Jump to content

Physical time alignment


MechEngVic
 Share

Recommended Posts

When physically aligning drivers, what should be lined up?

 

My first instinct is to line up the surface of the magnet upon which the diaphragm sits. My actual first instinct is the tip of the diaphragm dome but they are covered by phase plugs... Hard to measure. Maybe line up the tips of the phase plugs?

 

And what about phase plugs?  What about a horn's compression chamber?  Don't these structures alter the point at which the soundwave begins its propagation?

 

"Whatever sounds best" is what you're saying, but I keep finding spots that sound good but in different ways, all right AROUND the lined up position.

 

I guess what needs to be known is:  At what point in the driver's structure does the time dependent soundwave begin?

 

 

Link to comment
Share on other sites

4 hours ago, MechEngVic said:

I guess what needs to be known is:  At what point in the driver's structure does the time dependent soundwave begin?

If you're not measuring the alignment acoustically using a microphone, you can aim for the center of the voice coils of both drivers (...no kidding...). 

 

However as you now have probably read, this isn't enough.  You have to factor in the phase shift (a.k.a, time shift) of the electrical filters due to the crossover networks, which is at a minimum 90 degrees of phase lag (having to put the higher frequency driver farther away from your listening position than the lower frequency driver) evaluated at the center crossover frequency. 

 

Now you have to know the order of the electrical crossover filters used in your loudspeaker, as well as the crossover frequencies.  For many of the earlier Klipsch Heritage models, it's first order (90 degrees of phase lag of the lower frequency drivers), but for later versions, second order or higher (i.e., 180 degrees of phase lag at the center crossover frequency), including the KLF series.

 

So in general, start by aligning the voice coil centers, then move the higher frequency drivers farther back by at least another 1/4 wavelength at the crossover frequency.  In your case, you have to move the HF back 1/2 wavelength farther. 

 

You can temporarily invert the phase of one driver, then play pink noise at the crossover frequency, listening for a local null in response (i.e., phase aligned at multiples of 360 degrees), then once the time aligned position is found, return the inverted phase driver back to normal phase.

 

All the above is sensitive to the wavelength at the crossover frequency (13584 inches/second divided by the crossover frequency in Hz).  At tweeter-midrange crossover frequencies, this additional adjustment backwards for the HF driver is on the order of 0.8 inches per 90 degrees of crossover filter order phase shift (i.e., 1.6 inches for second order filters).  For midrange--woofer crossovers, it is usually 10x that distance--something like an additional 6-8 inches per 90 degrees of crossover filter phase shift.  That's an additional foot to foot and a half at 500 Hz crossover frequency for second order crossover filters.

 

So the most sure fire way of finding proper time alignment is with a calibrated microphone and laptop running REW plugged into your DAC or preamp/processor.  Then you can see the alignment or misalignment in the spectrogram view or the excess group delay plot.

 

Chris

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

1 hour ago, Chris A said:

 

So the most sure fire way of finding proper time alignment is with a calibrated microphone and laptop running REW plugged into your DAC or preamp/processor.  Then you can see the alignment or misalignment in the spectrogram view or the excess group delay plot.

 

Chris

 

Chris, I have spent enough time here to discern you are pretty much an expert on REW and have a great knowledge of Klipsch Heritage/Pro line in a mechanical and practical sense. But respectively I have to question this need to "time align" drivers. Carl mentioned this aspect couple days ago on the Texas pair custom exotic/reconditioned Klipschorns posted and got me thinking. 

 

One, if critical transducer time alignment is so vital, why wouldn't PWK/Klipsch have lengthened the overall horn length of the tweeter vs the squawker? Make them equal length. Or perhaps they addressed minor time alignment errors in the XO?

 

Second, sound travels @ approx 1100 feet per second or 13,200 inches per second (correct for local temp and pressure), doesn't matter which frequency. 20-20k hz. So given a missed time alignment of say 16" from diaphragm to diaphragm (the actual sound wave/pressure generator), this would account for a time error of 0.001212 of one second. Who thinks they can reasonably discern such a "time error" in a loudspeaker, in your LR or home theater?

 

Or the reflected sound vs direct sound in any listening room short of an anechoic chamber. Clearly reflected sound takes longer to arrive at one's ears, much less a one millisecond error in time alignment of transducers in the actual cab.

