FAQ & Mo’

* Acknowledging that Bose is an excellent company and that their L1 P.A. is used by many pleased clients: One often-stated conclusion is that the L1 lacks ‘sufficient’ focus. Clearly many like its less-than-totally-distinct sound. However, if this lack of focal clarity is not for you, please note that the Sonusphere P-18 P.A. ‘mains’ are different than the L1 in the following way. Sonusphere P-18 P.A. speakers are essentially designed to project warm, sound ‘and’ additionally provide the widest dispersion possible for each frequency present in a signal. That is most directly the result of the combination of ‘one’ point-source driver ‘combined with’ the geometry of our ‘spherically-surfaced’ cabinets. indeed, listeners notice the difference between the Bose L1 and Sonusphere P-18 styles right away.

* Sonusphere P-18 Mains and M-18 Monitors compared:

– M-18 monitor is basically the same as a P-18 main. Due to its wide dispersion, the M-18 serves well as a front-of-stage main/monitor combo, with its ‘main’ function good for 360 degrees and up to about 45′ away. Whether a group would want one or two M-18’s for this application is up to the user(s).
– The P-18 does not project complete content ‘behind’ its primary 140 degree full frequency basically ‘front’ facing projection arc (and certainly not at all beyond 180 degrees). The P-18 main on a stand projects complete frequency information to the same horizontal ‘width’ but to a greater distance (into an audience) than does the M-18 monitor.
– Due to the Sonusphere’s ultra-wide dispersion neither the M-18 nor P-18 is prone to feedback. So, one P-18 set in the middle and behind a band can serve well as a main/monitor. Two P-18’s set behind and to the sides of a band work great as well, while providing more power and pushing more air. When two P-18’s are used set in this kind of location, they may be rotated to project inward, straight towards the audience or outwardly as is preferred.
– For some, ‘pointing’ speakers in a chosen direction (although so-rarely required) can make the pointer feel more as if they are doing their job properly. Also, audience members have come to seeing P.A. mains as a framework to a band’s stage set-up. So this look can send the right visual ‘signal’ in a traditional setting. Therefore, the choice of which method to provide the main/monitor experience can be impacted by such aesthetics.
– Anecdotally, We have witnessed knowledgable live performance audience members, listening from 40+ feet, who have approached stages to ask where the totally clear vocals were coming from. These people were mighty impressed when finding out that it was all coming from one or two M-18 monitors doubling as mains.

* Please do not confuse the Acoustic Image Upshot with a Sonusphere !!!

Truly, most compelling is that the design theory behind the Upshot is completely opposite to that of all of their other, primarily (low frequency) down-firing, products. As a result this AI model directly validates the Sonusphere design, one which additionally provides an effective LF down-firing component and improved full frequency dispersion. However, if this is in itself not convincing:

Yes, you do see a vertically mounted driver on both styles of enclosure. Otherwise, there are notable geometric and sonic outcome ‘dissimilarities’ between the two. A sphere is universally considered to be a premiere choice, as has been analyzed redundantly over decades by sound engineers. In the Photo Gallery section of our website we have provided a cabinet geometry final response curve graph, taken from a renowned loudspeaker engineering reference book, and relating to the text excerpt re-printed below. This knowledge contributed, in part, to Meyer Sound’s development of some of their arrays. Even the Bose L1, Fender Passport P.A. and JBL CAL series are nods to curved cabinets as each relates to improving broad dispersion. Indeed, each implements a complimentary approach for similar reasons. And, globe-shaped bookshelf hi if speakers, which work amazingly well, are another iteration.

