Vintage K110 JBL Speakers

[Ed Monkiewicz]

This pair of Early 70's Vintage K110 JBL speakers is a rare find! FYI these are 10" 8 ohm speakers with solid Alnico magnets.
Very little usage despite their age and never driven b eing used used primarily for low volume Jazz playing.
Come with a 21-day free trial period. Buyer pays return shipping! Please contact if you have any questions. Your inquiry will be answered honestly and quickly.
$550 with free shipping.

[marcwhy]

Cool speakers!

[Ed Monkiewicz]

Marc. Can you help me out with that? I always have such a problem doing this each time I try to post something. Thanks

[Gitterbug]

Those look incredibly fresh for 50-year old speakers. HiFi experts are welcome to correct me, but I think very little positive development has taken place in that field. Rather, DSP is used to make inferior speakers sound ok. The Wharfedale speaker my dad got as a 50th birthday present in 1966 still sound great, and so do my MB Quart floor speakers from the late 1980s.

[Rex Anderson]

Good morning; Interested in your JBL's. Where are you located?

[Ed Monkiewicz]

thanks for your kind reply. Yes, that's what I found out, however some are of the opinion that speaker cones become 'flabby' or 'tired' after however that doesn't appear to be the case from my experience. I recently decided to replace the cabinet that I had these housed in where they sounded great. After selling the cabinet I carefully stored these in my bedroom closet for a few months. Upon buying a new cabinet I experienced an issue with distortion which I never encountered previously and thought " what in the world is going on?" At first, I connected the wiring harness incorrectly doing so in parallel instead of series so I thought that this is what was possibly wrong. Then changed it back to a series connection. Same issue? Then tried each speaker independently to ascertain which was working and which was distorting. I got one to sound fine and the other not, so I wondered if I could improve on these speakers given their age, by having them at least re-magnetized (since I heard on JBL's that can be an issue after a number of years) if not re -coned. I felt it would be worth the $200 to find out- since I'm all about the best sound money can buy. I sent the one off to California to a reputable JBL reconditioning service and they got to me explaining that the ______ has been damaged. How? I couldn't imagine! The speaker had been in the closet. The only thing I could think is that when I packed it, I pushed the cone into the box which had pre-formed styrofoam and thought perhaps I was too rough with the cone side of the speaker??? I'm not sure if the service pro guy was pulling my leg of not as I will explain shortly but I figured: " I already paid shipping out to Ca. and was curious as to whether a re-cone would make a difference so I told him to go ahead with the repair.
Now here is where it gets interesting. I was excited when the speaker came back but disappointed after installing it that I was experiencing the same distortion issue. I called a speaker specialist in town being in a quandary as to what was going on and he mentioned that when installing dual speakers both have to be connected wiring wise if they are both in the cabinet even if you are only checking one at a time which is what I was doing at least in this instance to get an of any sound difference. So I took each out and checked them again and each worked fine. So it made me wonder: " Is that what I possibly did wrong the first time?"
In hindsight I don't think so because I did connect both at the same after realizing I had connected them in parallel and went back to doing so in series, double checking my installation. At least I wish to think that was the case and that the repair pro guy was being honest with me. This is a circuitous way of responding to your observations mentioned in your message. The end result was this. Even after 50 years the reconditioned sounded no better than the other one which was untouched; even with the one being 're-magnetized'. Though costly, it answered some unresolved question in my mine and I leaned something about speaker installation and testing. Of course I'll never get my money back selling these at the price advertised but you don't always as I'm sure you've found out in life. I hope you enjoyed this little tale. Ed

[nevershouldhavesoldit]

These are wonderful speakers that I’d gladly buy if I weren’t so old. I have a 2x10 2x6L6 Fender clone that’d be perfect for them. But with big Mercury transformers, it already weighs 50+ pounds with two neos in it - so it hasn’t left home since I got it (it was Jazzkritter’s). These are a great buy.

But I’m confused about the “distortion” issue. At home volumes, a 4 Ohm mismatch either way shouldn’t cause distortion with most amps. Unless I missed it, you haven’t told us their nominal impedance. If these are 4 Ohm speakers and you connect them in parallel, a 2 Ohm load could be too low for many amps to drive at their rated power and distortion. But unless you push the amp close to its maximum rated output, even 2 Ohms should sound OK. Individually, a 4 Ohm load shouldn’t cause distortion from pretty much any amp at reasonable listening levels, even if you connect it to the 16 Ohm tap on a tube amp’s output transformer.

