DeVore Fidelity Orangutan O/96 loudspeaker Measurements

Sidebar 3: Measurements

I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the DeVore Fidelity Orangutan O/96's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield and spatially averaged room responses.

The Orangutan O/96 has a very high specified voltage sensitivity of 96dB/w/m. This is both unusual and means that the speaker will play very loudly with very low-powered amplifiers. My estimate of the DeVore's sensitivity was somewhat lower, at 91dB(B)/2.83V/m, though this is still usefully high. Concerned that I had mischaracterized the sensitivity, I checked my estimate by comparing the SPL produced by the O/96 with that from a BBC LS3/5a at the same drive level. The O/96 was 9dB more sensitive than the LS3/5a, which is within experimental error of the original 91dB figure (B-weighted).

As can be seen in fig.1, the O/96 has an unusually high impedance, conforming to the specified 10 ohms. At the 2.83V level used to calculate the speaker's sensitivity, the O/96 will therefore draw less than 1W from the amplifier, which will have a negative impact on the measurement. The impedance magnitude (solid trace) drops below 8 ohms only in the lower midrange and the mid-treble, reaching respective minimum values of 7.2 and 7.8 ohms. While the electrical phase angle (dotted trace) reaches extreme values in the bass, the magnitude is very high at these frequencies. Overall, the DeVore O/96 is one of the easiest speakers for an amplifier to drive that I have encountered.

Fig.1 DeVore Fidelity Orangutan O/96, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

The traces in fig.1 are disturbed by some discontinuities in the midrange, suggesting the presence of cabinet resonances of some kind. Listening to the cabinet walls with a stethoscope while I played the half-step–spaced toneburst track from my Editor's Choice CD (Stereophile STPH016-2), the side and rear walls were very lively between 130 and 230Hz, and some lower-level modes were audible higher in frequency. Investigating the cabinet's vibrational behavior with a simple plastic-tape accelerometer revealed very strong modes at 148 and 219Hz (fig.2), these coincident with the frequencies of two of the wrinkles in the impedance traces. These modes might have lent the speaker the richness on voices noted by AD.

Fig.2 DeVore Fidelity Orangutan O/96, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of rear panel (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

There were also peaks at these two frequencies in the output of the two ports on the rear panel when measured in the nearfield (fig.3, red trace). Though these are down in level, they do result in discontinuities in the nearfield woofer response (blue trace) and the overall low-frequency response (black trace below 300Hz). Other than that behavior, however, the ports' output peaks sharply in classic manner between 35 and 55Hz, its maximum level coinciding with the minimum-motion notch in the woofer's response at 43Hz, somewhat higher than the "mid 30s" mentioned by AD. (At this frequency, the back pressure from the port resonance holds the woofer cone still.)

Fig.3 DeVore Fidelity Orangutan O/96, anechoic response on HF axis at 50", averaged across 30° horizontal window and corrected for microphone response, with nearfield responses of woofer (blue) and port (red) and their complex sum (black), respectively plotted below 350Hz, 750Hz, 300Hz.

The black trace above 300Hz in fig.3 shows the O/96's farfield response averaged across a 30° horizontal window centered on the tweeter axis. Overall it is relatively flat, with small peaks balanced by small dips in the response. The region covered by the tweeter is very slightly less sensitive than the woofer's range; of more concern is the sharply defined peak just below 2kHz. This coincides with a wrinkle at the same frequency in the impedance graph ; this behavior might be due to a termination problem with the woofer cone and its surround at this frequency. However, this peak coincides with a lack of energy to the speaker's sides (fig.4), and so may well not result in coloration. What appears to be an off-axis "flare" between 3 and 4kHz in this graph is actually due to the on-axis suckout in this region filling in to the speaker's sides. Taking this into account, while the DeVore O/96's horizontal dispersion is narrower than usual above 1kHz, it is actually much better controlled and consistent with frequency than I was expecting from a design using a large woofer and a wide baffle.

Fig.4 DeVore Fidelity Orangutan O/96, lateral response family at 50", normalized to response on HF axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

In the vertical plane (fig.5), the optimal response is obtained just above the tweeter axis. This is sensible, given that the tweeter is just 32" from the floor when the speaker sits on its matching stand.