 

You thoughts/comments please. Perhaps I am missing the big picture here. Wouldn't be the first time.

 

"One of the more important properties of sound is that its speed is nearly independent of frequency. If this were not the case, and high-frequency sounds traveled faster, for example, then the farther you were from a band in a football stadium, the more the sound from the low-pitch instruments would lag behind the high-pitch ones. But the music from all instruments arrives in cadence independent of distance, and so all frequencies must travel at nearly the same speed."  source: https://www.texasgateway.org/resource/141-speed-sound-frequency-and-wavelength

 

 

  • Like 1
Link to comment
Share on other sites

18 minutes ago, polizzio said:

 

Chris, I have spent enough time here to discern you are pretty much an expert on REW and have a great knowledge of Klipsch Heritage/Pro line in a mechanical and practical sense. But respectively I have to question this need to "time align" drivers. Carl mentioned this aspect couple days ago on the Texas pair custom exotic/reconditioned Klipschorns posted and got me thinking. 

 

One, if critical transducer time alignment is so vital, why wouldn't PWK/Klipsch have lengthened the overall horn length of the tweeter vs the squawker? Make them equal length. Or perhaps they addressed minor time alignment errors in the XO?

 

Second, sound travels @ approx 1100 feet per second or 13,200 inches per second (correct for local temp and pressure), doesn't matter which frequency. 20-20k hz. So given a missed time alignment of say 16" from diaphragm to diaphragm (the actual sound wave/pressure generator), this would account for a time error of 0.001212 of one second. Who thinks they can reasonably discern such a "time error" in a loudspeaker, in your LR or home theater?

 

Or the reflected sound vs direct sound in any listening room short of an anechoic chamber. Clearly reflected sound takes longer to arrive at one's ears, much less a one millisecond error in time alignment of transducers in the actual cab.

 

You thoughts/comments please. Perhaps I am missing the big picture here. Wouldn't be the first time.

 

"One of the more important properties of sound is that its speed is nearly independent of frequency. If this were not the case, and high-frequency sounds traveled faster, for example, then the farther you were from a band in a football stadium, the more the sound from the low-pitch instruments would lag behind the high-pitch ones. But the music from all instruments arrives in cadence independent of distance, and so all frequencies must travel at nearly the same speed."  source: https://www.texasgateway.org/resource/141-speed-sound-frequency-and-wavelength

 

 

It would be a good idea to read up on the subject since there is a lot of discussion and science behind being able to hear alignment problems.  Easily measured and easily heard depending on the frequency.  In addition to the time smear, depending on the overlapping frequencies of two drivers directions, the effect at crossover point can be additive or subtractive, thus cause lobing or anomalies in the actual frequency response of the speaker.  One driver during crossover overlap (in the time domain) going out and other going in will produce a null.

 

So imaging and polar problems, frequency response, and time smear (no better word than that) are all things that can be attributed to poor driver / crossover alignment.

  • Like 1
Link to comment
Share on other sites

1 hour ago, pzannucci said:

It would be a good idea to read up on the subject since there is a lot of discussion and science behind being able to hear alignment problems.  Easily measured and easily heard depending on the frequency.  In addition to the time smear, depending on the overlapping frequencies of two drivers directions, the effect at crossover point can be additive or subtractive, thus cause lobing or anomalies in the actual frequency response of the speaker.  One driver during crossover overlap (in the time domain) going out and other going in will produce a null.

 

So imaging and polar problems, frequency response, and time smear (no better word than that) are all things that can be attributed to poor driver / crossover alignment.

 

Yes, I've read everything I could find on the subject here, and some research on the internet. Granted PWK didn't have the tools and resources we have today by a long shot, didn't have REW. No doubt he relied upon engineering, experience, and his ears ultimately. Thx for the explanation/input.

 

One thing I have seriously begin to question lately is the sonic accuracy of a bass reflex cab. Using both sides of the LF transducer to reproduce or create sound. Has to be some time smear there. And easily 90% of home speakers manufactured today are BR cabs. 

 

But on the flip side, what percentage of the music that we hear at home (our sound/music room/home theater) is reflected sound? Depends on the room, whats in it, and treatment no doubt.

