Crossover advice for beginner

[jcoffell1]

Hello, I am a beginner so please forgive incorrect or inadequate info. Just looking for a little advice about what crossover frequency to select. I will try and make it short. Have a pair of late 70's Audio Phase SV123's. They had a 3 inch or so 8 ohm ho ku tone tweeter with either a 2.2 uf or 4.7 uf cap in series. 6 db rolloff. Blew one early 80's and replaced both with elcheapo radio shack piezo horn tweeters that didn't even need a crossover. Recently updated the tweeter to an eminence APT80 and used their 3.5k 18 db rolloff crossover. Sounded so clear made the FHT-2 8 ohm 4 inch by 10 inch midrange horns sound horrible. The midrange horns had a 12 uf cap in series which I calculate to be around 1670 hz with 6 db. I decided to upgrade that to a 4 inch by 10 inch horn I got off ebay and threaded in a JBL Selenium D250X driver. I then installed the eminence 3 way crossover 500 HZ and 3.5 k (pxb3:3k5). I realized the 12 inch woofer was connected directly and originally had no low pass filter at all. The writing on the back is so faded I can't make out anything except electronics. Connected the woofers to the crossover and they performed horribly. Bottom line they turned out to be 4 ohm instead of 8 (I should have measured). The eminence crossover is for 8 ohm speakers so for the low pass I am closer to 250 hz with nothing between 250 and the 500. So I am going back and forth about changing out the low pass crossover value to about 1650 or 2250. The selenium drivers will go down to 400 (I have them at 500) but the horn size 4 X 10 is going to limit the lows. Since the original with that size horn was about 1670 I want that to be the minimum. But for extra support in the horn range I was thinking the 2250 may sound better. The amount of work (not counting changing the crossover parts) is about 2 hours each speaker. Crossover is a pain to get in and out. Any body out there with any ideas would be greatly appreciated. Since I can't see anything on the woofers except electronics (Extremely faded) I have no clue what they really are. One thing I can say is that the rubber surrounds are in excellent condition and still very soft and plyable. I use them for the fronts of the surround system for the television so really they are used for watching movies so no hardcore music. Thank you in advance for any ideas. And its just ideas I looking for. You don't have to be a professional but hopefully somebody that has played with crossovers etc. Thank You Jerry

 

[Swerd]

To summarize, you have in Audio Phase SV123 cabinets:

Unidentified 12" woofer provided by Audio Phase
JBL Selenium D250x mid range on a 4×10 horn
Eminence APT80 tweeter​

And you want suggestions for a 3-way crossover. You noted your previous trial & error methods were mainly error, and that you've worked 2 hours or more per speaker to do various changes in the past. But you want "nothing professional".

To do anything reasonable will require that you first measure the unfiltered frequency response vs. frequency and impedance vs. frequency for each driver while it's mounted in the cabinet. That data can be used by one of several crossover design software programs that guide you while designing an appropriate crossover. Anything less than that will leave you with trial & error efforts. The problem… my suggestions may cost more than buying new speakers.

 

[j_garcia]

New speakers. Without measurement gear, and since the drivers are so randomly chosen, it will be a futile effort to try to build a x-over around the franken-speaker you have.