Fig.5 DeVore Fidelity Orangutan O/96, vertical response family at 50", normalized to response on HF axis, from back to front: differences in response 15–5° above axis, reference response, differences in response 5–10° below axis.

I visited Art Dudley to give a listen to the O/96s in his system and to measure their in-room response before bringing them back to my place for further measurements. I averaged 20 responses taken in a rectangular grid 36" wide by 18" deep, and centered on a position 36" from the floor at AD's listening position. (We have found that 36" is the height of a typical seated listener's ears; AD actually sits a little higher.) The speakers were driven by AD's Shindo Corton Charlemagne amplifiers; the result is the red trace in fig.6. The treble slopes down smoothly, if a little more than I would have liked—I found the balance in Art's room somewhat lacking in top-octave air, though the low frequencies were well extended.

Fig.6 DeVore Fidelity Orangutan O/96, spatially averaged, 1/6-octave response in AD's listening room (red); and of Audio Note AN-E/SPe HE (green).

What is fascinating about the O/96's in-room response is that it is almost identical to that of AD's reference speaker, the Audio Note AN-E/SPe HE (green trace). The Audio Notes were placed in the room corners for this measurement, with a severe toe-in; the DeVores were well away from the wall behind them but fairly close to the sidewalls. As with the Audio Notes, there is a peak between 500Hz and 2kHz, and a lack of energy between 100 and 200Hz. I suspect that, with both speakers, the latter is due to destructive interference between the direct sound from the woofer and the reflections from the walls and floor. In the case of the O/96s, these reflections would be reinforced by the fact that the distances between each woofer and the two closest room boundaries were very similar.

I was aware of the lack of lower-midrange energy when I first started listening to the DeVores in AD's room, though that receded as I continued listening. I suspect that this kind of interference is something we accommodate to. I investigated further when I got home, setting up the O/96s in my own listening room and driving them with the Devialet D-Premier integrated amplifier. The red trace in fig.7 again shows the Devore's spatially averaged response in AD's room; the blue trace shows the O/96's response in my room, measured in identical manner. Because I could place the speakers farther away from the sidewalls in my room, which is wider than AD's, their lack of energy in the lower midrange has filled in nicely. Without the boundary reinforcement in my room, the bass is slightly shelved down, though it still extends down to below 25Hz. Though there is still a bit too much energy in the upper midrange, with the solid-state amplifier the treble is considerably more extended in my room, if with the same smooth characteristic measured in AD's room.

Fig.7 DeVore Fidelity Orangutan O/96, spatially averaged, 1/6-octave response in: AD's listening room (red), JA's listening room (blue).

The O/96's step response (fig.8) indicates that both drive-units are connected in positive acoustic polarity, and the smooth integration of the decay of the tweeter step into the start of the woofer step confirms optimal crossover design. The cumulative spectral-decay plot (fig.9) reveals a generally clean decay in the treble and midrange, but with some low-level hash evident in the low treble and a prominent ridge of resonant energy coincident with the on-axis peak at 1730Hz.

Fig.8 DeVore Fidelity Orangutan O/96, step response on HF axis at 50" (5ms time window, 30kHz bandwidth).

Fig.9 DeVore Fidelity Orangutan O/96, cumulative spectral-decay plot on HF axis at 50" (0.15ms risetime).

After I'd finished measuring them, I spent a day listening to the Orangutan O/96s in my room. Even though I knew about the low-treble resonance and the lively enclosure, these problems were considerably less audible than I was expecting. Only with recordings of solo acoustic piano did they get in the way of the music by producing noticeable coloration, the piano's midrange sounding uneven, with some notes obscured. But with well-recorded rock and classical vocal recordings, the measured problems seemed to step into the background, letting me appreciate the O/96's full-range, evenly balanced sound and superb clarity. It looks as if John DeVore has accepted the inevitability of the problems caused by the O/96's physical concept and had carefully worked around them to produce a well-balanced speaker that is also drop-dead gorgeous.—John Atkinson

Company Info
DeVore Fidelity
Brooklyn Navy Yard, 63 Flushing Ave., Unit 259
Brooklyn, NY 11205
(718) 855-9999
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Comments
JohnnyR's picture
This is Why

"I won't get into techno babble with you....."

