[avahifi]

First of all, I consider that ANYTHING the listening room adds or subtracts to the playback is wrong.  Of course this is an impossible condition to achieve, but we try the best we can to minimize room effects.  Thus my sound room is stiff, concrete floor, heavy carpet, walls completely done in acoustic fabric (available at high end room finishing stores in a nice selection of colors and textures) and the ceiling is done in Sonex.  It is a very dead, very quiet room.  You can hear a pin drop, with no echoes.

I want loudspeakers with the resolution to allow us to hear even minor changes in the electronic designs.  When we come up with sometime that we know is technically an improvement, we want to hear it.

Our listening arrangement for new electronic design ideas is as follows.  We put the two loudspeaker we are using side by side far away from the walls.  We make the electronic changes to one channel only of the device we are testing.  We set the preamp to mono.  One of us makes the hookup of speakers, amplifier, preamp, and so on, randomly scrambling the cables as he goes, so nobody knows which channel is which when we start the playback.  Then we play back the familiar source material in mono, and use the balance control to switch from channel to channel.

We then ask the following questions as we are listening.  First can we hear any differences at all?  (Often we cannot and that is annoying and makes me long for a higher definition loudspeaker).  Second question, which one is "better"?  Then finally after or opinions are written down, we untangle the wiring maze to find out which channel was which.  And of course sometimes it is the old channel we like better, go figure.

So I need a speaker that does not try to make the room part of its output (Bose and similar are out as are rear firing planars) and is wide range, high definition and with no vowel tone colorations at all.  So far, SPPRES has been the most interesting in what has been said about my search.  I need another good month of sales and maybe then an order.

Keep the help coming, I am thoroughly enjoying your comments.

Thank you.

Frank Van Alstine

[Aether Audio]

Well Gentlemen,

I want loudspeakers with the resolution to allow us to hear even minor changes in the electronic designs. When we come up with sometime that we know is technically an improvement, we want to hear it.

and...

So I need a speaker that does not try to make the room part of its output (Bose and similar are out as are rear firing planars) and is wide range, high definition and with no vowel tone colorations at all.

This is exactly as I thought.  I know that if I were designing amplifiers – that’s what I’d want to use.  And this is also the premise of my previous dissertation regarding the word “reference.”  From an engineering and product design standpoint, this is the type of product an engineer needs in order to evaluate the other links in the chain.  One needs a tool that neither adds or subtracts anything from the signal being fed into it.  The words “neutral” and even to many… “sterile” come to mind.

Think of it this way.  A certain engineer wants to test the amount of distortion generated by an amplifier.  To do so he needs a device commonly known as a distortion analyzer.  Such an instrument has an input wherein the output signal from the amplifier under test must be injected.  Just inside this instrument there is likely to be a small voltage amplifier/buffer stage.  After that stage there are other circuits that ultimately perform the analysis and give some sort of readout such that the engineer is able to quantify the percentage and/or voltage of the distortion components generated by the amplifier under test.

So far, so good.  The key issue here is that the input buffer stage of the analyzer must generate distortion products that are lower in magnitude than those of the amplifier under test. This is absolutely vital in order for the test to have any meaning whatsoever.  In the case of any modern analyzer intended for such use, the residual distortion and noise of that buffer stage must be extremely low.  From time to time we see reviews in publication where the device being tested generated distortion levels below that which the analyzer being used was able to measure.  Obviously this is very good performance – depending on your point of view regarding the importance of distortion measurements.

The upshot here is that in any circumstance wherein an engineer is attempting to evaluate the performance of a product in the design stage, it is vital that his “test system” not interject artifacts that are greater in magnitude than those of the product being designed (or at least not more than absolutely necessary).  In such a case, whether it be a distortion analyzer in a test bench rig or a loudspeaker in a “reference” playback system, the needs are the same.  This is the engineering definition of “reference” as it applies to engineering applications.  And from what I gather, this is the type of “reference” level performance Frank needs in his application.

Now, should this “reference” speaker be an SP Technology product?  Maybe – this is where the subjective analysis comes in.  Are there other products out there that equal or exceed ours at a given price point?  Maybe.  What Frank needs to do is evaluate those product that make such “reference level” claims to begin with and compare between them.  There is no need and no point in his attempting to evaluate every possible suggestion.  Only those products that fall within the scientific constrains as outlined above should be on his ‘short list.”

Are SP Tech products “perfect” in that regard.  No, and as Bill Baker has clearly pointed out, there is no “perfect” speaker (well, except for that speaker which satisfies your requirements I suppose).  But…our claim at SP Technology IS reference level performance of the engineering kind.  Do our products add coloration and distortion to the signal.  You can bet they do – every loudspeaker forced to operate in our physical universe will.  Do our products have a “sound” of their own?  Unfortunately, under sufficient scrutiny, they probably do.  As much as we try to eliminate every possible form of distortion (the source of such “sound”), inevitably we fall short – as all others do to some degree.

