Hi, hoping someone can help me figure out what's wrong here. I just bought a pair of Joseph Audio Profile speakers second hand and when I unpacked them and hooked them up, one doesn't function. Apparently they were fine before being packed up and there is no refund or option for me other than to fix them or send them out for repair. The seller swears they functioned perfectly prior to boxing and selling and has been trying to help by getting the receipt from authorized dealer he purchased them from, but the dealer is not responding and the seller now thinks the dealer lied about them being his demo pair and that they may actually be used which is why no receipt is being provided. Jeff Joseph has been helpful but stated he needs a copy of this receipt for warranty repair for seller. The paypal receipt won't work and Albert from Precision Audio and Video in Chicago who sold the speakers on Audiogon as new/demo appears to be ignoring the seller's requests for a receipt. Unfortunately, from what little research I have done, it appears this "authorized dealer" has a reputation for schiesty business practices. The two reviews of his business, both one star, complain of dishonest practices, bait and switch type stuff, and not holding to agreements. Now refusing or ignoring a request for a sales receipt by the purchaser so he can have the speaker repaired under warranty. The seller has been in constant communication with me trying to fix the issue, but it is a case of he said/she said regarding my purchase. I didn't get to hear the speakers prior to taking them home. He claims they worked perfectly when he boxed them and that he had been enjoying them in his system a few weeks prior to me picking them up and I know I did nothing but unpack and hook up and one didn't work. It is my fault for being trustworthy and agreeing to meet up and purchase unheard. Lesson learned. Regardless the seller is not ignoring the issue, and I feel he is being honest with me and is trying to help. He has a long history of perfect feedback and I believe it to be accurate. I believe he is also willing to split repair costs if it comes to that, but I'd like to get the receipt and have warranty repair if possible, or figure out what is wrong with all of your help. Thanks for your time and input ahead of time! Please just reply to what you think is wrong with the speakers and how they might be fixed. I don't want responses regarding what I should have done with the purchase. I know what I did wrong and have learned my lesson.
This is what is happening. I unboxed them and hooked them up to my amplifier. I am using a VTA ST-120 and VTA SP-14 exactly like Don Sachs line stage. Romex wire runs from the 4 ohm taps of the ST-120 amp. I have verified that there is a signal coming from the amp on both channels, so I know everything up stream is functioning perfectly. One speaker has sound, the other doesn't. Switch channels and the good speaker works on the other channel but the one in question does not. Speakers are 6 ohm. On multi-tester I get resistance of 5.5 ohm on good speaker and 0.5 ohm on one not working. There is zero sound from any of the drivers. That includes tweeter, mid-bass , and woofer. Not a sound at all. The speakers both have continuity when I touch multi-tester leads to negative and positive speaker posts. Does this mean I don't have a disconnected wire or break in the circuit anywhere?
So what could be wrong here? I know I have signal getting to the speaker, but I get no sound from any of the drivers at all! The resistance is off, but it appears that I still have a closed circuit and therefore nothing is loose or disconnected. Is this a correct interpretation of continuity at the speaker posts? What could be the issue? Why no sound at all? Shouldn't there be noise coming from one or more of the drivers if the crossover had a problem? Does no sound at all mean there is a disconnect somewhere? If so why am I still getting continuity at the posts? I did open it up and look inside and although I can't see everything, I did not see anything loose. Please help!!! I don't want to have to pay to ship these to Joseph audio and then pay for repairs on top of the cost of the speakers, but will if there is no other option.
This is what is happening. I unboxed them and hooked them up to my amplifier. I am using a VTA ST-120 and VTA SP-14 exactly like Don Sachs line stage. Romex wire runs from the 4 ohm taps of the ST-120 amp. I have verified that there is a signal coming from the amp on both channels, so I know everything up stream is functioning perfectly. One speaker has sound, the other doesn't. Switch channels and the good speaker works on the other channel but the one in question does not. Speakers are 6 ohm. On multi-tester I get resistance of 5.5 ohm on good speaker and 0.5 ohm on one not working. There is zero sound from any of the drivers. That includes tweeter, mid-bass , and woofer. Not a sound at all. The speakers both have continuity when I touch multi-tester leads to negative and positive speaker posts. Does this mean I don't have a disconnected wire or break in the circuit anywhere?
