Fender PRO 810, 8ohm drivers read 3.8ohms

[Steve Dallman]

I have had dozens of meters over my decades of fixing amps, and a few of them were RS meters, including one very expensive (for RS) digitals. All have failed on me over time, getting false readings, and eventually just not working. I would check with a meter known-to-be-good. Although I use a Fluke most of the time (never failed me over the last 15 years) I have a bunch of inexpensive digital meters that, while purchased around the time I had the RS meters, have never given me false readings. I would want to double check with a different meter that these are indeed 4 ohm speakers, which would be a screwup from Fender.

 

[Bassmec]

Stand aside chaps!
I will measure a professional 8 ohm nominal impedance loudspeaker, made by a proper British chap
who it appears, gets things right all the time, I will measure with a proper professional standard meter that'd does very much the same.
You know waterproof to 200 mts, capable of withstanding 30G in a free fall decent, calibrated to government standards ETC.
All tube digital is far better than solid state digital don't cha know old chap!.
Link Removed

 

[Mykk]

After some online snooping I found out a little more bout these speakers.

Fender part #0057982000

The only number on the speaker itself that got me anywhere was 101241.
"Eminence 101241 10" 250 Watt 8 Ohm Bass Guitar/PA/Mid Bass Speakers - Cast frame models feature 56 ounce ceramic magnets and smooth cones with accordian surrounds. Similar to Delta Pro model."

According to Eminence the Delta Pro 10 is a 350watt 8ohm, 56 oz magnet speaker with a DC resistance (Re) of 5.42 ohms....

I'm about to go get a new DVOM and retest.

Edit: Picked a new RS DVOM, although cheap.... gave me the same reading as the previous.

 

[will33]

+1 to trying another meter. Testing a resistor or 2 you have laying around can help to verify you're getting accurate readings.

Can't believe I didn't think of that seeing as recently I have destroyed 2 speakers and an amplifier by trusting readings from a cheap meter...which I summarily cursed and threw in the trash.

 

[Mykk]

I wired the cab up in a series-parallel for 8ohms (according to my readings). It just didn;t sound right and it's ouput took a back seat to the Mesa 2x15. So instead I wired it up like original and I employed my old Behringer Inuke Nu6000DSP as a slave for just the 8x10. Yes, I know. Cheap poweramp, but it works, it sounds decent and it gets damn loud

Mesa head to mesa cab... FX loop send to Behringer for the Fender8x10. It does lose a bit of it's tube grit getting run through the slave poweramp, but it's nice having the independent volume controls for each cab.

I know the FX send from the boogie is a crossover. But with it set in the middle it sounds to be full range and works for me.

 

[Mykk]

Update:

A while back during a rehearsal I managed to sieze a driver. The coil froze solid to the magnet, so I ordered a replacment. Here is a brand new, from Fender direct replacment (via third party supplier) speaker with identical part #'s-

Checked with both DVOM's. They do match my existing drivers. So, to answer my OP... Yes, Fender 8ohm drivers for PRO bass cabs measure between 3.8-4.1 of DC resistance.

And a 8 x 10" cab loaded with these speakers & 3ft speakon cable measures:

...still freaks me out.

 

[troemer]

Old Thread but... I have just finished going through this situation and in the event someone else experiences this same problem, this information may be helpful.
I think the meter is fine. I checked my speaker with both an Extec and Amprobe meter and came up 4.0 ohm on both.
The labeling on the speaker states a spec of 8 ohm 250w .So I contacted Eminence requesting specs of this speaker and this is the email they replied with :

Hi Troy,


101241 was a custom designed OEM speaker that we manufactured to their specifications. It is a 4 ohm speaker with a 2" voice coil and a 44 oz ceramic magnet. We do not rate OEM designs (that is left up to the customer to test and rate their cabinet or amp), but a conservative thermal power rating based on the voice coil diameter would be about 150 watts. Here are the T/S parameters:


05-RE OHMS 3.90 13-FS HZ 54.84

06-LE MH .45 14-MMS GMS 31.30

07-QM 14.50 15-CMS mm/N .2690

08-QE .480 16-RMS NS/M .7430

09-QT .470 17-VAS LTRS 46.34

10-XMAX MM 3.20 18-SD SCM 350.08

11-BL TM 9.33 19-EBP 113.5

12-EFF % 1.52 20-SPL dB 93.8


Our most similar current stock model is the Legend BP102-4.

Nice to know. I happen to have a BP102-4. I am going to put it in the cabinet tomorrow and see how it sounds and check phase, etc.