crossover is the heart of every speaker and determines more than any component the quality of the speaker and how it sounds.

The other issue is that you need to have at least a rough crossover before purchasing drivers. It is far from even possible to design a decent crossover for a lot of driver combinations.

 

[maxx103]

ahhhhhhhh

ok well this is my first ever build so i guess i wont be doing that if i do this and single amp it will 145 watts be enough because i dont know how to figure power or even begin to understand all that but thanks for fast input

 

[TLS Guy]

ok well this is my first ever build so i guess i wont be doing that if i do this and single amp it will 145 watts be enough because i dont know how to figure power or even begin to understand all that but thanks for fast input

I can't answer those questions yet, until the crossover is complete.

Now there will be many hours of work in this. The cost of the components for two three way crossovers is going to run to between $300 and $400 dollars. Are you sure you want to proceed?

I have taken a quick look at your plans. Already I see problems.

The tweeter you have chosen will require a crossover around 4 kHz, the woofer about 350 Hz. That is fair enough, but your mid range is only 25 watts, and yet has to handle about half the power at least with the crossover where it needs to be.

Even if you used two midranges per side it would be marginal, and you would have to use at least two per side in MTM configuration.

Your tweeter is not suitable for MTM.

The mid is metal coned with nasty break up modes, which will need notching in the crossover. This will be a complex expensive crossover.

A bigger problem is that Dayton state there acoustic data is unreliable below 200 Hz. I absolutely have to have reliable acoustic data in this region to begin to design a crossover. There is also no off axis data for the mid range you selected.

The nest issue is that this design is not worth the trouble. F3 will only be 35 Hz. You can design a two way or 2.5 way speaker a lot cheaper and with better results than in your approach. Multiple crossover points are not an advantage. They are a disadvantage, with each crossover point introducing a whole set of problems and stealing amp power as line insertion losses really mount. You will end up with a design with a sensitivity of only about 82 db 1 watt one meter.

I'm sorry but this design can easily be outclassed by something simpler and cheaper.

These days to make a three way speaker worth the trouble and expense, you need at least two 10" drivers, a 12" or 15" driver.

I'm sorry but I have seen enough of this project to see that it is not worth the effort, so I respectfully decline to get involved further.

 

[maxx103]

Ooooh

OK thanks i wanted a three way but if you say that a two way is good i trust you . You are a wealth of info and deserve a cookie. I am a total newb so expect to see me asking about a 2 way bookshelf. Anyway is hivi a good brand because i really like there looks but if they suck then forget them. Also any parts you recommend just a general opinion by the way

thank you sincerely and whole-heartily

 

[TLS Guy]

OK thanks i wanted a three way but if you say that a two way is good i trust you . You are a wealth of info and deserve a cookie. I am a total newb so expect to see me asking about a 2 way bookshelf. Anyway is hivi a good brand because i really like there looks but if they suck then forget them. Also any parts you recommend just a general opinion by the way

thank you sincerely and whole-heartily

A good three way is a lot of money. A two way does not have to be a bookshelf speaker.

Two 6.5" or 7" drivers as either a 2.5 way or two way MTM can easily match what you proposed in bass extension. It makes for a simpler much less expensive crossover with better results.

What are your goals and budget anyway?

When you begin choosing drivers that can potentially work together with a fairly simple crossover is key.

It is best to pick European drivers, as they have data that is far more likely to be reliable and less unit to unit variation. Also they tend to be much better drivers.

 

[GranteedEV]

why not start with something well documented as simple to get your feet in the water?

ie

http://www.zaphaudio.com/ZBM4.html

 

[maxx103]

mmk

well im going with a kit i guess or just something i wont feel bad if i mess up anyway my goals are for some bookshelfs i can place on my desk that fill up my room nicely my room is pretty small and they will be faced right at me so yah but i also want them to be versatile and since this is my first time no more than 250 for drivers for each speaker. I thing mdf is pretty cheap anyway and my dad has lots of tools (im only 14 by the way) SOO if theirs anything you recommend ill be happy to try it. Also I just wanted to thank you for all the help and also if you need more specs or info pertaining to my requirements just ask

 

[TLS Guy]

well im going with a kit i guess or just something i wont feel bad if i mess up anyway my goals are for some bookshelfs i can place on my desk that fill up my room nicely my room is pretty small and they will be faced right at me so yah but i also want them to be versatile and since this is my first time no more than 250 for drivers for each speaker. I thing mdf is pretty cheap anyway and my dad has lots of tools (im only 14 by the way) SOO if theirs anything you recommend ill be happy to try it. Also I just wanted to thank you for all the help and also if you need more specs or info pertaining to my requirements just ask

Good move for your first build. Pick one of these. You will learn a lot building one of those kits.