The cone surround is vulnerable to deterioration from aging, and the voice coil can be knocked out of coaxial alignment. But both would have been fixed by a recone, and you also had it remagnetized. So I don’t understand the distortion issue. My bet would have been a cabinet problem, especially if it occurred with one in and one out of the baffle.

The speakers are almost certainly fine, and these are truly great ones. But buyers should know the impedance. If you stated it but I just don’t see it, I apologize.

[Ed Monkiewicz]

You make a great point1 I just assumed everyone would know that these are 8 Ohm speakers. It wished that I knew you when I was having all these issues, but I think you misunderstand what I was saying.
The problem was one I never thought would occur, only to find out from a local guy who specializes in speaker design etc. This sounds crazy but in a two-speaker cabinet you can't have one hooked up and the other simply mounted or the unconnected one somehow interferes with the other one causes a lack of clarity or mild distortion. I had to test one speaker at a time with the other out of the cabinet, then install them both wired in series, although I don't believe that matters.
In addition, here's the real problem. I sold the original cabinet these were in which was a Port City designed for two 12's It was a great cabinet but like yourself I'm no youngster and it was killing my back. With the JBL's it was well over 50#. So, I sold it and bought one from Mojo Tone. An American Custom touted for being light. However, unless there is something I"m missing the tonal output was nothing like I experienced when I had these speakers in the Port City. I Am a real aficionado when it comes to sound so immediately noticed the difference. Can a speaker cabinet make that much difference in sound quality?
Before I leave I'd like to address the re-magnetizing matter. I've been told from JBL forums that the Alnico magnet on these speakers have a half-life of 50 years meaning they lose half of their 'verve' after this period which was another reason I had the one speaker re-magnetized to see if it really made a substantial difference since this is the speaker I was having re-coned and the cost was only $35. My conclusion is, I didn't hear a difference. Audio Sound in Atlanta told me that this is a 'scam' but they also said that JBL's should not be housed in a closed cabinet or it ruins them. I've never experienced that. So you don't know who to believe.Hey it's great meeting someone like you that knows so much. Wish we could meet you in person sometime. Lert me know what ideas you have cabinets and speakers in general. I'd love to hear from you on this. ED

[nevershouldhavesoldit]

I think you misunderstand what I was saying. The problem was one I never thought would occur, only to find out from a local guy who specializes in speaker design etc. This sounds crazy but in a two-speaker cabinet you can't have one hooked up and the other simply mounted or the unconnected one somehow interferes with the other one causes a lack of clarity or mild distortion.

That's not exactly true. What you describe is called a passive radiator system - an active driver and a passive driver in the same cabinet. These are usually sealed cabinets, since the passive driver is being "driven" by the back pressure from the active one. It can be done in an open cab, but the effect is very limited unless the cabinet is airtight. In truth, the effect is not huge even in the best designed systems. But it does tighten up bass and can sound great in some cases.

Resistance is applied across the passive speaker's terminals to make the voice coil a kind of regenerative brake that damps the movement of the passive cone. This control affects the cabinet's internal pressure, so it also damps the active radiator to some degree. You can use a variable resistor (eg a pot) to tune the damped passive speaker for best frequency response in a given cab. This approach only works in the lows, so it's typically used in a subwoofer or the low frequency section of a multiple driver speaker system.

I've built several subs like this and it works great. But leaving the passive radiator with open terminals only makes the bass a bit flabby at the worst. You described hearing unspecified distortion from one of the two speakers but not the other. Your description suggested that you simply connected one at a time in the same cabinet, leaving the other in place but unwired. So why one would sound right but the other distorted (if that's what you did) makes no sense to me. And if the cabinet has an open back, I wouldn't excpect any audible difference from a passive radiator in the same cabinet.

Parenthetically, this is a big problem in audio and musical instrument showrooms. A single passive radiator won't have much effect. but all of the speakers in the room are effectively passive radiators, and the presence of multiple units has an effect on what you hear when you audition speakers. This is one reason for guitar amps and audio systems to sound different in a showroom from the way they sound when you get them home. The only way to even approximate what you'll hear at home is to audition amps and speakers in a room with no others. One driver won't affect much, but 30 will.

