I purchased a 15 inch Signature Speaker Model JBL D130F, serial # 68678. I purchased it as an 8 ohm spkr and the label does say 8 ohm impedance. However, it measures 20 ohm resistance.
Do I in fact have an 8 ohm speaker and based on the resistance reading of 20 ohm, is the spkr in proper working condition impedance wise anyway ? Seems to me that measuring 20 ohm resistance, the impedance couldn't be less than 20 ohm either so I am confused. Maybe I puchased a bogus spkr ?
A speaker's actual impedance varies with frequency and is not determined by its DC Resistance. Its nominal impedance is usually higher than its DCR, but can't be determined by measurement of the DCR.
I'll just write this off as a bad purchase and move on. I don't plan to use the spkr. I'll definitely use more scrutiny if I decide to buy another 15 in spkr in the future. Hope you can see why I wanted a 15 in since Chet said he liked a 15 in.
I also would like to see how it sounds. Thanks for getting me refocused. Instead of building it into a quad external spkr like I had planned I'll just put it alone as the external. Can't hurt anything. Your right in line with Chet's thinking. He used to ask Paul every day what he had done to tweak his amp.
Tried the 15 in jbl as external spkr. Sounds great. Adds some subtle depth. If I ever want to play out with though as an external spr I will have to put it in a small exclosure that is manageable.
'I love how she loves me' so I cranked up the tremolo and it sounds great using the Stryman Hall setting (in fx loop) at Big Mo setting. When I had the Revera mod made 30 years ago I opted to save the amp Tremolo circuit rather than save the pristine look of the front panel. I am glad I did. The mod I made installed a Master volume and since I opted to keep the Tremolo, Rivera needed to drive a new hole in the front panel for the Master control over the top of the 'Deluxe Reverb' Logo. My only problem now is short term memory. I am a long ways away from what I did 40 years ago when I practiced the same song for 40 hours on vacation. It's a wonder I'm still married.