I built an F5m amp and used an old pair of infinity bookshelf speakers for testing. I inspected them and the foam just disintegrated when I touched it. I need new test speakers.
Does anyone have suggestions on the cheapest/best minimum test speaker setup? I was just going to buy pawnshop speakers tomorrow but am now thinking I should ask since used/blown/old/defective speakers could harm the amp? Since they will only be used for testing, is there something simple I should get like a car speaker or desktop PC speaker? If I buy used, I would need to test the speakers first. ( chicken and egg ) I guess I need something geared for testing and that will be 'easy' on my amp during testing. ( unlike my blown 30 year old infinity speakers )
I though I should ask before I buy, since I don't want to cause damage during testing. Also, someone may have ideas like incorporating dummy load resistor with a switch.
Does anyone have suggestions on the cheapest/best minimum test speaker setup? I was just going to buy pawnshop speakers tomorrow but am now thinking I should ask since used/blown/old/defective speakers could harm the amp? Since they will only be used for testing, is there something simple I should get like a car speaker or desktop PC speaker? If I buy used, I would need to test the speakers first. ( chicken and egg ) I guess I need something geared for testing and that will be 'easy' on my amp during testing. ( unlike my blown 30 year old infinity speakers )
I though I should ask before I buy, since I don't want to cause damage during testing. Also, someone may have ideas like incorporating dummy load resistor with a switch.
6.5, 8 or even 12” single wide range driver. Higher power is better, but can get expensive. The BOFU clones are good enough and cheap enough and will take small mishaps before having to spend another $20 on a new one. 12” dual cone PA driver (Eminence, Celestion, etc), can easily take 15 or even 30 Volt DC faults but start over $100. They can also be used to blast test at clipping (with music) with up to 200W if the bass isn’t cranked.
Is lower sensitivity and higher impedance easier on the amp? Since I will use them just for testing and not enjoying music, I'd be ok with a full range car speaker or something outside of an enclosure too. So far, I'm thinking of going to the pawnshop but rather get something new I think. Car speakers are the cheapest but at 4ohm and not sure on sensitivity. I'm thinking maybe old speakers can have damaged coils that could short or mess with the DC offset or something.
I suggest you consider a re-foaming kit for your current speakers if the disintegrating foam is their only problem. It's usually not very difficult.
To give you protection from large DC offsets from faulty amplifiers - consider fitting a series capacitor?
The largest value capacitor intended for use in a crossover network will be fine.
The largest value capacitor intended for use in a crossover network will be fine.
@jordheis I considered re-foaming but then I though there was a risk I would damage or cause the coil to short or introduce a DC offset. The speakers are worth just about as much as the re-foaming kits. I'll consider this in the future but maybe not for my test speakers. ( also would take several days to get it )
Yep, since you have time pressure any functioning speaker will get you going. I like small size speakers as my testers so they take up less space on the bench shelf. Good luck!