So what could be wrong here? I know I have signal getting to the speaker, but I get no sound from any of the drivers at all! The resistance is off, but it appears that I still have a closed circuit and therefore nothing is loose or disconnected. Is this a correct interpretation of continuity at the speaker posts? What could be the issue? Why no sound at all? Shouldn't there be noise coming from one or more of the drivers if the crossover had a problem? Does no sound at all mean there is a disconnect somewhere? If so why am I still getting continuity at the posts? I did open it up and look inside and although I can't see everything, I did not see anything loose. Please help!!! I don't want to have to pay to ship these to Joseph audio and then pay for repairs on top of the cost of the speakers, but will if there is no other option.
Quite a daunting wall of text.
If you have 0.5 ohm then you have a short somewhere by the look of it.
You say you've had the speaker cabinet apart already. I'd suggest having a close look at the crossover.
But first, if possible, disconnect the speaker driver from the circuit and test for continuity directly at the speaker terminals. Hopefully that'll help narrow things down.
Is there a reason why you are running 8 ohm speakers from a 4 ohm tap?
Looking at the Joseph Audio website, they dont seem particularly forthcoming with the technical specs of those speakers. Any idea what power handling these speakers can manage?
If you have 0.5 ohm then you have a short somewhere by the look of it.
You say you've had the speaker cabinet apart already. I'd suggest having a close look at the crossover.
But first, if possible, disconnect the speaker driver from the circuit and test for continuity directly at the speaker terminals. Hopefully that'll help narrow things down.
Is there a reason why you are running 8 ohm speakers from a 4 ohm tap?
Looking at the Joseph Audio website, they dont seem particularly forthcoming with the technical specs of those speakers. Any idea what power handling these speakers can manage?
Measuring 0.5 dcr means very bad news, usually toasted driver voice coils and the small dcr is probably from the low pass inductor which appears to be still alive. As avtech said, each driver is to be detached from circuit and remeasured in regard to its dcr. Either have the drivers repaired by a professional to the same spec as the other functioning ones, or purchase new ones. No need to send the speakers to manufacturer. Just order the parts needed. The crossover should be checked also.
So I took all the drivers out of circuit and tested them individually. Both mid/woofers measured around 5.5 ohm. The speakers are 6 ohm speakers. The tweeter measures a little less around 5 ohm. So it appears the drivers are good. Does this mean I have a bad inductor somewhere in the crossover? there are 4 of them I believe in this infinite slope crossover. Can I test them in circuit or do I need to remove the crossover and take them out of the circuit to test them? How do I know what they should measure?
I need to clarify. Not 4 inductors. It appears there are three chokes? These look like a coil but have a magnet in the middle right? Then there is a single inductor?
Please take a photo of the crossover and post the picture here. Coil with a "magnet" in the middle is a ferrite core coil.
Ask the manufacturer for crossover schematic. Carefully examine the crossover for any short circuit. "Infinity slope" crossover uses magnetically coupled inductors, as I recall.
Ask the manufacturer for crossover schematic. Carefully examine the crossover for any short circuit. "Infinity slope" crossover uses magnetically coupled inductors, as I recall.
Bennyhaha81,
1) There are a number of components and wires in a crossover that could short out the input, a shorted inductor is unlikely unless it appears charred to a crisp, and would not result in "no sound", just "different sound".
Look for anything that may have got loose and shorted the input.
If a series capacitor shorted it could result in a parallel inductor causing a short.
You can measure for shorted capacitors while in circuit.
2) Coils DC resistance may be anywhere from near a dead short, <.05 ohms, to upwards of an ohm depending on the length and gauge of the wire, so measuring resistance in circuit would be of little use. Inductor values (in millihenries) can be checked out of circuit with an LCR meter.
3)You'd need a schematic, or could compare them to the working speaker.
4) Choke, coil and inductor are three names for the same component, which can have either an air core (empty bobbin) or a solid core, usually made of iron or ceramic ferrite which looks like the same material as a speaker's "slab magnet".
Art
I only have a multimeter. I have never worked on speakers before. I build amps and preamps for Bob Latino and Roy Mottram. This is a first for me. A quick online look shows these meters your referring to are pricey. I wonder if it’s possible to troubleshoot this without one? If not, it maybe cheaper to pay someone to fix it? I am in western MA. Anyone near me?
Found the problem. Speaker posts were shorting on the metal plate they run through on the back of the speaker!
My factory built Tubes4HiFi / VTA M-125s were built by one Ben Woloss.
As delivered the amps were very noisy < 55db. Assembly was extremely poor.
Cold solder joints, uncleaned PCBs, bolts not tight, 500VDC lead pinched between transformer and case, wiring errors.
Before & After rework noise:
Complete sad story of non-support and changes that increase the SNR to > 90db in teaching the Tubes4HiFi / VTA M-125 to sing