 

 

 

  • Like 1
Link to comment
Share on other sites

3 minutes ago, polizzio said:

 

Yes, I've read everything I could find on the subject here, and some research on the internet. Granted PWK didn't have the tools and resources we have today by a long shot, didn't have REW. No doubt he relied upon engineering, experience, and his ears ultimately. Thx for the explanation/input.

 

One thing I have seriously begin to question lately is the sonic accuracy of a bass reflex cab. Using both sides of the LF transducer to reproduce or create sound. Has to be some time smear there. And easily 90% of home speakers manufactured today are BR cabs. 

 

But on the flip side, what percentage of the music that we hear at home (our sound/music room/home theater) is reflected sound? Depends on the room, whats in it, and treatment no doubt.

 

 

 

Group delay for bass reflex and reflections are definitely measurable.  Walk around the room and clap, wait for the echo 🙂

  • Like 2
Link to comment
Share on other sites

21 minutes ago, polizzio said:

And easily 90% of home speakers manufactured today are BR cabs. 

 

There seems to be a general consensus that "more bass" is more important than "good bass". Adding that extra octave of response on the bottom, even if it has poor transient response and large group delay, is judged to be better than the improved transient response and lower group delay of a sealed box or horn.

  • Like 3
Link to comment
Share on other sites

3 hours ago, polizzio said:

One, if critical transducer time alignment is so vital, why wouldn't PWK/Klipsch have lengthened the overall horn length of the tweeter vs the squawker? Make them equal length. Or perhaps they addressed minor time alignment errors in the XO?

PWK was sensitive to phase alignment, being that his designs were typically multiples of 360 degrees in-phase at the crossover frequency (as much as 1024 degrees out of time alignment...tweeter--to--midrange).  As you might have realized, there are a lot more than just phase issues going on with horn-loaded loudspeakers, and PWK had to balance the overall design to meet the constraints of cost and visual format acceptable to his customers.  He did a pretty good job, as evidenced by the return business of his loudspeaker models (Khorn, La Scala, Cornwall, Heresy) and closely related models (Forte, Chorus, KLF, etc.).  His basic designs are little changed since the early 1960s. 

 

However, in light of today's technology and understanding of psychoacoustics of reproducing realistic and accurate music playback, some aspects of his original design balance have shifted, perhaps shifting the balance of his original design trades. 

 

Now that we've addressed that (delicate) subject, to answer your specific question, PWK traded the placement of the tweeter relative to the midrange horn mouth a couple of times, but was never in time alignment (to my knowledge).  My guess is that the fidelity of most recordings and playback devices was such that it wasn't immediately obvious that there were time misalignments in the loudspeaker designs.  To move the tweeter back to the plane of the K-55 driver on the midrange horn implies that the loudspeaker would look different (something he was careful to manage the changes of over time--to the benefit of his earlier customers), have different vertical coverage (i.e., it cuts off the downward coverage of the tweeter toward the floor relative to the midrange), and introduces more vertical spacing of the tweeter horn mouth to the midrange horn mouth, which causes increased lobing and coverage issues relative to the midrange.  These are all the effects of moving the tweeter back to achieve time alignment.  (The advent of using multiple entry horns [MEHs] that Renkus-Heinz and Danley uses, among others, was not yet understood.)  Patents have prevented the widespread use of MEHs in the past, but that IP is now free and clear for other manufacturers to use. 

 

Nowadays, we have DSP crossovers that can time align the drivers without having to physically move them from their baffle-mounted positions.  This is the best solution.  PWK's successor, Roy Delgado, has strongly advocated time alignment of drivers starting as far back as more than 20 years ago. So PWK's design choice was to leave the tweeters where they were.  It has been successful design decision up to the advent of DSP crossovers (now used in the JBL M2, and all of the Klipsch Profession Cinema behind the screen loudspeakers, among many others).  DSP crossovers increase costs slightly nowadays, but the acoustic benefits far outweigh costs.

 

3 hours ago, polizzio said:

Second, sound travels @ approx 1100 feet per second or 13,200 inches per second (correct for local temp and pressure), doesn't matter which frequency. 20-20k hz. So given a missed time alignment of say 16" from diaphragm to diaphragm (the actual sound wave/pressure generator), this would account for a time error of 0.001212 of one second. Who thinks they can reasonably discern such a "time error" in a loudspeaker, in your LR or home theater?

