AudioCircle
Audio/Video Gear and Systems => Single Driver, Wide-Bandwidth Speakers => Topic started by: Ultralight on 27 Oct 2017, 09:09 pm
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Seeking understanding.
Lets say one has a 4" and an 8" full rang driver. The 8" is four times the area of the 4" driver. Not only that, the 8" also generally goes lower in the frequency response when built as a speaker and plays with more authority.
What if one stack FOUR 4" driver in a vertical line just about touching each other.
At that point: Does the four 4" driver in a properly designed cabinet play lower and with more authority, or does the frequency response still look like a single 4" driver, but they simply play louder?
And any disadvantage to that type of design of multiples full ranger driver in a vertical array?
Thanks.
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Some prob are:
Comb filter in low treble freq(maybe not a big prob in a 4''FR but a concern in 8'')
Impedance too low in parallel
Impedance too hi in serie
Instead I would suggest these 2 FR in parallel yet a usable 4 ohms and 96dB spl and none xover or inductor.
Hemisphere FR 8 $128
Hemisphere MW 8 $115
http://www.hempcone.com/hemptone.com_new/hemptone%20website_003.htm
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Seeking understanding.
Lets say one has a 4" and an 8" full rang driver. The 8" is four times the area of the 4" driver. Not only that, the 8" also generally goes lower in the frequency response when built as a speaker and plays with more authority.
What if one stack FOUR 4" driver in a vertical line just about touching each other.
At that point: Does the four 4" driver in a properly designed cabinet play lower and with more authority, or does the frequency response still look like a single 4" driver, but they simply play louder?
And any disadvantage to that type of design of multiples full ranger driver in a vertical array?
Thanks.
Your big issue will be comb filtering, making any such attempts doomed from the start.
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Ah....just read on comb filtering. I see. Some debate about its impact it seems...?
As to impedence, it is not a problem. Wire two speakers in parallel. And then run the two separate pairs in series. So we are back to original impedance.
Anyways to my question - would four 4" in a larger cabinet then play lower or just louder than a single 4"?
Thanks.
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Ah....just read on comb filtering. I see. Some debate about its impact it seems...?
As to impedence, it is not a problem. Wire two speakers in parallel. And then run the two separate pairs in series. So we are back to original impedance.
Anyways to my question - would four 4" in a larger cabinet then play lower or just louder than a single 4"?
Thanks.
Parallel increase spl in 3dB when the amount of drivers doubles.
Serial no increase at all, keep same spl level.
If possible avoid serial connection, in this the music signal came and go alternately.
EDITED
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You can try serial w/this Bose replacement 1 ohm driver:
https://www.parts-express.com/grs-replacement-speaker-driver-for-bose-901-4-1-2-1-ohm--290-922
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Multiple drivers can't go lower, just louder. The Unity driver is one such beast (a large horn with drivers mounted in each interior face), but haven't seen it around for a few years.
Vertical arrays increase efficiency by projecting sound in a 2 dimensional pattern vs. 3 dimensional as from a single source, but to be effective the array must span from floor to ceiling. Which means buying 18 drivers (8 foot ceiling) and lots of wire, thus driving costs up or quality of drivers/wire down (which beyond DIY becomes a horrendous issue as drivers normally amount to 10% of speaker MSRP and the quality of cheap drivers used in such applications is strikingly poor).
And of course there's the dreaded comb effect. That's why most vertical arrays are 2-way, adding either ribbons or even more tweeters and more wire (more cost or even cheaper drivers).
Worse of all you lose vertical imaging as everything sounds 8 feet tall.
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THANK YOU EVERYONE for the information. Saves me from trying some hair brained ideas and wasting $$$. :)
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The IDS25 is everything that JLM said, but I would want to listen this tower some say>
http://www.ids25.com/
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Multiple drivers can't go lower, just louder.
Not true. You can design the crossover to sacrifice efficiency for playing lower with more volume. The reason it can work as you multiply drivers is because it you divide up the Xmax needed to get there, that otherwise would never be sufficient.
