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Post by boomzilla on Jun 6, 2020 17:08:31 GMT -5
So I've got a new set of speakers in the house for review. The left one is significantly louder than the right. It is not a room acoustics thing - I can put my fingers on the woofer of the left and feel it moving a LOT more than the woofer of the right.
So I troubleshot, working from the source forward.
The Roon player program has no way to alter balance, so the signal out must be identical.
I checked the DAC by substitution - using the MacBook Pro's internal DAC instead - no difference - the left is still louder.
I changed the interconnects (twice) between the DAC/Preamp and the power amp - no difference - the left is still louder.
I changed the power amplifier (twice) between the DAC/Preamp and the speakers - no difference - the left is still louder.
So far as I can deduce it's got to be either a bad speaker wire (?) or a defective speaker.
I'm taking an "irritation break" just now, but would welcome any other ideas.
Thanks - Boom
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Post by creimes on Jun 6, 2020 17:14:40 GMT -5
Crossover issue, are all the drivers in each speaker producing sound ??
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Post by boomzilla on Jun 6, 2020 17:21:13 GMT -5
Yes - All drivers are producing sound - but all three drivers on the right are at a lower amplitude than the three on the left.
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Post by Gary Cook on Jun 6, 2020 17:30:53 GMT -5
Do the speakers come in different impedances, say 4 ohms versus 8 ohms? Maybe you have a 4 ohm one and an 8 ohm one?
Cheers Gary
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Post by boomzilla on Jun 6, 2020 17:34:08 GMT -5
I measured the speaker wires with the VOM:
R+ = 0.10 Ohms R- = 0.15 Ohms
L+ = 0.01 Ohms L- = 0.01 Ohms
So amps would see 8.25 ohms on the (weaker) right speaker to 8.02 ohms on the (louder) left one. Is that extra 0.23 Ohms enough to make an audible difference? It's only a 2.9% difference between the two speaker cables...
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Post by ttocs on Jun 6, 2020 17:40:38 GMT -5
Have you switched Left to Right? Play the Left Channel on the Right Speaker, Right Channel on the Left Speaker.
edit: Actually, I'd take the speaker wires and switch them between the speakers so EVERYTHING up to the speaker has been switched. Then if the levels stay where they were you know for sure it's a speaker.
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Post by boomzilla on Jun 6, 2020 18:01:25 GMT -5
Have you switched Left to Right? Play the Left Channel on the Right Speaker, Right Channel on the Left Speaker. I‘m going to swap speaker wires next. If the right speaker remains weak, it’s defective. And as Mr. Jim Nabors used to say, "Surprise, surprise, surprise!" I changed speaker wires and the imbalance immediately went away. One problem solved. The next is going to be thornier - There is NO bass from the speakers in my room, regardless of placement. A break-in issue? Maybe. What bass that is there is very muddy. Neither of the tube amps (10-watt Monoprice or 12-watt Heathkits) can control the woofers. Another break-in issue? Maybe. I've tried boosting the bass with Roon's DSP and with the Monoprice's bass tone control. Both give me more bass, but NOT crisper bass. So tomorrow I'm going to use a "no-tube" system: AURALiC Vega directly into the PA-1 mono blocks. If that doesn't tighten up the bass, I'll borrow a Crown DC-300a. And there's another issue: I put on DJ Magic-Mike's "You Want Base?" (sic). The woofers distort heavily and sound like their voice coils are dragging at any frequency significantly below about 36 Hz. There's also a "rattling" sound from the cabinets. At first, I thought it may have been the magnetic grills vibrating, but it persisted even with the grills off. The amplitude for the "bass limbering" Magic-Mike cut was NOT that high, either. If FedEx dropped the pallet on the way to me, Both woofers may have become "off center" and be dragging their voice coils. This would account for both the lack of bass and the muddy bass. Tomorrow, I'll physically stroke the woofers with the power off and my ear immediately proximate to the voice coil cap. If I hear dragging, I can upend the speakers and play them for a day or two with the woofer suspension being pulled in the opposite direction by gravity. I can then repeat the test to see if I still hear the voice coils dragging. Yes? The speakers are damaged & need to go back home. No? Maybe I can put them right side up again. That's one of the problems with big woofers - the weight of the cone, surround, and voice coil can sometimes pull the spider and surround off-center. If youse guys got any other ideas, I'm open to them. Thanks again - Boom
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Post by Ex_Vintage on Jun 6, 2020 22:23:18 GMT -5
Request new speakers. The uncertainty of the review is too high. The manufacturer should agree.