Anything resembling technical becomes "techno babble" in your mind. Why bother trying to explain to some one that thinks this way?  You WANT.........WAHHHHHH  cry somehwere else what you WANT. I can't be bothered satisfying your demands when all you do is cry and insult.Like I stated earlier, I have shown my competency by bringing up well thought out technical details about the speaker in question. I know what I am talking about unlike you who doesn't bother to learn anything other than what Stereophile spoon feeds you.,By the way the $ sign goes BEFORE the numbers NOT after them *sigh* Have a nice day Mr Ragahead.

Regadude's picture
Johnny is a coward

Exactly what I thought! Johnny is a big talker and nothing else. You hide behind your insults and and arrogance to cover up your inadequacies. Johnny is a fraidy cat (I would have used the word that starts with a P, but it would have been deleted). But of course, Johnny is a legend IN HIS OWN MIND. 

You seem to have anger problems. Anger and frustration. Maybe its been a while since you have touched a hot knob... Don't let plankton have all the fun.

As for the $, I am not american and it goes after the numbers where I come from. If you don't like it, that's your problem. 

JohnnyR's picture
A Big Talker?

I have already pointed out various defects in the speaker design and why they are so. What have YOU contributed? NOTHING. All you ever do is insult and hide behind inuendo.

"Maybe it has been a while since you touched a hot knob"

Just how much more childish can a person get? If anyone is frustrated it's YOU Ragahead.Grow up.

Glotz's picture
I agree.

It is obvious that JA has answered every issue either of these micreants posited, and neither have basic respect towards anyone that disagrees with them (especially when it is extended to them unconditionally).

I, for one, am (really) glad JA finally acts assertively to end these types of devolving conversations when it's pointless to continue.  Keep it in the other forums, or just leave.

I am equally glad that AD has shown Mr. Plank's character in its true light. 

This speaker could be their favorite speaker of all time, and they would never know it- 'cause they haven't heard it. 

They apparently don't listen through their equipment, they measure it.  Sounds like fun...

for an engineer.

JohnnyR's picture
Wahhhhhhhhhhhhhhhhhhhhhh

Had you nice little rant and feel better now? No one cares.

pi's picture
Quote: Lets just say I have

Quote: Lets just say I have designed quite a few well regarded speaker systems over the YEARS... 

In all fairness, just as for Mr. Plankton, common courtesy for any forum particpation requires that any commercial affiliation and interests should be disclosed.

PI - What goes around comes around

JohnnyR's picture
Oh Look............

........it's the forum police trying to be all manly. Who cares what you WANT? Have I tried to sell anything on here? You show up making demands. Go fly a kite.

John Atkinson's picture
Affiliation is required for industty professionals

JohnnyR wrote:
Lets just say I have designed quite a few well regarded speaker systems over the YEARS and I have put in the man hours of study and research REQUIRED to know what I am talking about.

If you are actively involved in the audio business, our policy does require that you include your affiliation at the foot of every post, as I do. It doesn't matter if you try to sell something or not. This is to prevent employees of one company flaming another company's products under a cloak of anonymity.

So please, if you are actively involved in designing speaker systems for sale, you must include your affiliiation as requested. You cannot remain anonymous.

John Atkinson

Editor, Stereophile

JohnnyR's picture
My Hobby......

........is NOT a company. I design and build as a hobby, hence it is not a company business. Maybe I give my speakers away. Stop tying to be a bully Atkinson it demeans your aleady shakey status as  fair and trust worthy. If you keep insisting on an affiliation I will make one up because I DON"T HAVE ONE. Get it?

John Atkinson's picture
Admissions

Johnny wrote:
My hobby is NOT a company. I design and build as a hobby, hence it is not a company business.

Thank you for the admission. Until your speaker designs have been acknowledged by end users in the competitive marketplace, I don't think you can claim any particular authority as a speaker engineer.