Mr. Zannucchi pretty much addressed this question, above.  A lot of people seem to fasten on the "absolute phase" and "absolute time delay" issues, but they forget that it's mostly the relative phase and relative time delay issues by which the human hearing system detects these issues: time-based behavior and impulse response. These are clearly audible.  If they were not audible, then sales of loudspeakers like Magnepan and Martin-Logan would drop off to a small fraction of what they are today.  Really, the biggest issue here is being able to hear the difference for yourself.  Once you do, you'll never want to go back to time-misaligned loudspeakers (in my experience).

 

3 hours ago, polizzio said:

Or the reflected sound vs direct sound in any listening room short of an anechoic chamber. Clearly reflected sound takes longer to arrive at one's ears, much less a one millisecond error in time alignment of transducers in the actual cab.

Of all the subjects that are mired in misunderstanding, this subject (direct arrival vs. reflected acoustic energy in-room) is one of the most misunderstood.  Again, once you hear the difference (like, say, comparing a Bose 901 to a dialed-in Klipsch Jubilee), you'll typically have all your questions answered in this area, and create new questions to replace them.  Even having the experience of being inside the anechoic chamber in Hope and listening to different loudspeaker types/configurations and then moving them outside the chamber to the adjacent listening room.  These kind of demonstrations will help to form a strong subjective feel for what is occurring.

 

3 hours ago, polizzio said:

"One of the more important properties of sound is that its speed is nearly independent of frequency. If this were not the case, and high-frequency sounds traveled faster, for example, then the farther you were from a band in a football stadium, the more the sound from the low-pitch instruments would lag behind the high-pitch ones. But the music from all instruments arrives in cadence independent of distance, and so all frequencies must travel at nearly the same speed."

One of the jobs that I had in the late 1970s/early 1980s was working for a large geophysical exploration company, engineering Vibroseis "earth shakers" and air gun arrays/hydrophone arrays for marine work.  Without the ability to distinguish between modes of vibration (compression waves--"P waves", shear waves "S", Love waves, and Rayleigh waves which all travel at different velocities through the rock strata and the surface of the earth), our ability to discern what's "down there" would be almost completely impaired.  And the property that, within each type of transmission, the frequencies remain mostly at the same relative phase to each other, were it not largely true would also completely impair reflection seismology (especially decades ago when digital computers were not available to correct for the issues that arise). 

 

The good thing about air is that it is mostly homogeneous, it transmits sound in one mode only (compression waves), doesn't absorb very much acoustic energy in home-sized living rooms, and obeys (mostly) optical reflection analysis techniques at higher frequencies. 

 

43 minutes ago, polizzio said:

One thing I have seriously begin to question lately is the sonic accuracy of a bass reflex cab.

Me too.  The human hearing issue of bass reflex turns out to be the rate of the shifting phase at frequencies close where the reflex ports kick in.  The human hearing system can easily detect that rise in group delay, and it isn't good.  And the more phase-coherent our listening rooms and loudspeakers are, the better we can hear it.  Bass reflex is not a trade that I take in my loudspeaker designs, generally speaking.  In fact, I traded out my Cornwall bass bins for Belle bass bins for my surrounds, both using an ESS AMT-1 on top to replace the midrange and tweeter top hat assemblies.  The sound got better and cleaner, even though I lost about a 3/4 octave of low bass extension.  It was a good trade in my room. 

 

When I look a what loudspeaker manufacturers are producing nowadays (and excuse me for saying this, Roy), it seems to me that the "customer is king" and many customers have very poor taste in their bass reproduction.  (Roy already knows and understands that I also enjoy his Jubilees every day for the past 12 years and would not give them up.)

 

Chris

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

 

13 minutes ago, Chris A said:

 

When I look a what loudspeaker manufacturers are producing nowadays (and excuse me for saying this, Roy), it seems to me that the "customer is king" and many customers have very poor taste in their bass reproduction.  (Roy already knows and understands that I also enjoy his Jubilees every day for the past 12 years and would not give them up.)