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Post by vcautokid on Jun 7, 2020 0:05:42 GMT -5
I agree the usual swap left to right and right to left issue does not move. Issue is the speakers. Not what anyone would be pleased about, but at least that is what it sounds like to me.
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KeithL
Administrator
Posts: 9,902
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Post by KeithL on Jun 7, 2020 3:39:53 GMT -5
I must be missing something... I don't hear any "uncertainty"... If the voice coils of any of the drivers were "dragging" then you would hear grating noises when they play... You would also notice that they either drag, or don't move at all, when you push on them...
Now, if one or both sat on their face, or on their rear, for several days in shipping... The cones may have sagged forward or back... And, depending on the speaker, this could put the voice coil partially out of the gap, which could reduce efficiency...
(But you would be able to see that the drivers were sitting forward or back of center.)
The imbalance went away when the speaker wires were changed... That seems to implicate a bad speaker cable or, more likely, a loose connection somewhere... (A loose connection could be pretty well anywhere.)
As for bass... we are talking about 10 watt tube amps here. That means relatively little power... and very low damping... so very little ability to "force the woofer to do what you want"... If the woofers are relatively stiff, with relatively powerful motor assemblies, they may require a powerful amp with good damping to drive them well...
I would expect a bit more bass as they break in - because, as they break in, the surrounds on the woofers will get softer... Depending on the speakers they may also simply have slightly rolled-off bass... which is going to exacerbate this issue.
Have you switched Left to Right? Play the Left Channel on the Right Speaker, Right Channel on the Left Speaker. I‘m going to swap speaker wires next. If the right speaker remains weak, it’s defective. And as Mr. Jim Nabors used to say, "Surprise, surprise, surprise!" I changed speaker wires and the imbalance immediately went away. One problem solved. The next is going to be thornier - There is NO bass from the speakers in my room, regardless of placement. A break-in issue? Maybe. What bass that is there is very muddy. Neither of the tube amps (10-watt Monoprice or 12-watt Heathkits) can control the woofers. Another break-in issue? Maybe. I've tried boosting the bass with Roon's DSP and with the Monoprice's bass tone control. Both give me more bass, but NOT crisper bass. So tomorrow I'm going to use a "no-tube" system: AURALiC Vega directly into the PA-1 mono blocks. If that doesn't tighten up the bass, I'll borrow a Crown DC-300a. And there's another issue: I put on DJ Magic-Mike's "You Want Base?" (sic). The woofers distort heavily and sound like their voice coils are dragging at any frequency significantly below about 36 Hz. There's also a "rattling" sound from the cabinets. At first, I thought it may have been the magnetic grills vibrating, but it persisted even with the grills off. The amplitude for the "bass limbering" Magic-Mike cut was NOT that high, either. If FedEx dropped the pallet on the way to me, Both woofers may have become "off center" and be dragging their voice coils. This would account for both the lack of bass and the muddy bass. Tomorrow, I'll physically stroke the woofers with the power off and my ear immediately proximate to the voice coil cap. If I hear dragging, I can upend the speakers and play them for a day or two with the woofer suspension being pulled in the opposite direction by gravity. I can then repeat the test to see if I still hear the voice coils dragging. Yes? The speakers are damaged & need to go back home. No? Maybe I can put them right side up again. That's one of the problems with big woofers - the weight of the cone, surround, and voice coil can sometimes pull the spider and surround off-center. If youse guys got any other ideas, I'm open to them. Thanks again - Boom
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Post by vcautokid on Jun 7, 2020 7:50:28 GMT -5
