JBL L110A refoam and stands

[vrobec]

Hello all!

I refoamed the woofers of my beloved L110A speakers . Please let me know is my refoam job done OK? There is no collision between the coil and the magnet, tested it with 50Hz tone.

87025 87026

[vrobec]

I use stands shown on the picture I attached. Is it better using these stands or go for lower JBL stands?

87027 87028

[Earl K]

I use stands shown on the picture I attached. Is it better using these stands or go for lower JBL stands?

87027 87028


The refoams look great !!

:)

[SEAWOLF97]

stands ? tweet closer to ear level the better., but closer to floor or room corners reinforces bass.

[RMC]

Hi vrobec,

Nice refoam job.

As for the speaker stands, the higher they are and the further you move from 2Pi placement going more in the direction of 4 Pi placement (free field). This decreases room low frequency reinforcement or gain. You decide which LF sound you prefer most based on stand used. The speaker's owner manual should provide some placement guidance.

On the other hand i note you seem to have a hard tile floor which is generally not great acoustically because of sound reflexions it promotes. Another reason why you need to experiment with placement/stands and play this by ear... Regards,

Richard

[macaroonie]

Excellent refoam. Very tidy :applaud:

[BMWCCA]

Your re-surround job looks fantastic!!

Want to do my 10-inchers for me? ;)

[vrobec]

Thank you all! I tried my best. :)

[vrobec]

Hello all!

Just a short question about L110A. Today I measured with DMM the resistance on speaker terminals. One speaker is 5.1ohm, the other is 5.2ohm.
I know the crossovers determines them, but are these values OK? The speakers sounding fine, but the specification say 8ohm.

[RMC]

Can't say if what you measured is correct or not. But the 8 ohm spec is a NOMINAL figure only. Its not unusual for speakers to actually measure lower than spec.

Richard

[vrobec]

Can't say if what you measured is correct or not. But the 8 ohm spec is a NOMINAL figure only. Its not unusual for speakers to actually measure lower than spec.

Richard

Just measured L19 speakers with DMM. They are 5.7ohm and 5.8ohm.

[RMC]

Just checked, i have DCR factory specs for most drivers alone, but not for systems unfortunately.

Richard

[vrobec]

Just checked, i have DCR factory specs for most drivers alone, but not for systems unfortunately.

Richard

Thanks for posting. Please, where can I find these specs for JBL drivers?

[RMC]

You can find some of this info in the Technical Manual of a driver or system (for those who have such sheet). In the attached example for L100T3 system look at the top of page 2 the DCR min./max. of each driver used is indicated. I have a JBL document with an extensive DCR numbers listing but cannot pass-on this one to you. If you have a specific driver DCR range enquiry i'll try to answer it.

88305

[vrobec]

You can find some of this info in the Technical Manual of a driver or system (for those who have such sheet). In the attached example for L100T3 system look at the top of page 2 the DCR min./max. of each driver used is indicated. I have a JBL document with an extensive DCR numbers listing but cannot pass-on this one to you. If you have a specific driver DCR range enquiry i'll try to answer it.

88305

Thank you. I need the specs for the following drivers: LE26, 116H, 033, LE5-10, LE111H

[RMC]

I added the comments on the list

LE 261 (might be LE26-1? no LE 26 on the list), 3.4-4.3 ohm, Plastic Flange

116H 4.8-5.6 ohm

033 3.6-4.4 ohm, Test with Network

LE5-10 4.9-6.1 ohm

LE 111H 4.3-5.2 ohm, Aquaplas on back of cone

* Not too many drivers at a time please, i do this when i get some spare time.

[vrobec]

I added the comments on the list

LE 261 (could be LE26-1? no LE 26 on the list), 3.4-4.3 ohm, Plastic Flange

116H 4.8-5.6 ohm

033 3.6-4.4 ohm, Test with Network

LE5-10 4.9-6.1 ohm

LE 111H 4.3-5.2 ohm, Aquaplas on back of cone

* Not too many at a time please, i do this when i get some spare time.

Thank you very much, you helped a lot. :)
If you have a little time to take look at LE111A woofer specs and post it here.

[RMC]

Requested DCR specs for LE111A

Min. 5.5 - Max. 6.5 Ohms, Aquaplas on the back of the cone

[vrobec]

Requested DCR specs for LE111A

Min. 5.5 - Max. 6.5 Ohms, Aquaplas on the back of the cone

Thank you!
According to the posted specs the LE111A has nearly 1.2 ohm higher DCR than the LE111H.
The L110 has (with 033, LE5-10 and LE111A drivers) higher resistance (6.3-6.6 ohm) measured on speaker terminals. My L110A (with 033, LE5-10 and LE111H drivers) has 5.1 and 5.2 ohm.

[RMC]

Just to be sure your results are correct, have you "calibrated" your DMM, meaning measured its residual resistance? Put DMM in ohm mode, join the two test leads together for a few seconds until data stabilizes, and note the number indicated, which you must subtract from DCR driver or speaker readings.

Depending on DMM accuracy (quality and price) it may show enough resistance by itself to falsely indicate a driver is off specs. My low cost ($25-30.) DMM has 0.6 - 0.7 ohm residual resistance (enough to fool a DCR reading), while the $80. unit has 0.0-0.1 (nice), and the $150. DMM is a perfect zero residual resistance. Try it with yours, you'll see. Mabe you'll need to revise your DCR numbers.

It is possible JBL's switch to ferrite magnets has caused some other changes, like in DCR numbers.

[vrobec]

Depending on DMM accuracy (quality and price) it may show enough resistance by itself to falsely indicate a driver is off specs. Maybe you'll need to revise your DCR numbers.


You were right. I have to subtract 0.2 ohms. So the real DCR values for speakers are 4.9 ohm and 5.0 ohm, measured on terminals.