[Ed Monkiewicz]

Your information in very interesting. I always wondered why an amp can sound so different in a music store and when I get home it doesn't sound quite the same.
Anyway, here's my next question. Why would one speaker be passive and the other active when they are identical in every way. What would constitute the difference in such a situation. For clarification on this [You described hearing unspecified distortion from one of the two speakers but not the other. Your description suggested that you simply connected one at a time in the same cabinet, leaving the other in place but unwired. So why one would sound right but the other distorted (if that's what you did) makes no sense to me] When two were installed in the cabinet and only one was wired or connected, the OVERALL effect was distortion. I had no way of testing the other speaker without removing the unwired one from the cabinet and conversely doing the same with the other, which is what I did, and it worked. The original cab (Port City) was a closed unit) the newer one had an open back but that still shouldn't account for the sound difference I experienced. I'm still investigating it perhaps with the help of the local amp guy here in town who specializes in speaker design etc. Thanks again for your input.

[nevershouldhavesoldit]

Why would one speaker be passive and the other active when they are identical in every way.

The speaker that's wired to the amp is active because it's powered by the amplifier. The one that's not connected is passive because the cone assembly is only being pushed back and forth by ambient air pressure waves. This is why the passive radiator concept only works successfully in a closed cabinet. In an open cab, the active cone isn't changing the pressure on the back of the passive cone very much because the pressure waves are propogating through the open air. This presumes that the two are in the same cabinet.

I had no way of testing the other speaker without removing the unwired one from the cabinet and conversely doing the same with the other

Why not? All you had to do was disconnect one at a time and put it back. If you'd done that, you would have heard the same thing regardless of which speaker was active and which was passive if both were fine. Similarly, you could have removed one at a time to hear what the other sounded like on its own.

If you removed one speaker at a time from a sealed cab, the cab was no longer sealed. A 10" hole is far larger than any functional port would be in a cab for twin 10s, so the hole itself would have virtually no effect on the frequency response of the speaker. But the difference between a closed cab and an open one can be startling. Depending on the Qts and overall design parameters of the speaker, an unsealed cab might have a large overall effect on its sound compared to a sealed cab. But it would obviously have the same effect on both of your speakers if they're fine. One wouldn't sound any different from the other.

The Qts of a K110 is 0.36, which means that the cone & VC assembly are well damped and have few significant resonant peaks. Most speakers with total Qs below about 0.4 sound best in ported or ducted enclosures. Most of those with total Qs between about 0.4 and 0.7 sound best in sealed cabs, and most of those above about 0.7 sound best in open back cabs. There are many exceptions to this, and I've had a few low Q speakers that sounded great in open back cabs. But the quality of sound from a speaker is not infrequently quite different in open and in closed cabs.

I'm glad you have them in fine shape and hope you soon find a buyer who appreciates how great these speakers are. I love their sound!

[Ed Monkiewicz]

Thanks so much, never should have sold it. You're very generous with your time and knowledge. I really appreciate it.
The original cab the speakers were in, was a closed cabinet designed for two 12" speakers although I did see how that would really matter. The issue I had was when both speakers were installed but only one was hooked up. I was told this was the crux of the matter and it panned out to be true whether that makes acoustic sense or not. The replacement cab is ported and very light compared to most cabs. which I why I bought it. I agree with you that these are 'great speakers' but can't figure for the life why I seem to be experiencing a different tonal response since I changed out the cabs. Both speakers sound equally good when played through separately, so it's not like one speaker is affecting the overall sould output of the two. I hear very little difference.
You are right when you say that these are great speakers and I"ve enjoyed having them the last six years or so. But I own a 12", 16-ohm 1961 JBL speaker[D131] (which sounds awesome) in a custom cabinet as well as a Raezers Edge cab so the additional speakers are more than I need at this point in my life even though I bought a new cab to house them in. If I find out more, I'll let you know. That's all for now. Stay tuned. ED
PS The reason I had the other speaker repaired; even though it was in perfect condition before putting it in storage for a few months, was that it seems in handling it, I inadvertently damaged the voice coil: at least that's what the repair shop thinks.??? Guess I'll never know but I do know who to call in the future when dealing with speaker issues or decisions.