John Atkinson

Editor, Stereophile

JohnnyR's picture
Hurr Hurr Hurr

How funny Atkinson. You just defamed hundreds of audio hobbyists on several DIY forums by that statement. Not only can we design and build WAY better speakers than the so called "experts" that make FLAWED speakers but we ALSO know the technical aspects and what is NEEDED to do so.

This just shows your mentality when it comes to the DIY field and how dated your pathetic outlook is and  that perhaps just perhaps you aren't as smart as you think By your own logic YOU certainly can't call yourself an expert since you haven't even designed or built one yourself.So please stop commenting on the speakers you test here

Regadude's picture
Johnny is a hobbyist!!!!!!

HA! I knew it. Johnny has no credentials in speaker design. He builds speakers in his basement as a HOBBY, and he thinks he is an expert. He thinks he knows better than people who actually manage to sell their speakers. But of course, he also knows more than industry pros.

You're just like that guy who drinks beer while watching NFL football, and who tells people he could do a better job than the actual coach of the team. Sure you can... Have another beer.

A sham and a big talker. Expert, an EMPHATIC NO!

I play the piano as a hobby. I guess I am the next Bill Evans! Yup, no one will ever hear me play, but trust me, I am even better than he was... cheeky

JohnnyR's picture
FYI

A "professional" who sells speakers is also a hobbyist. Where do you think they learned HOW to design an make speakers? They just didn't pull it out of their ass............well MOST well designed not FLAWED speakers are at least.

Ragahead, at least I have put in the years of research and study, what have you put into your education other than how to taunt and belittle others? Can you tell me how to go about designing a speaker that will stand up to the "best" on the market? Can you show ONE little iota of technical knowledge in the field of speaker design? Then I kindly ask you to STFU.

There are plenty of "professionals" that market their sham products. Just keep reading the Stereophile forums , you will find several that are willing to take money from the gullible. YOU paid dearly for your audiophool cables. BWAHAHAHAHA so much for your "arguement" The more you post the more childish your posts become. My friends that bother to read your drivel have a good laugh at your expense.

mrplankton2u's picture
Constantly with the pissing matches....

I've designed and installed dozens of custom home and a few mobile systems over the past 5 years. So who cares? This is not about me or for that matter you or JohnnyR. We are citing technical aspects that are easy to see with, and even without, the benefit of measurements. The magazine's job is to be critical of differences between reviewed products - not apologetic, defensive, equivocating, or otherwise obtuse. Today, the actual audible differences between quality components in the marketplace is nowhere near as great as the vast price differences would seem to suggest. This makes it far more important for a reviewing magazine to conduct critical evaluations as objectively and dispassionately as possible. If flaws are present that are clearly audible, the product shouldn't be on the "recommended" list as there are too many competing products that don't have the obvious flaws that deserve to be on a "recommended" list. You as others could say - "who cares, just go listen to them for yourself".  On the surface, that sentiment might have merit. But beyond the obvious reason that the magazine's job is to help whittle down the vast field for a prospective buyer,  if the "impartial" third party reviewers entrusted with evaluating product aren't subscribing to reasonable standards of honesty, authenticity, and accuracy in what they do - the merit system gets displaced by the hype system. And the hype system means ever increasing effort on advertising and promotion with ever increasing product prices to support the promotional effort at the expense of resources that would otherwise be devoted to improving the products in question. And that is precisely where we find ourselves today with a magazine that considers a $2000 low watt tube amp to be the "low, affordable end" of a "best of" list and endorses a pair of $12,000 stand mount speakers that have serious, yet totally avoidable design flaws and significant associated performance problems. Taking in the entire picture, it is not unreasonable for the average person to conclude that "Houston, we have a problem."

pi's picture
I've designed and installed

Quote: I've designed and installed dozens of custom home and a few mobile systems over the past 5 years.

In all fairness, common courtesy for any forum particpation requires that any commercial affiliation and interests should be disclosed.

PI - What goes around comes around

mrplankton2u's picture
Like there's a lot of common courtesy around here?

