n00b with a project! xover question (1 Viewer)

[Gavin_mi]

well for some time now I have been looking at get studio series paradigms for my HT system. after doing alot reading I think I might like to make my own speakers and maybe save a little money and have something that is mine all mine! anyways. after reading through some other peoples projects I feel confident that I can do all the cabinate making and wiring and soldering and finishing. the only dought that I have is how in the world do I figure out what components to put where in the crossover. so I guess my question is; Is there a program that I can just tell it my driver resistance, watts input, sensitivity of drivers, and frequency range that I want and have it spit out a components list with a diagram? I think if i had that I could hot glue it all to a piece and MDF and solder it together. Im have heard good things about Seas drivers and Fostex ribbon tweeters so I think I like the Seas M15CH-001 for mid from 300-2500Hz and the Seas W22EX-001 for a woofer from 80-450Hz and Fostex FT33RP ribbon tweeter from 2500-30000 Hz. these are all 8 Ohms and have sensitivites from 90-91 dB. do you think they will blend well together? I have and use solidworks at work all day long so I will be designing the enclosure in that and running it by you guys to see what you think. I really dont care if these speakers weigh 250 lbs a pop (this will be for the front L/R for now to get my feet wet). If I/you guys think that making the entire thing triple thick 3/4 MDF will make them sound better then that is what I will do. we will start there for questions and after this one gets answered I will have many more!

thanks for your time and input

Gavin

PS. I have downloaded the shareware version of boxplot and it seems to be what im looking for except the shareware version doesnt allow you to design for more than 2 way and limited xover designs.

 

[Rory Buszka]

What you want is Audua's excellend Speaker Workshop, which can take FRD files (These contain frequency response and impedance data; FRD Consortium has tools to make your own from any FR chart through a "tracing" method) and show what the total response of your speaker system will be. Also, get David Weems' _Great Sound Stereo Speaker Manual_ which discusses crossover design in greater detail. Unfortunately there isn't just a straight-up crossover design web page, since there are so many different driver combinations. However, I think there should be a web page. But if I were to embark on such an endeavor, you probably wouldn't get the results soon enough for them to be useful, but if you get that book and then use Speaker Workshop, you can play around and see what does what. It uses a very interesting drag-and-drop circuit modeler, and actually integrates data from the drivers in predicting the final output. Start with textbook high pass, band pass, and low pass networks and then read about Zobel networks, L-pads, and Notch Filters in the Weems book.

 

[Gavin_mi]

sounds like a plan, thanks for the advice.

 

[Gavin_mi]

Im trying to set up the drivers I want to use in a MTW speaker using Speaker workshop and im not sure what number the program is wanting for motor strength and for voice coil series (L1)
here is a link to the driver I want to use.
http://www.oregondv.com/Seas_Speaker...X-001_E022.htm
any info on this matter will be great, and I assure you I will have more questions seeing as this will be my first DIY speaker build ever.

 

[Rory Buszka]

That's quite a woofer to be using on your first speaker build. If you haven't bought the woofer yet, I recommend that you start with a less expensive driver for your first multi-way project. A good Vifa 8" woofer and Seas tweeter (but not the Millennium ones) should do well. You can select a midrange from a similar price class. Also, do a Google search for FRD Consortium, and then from the page that opens up, download the SPL-Trace program. You can load the image, and then you plot points by clicking on the graph at regular intervals. Before you can start tracing on the picture of the FR plot, you will need to set the bounds of the graph, and the zero point and max value, and then the start and end frequencies of the trace and the interval of each point on the plot. The more points you plot, the higher resolution your trace will be, and the less likely it will be that you lost some detail.

 

[Gavin_mi]

ok will do at work tomorrow, the reason I picked those drivers is so that the end product will be able to perform as good if not better than studio 100s or 60s from paradigm. If I cant do equal or better than those Im wasting my time because I have heard those and loved them. anything less and I will be unhappy and THAT would be a waste of money lol.

I will try and figure out the plot at work tomorrow while im killing time, thanks for your help Rory.

Gavin.

PS on the Speaker Workbench I figured out that force factor is the same thing as motor power but what is that L1 thing that is right below the voice coil inductance? they both have the same units of measure, mH.....not sure any idea?

 

[Rory Buszka]

I didn't put anything for my L1. I don't really know if that applies but SW's calculations system seems to make do without it.

There is a woofer made by Vifa that Mackie used in their HR824 monitor.