At 14 years of age please take the time to study and in a few years you will be able to design some great speakers. I started around 7 and was very active in my teen years.

 

[maxx103]

so helpful

Ok i chose the SR-71 by zaph. Ive heard good thing and i have been studying. I have the loudspeaker cookbook and its interesting. I hope i make these well and im sure they will be perfect for what they are. Also do you recommend i build my own encloser. I know that the full kit includes them but i just wanted to know if i could get better sound. Thanks for all the help look forward to receiving advice in the future

 

[GranteedEV]

Go for it on the enclosure if you have access to a router!

 

[TLS Guy]

Ok i chose the SR-71 by zaph. Ive heard good thing and i have been studying. I have the loudspeaker cookbook and its interesting. I hope i make these well and im sure they will be perfect for what they are. Also do you recommend i build my own encloser. I know that the full kit includes them but i just wanted to know if i could get better sound. Thanks for all the help look forward to receiving advice in the future

Yes, you absolutely will be able to build a better box. So yes, by all means build you own well braced enclosure.

At your age you absolutely have to build your own enclosure. Now is the time to develop skills, the more the better. This will stand you in good stead all your life. We are all called to be skillful people and to lifetime learning.

 

[maxx103]

alright

OK so i can build my own, but how. Is it simply slap some mdf boards together and internally brace or is there something else also if anyone randomly comes up with a case design tell me why its built like that or if its just simply "DON'T MAKE IT SQUARE" then that's OK to i just want my first build to be a good one.

 

[highfigh]

OK so i can build my own, but how. Is it simply slap some mdf boards together and internally brace or is there something else also if anyone randomly comes up with a case design tell me why its built like that or if its just simply "DON'T MAKE IT SQUARE" then that's OK to i just want my first build to be a good one.

If you haven't done any woodworking before now, buy the boxes and take a woodworking class for anything you would build later. The ones at Parts Express and Madisound (I think they're the same) are actually very nice. Also, if you have no woodworking tools or machines, you'll never be able to build a pair of boxes for what they charge. For that matter, it's impossible to make them for the same price if someone does have all of the tools and machines. The materials alone will cost more.

 

[TLS Guy]

If you haven't done any woodworking before now, buy the boxes and take a woodworking class for anything you would build later. The ones at Parts Express and Madisound (I think they're the same) are actually very nice. Also, if you have no woodworking tools or machines, you'll never be able to build a pair of boxes for what they charge. For that matter, it's impossible to make them for the same price if someone does have all of the tools and machines. The materials alone will cost more.

From his question I assume he does not have woodworking skills. However he may have a relative or acquaintance that does, to show him the way.

Except for ports the system should be air tight and very rigid. Dato joints are better than butt joints. Make height, width and depth different dimensions, so reflections do not sum.

 

[highfigh]

Since we don't know who he knows, or their woodworking skill set, I would rather he get formal woodworking training because I'm pretty sure we have all heard stories about someone who had an "I didn't think it would happen so fast/that way" event. Accidents happen, but most happen when the person becomes over-confident, tired, bored, distracted or doesn't have proper training.

Using a dado isn't the first task I would recommend for a beginner. Butt joints with fasteners work well, although more glued surface is preferred. For someone starting out in woodworking, I would recommend that they take the cutter to the work, rather than the wood to the cutter.

 

[maxx103]

mmmk

well my dad has some experience and my friends dad has a lot of experience with wood working. I do have some but i don't know what those two joints are so yes i would love to take a class i don't know were any are but i can probably find them somewhere also amuse i have the tools because if my dad or friends dad does not have them then my dad might be coaxed into getting it but i know he has a jigsaw , router, basic wood working stuff. Anyway i know about volume calculates but how should i stuff the box and for final sealing do i use glue and screws or like caulk or what. Also if this is all written in a book some where just tell me the name and i will be happy to purchase it.
Thanks

Edit: do you mean dado like thats just having a cut and putting the wood in it