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 ?
Re: JBL D130F Spkr question
Put it face-up on your bench. Connect the meter. Carefully, slightly depress and release the center, pressing just outside the perimeter of the dust cap--keep the cone centered (not rub). Does the meter return to the same reading each time when released? I think some of the old jbl's were all 16 ohms, even though they might have been labeled otherwise. Bad speakers, they say, usually read really low, or way, way high--in the megaohms. Hook it up and play it! LMark
- LMark
- Posts: 360
- Joined: Tue Aug 17, 2010 10:23 pm
- Location: Minneapolis
Re: JBL D130F Spkr question
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.
- bill raymond
- Posts: 124
- Joined: Mon Aug 16, 2010 10:58 pm
Re: JBL D130F Spkr question
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.
- lovechet
- Posts: 18
- Joined: Sat Jan 28, 2012 7:56 am
Re: JBL D130F Spkr question
How does it sound?
- PaulBennett
- Posts: 41
- Joined: Fri Aug 20, 2010 4:25 am
Re: JBL D130F Spkr question
Yeah! @lovechet, hook it up and play it! Don't ditch it just yet. LMark
- LMark
- Posts: 360
- Joined: Tue Aug 17, 2010 10:23 pm
- Location: Minneapolis
Re: JBL D130F Spkr question
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.
- lovechet
- Posts: 18
- Joined: Sat Jan 28, 2012 7:56 am
Re: JBL D130F Spkr question
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.
- lovechet
- Posts: 18
- Joined: Sat Jan 28, 2012 7:56 am
Re: JBL D130F Spkr question
Bravo!
- LMark
- Posts: 360
- Joined: Tue Aug 17, 2010 10:23 pm
- Location: Minneapolis
Re: JBL D130F Spkr question
Ext spkrs as I am finding make a large difference, however in my secluded 12 x 12 office the extra spkr although adding bottom makes the air flow overbearing and you can't turn the amp up at all. In a large room I think that's where they should be used. I am 75 and will most liklely will never go beyond my practice room, ie I am a back porch picker although having been doing it for 55 years. In any case I am moving on and concentrating on just my Delux amp and my setup with possibly changing out to a Patriot Canibus Rex. I changed the V2 ch 2 preamp and the fx loop tube to JJ's and am experiencing satisfaction never had before. In addition to the JJ tubes change I think the Signal Pad is a big part of what made my sound satisfactory since I can turn if down and still get the tone from the pickups. Just recently I heard
'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.
'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.
- lovechet
- Posts: 18
- Joined: Sat Jan 28, 2012 7:56 am