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Yep, this is a common misconception. Say a midwoofer is down 8 db at 30hz. Normally you would never hear that 30hz note, but drop the rest of the signal by 8, and it's right on line with every thing else. Do it 12 times, and you've got a lot of output at 25-30 hz with a mid driver...and it's a helluva lot faster than a couple of sluggish 12" woofers. This is something that I actually know a bit about. And comb effect is related to frequency and spacing. If the designer knows what he's doing, he can avoid it.
(http://www.audiocircle.com/image.php?id=57074)
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Seeking understanding.
Lets say one has a 4" and an 8" full rang driver. The 8" is four times the area of the 4" driver. Not only that, the 8" also generally goes lower in the frequency response when built as a speaker and plays with more authority.
What if one stack FOUR 4" driver in a vertical line just about touching each other.
At that point: Does the four 4" driver in a properly designed cabinet play lower and with more authority, or does the frequency response still look like a single 4" driver, but they simply play louder?
And any disadvantage to that type of design of multiples full ranger driver in a vertical array?
Thanks.
The multiple 4" driver plays faster, and with more detail. Recovery time is less, inertia is less. Lower??? Depends on the driver. The only system I've heard that can rival the accuracy and output of a big line source bass are the servo subs.
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It will work, but I don't think it's a great idea... others disagree and if you google "line array full range driver" you'll find them.
The comb filtering effect looks ugly but it's effect is debatable. Obviously, it doesn't bother some, ymmv... I don't have enough experience w single driver line arrays to give you any good opinions on this, I heard one briefly at a show and didn't like it. If you want a line array I'd look into a GR LS9/LS6.
On the design, I think it's technically flawed to some degree but had advantages in large spaces as SPL doesn't drop off as fast. It adds complexity with all sorts of things, you'd need to research and learn about them... If you're a single driver fan and want more frequency extension and SPL ability, rather than deal with that complexity I'd go with an augmented single driver, add a woofer and maybe a tweeter while using the single driver in the frequency range it can maintain a fairly flat response in, which will differ a bit by design and surface area of the cone. If you want to fill an auditorium or something a line array is worth considering but otherwise adding a woofer is a far better ideal imo.
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Thanks for all the additional conversations.
Looking at 'comb filtering', it seems that they occur at higher frequencies. So for those who run 1.5 type system where the 2nd full range is low passed, then comb filtering does not exist? Or am I not understanding what comb filtering does?
The line array does look very fascinating - would love to hear one of full range drivers without augmentation from tweeters but unfortunately these are not common at dealers I don't think. My challenge is always wanting to play in a small room and yet have the speakers sound huge, which to me means a small driver with wide dispersion and even bipoles and speakers pulled out at least 4 feet away from the wall. But the problem with full ranger is the lack of bottom octaves.
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Usually manufactured 1.5 way speakers use a xover or inductor, cap etc to cut the woofer under 500Hz.
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But the problem with full ranger is the lack of bottom octaves.
Who have to made a big bass is the enclosure not the driver, but DIYers dont know how to stufffing the enclosure, they put Sonex 20mm layer and want hear a big bass so when it dont happen they blame the FR driver.
>:
http://www.audiocircle.com/index.php?topic=100689.0
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But the problem with full ranger is the lack of bottom octaves.
My Fostex F200A drivers are rated 30-20,000 Hz, 89 dB/w/m, 8 ohms, 27 watts continuous/80 watts peak but sadly no longer in production.
8 inches, huge AlNiCo magnet, no whizzer (mechanical crossover) so they beam like crazy at higher frequencies, $575 each when last available.
I know of no other comparable drivers, but some exotic field coils from Europe might go as low.
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But 2mm Xmax.
This is just a question of personal preference, there's no point in arguing about it. Either the bass from a particular implementation is good enough for you in a particular listening situation, or it's not.
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My Fostex F200A drivers are rated 30-20,000 Hz, 89 dB/w/m, 8 ohms, 27 watts continuous/80 watts peak but sadly no longer in production.
8 inches, huge AlNiCo magnet, no whizzer (mechanical crossover) so they beam like crazy at higher frequencies, $575 each when last available.
I know of no other comparable drivers, but some exotic field coils from Europe might go as low.
I dont said it, I quoted an other post.
FullRangeMan on Today at 01:29 am
But the problem with full ranger is the lack of bottom octaves.
Its flat knoiw that whizzer cones collateral efect is made the mid range wild uprise over 2kHz and increase the MMS.
