loudspeakers L/R matching are sometimes terrible !

[thewas]

From my own experience, 1 dB difference in the midrange is audible as a slightly worse stereo perception.

A wide 1 dB deviation can be audible also in my experience.

So why are there still people who says that much larger deviances between L/R speakers doesnt matter ?

Who said that? Also on most loudspeakers measurements you linked from HFN the deviation in the important mid range seems not to be higher than that 1 dB limit.

 

[MAB]

Such quality analysis posts are what I love in ASR, thank you!

Thanks. I struggled with this concept of matched components for years. I remember the first time I built a pair of expensive DIY kits (Seas Thor) I got the drivers in matched pairs from the distributor for extra money. I then got the supposedly matched-pairs mixed up in my shop, and was so unhappy. Then, I started making measurements and I got happy again realizing the matching criteria was bogus, except I realized I wasted money on paying the distributor the extra money. Same with building the crossover, I did every snake-oil move on the planet (except cryo, it wasn't invented when I built these...)

The money I wasted, but it sure was fun!

 

[thewas]

Thanks. I struggled with this concept of matched components for years. I remember the first time I built a pair of expensive DIY kits (Seas Thor) I got the drivers in matched pairs from the distributor for extra money. I then got the supposedly matched-pairs mixed up in my shop, and was so unhappy. Then, I started making measurements and I got happy again realizing the matching criteria was bogus, except I realized I wasted money on paying the distributor the extra money. Same with building the crossover, I did every snake-oil move on the planet (except cryo, it wasn't invented when I built these...)
View attachment 218672

The money I wasted, but it sure was fun!

Yes, since it is a hobby the trip and fun counts more than the wasted money and time almost all of us had at some time point.
Luckily I never really believed in such crossover legends and was confirmed when I changed all crossover components of my quality 1979 Technics SB-10 to brand new and "better" ones:

Capacitor upgrade in crossover - Is it audible?

If you wonder why the phase of the measured capacitors (which should be at -90°) suddenly becomes "inductive" (phase at +90°) from a certain frequency on, this is due to my laziness. The correct calibration of Arta-LIMP is time consuming and was not necessary for these measurements (up to...

www.audiosciencereview.com

 

[Doodski]

1979 Technics SB-10

I ran the aluminum cabinet Technics bench monitors for years and they sounded fantastic and the tweeters where priced very very well for when I fried them. I drooled over the SB-10's a lot. A very intriguing speaker model.

Technics SB-10 on thevintageknob.org

vintage Technics honeycomb disc flat loudspeaker with leaf tweeter

www.thevintageknob.org

 

[thewas]

I ran the aluminum cabinet Technics bench monitors for years and they sounded fantastic and the tweeters where priced very very well for when I fried them. I drooled over the SB-10's a lot. A very intriguing speaker model.

Technics SB-10 on thevintageknob.org

vintage Technics honeycomb disc flat loudspeaker with leaf tweeter

www.thevintageknob.org

I agree and am glad to have them in my vintage loudspeaker collection, not many loudspeakers out there with an AES paper about them!
https://www.aes.org/e-lib/online/browse.cfm?elib=3882 (free download here http://jahonen.kapsi.fi/Audio/Papers/Loudspeaker with honeycomb disk diaphragm/ )

Also some more measurements and comparisons with references like the B&W 801 of that time here:

https://www.madagascarsound.com.au/wp-content/uploads/2018/09/Technics-SB-10-review.pdf

and

 

[MAB]

Yes, since it is a hobby the trip and fun counts more than the wasted money and time almost all of us had at some time point.
Luckily I never really believed in such crossover legends and was confirmed when I changed all crossover components of my quality 1979 Technics SB-10 to brand new and "better" ones:

Capacitor upgrade in crossover - Is it audible?

If you wonder why the phase of the measured capacitors (which should be at -90°) suddenly becomes "inductive" (phase at +90°) from a certain frequency on, this is due to my laziness. The correct calibration of Arta-LIMP is time consuming and was not necessary for these measurements (up to...

www.audiosciencereview.com

Thanks for pointing me this thread. Very nice experiment and analysis. Nice old speakers too!

 

[Doodski]

Also some more measurements and comparisons with references like the B&W 801 of that time

I was test driving a B&W 801 Matrix and I bashed the voice coil to bits with a Luxman M-03. It was some very thumpy music and I was dialing in the bass and whamO thwack! It took a hit and was dented/destroyed. The sales rep came over and replaced the woofer in warranty and never said a word. I felt bad but the Infinity Kappa 9's took it and so I figured why not give it a try with the B&W's.

