I found an old pair of 8" 2-way speakers from the late 1960's in a thrift store and set them up in a small listening room. The sound was okay but vocals and piano sounded veiled.
I opened them up and saw that the crossover consisted of only one 5 uF capacitor in series with the tweeter. I had a couple of Solen 6.2 uF caps so I replaced only one for a side-by-side comparison. No difference in sound.
I also had some Jantzen .4mH inductors so I soldered one in series with the woofer. Vocals and piano from the same recording came to life.
On my to-do list is to purchase a UMIK-1 and do some measurements so that I can try to design a proper crossover for them (and others) but for now, this ad hoc crossover is doing fine.
I opened them up and saw that the crossover consisted of only one 5 uF capacitor in series with the tweeter. I had a couple of Solen 6.2 uF caps so I replaced only one for a side-by-side comparison. No difference in sound.
I also had some Jantzen .4mH inductors so I soldered one in series with the woofer. Vocals and piano from the same recording came to life.
On my to-do list is to purchase a UMIK-1 and do some measurements so that I can try to design a proper crossover for them (and others) but for now, this ad hoc crossover is doing fine.
Measurement is the way to greater refinement. Taking good acoustic measurements is not necessarily easy. If you don't already know some stuff about it be prepared to read up and get some practice. Some folks prefer the dual channel soundcard + analog mic to the USB mic, so that you can get a timing reference. That is what I have moved to, though I did do USB mic with the interference method for a time and was able to make it work for my projects.
I wouldn't monkey with USB mikes. Time alignment is important for a second dimension of quality.
If you have an old PC with a stereo (blue) input jack, you have a stereo sound mainboard. A/D by Intel. No, it won't measure .001% HD. I can't hear that anyway.
What may be missing for condensor mikes, is phantom power. I put a new volume pot in a worn out PV8 mixer for $40. Other mixers worth working on, Alesis, Allen & Heath, early Mackie.
If you are measuring indoors you have to have an omni mike. Also individual driver measurement have to be close miked. Outdoors, I can move 2 m away and the prox effect does not destroy the bass. It is quiet here at 3 AM except for UPS jets.
If you have an old PC with a stereo (blue) input jack, you have a stereo sound mainboard. A/D by Intel. No, it won't measure .001% HD. I can't hear that anyway.
What may be missing for condensor mikes, is phantom power. I put a new volume pot in a worn out PV8 mixer for $40. Other mixers worth working on, Alesis, Allen & Heath, early Mackie.
If you are measuring indoors you have to have an omni mike. Also individual driver measurement have to be close miked. Outdoors, I can move 2 m away and the prox effect does not destroy the bass. It is quiet here at 3 AM except for UPS jets.
The ES-615 is an omni mike. That is correct for speaker measurement. There is a low frequency roll off, I cannot read it. Flat to 100 hz maybe, one line down at XX hz? I cannot read now many db down that is on the left axis.
Depends on the speaker you are building. I am building a 54-15000 hz speaker, so having 54-100 hz down 10 db from the mike would mess up my measurements. If you are building 100 hz up with a 6" woofer or so, no problem.
The ES-615 is dynamic, so no phantom power required. Your cables had best be short and real twisted pair, to avoid 60 hz hum (or 50 hz in eastern hemisphere). Condensor mikes have a transistor in the mike that boosts signal up to 1 v signal and swamps hum up to 100' or so cables.
Depends on the speaker you are building. I am building a 54-15000 hz speaker, so having 54-100 hz down 10 db from the mike would mess up my measurements. If you are building 100 hz up with a 6" woofer or so, no problem.
The ES-615 is dynamic, so no phantom power required. Your cables had best be short and real twisted pair, to avoid 60 hz hum (or 50 hz in eastern hemisphere). Condensor mikes have a transistor in the mike that boosts signal up to 1 v signal and swamps hum up to 100' or so cables.
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Yeah, ES-615 is 3 db down at 50 hz. 2 db rise at 2200 hz. Not too bad.
Box most likely is not tuned to have F3 below 50 hz anyway. Is box ported or sealed? Sealed response tends to end at 70 to 100 hz anyway.
Read all the tips on indoor measurement with REW on this thread https://www.diyaudio.com/community/threads/4-800-hz-wiggle-i-my-3-way-diy.414081/unread to avoid some common mistakes from the beginning.
Box most likely is not tuned to have F3 below 50 hz anyway. Is box ported or sealed? Sealed response tends to end at 70 to 100 hz anyway.
Read all the tips on indoor measurement with REW on this thread https://www.diyaudio.com/community/threads/4-800-hz-wiggle-i-my-3-way-diy.414081/unread to avoid some common mistakes from the beginning.
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Hi !!
This sounds like an excellent learning exercise, but I caution you that gauging the quality of a crossover by the number of parts is not always a good idea. The famous Seas A26 kit has 2 parts.
I don't know why anyone is against USB mics, they are fine. You'll also need a Dayton DATS for the impedance of the drivers and XSim or VituixCAD or similar to put it all together. Good luck.
This sounds like an excellent learning exercise, but I caution you that gauging the quality of a crossover by the number of parts is not always a good idea. The famous Seas A26 kit has 2 parts.
I don't know why anyone is against USB mics, they are fine. You'll also need a Dayton DATS for the impedance of the drivers and XSim or VituixCAD or similar to put it all together. Good luck.
That's exactly how I plan to use these, as a project to learn the basics of crossover design. So far I learned one valuable lesson, replacing an old capacitor with a new one will not necessarily improve the sound of a speaker. Since the new, higher quality capacitor did not improve the muffled mid-range (but adding an inductor did), my guess is that the drivers may have aged more so than the capacitor has, necessitating a crossover redesign for the current driver parameters. This is just an uneducated guess.
I have a Smith & Larson Woofer Tester 2 which the Dayton DATS is based on. I've used it to provide basic data on the drivers but need to setup my computer for acoustical measurements. I'm very happy that my Shure ES615 is an appropriate microphone for testing purposes.
I have a Smith & Larson Woofer Tester 2 which the Dayton DATS is based on. I've used it to provide basic data on the drivers but need to setup my computer for acoustical measurements. I'm very happy that my Shure ES615 is an appropriate microphone for testing purposes.
I found this article you may want to read. In it it has Lozjek's changes to the A26. He suggested leaving the woofer alone but updating the tweeter high pass. I'm not sure he ever actually implemented it, but it was a great and simple suggestion.