Do you think filed coils dont beaming?
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Acoustic impedance is what you're asking about. Impedance is the scientific name for the driver's grip on the air. The higher the acoustic impedance, the better grip the driver cone has on the air, the better it can control the air and the more efficiently energy (and information) is transformed from kinetic to acoustic.
In general, impedance decreases with wavelength, and increases with cone area and velocity.
In practical terms, reduced impedance means the cone cannot pressurize the air molecules efficiently. Air escapes pressurization because the cone is too small and/or moving too slowly to contain it. Increasing the cone size or velocity pressurizes air before it can escape the cone.
Adjacent small drivers can cooperate to contain the air for more efficient pressurization. A rectangular array is better at this than a line array which only cooperates in the vertical. Line arrays of full range drivers need EQ to boost the bass, but a rectangular array would need less because it's simulating a single large cone.
Treble in line array is attenuated by comb filtering and requires some EQ for flat response, but the comb filtering itself is not audible once you get some distance away from the arrays. The treble tone of FR line array is different than a single tweeter, or line array tweeters, but the combing is not noticeable unless you are close to the array. Some people love the treble quality of well engineered FR line array. It is not inherently "bad" as some have suggested. ymmv :)
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you could do a focused array for full range drivers.
(https://www.audiocircle.com/image.php?id=201378)
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Nice, what drivers are these?
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w4-1337sdf
they've gone up a bit in price lately ($57.6 or 55.8 in 8+ quantity).
learned a lot from it.
1. baffle step (ouch).
2. don't make the micro enclosures a bunch of cubes (nice broad peak past 1khz).
3. still only the sd of a wide open 12".
4. really sends a lot of sound up and into the air (hard to describe).
5. neo magnets (to hold on grill cover) do funny things to metallic paint.
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It is a interesting driver.
There is any comb filter ?
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Nope
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Every line array I have heard has had a strange imaging problem: The sound seems to be emanating from an invisible wire strung between the tops of the arrays. I noticed this on the megabuck Vandersteens, where the image also stopped dead in its tracks at the speaker axis (there was no stereo image outside the speakers whatsoever). The image from the Carver line array speaker the year before (2017; I skipped the show this year) had the interesting property of moving further up the tower the closer I got; I didn't try different positions with the Vandersteens but I was almost dead center and well back (a position I chose because the Carvers, like bagpipes, sounded better and better the further away you moved).
I have noticed at shows that the simpler the design, the more I tend to like it; the AudioNote rep summed up well when I told him this: "The more drivers you implement, the harder it is to create the illusion that the sound is coming from a single source." Lobing, cancellations, and comb-filter effects are almost impossible to eliminate except for a 'sweet spot' that gets smaller and smaller as the complexity of the design increases.
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My array seemed to only come from the middle 3 drivers.
I agree, 6 to 30' away, a flat array seems like a closeup of lips on a movie screen, like 6' tall lip.
Drives me crazy.
I may build another this year.
Mine are no more.
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Photo show this baffle not straight it is concave, what may reduce comb filtering.
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I found horizontal dispersion was as good as a single driver.
But out of the sweet spot sounded fine, further back, standing up, etc.
Unlike my 4 driver focused array. That one, if you stood up, the high end died off so fast, it seemed like you instantly got a head cold.
Disorienting even.
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(https://www.audiocircle.com/image.php?id=201439)
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As I understand the concept, if one mediocre driver doesn't cut it, try spending more on multiples of the same in a bigger cabinet.
Driver efficiency and frequency response won't change and either without using EQ and pushing them beyond their intended use. If increased bass output is the goal, why not just add a subwoofer?
Yes power handling and thus ultimate attainable sound pressure levels go up for a given driver by using multiples. But bigger drivers that can fill the room with bass can handle the power needed to attain live music peaks in residentially sized spaces.
As frequency goes up and waveform size decreases compared to driver size combing effects from an array are inevitable.
The vertical array has to spread from floor to ceiling in order to gain the advantage of 2-dimensional versus 3-dimensional efficiency, but will project all images as floor to ceiling.
Bottom line, IMO simple arrays, even with EQ added, are a flawed concept. Better to use a small full range driver and add a subwoofer with appropriate crossover if desired for additional bass response and increased ultimate sound pressure levels.