"So tomorrow I'm going to use a "no-tube" system: AURALiC Vega directly into the PA-1 mono blocks. If that doesn't tighten up the bass, I'll borrow a Crown DC-300a." Keith maybe on point here. If you are talking about control, many but not all necessarily. Can you see the ire I am about to create, that is related to damping. If the Bass is sloppy that could be the culprit. Bass control is not necessarily only a point of power but many factors. It starts at the power supply really. It is going to deliver the needed current or voltage to satisfy the load and signal requirement the rest of the amplifier is tasked to deliver. The assumption, yeah dangerous on that too, you are running Klipsch Cornwall IVs because nothing else is listed. Reasonably safe assumption I hope. FREQUENCY RESPONSE (+/- 4 dB) 34Hz - 20kHz SENSITIVITY1 102dB @ 2.83V / 1m POWER HANDLING (CONT/PEAK) 100W/400W MAXIMUM SPL 119dB Continuous NOMINAL IMPEDANCE 8 ohms Compatible CROSSOVER FREQUENCY HF: 5000Hz MF: 700Hz HIGH FREQUENCY DRIVER K-107-TI 1” (2.54cm) Titanium diaphragm compression driver MIDRANGE K-702 1.75” (4.45cm) Polyimide diaphragm compression driver LOW FREQUENCY DRIVER K-33-E 15” (38.1cm) Fiber-composite cone woofer ENCLOSURE MATERIAL MDF with fine veneers INPUTS Dual binding posts / bi-wire / bi-amp The specs I got directly from Klipsch. 102 db efficiency is great. Now if this follows the trend Klipsch and I am not saying that is the case such as the RP-600M bookshelves for instance which they claim 92db efficiency, it really is more like 88 or 89db efficiency. So even still 90db something efficiency should be great right? Well hold on there a minute. Again I was saying there are many factors for getting good dynamics and bass response. One is also the bandwidth of the power transformer. It starts right there! The Transformer does not have the swing to deliver, your bass will be weak and lacking control. Like I said I will derive the ire of all tube aficionados here. Later down the chain we speak of damping factor and control. The Heathkit or the Monoprice, if they do not have at least 20 something Damping Factor, those woofers won't be that decisive to hear. Tube amplifiers by nature, but not all, but many lets say lack damping factor vs. your solid state amplifier designs like an Emotiva XPA whatever or DR whatever and so on. Or the Crown you are talking about and so on. Again I have to run on the assumption it is the Klipsch Cornwall IV. The Cornwall is an awesome speaker and uses usually quality Eminence Woofers which are peachy keen good woofers. Used a bunch in my speaker projects when I was a kid, yeah, stayed out of trouble and got into hifi instead. Different kind of trouble. But it is not out of the realm of possibility there may be a defect. Any scraping you hear gently pushing against the woofer cone is not a good deal. You may want to contact Klipsch for more support too. Bunch of nice guys down there too. If these aren't the speakers you said are the "new" ones I apologize and will allow all to rejoin our regularly scheduled program already in progess.
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Post by boomzilla on Jun 7, 2020 8:39:09 GMT -5
Hi vcautokid - I've used the Heathkits before with: Tekton Pendragon speakers Emotiva T2 speakers Klipsch Heresy speakers Klipsch RP600m speakers Magnepan LRS speakers In none of those instances was the amp anything less than tuneful, fast, and neutral in the bass. It didn't play LOUDLY without breaking up, true, but within my listening envelope, it was great. That the amp should suddenly sound like a transistor radio with this easy 8-ohm load is not credible to me. I've also put the Emotiva PA-1 amps into the system - THEY should have an overkill of control on these speakers. But the outcome is the same - very little bass, and very mushy sounding. Is it possible that the speakers just aren't broken in? I reread the owner's manual, and not one word about break in - presumably they're ready to play right out of the box. I also checked the woofers - no audible or tactile evidence of voice coil rubbing. Maybe it's just the room - but every other speaker I've used here (including the Magnepans) had more bass, and in exactly the same locations as these speakers. What the heck?
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Post by MusicHead on Jun 7, 2020 8:59:55 GMT -5
Did you check the polarity of the speaker cables? 🙂
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Post by boomzilla on Jun 7, 2020 10:56:47 GMT -5
Did you check the polarity of the speaker cables? 🙂 Multiple times and checked phase with the Stereophile test disc.
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DYohn
Emo VIPs
Posts: 18,333
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Post by DYohn on Jun 7, 2020 10:59:02 GMT -5
I don't care how many times you may have checked, the symptoms you describe define a phase issue.