 

Chris

 

Chris, thanks for taking the time/detailed explanation. Makes a lot of sense. I have never heard Jubes, much less Jubes with DSP/active XOs. Perhaps one day I will have the opportunity to hear a properly time aligned system. 

  • Like 1
Link to comment
Share on other sites

Go to a pilgrimage or a Roy D./Klipsch Museum training class sometime.  You'll gain information and experience that will definitely serve you for the duration.  I know this because it worked for me...

 

Chris

  • Like 2
Link to comment
Share on other sites

I just did this a few days ago and I noticed my center image is improved at my close listening position but I also placed thick absorption panels covering the wall behind my head and to the sides and on the top hat just some thick pillow cover folded under the k77 and a cushion hanging over the edge of the top hat to try and tackle cieling reflection.

 

I'm not articulate in general so I dont know how to really explain what I hear but all I can say is I notice the k77 now and can place it whereas before maybe i couldnt so much and was seriously considering the crites tweeter and while I still am due to curiosity of all the positive reviews, I quite like the "softness" of the k77 right now. At my distance, its gentle on my ears I suppose.

 

I'd like to place it higher but the soldered wire isnt long enough

 

(Should I add something directly behind thr tweeter and sides of the wall like more thick pillow cases pinned to the walls?)

 

Sent from my SM-G965U using Tapatalk

 

 

 

c685cfb137a479f540c35e8c415810b8.jpg

 

 

Link to comment
Share on other sites

8 minutes ago, Maximus89 said:

(Should I add something directly behind the tweeter and sides of the wall like more thick pillow cases pinned to the walls?)

The K-77 tweeter is high-passed at about 5 kHz, so at that frequency and above, reflection/refraction of its acoustic output at wide and extreme angles to be able to reflect off the nearby walls behind it isn't of real concern.  The direct reflections from the front of the K-77 across the top of the top hat and diffracted off the front edge of the top hat is something that's probably audible if your room is very clean acoustically and you've got very good recordings. 

 

Chris

  • Like 1
Link to comment
Share on other sites

9 hours ago, Edgar said:

 

There seems to be a general consensus that "more bass" is more important than "good bass". Adding that extra octave of response on the bottom, even if it has poor transient response and large group delay, is judged to be better than the improved transient response and lower group delay of a sealed box or horn.

I think we all initially fall for the impressive display of subwoofer power... But eventually our ears tire of it. I have a sub (klipsch sub12, down firing with rear port) that I spent a lot of time moving around because I was tired of how it did nothing for sound quality, just boom. I found placing the port sideways instead of facing back sounded better, and having the crossover frequency all the way up helps too, it becomes less boom and more a "filling in" of the higher bass frequencies. At least now it sounds like it's adding to the quality of sound, not just making an impression.

Link to comment
Share on other sites

9 minutes ago, MechEngVic said:

I think we all initially fall for the impressive display of subwoofer power... But eventually our ears tire of it. I have a sub (klipsch sub12, down firing with rear port) that I spent a lot of time moving around because I was tired of how it did nothing for sound quality, just boom. I found placing the port sideways instead of facing back sounded better, and having the crossover frequency all the way up helps too, it becomes less boom and more a "filling in" of the higher bass frequencies. At least now it sounds like it's adding to the quality of sound, not just making an impression.

 

This is why I really like my SVS SB-3000. Sealed cab sub and SVS employs a user adjustable DSP amp to make the response flat down to 20 hz. I've owned six subs over the years (20) to date, 3 vented or bass reflex, and 3 sealed. BR never again.

I purchased some dense rectangular foam sheeting from the local hobby store. Going to try plugging my CW3 ports and see what it does to LF output. An experiment, have an idea what will result, behave like a sealed cab, lose output below 50-60 hz or so. I listen to lower sound levels anyways, try to preserve my old ears, already damaged from career, past hobbies, and age. Rarely do I exceed 90/95 db peaks, music output.

  • Like 1
Link to comment
Share on other sites

3 minutes ago, polizzio said:

 

This is why I really like my SVS SB-3000. Sealed cab sub and SVS employs a user adjustable DSP amp to make the response flat down to 20 hz. I've owned six subs over the years (20) to date, 3 vented or bass reflex, and 3 sealed. BR never again.