Dear Anthony (at Eminence)
Does Eminence (or any other manufacturer) who produces a 10″ (bass) driver, manufacture one that will operate properly (ie. produce sufficient low end… to 42 hz/low E) in a sealed or ported cabinet that has an internal unloaded volume of 0.27 cu. ft.? FYI: This is the internal volume of another bass enclosure manufacturer’s cylindrical-shaped cabinet: 11” O.D. diameter x 6” height.
Steve at Sonusphere

No, we do not have a 10″ that will play that low in a .27 cu. ft. enclosure. I’m not sure that is possible unless you make a very inefficient speaker.
Best Regards,
Design Engineer/Technical Support
Eminence, KY 40019

Regarding the following Sound Pressure Level review:
– These response curve analysis’ were conducted utilizing standard/classic 1W/1M methodology, including microphone placement at 1M from each enclosure’s front-of-cabinet ‘baffle’.
– The dB@Hz figures provided are taken from complete final response curve analysis’ performed on 11-21-17.
– No DSP was applied to either cabinet.
– Due to the traditional 1W/1M, in this case, center of up-firing driver mic placement regime employed, the full impact of the down-firing Sonusphere radiator (the low frequencies that it provides) is not reflected in the findings presented below.
– Regarding the Upshot’s 0.27 cu. ft. unloaded internal cabinet volume: In engineering terms, the sole way to increase it’s efficiency (up) to normal levels would be to increase enclosure size or further decrease the dB outcome within the bass/lower frequencies.
– For reference: The B-18 cabinet has an internal volume of 0.88 cu. ft. Without addressing the B-18 cabinet’s even and ultra-wide dispersion characteristics, please note that the volume of the Sonusphere cabinet allows for effective fundamentals in the low frequencies. It also results in an overall dB efficiency level that is within common standards for bass speaker enclosures.

A spot check comparison of Cabinet SPL:
Sonusphere bass model B-18
75 dB @ 41.2 Hz (open low E)
86 dB @ 60 Hz (open A = 55 Hz)
89 dB @ 80 Hz and above: virtually ‘flat’; (open D = 73.42 Hz)
AI bass model Upshot
71 dB @ 41.2 Hz (open low E)
78 dB @ 60 Hz (open A = 55 Hz)
76 dB @ 80 Hz (open D = 73.42 Hz)
75 dB @ 100-160 Hz (open G = 98 Hz)
78 dB @ 500 Hz

The following is an excerpt, re-printed from a well-known and reputable engineering reference book, which accompanies the reference graph provided in the bottom of the ‘Your Problems Solved…’ section:
High Performance Loudspeakers; Third Edition Martin Colloms Pentech Press
pages 228-229
The 6 dB response step
‘Consider an ideal piston drive unit which possesses a theoretical uniform response when mounted in an infinite baffle. If positioned on the front face of a tall tubular enclosure, the resulting axial response would exhibit a distinct step of 6 dB at the transition between omni-directional radiation at the lower frequencies and the forward directed hemispherical radiation at higher frequencies. This irregularity is difficult to equalise and in consequence this cabinet shape is avoided by designers. Olsen’s classic set of responses for an identical driver in a series of cabinets shows that the 6 dB step is not present at a single frequency but appears as a series of ripples in the response curve at multiples of basic frequency, with a peak amplitude as high as 10 dB (Fig. 7.11).
These curves are valuable to all designers who seek to experiment with unusual cabinet shapes. Olsen appears to have tried most of them, and the resulting responses are worthy of closer inspection. ‘A’, the sphere, undoubtably gives the smoothest characteristic. This is not surprising, as its shape is free from sharp discontinuities in the path of the expanding sound field.’

* Regarding speaker manufacturer driver testing vs. Sonusphere enclosure application

Speaker cabinet designers compensate for what a cube or 3-D rectangular enclosure can provide, at times addressing flat response, through dialing in electronics. Components are provided to effect the audible outcome in a number of ways, including and in addition to influencing the overall final response curve. The given geometry of a sphere does not require this. In fact, the sphere-based cabinet compensates/evens out much of installed driver’s response anomalies. Eminence and others define their chosen methodologies for determining driver frequency curves for your reference through public disclosure. The infinite baffle ‘cabinet’s style often used is classic, but not at all like that of a tuned sphere. One can make a fairly accurate comparison between drivers that are all analyzed when similarly mounted in a classic infinite baffle enclosure. However, attempting to directly compare those driver frequency response outcome curves with the same driver(s) installed in a sphere-based enclosure is not an accurate comparison. Apples to bananas….