 

[Ruhled]

With conventional speakers with identical crossovers, I think it's time well spent to measure then swap L and R, and remeasure. I found usually one of these will result in overall slightly more cohesive response when the room the speakers have to live in is factored in. I've gone so far as so even swap tweeters around and remeasure twice again. Or in the case of compression drivers swap diaphragms between the two channels. I've fixed some 5 or 6db narrow band anomalies this way. Just my .02. There's some variables you can play with here having two of everything. I have a set of old Snell speakers in my arsenal that also have slightly different crossovers in their attempt to voice all their speakers as close to a production ideal as possible but once the speakers are in a room all that goes out the window imho.

 

[Doodski]

This thread is interesting. I've bought and collected matched tweeter sets and now I'm learning that it was in vain.

 

[MAB]

I was test driving a B&W 801 Matrix and I bashed the voice coil to bits with a Luxman M-03. It was some very thumpy music and I was dialing in the bass and whamO thwack! It took a hit and was dented/destroyed. The sales rep came over and replaced the woofer in warranty and never said a word. I felt bad but the Infinity Kappa 9's took it and so I figured why not give it a try with the B&W's.

Uff da! Kappa 9's at running at full-beans makes me more scared for the amp!
Neat amp!

 

[Doodski]

Uff da! Kappa 9's at running at full-beans makes me more scared for the amp!
Neat amp!

Lol. Yes it was a bit of a load for the amp but stuff like the M-03 could take it. High wattage, under-rated amp.

 

[Tangband]

This thread is interesting. I've bought and collected matched tweeter sets and now I'm learning that it was in vain.

No its not . If the matched tweeters measures more alike , then there is a real difference .

Just because one person says its bogus doesnt mean that its true in all cases.

Just like the importance of calibrated microphones within 1 dB - everyone with a dsp should also calibrate each of their speakers so they sound the same within 1 dB .

The room will change the sound , but its still the direct sound from the speaker thats gonna do most of perceived listening experience depending on the precedence and HAAS effect,- the first arriving sound , where your brain will focus on the direct sound from the speaker , and the room sound will be attenuated in the brain as much as -10 dB .
(You dont hear like a microphone with distances bigger than 5 ms soundtravel .
The brain selects sounds, the microphone takes up all the sound . )

So - yes , matching loudspeakers L/R sometimes DOES make a difference in the spatial sound experience .

This discussion is needed for better high fidelity and better sound with 2 channels in stereo.

 

[Doodski]

Uff da! Kappa 9's at running at full-beans makes me more scared for the amp!
Neat amp!

Luxman M-03 at quiescent condition had +/- 81VDC for a peak-out possibility of 410W RMS peak @ 10A DC peak/ch. It was renowned for power output exceeding it's factory rating of 200W/ch RMS.

 

[Tangband]

With conventional speakers with identical crossovers, I think it's time well spent to measure then swap L and R, and remeasure. I found usually one of these will result in overall slightly more cohesive response when the room the speakers have to live in is factored in. I've gone so far as so even swap tweeters around and remeasure twice again. Or in the case of compression drivers swap diaphragms between the two channels. I've fixed some 5 or 6db narrow band anomalies this way. Just my .02. There's some variables you can play with here having two of everything. I have a set of old Snell speakers in my arsenal that also have slightly different crossovers in their attempt to voice all their speakers as close to a production ideal as possible but once the speakers are in a room all that goes out the window imho.

I agree. But the room does not destroy your ability to hear differences , if they are big enough .

 

[Tangband]

System Audio Legend 40.2 Silverback Loudspeaker Lab Report

Lab Report Tested here without any 'RAM Tweaks' this active version of the Legend 40.2 employs the same cabinet and trio of 135mm carbon-fibre reinforced bass and mid units, but with the rear-facing reflex port internally 'shorted' to yield a 2nd-order sealed-box bass alignment. Incidentally...

www.hifinews.com

Another example of a loudspeaker that gonna do less good in a stereo setup because of the differences between L/R speakers . Red is R , black is L .

”Pair-matching, again, was a slightly poor 2.2dB as one of our speakers possessed a higher 2kHz-20kHz output than the other”

 

[MAB]

This thread is interesting. I've bought and collected matched tweeter sets and now I'm learning that it was in vain.

Actually, hold your horded goods for just a minute more before you post it all on eBay...
Manufacturers do change over time.
For instance, current Seas Excel W18 driver (V2) vs. V1 from 20 years ago.
They look different (V2 on left, V1 on right). Aside from the cosmetic differences, the surrounds, and voice coil former to cone junction are different. The surrounds appear different. The baskets are slightly different (not likely interesting). Spider looks different too.