I purchased some dense rectangular foam sheeting from the local hobby store. Going to try plugging my CW3 ports and see what it does to LF output. An experiment, have an idea what will result, behave like a sealed cab, lose output below 50-60 hz or so. I listen to lower sound levels anyways, try to preserve my old ears, already damaged from career, past hobbies, and age. Rarely do I exceed 90/95 db peaks, music output.

OK, lose output below 50-60 hz, but a gain at higher bass frequencies? Because I'm all for filling in the higher bass frequencies.

Link to comment
Share on other sites

13 hours ago, Chris A said:

If you're not measuring the alignment acoustically using a microphone, you can aim for the center of the voice coils of both drivers (...no kidding...). 

 

However as you now have probably read, this isn't enough. 

Chris,

Thank you for taking the time to lay out all this info. I will be using your comments as reference as I continue my time alignment experiments. 

 

Since at this time I will continue using one amp and passive tuning, I have crossover questions.

 

A first order crossover (6db slope) is one component: A cap or an inductor; and every succeeding component is an increase of one order (12db, 18db, etc). So what you're saying is that every component introduces 90 degrees of phase shift? So my KLF's third order horn crossover is 90 degrees shifted from the woofer's second order? So maybe the difference in physical alignment is made up by the difference in orders to end up mostly in phase?

 

And, since resistors do not factor in order calculations, do they also have no effect on phase shift? I am assuming this is the case.

 

And finally, my alignment experiments are with a super tweeter I have mounted atop the KLF's. The super tweeter is second order, so, as with the woofer/horn, should the tweeter sit a bit ahead of the horn? I am trying to avoid setting the super tweeter any further back than I have to because the reflections/diffractions against the top of the cabinet are horrible.

Link to comment
Share on other sites

11 hours ago, MechEngVic said:

So what you're saying is that every component introduces 90 degrees of phase shift?

I believe it's 45 degrees for each reactive element in the circuit.  A first order high pass introduces 45 degrees of phase lag on the lower frequency driver, and a first order low pass introduces another 45 degrees lead on the high frequency driver--for a total of 90 degrees per order of the high pass and low pass filters used.

 

11 hours ago, MechEngVic said:

So maybe the difference in physical alignment is made up by the difference in orders to end up mostly in phase?

I don't believe that I've yet encountered a passive-crossover loudspeaker that was time aligned without physical correction of the driver distances to listeners on the front baffle.

 

They can be "phase aligned", meaning that the lower frequency drivers are multiples of 180 degrees of lag (with polarity reversals used on the lower frequency drivers where odd-order passive filters are in use), but not really time aligned without moving the HF drivers farther away than the LF drivers.  Most Klipsch loudspeakers using passive crossovers seem to be phase aligned at multiples of 360 degrees of lag, but not time aligned (EDIT: the original "Cornwall II" 1979 midrange to woofer is almost time aligned, but the tweeter-midrange crossover lags by 0.7 ms):

1109092685_Cornwall(corrected)Spectrogram.thumb.jpg.fac562278afcaa934300f5b2c58447ec.jpg

 

 

Resistors, by definition, have no appreciable reactive value, they are purely resistive elements, so no real phase leads/lags are present.

 

11 hours ago, MechEngVic said:

The super tweeter is second order, so, as with the woofer/horn, should the tweeter sit a bit ahead of the horn? I am trying to avoid setting the super tweeter any further back than I have to because the reflections/diffractions against the top of the cabinet are horrible.

Higher frequency drivers must be set farther back--never forward of the lower frequency driver's acoustic center if using passives.  But this is not true if using a DSP crossover--which has digital delay that can be used on the higher frequency channels which can be used to place the driver where you need it and time align it.

 

And the alignment requirements due to the very short wavelengths at the crossover frequency are so small that even if you do manage to time align the super tweeter for one listener position, if the listener simply stands up, the super tweeters are out of alignment to next the lower frequency drivers/horns by more than 90 degrees (i.e., about 1/4 inch alignment requirements or less are typical).  It's a "head in a vise" problem that cannot be fixed.  I recommend using dual-diaphragm coaxial drivers instead to eliminate this problem.

 

Chris

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...