I'm not in the retail speaker space. I work with a small company that does mostly custom installations. We don't sell free standing speakers per se and if we ever decided to enter that retail market - it probably would be an internet based direct marketing approach that avoided most of the advertising whores and pushy, ignorant, and obnoxious middlemen that make up much of what is left of the "high end" audio business. Anyone who has read my comments on here extensively knows that I don't have an axe to grind against any company. My concern has been the legitimacy and long term survival of the industry overall and what efforts are being taken to keep players in the industry like Stereophile honest. I've readily acknowledged excellent products from brands like Quad, Revel, KEF, Vivid and other well known non speaker brands like Threshold/Pass. And I normally don't comment negatively on a post unless there is a clear indication that Stereophile is not "coming clean" in a particular review. On the other hand, I've positively commented on a few rare occasions when Stereophile got it right with an excellent, insightful review - such as was the case with the recent MBL or Quad reviews. I may sound like a one trick pony from time to time but that is essentially because the circumstances tend to repeat themselves. I prefer not to pick on a manufacturer but they sometimes get caught in the crossfire when they produce a substandard product and Stereophile starts making excuses.

John Atkinson's picture
Professional affiliation required, please

mrplankton2u wrote:
I've designed and installed dozens of custom home and a few mobile systems over the past 5 years. So who cares?

We do, for the reasons expained in my reply to JohnnyR. If you are professionally involved in the audio industry, you cannot hide under a cloak of anonymity in order to criticize products made by someone else.

John Atkinson

Editor, Stereophile

mrplankton2u's picture
There is an important flip

There is an important flip side to your weak argument. People who work for a company in the audio business do not necessarily speak for the audio business they work for and are not at liberty to discuss who they work for or what their company's official stance is on any product in the marketplace. My comments stand on their own. I have praised products where praise is due and criticized obvious flaws that are evident in the measurements and the overall design itself ( like pairing a 10 inch woofer to a 1 inch soft dome tweeter).  Anyone with the slightest bit of reading comprehension can see that the thrust of my concerns/arguments have centered around Stereophile's approach to its job - not the competency of the products being reviewed.

 

Furthermore, what do experienced engineers/designers who've retired do? Your argument has enough holes in it to rival swiss cheese.

 

Further, furthermore, a number of salepeople and audio retailer establishment owners have commented in these threads. They actually have a very high level of conflict of interest - advocating products they sell and casting apersions on those they don't or those they compete with. Have you ever requested disclosure of their affiliation before?

The difference between myself, JohnnyR and others that have voiced informed comments and the BS artists pretending to be experts that occasionally sling poo on here is that we focus on that which is incontrovertable - measurements published in black and white and design aspects that are obvious from visual inspection. We don't waste our time with blathering nonsense like "the turntable/cartridge combination effectively sweeps all obvious vinyl surface noise to the side walls of the listening room". That's your job.

John Atkinson's picture
Company affiliation required regardless

mrplankton2u wrote:
There is an important flip side to your weak argument.

It is not a weak "argument" it is our policy. No exceptions.

mrplankton2u wrote:
People who work for a company in the audio business do not necessarily speak for the audio business they work for and are not at liberty to discuss who they work for or what their company's official stance is on any product in the marketplace. My comments stand on their own.

Nevertheless, if you are professionally involved in audio and do not wish to include your company affiliation, you will no longer be allowed to post to this website.

John Atkinson

Editor, Stereophile

mrplankton2u's picture
You apparently do like to

You apparently do like to make up the rules as you go along. The Online Community Code of Conduct specifies no such thing. As a matter of fact, "your" requirement runs counter to rule 10(d):

 

 

(d)

You will not post or upload User Content that includes personal or identifying information about another person without that person's explicit consent.

John Atkinson's picture
A solution

mrplankton2u wrote:
You apparently do like to make up the rules as you go along.

No, this has been our policy since 2005.

mrplankton2u wrote:
You will not post or upload User Content that includes personal or identifying information about another person without that person's explicit consent.

Okay, as you don't appear willing to give that consent, you will no longer be allowed to post to this website. I will ask Ariel Bitran to delete your user account.