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Post by boomzilla on Jun 7, 2020 11:10:52 GMT -5
If it's a phase issue, David, it's inside the speaker cabinet. But the Stereophile disc delivers a crisp center image (in phase) and a widely separated image with no center (out of phase).
Could it be possible that one cabinet's woofer is wired out of phase while the midrange and treble are wired correctly? Easy to check - I'll use biwire cables and reverse the phase on each woofer independently.
Did the phase swap between woofer/ mid-treble sections. Not the problem - both speakers are wired correctly.
But as I’ve played the speakers through this afternoon, two things seem to be happening - the left speaker is becoming louder and bassier - and both speakers seem to sound better balanced. Is this my ears becoming better adjusted to the voicing of these speakers, or is it a break-in issue where the speakers’ sound is changing? I suspect both...
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Post by AudioHTIT on Jun 7, 2020 16:29:28 GMT -5
I measured the speaker wires with the VOM: R+ = 0.10 Ohms R- = 0.15 Ohms L+ = 0.01 Ohms L- = 0.01 Ohms So amps would see 8.25 ohms on the (weaker) right speaker to 8.02 ohms on the (louder) left one. Is that extra 0.23 Ohms enough to make an audible difference? It's only a 2.9% difference between the two speaker cables... What are you using to get that kind of accuracy with low resistance measurements? My wife has decided that ‘my’ Digital VOM belongs in the downstairs tool closet, not at my upstairs workbench. I’m thinking the solution is to get something better, as that one’s not so great.
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Post by AudioHTIT on Jun 7, 2020 16:34:40 GMT -5
If it's a phase issue, David, it's inside the speaker cabinet. But the Stereophile disc delivers a crisp center image (in phase) and a widely separated image with no center (out of phase). Could it be possible that one cabinet's woofer is wired out of phase while the midrange and treble are wired correctly? Easy to check - I'll use biwire cables and reverse the phase on each woofer independently. Did the phase swap between woofer/ mid-treble sections. Not the problem - both speakers are wired correctly. But as I’ve played the speakers through this afternoon, two things seem to be happening - the left speaker is becoming louder and bassier - and both speakers seem to sound better balanced. Is this my ears becoming better adjusted to the voicing of these speakers, or is it a break-in issue where the speakers’ sound is changing? I suspect both... How about hooking both speakers to the same amp channel and just listen to mono, you should then (assuming you're centered) only be listening to a center image, you can eliminate all other variables except speaker wire.
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KeithL
Administrator
Posts: 9,902
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Post by KeithL on Jun 7, 2020 22:41:00 GMT -5
I kind of suspect that your last set of conclusions are the correct ones.... These new speakers you're reviewing simply don't make much bass....
They probably will make somewhat more bass as the suspensions loosen up a bit (as they break in).... At the same time, as you grow accustomed to the way they sound, you will simply become more used to the way they sound... And, also, if you were playing them more loudly, you would be hearing more bass, and they would sound "flatter"...
(If you tend to listen quietly, it's going to accentuate a weak low bass response, due to Fletcher Munson and all that...)
Hi vcautokid - I've used the Heathkits before with: Tekton Pendragon speakers Emotiva T2 speakers Klipsch Heresy speakers Klipsch RP600m speakers Magnepan LRS speakers In none of those instances was the amp anything less than tuneful, fast, and neutral in the bass. It didn't play LOUDLY without breaking up, true, but within my listening envelope, it was great. That the amp should suddenly sound like a transistor radio with this easy 8-ohm load is not credible to me. I've also put the Emotiva PA-1 amps into the system - THEY should have an overkill of control on these speakers. But the outcome is the same - very little bass, and very mushy sounding. Is it possible that the speakers just aren't broken in? I reread the owner's manual, and not one word about break in - presumably they're ready to play right out of the box. I also checked the woofers - no audible or tactile evidence of voice coil rubbing. Maybe it's just the room - but every other speaker I've used here (including the Magnepans) had more bass, and in exactly the same locations as these speakers. What the heck?
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Post by 405x5 on Jun 8, 2020 7:48:35 GMT -5
VERY rare, but I’ve seen out of phase drivers (that were not intended to be) within the same cabinet.
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