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Line arrays work exceedingly well when well designed. Comb filtering, bass response, imaging, and any other flaws are the result of a failure of design and not a limitation of line arrays per se.
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Line arrays work exceedingly well when well designed. Comb filtering, bass response, imaging, and any other flaws are the result of a failure of design and not a limitation of line arrays per se.
Perhaps, but not in a simple/affordable application of extended range drivers as being discussed here.
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These TangBang drivers are titanium cone and rubber suspension not crap, they are perfectly suited for this application and not having xover exempt him of micro signal loss and from what we see in the pictures they were correctly implemented by Norman.
What is not nice is depreciating the work of people who know how to do things happen.
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Perhaps, but not in a simple/affordable application of extended range drivers as being discussed here.
Agree. They are not an easy DIY design.
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Can be done with the liked tc9 driver ($12 from parts express).
I saw the original design using the nsb 4" drivers ($1) in a focused open baffle.
3 drivers per flat section, 5 sections angled at listening spot.
I want to try the tg9, planet10 sort of liked it.
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Line arrays work exceedingly well when well designed. Comb filtering, bass response, imaging, and any other flaws are the result of a failure of design and not a limitation of line arrays per se.
I'm mystified by what I'm reading here vs what I've heard at shows.
Apparently Carver can't do it. Heard his at Capital Audiofest a couple years ago and the inaging was bizarre- the image climbed further and further up the tower the closer I got. In the front row the image was a 'clothesline' strung between the tops of the towers.
Von Schweikert evidently can't do it either- for a quarter of a million bucks no less. Their tower also provided an image strung between the tops of the towers. No height, no front-to-back. nothing outside the speakers. I was bewildered by the praise heaped on this system by the audio press. I thought it was easily bettered by many systems at the show for five cents on the dollar.
To be fair though, neither of these systems was a classic line array. The Carvers had about two dozen speakers in each tower- front-firing tweeters and side-firing midranges. The Von Schweikerts had a very elaborate multi-way version of an MTM layout. But they shared the characteristics of a many-drivered system with the speakers arranged in a long vertical layout.
So maybe I will run into these well-designed line arrays at some point, but all the ones I have been exposed to so far have not floated my boat. In fact, I have noted over time that the simpler the driver arrangement, the better I tend to like it. When I mentioned this to an AudioNote rep, he said, "The more complicated the design, the harder it is to create the illusion of a single point source." This tends to sum up my listening experiences pretty well.
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I'm mystified by what I'm reading here vs what I've heard at shows....
...So maybe I will run into these well-designed line arrays at some point, but all the ones I have been exposed to so far have not floated my boat.
Danny Richie hasn't been at the RMAF in several years, but beginning in 2007 his line sources have been top notch. His latest is, without any doubt, the best sounding speaker I've ever had the pleasure to hear. Rich Hollis has a similar design with much more complex amplification and digital control that I'd like to hear. None of these use full range drivers.
Not saying you would like any of them, as individual taste vary, but I'm not the only fan of these designs.
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I'm glad there still is some life here on this circle.
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Photo show this baffle not straight it is concave, what may reduce comb filtering.
You may reduce the effect at one position, so head needs to be precisely aligned with the speaker. But, there is going to be lots of comb filtering everywhere else so the experience will be "head in a vice" and it'll throw off the integrity of the reflections, they will not be spectrally correct.
Despite this there have been several commercail examples of line arrays using full-range drivers, IMO it's a bad idea that can't be fixed.
For a great majority of situations I think a line array of any type is far inferior to a conventional speaker, I've never heard one that images properly. These designs need a ton of SPACE and are never given enough space to operate properly outside of concert venues, ime.
I'd MUCH prefer to spend my money on a smaller quantity of higher end drivers and smaller, higher-end cabinet. 99.99% of the time this will result in better sound in a home environment, unless you really need 120 dB at the LP or all you listen to is symphony in a VERY large room.
If you want to try multiple full rangers, arrange them in a square or clustered together as tightly as possible, like that crazy Tecton design with 1000 tweeters trying to play midrange, lol...
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All good, all good.
You can't believe the resistance to a focused array on diyaudio.
I was suprised at how good it sounded out of the sweet spot.