John Atkinson

Editor, Stereophile

JohnnyR's picture
What A Sore Loser You Are

ANY excuse to delete people that don't agree with your personal outlook is the reason you are doing this Atkinson. Pathetic. You can't stand anyone criticising your precious opinons. So out they go. You are one sad person.

John Atkinson's picture
Nope

JohnnyR wrote:
You can't stand anyone criticising your precious opinons. So out they go.

Not at all. You will see that mrplankton2u's comments have not been deleted. However, he had a choice: either stop posting to the site, or, as he is, by his own admission, professionally involved in audio, add his affiliation to his comments and be allowed to present his opinions. He did neither. Instead, he argued that the rules were inappropriate and by extension didn't apply to him, leaving me with no option but to ban him. Arguing with the ref is never a winning strategy, please note.

John Atkinson

Editor, Stereophile

 

JohnnyR's picture
Just a Convenient Excuse

You never liked the guy, never liked that he criticised you and your magazine, never liked that he showed you up as the buffoon you are........shall I go on?  Yeah yeah the rules and you are the "ref" Tell me just how many professionals have you banned over the years due to your "rules"?  Too many sadly, so all you are left with in your precious forums are dullards, morons, halfwits and the gullible. No wonder it's so empty in there. They all left for better places to talk about FACTS instead of magic bowls, cables, rocks and rainbow foil. So it goes. You must be proud of your "great" forum lmao.

King of the Dullards all hail the King!

Regadude's picture
Does JA like you?

Your argument about JA banning plankton, because he did not like him, is wrong. If JA banned everyone who was a nuisance and caused problems, you would have been gone a long time ago Johnny. 

All hail king troll!

pi's picture
Speaker measurements

Really don't get your arguments - there is any number of speakers (some of them commonly highly regarded), that measure much worse than this one - none of those has the excuse of being guided by the effort to make it tube friendly. For example:

Vandersteen Quatro $7,000: Significant on axis suckouts at 800Hz (very problematic) and 4000Hz, off axis response is not offsetting like it is for the Devores. In room response shows a major in room depression for the midrange and bass emphasis, which even careful placement does not remove.

Verity Sarastro $40,000: 10dB depression from 100-300Hz, uneven response above 1KHz, off axis dips at 3KHz. In room depression for the critical lower midrange/upper bas and with significant 10dB lower bass emphasis. Midrange driver of the verity is crossed over at a very high 4KHz.

MBL 101E MKII $70,500: Questionable concept (radial transmission), low impedance with significant phase roller coaster down to 3Ohm, so difficult to drive. Several resonance above 10KHz. Again, in room depression for the critical lower midrange/upper bass and with significant 10dB lower bass emphasis. 

In this context, it seem Devore HAS actually taken the effort to carefully balance the design to achieve reasonable measurement (e.g. balance off axis reponse with on-axis response), while providing a speaker that is extremely easy to drive and sufficiently compact to place in small NY style apartment.

So, JA seems spot on with his assessment.

JohnnyR's picture
Flawed is Flawed

The above speakers you mentioned obviously are flawed also and poorly designed regardless of them being"highly regarded" There are "reveiwers" that will give a turnip praise on some websites. Just because the OP review is about a speaker that doesn't have the same flaws , doesn't make it a $12,000 speaker nor a well designed one. We can always find something worse than what we are listening too to "compare". Doesn't make it worth buying though,

tmsorosk's picture
LOL

 Mr. A, please don't ban or delete mrplankton2u's comment's , he's the Archie Bunker of audio. Haven't had this many laughs in years. 

 

 Hot nobs, LOL.

Glotz's picture
He needs to be gone.

I was really hoping half-way through the posts he would admit his obvious ignorance regarding the neccessity of multiple measuring points for an accurate picture of measurements.

Instead, he did turn into Archie... and showed his true self. 

I just hope he doesn't slap Edith around when he's mad. 

JohnnyR's picture
Typical

Multiple measuring points are a good way of getting an overall picture but can't turn a sows ear into a silk purse. $12,000 worth of speaker? Hardly.

 What's with the Archie Bunker reference one fo your heros?

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