* Passive vs. powered down-firing woofers:

The B-18 Sonusphere utilizes a ‘passive’ radiator to perform the same 80 Hz and below frequency reproduction function as an active/powered down-firing driver. Sonusphere’s instead provide power to activate the up- and lateral-firing driver.

* Regarding Sonusphere Porting Systems:

There are two different Sonusphere porting systems, by model.
– The B18 uses the passive radiator embodiment in a sealed cabinet. In order to maximize function, it is located at a ‘calculated’ distance from the floor. This essentially results in a 360 degree ‘tuned’ final port aperture. In contrast, a ‘stand’ that a player may not use or may use while variably extended to elevate a down-firing woofer off the floor does not provide a ‘constant’, ideal, ‘tuned’ function.
– The dual port system incorporated in the P.A., monitor and optionally on guitar models, is an entirely different approach to enclosure ‘port’ style tuning. This approach includes either one or two port chambers, dependent on the outcome required. To correctly design cabinet tuning with a port that atmospherically connects the enclosure’s interior cavity with room, there needs to be a calculated chamber volume that has cavity ingress and egress cross-sectional areas of equal and correct size. In the case of a Sonusphere-style multi-port, the ingress from the cabinet interior is a singular opening and the egress is split to be 5 (or multi) radiating openings whose sum is equal to the total ingress cross-sectional area.

* Sonusphere cabinet bottom faces described:

The bottom plate has a grill that purposefully protrudes beyond the back plate face to protect the down-firing radiator. The bottom plate and all other elements must be securely held due to the tremendous pressure produced within this sealed enclosure during performance. The internal cabinet pressure produced by the ‘firing’ driver activates the radiator. As above, the rubber feet contribute to elevating the Sonusphere to the correct calculated distance off the floor, with the total gap present between the bottom of the enclosure and the floor serving as a tuned 360 degree lower frequency final aperture. The rubber feet additionally aid in isolating the cabinet from the surface on which it sits while gripping any slippery floor surface. This helps insure that these super light yet stable cabinets do not move around the floor when substantive bass frequencies are introduced. Each B-18 cabinet is sold with a portable rug on which a B-18 may be set to further stabilize as needed.

* About the cabinet material:
As is common to those who produce composite-based cabinets (some JBL’s, AI’s & QSL’s are examples), the Sonusphere’s are an injection-style molded thermoplastic enclosure. We could produce them out of carbon fiber (Sonuspheres would thus be less-than featherweight and look super cool,… but notably would not function any better). Those listed above, others and Sonusphere have all determined that thermoplastic materials are durable and cost-effective. The reality is that other modern materials would be too costly for the market. However, Sonusphere can and is willing to ‘custom-produce’ glossy exposed carbon fiber enclosures for those who would appreciate them.

VIIi: Regarding live performance: one bassist’s story.

The head of Sonusphere uses the B-18 speakers for jazz gigs, performing on upright (one B-18 with a Walter Wood head). Historically, he gigged with B-18’s during product development, playing electric bass for two years prior to B-18 introduction. This electric band had a kick ass (ie. loud as fuck/ had to practice outside of town under bridges) trap set drummer and a full ’14 foot’ spread percussionist, along with two electric guitarists. The music was Little Feat, Steeley Dead, gumbo inspired. He placed one B-18 between the drummers and one stage front by his mic stand. The overall focused stage fill was comprehensive. Both drummers could hear articulated and focused bass with a satisfying warm depth perfectly. The front B-18 served as a personal monitor/main. The back B-18 did the same for the drummers. The use of the two allowed him to actually play louder than with his previously used point source speaker ‘boxes’, this without causing fellow band members to complain about in-your-face/rude volume. This band played indoor venues up to 60″ sq. x 25′ ceiling without P.A .re-enforcement on the bass. He could make the band bass heavy when appropriate.