Datasheets for V1 vs. V2 show significant differences:

Parameter	W18E001 E0018 v1	W18E001 E0018 v2
Voice Coil R	6.1 Ω	6.1 Ω
Voice Coil L	0.4 mH	0.65 mH
Force Factor	7.2 N/A	6.6 N/A
Free Air Resonance	31 Hz	34 Hz
Moving Mass	15.5 g	15.5 g
Suspension Compliance	1.6 mm/N	1.4 mm/N
VAS	37 l	30 l
QTS	0.34	0.42
QMS	2.5	2.91
QES	0.39	0.49

I tried to attach both datasheets below. While the cone and motor appear unchanged, the changes to the surround and suspension components appear to have made a systematically different speaker.

The driver doesn't even look the same on the baffle, the surround and VC to cone junction stand out. They both sound similar sweeping a variety of tones. You can certainly still hear the 4-5 kHz shriek cause by the breakup mode of the cone, but I can't tell that it has moved up in frequency by 400 MHz or so.

Also, manufacturers struggle mostly with changes over time, all sorts of reasons. Many are not reported, or noticed. Seas actually releases new datasheets to reflect the fact that they changed stuff. Many don't notify, and surprises happen.

 

[Doodski]

Actually, hold your horded goods for just a minute more before you post it all on eBay...
Manufacturers do change over time.
For instance, current Seas Excel W18 driver (V2) vs. V1 from 20 years ago.
They look different (V2 on left, V1 on right). Aside from the cosmetic differences, the surrounds, and voice coil former to cone junction are different. The surrounds appear different. The baskets are slightly different (not likely interesting). Spider looks different too.
View attachment 218685

Datasheets for V1 vs. V2 show significant differences:

Parameter	W18E001 E0018 v1	W18E001 E0018 v2
Voice Coil R	6.1 Ω	6.1 Ω
Voice Coil L	0.4 mH	0.65 mH
Force Factor	7.2 N/A	6.6 N/A
Free Air Resonance	31 Hz	34 Hz
Moving Mass	15.5 g	15.5 g
Suspension Compliance	1.6 mm/N	1.4 mm/N
VAS	37 l	30 l
QTS	0.34	0.42
QMS	2.5	2.91
QES	0.39	0.49

I tried to attach both datasheets below. While the cone and motor appear unchanged, the changes to the surround and suspension components appear to have made a systematically different speaker.
View attachment 218691

The driver doesn't even look the same on the baffle, the surround and VC to cone junction stand out. They both sound similar sweeping a variety of tones. You can certainly still hear the 4-5 kHz shriek cause by the breakup mode of the cone, but I can't tell that it has moved up in frequency by 400 MHz or so.

Also, manufacturers struggle mostly with changes over time, all sorts of reasons. Many are not reported, or noticed. Seas actually releases new datasheets to reflect the fact that they changed stuff. Many don't notify, and surprises happen.

I dig the physics of drivers and think it's beaucoup cool. Most of it goes over my noggin. The speaker guru/experts here @ASR make my knowledge look pretty base...lol. So I leave it to them. But yeah I collected matched pairs of Energy Connoisseur 22 and KEF 107.2 tweeters.

 

[MAB]

I dig the physics of drivers and think it's beaucoup cool. Most of it goes over my noggin. The speaker guru/experts here @ASR make my knowledge look pretty base...lol. So I leave it to them. But yeah I collected matched pairs of Energy Connoisseur 22 and KEF 107.2 tweeters.

Candy

 

[Tangband]

Yamaha NS-1000M loudspeaker Lab Report

Lab Report With speakers of this vintage – even a pair in such immaculate condition as these – there is always a question mark regarding ageing effects. So when I plotted the forward frequency responses of this pair of NS-1000Ms [Graph 1, below] measured at 1m on the tweeter axis and saw the...

www.hifinews.com

And another ….

”Pair matching over the same frequency range is poor at ±2.3dB”

 

[Tangband]

ELAC Adante AF-61 loudspeaker Lab Report

Modern floorstanders as large as the AF-61 typically record sensitivities of 89dB or 90dB so it’s a surprise to find that ELAC specifies 87dB, and that our measured pink noise figure is just under 86dB. Classically, you’d expect this to be accounted for by the AF-61 having greater bass extension...

www.hifinews.com

”Pair matching is disappointing at ±2.0dB, the largest disparities again occurring in the treble.”