And therein lies the rub…it’s a matter of degree – not “IF.”  I would submit that if our claims are to avoid being shot down under close scrutiny and our reputation ruined, our products had better be VERY adept at fulfilling the engineering definition for “reference.”  Yet, this in itself is proof of nothing.  In the end, Frank or anyone else considering our products will simply have to find out for themselves whether or not they live up to our claims and/or whether or not they meet their individual needs.  I guess in the end, we’re right back where we started.

-Bob

[woodsyi]

Bob,

Are you saying that my quest for speakers that will make Michael Bolton sound like Luciano Pavarotti is impossible? I am looking forward to hearing what Bill does with your Essence speakers.  

[Aether Audio]

woodsyi

Sorry man...I'm afraid not.  I'm not even sure I'd know how to do that.  More to the point, I doubt that I would if I could.

-Bob

[John Casler]

First of all, I consider that ANYTHING the listening room adds or subtracts to the playback is wrong.  Of course this is an impossible condition to achieve, but we try the best we can to minimize room effects.  Thus my sound room is stiff, concrete floor, heavy carpet, walls completely done in acoustic fabric (available at high end room finishing stores in a nice selection of colors and textures) and the ceiling is done in Sonex.  It is a very dead, very quiet room.  You can hear a pin drop, with no echoes. ...

A man after my own heart.

No room sound, is "good" room sound, as far as I'm concerned.

Room..Speakers...Equipment...Get out of the way, I want to hear the recording.

[WEEZ]

So far, it sounds like the SPTech loudspeakers fit what Frank is looking for in a 'reference' speaker, namely:

1) sonically neutral
2) high resolution
3) wide frequency range
4) high power handling

If the listening room is large enough, a full range speaker is needed because the room can support deep bass. And deep bass would certainly be a requirement for evaluating amplifiers- as well as all the other attributes listed above.

JLM's comment regarding small studio monitors needs some clarification, IMHO. It might be true that some studios use small speakers for monitoring a mix- but a good studio would not use small monitors exclusively. The small speakers would be used for nearfield monitoring- usually for vocals. A full range speaker would be used in the final mix and would likely be something more akin to the SPTech line, or even those great big B&W speakers, and others already mentioned here before.

I would only say, that most music lovers (and even some audiophiles) listen on less than full range speakers at home. I do. And the reason is, that my listening room is too small to support really deep bass. The full range speakers I've owned or tried have overloaded my room. The sound, therefore, was simply "too much"; and over-rided the clarity of the midrange- which is where most of the music is. Besides, some LP records have nothing but noise and rumble below around 50hz anyway.

So, back to the topic- If I were designing amplifiers (which I am thankfully NOT   ); I would want my amplifiers to sound 'right' on everything from a typical 6&1/2" two-way; up to a 'full range' type speaker. Therefore, if contemplating a line of speakers to sell (or recommend to clients) I would take that into consideration too. Maybe having just one "reference" speaker isn't enough?

WEEZ

[audiojerry]

Good points, Weez.

The words “neutral” and even to many… “sterile” come to mind.

Sterile might be a bit uncomplimentary, but SP speakers are definitely neutral and uncolored, squeaky clean even. If you want to know what your components and your recordings sound like, SP will let you know. You may not like what you hear, but as Jack Nicholson said, "Maybe you can't handle the truth".  

[Bill Baker]

"You can't handle the truth"

 My most favorite line from my favorite movie from my favorite actor!! Soory, I just had to throw that in.

[dlowman]

Some of the best speakers I have heard are the EFE t-22cf's  I put them up against the B&W802's and they stood right up there with them with a sub.  Best $1200 I ever spent.

[Karsten]

Good points, Weez.

The words “neutral” and even to many… “sterile” come to mind.

Sterile might be a bit uncomplimentary, but SP speakers are definitely neutral and uncolored, squeaky clean even. If you want to know what your components and your recordings sound like, SP will let you know. You may not like what you hear, but as Jack Nicholson said, "Maybe you can't handle the truth".  

Yes, the SP's can sound sterile, but only with a sterile sounding front end.

They do however not have this "full" sounding midrange that controlled break up modes in a large kevlar mid driver will create, but then again this does not belong in a reference speaker. Well, some wants to ride a chopper, others a full blood racing bike, I know what I prefer  

Brg,
Karsten

[lonewolfny42]

Less talk...and more action. Get Frank a pair of speakers he can listen to....(if he lived closer, I'd loan him mine).  

[ctviggen]

Lonewolfy, which SP techs do you have?  I'd like to hear these (though I'm not sure when I'll have time to come there; I'm so burnt out on home improvement projects that I might not do one for a while and will have some time off).

[ctviggen]

Lou,

For designed speakers, I think one of the things relied upon is the designer's ears.  This is why many speakers have a "signature" sound.  On the other hand, I like science and feel that science can aid our understanding of speakers.  Why is it that one speaker sounds better than another? (and even to individual users?)  I think science can answer that question, given enough time.  As for choosing with your ears, I heard hundreds of different speakers (dynaudio, dunlavy, thiel, linn, sonus faber, wilsons, B&W, I could go on and on) before I settled on my VMPS RM40s, which I think are great speakers.  However, I was cruising "main stream" stores and have never heard most of the speakers on this board, including SP Tech's.  So, even though I like data, I chose with my ears, too (although I'd still like to hear many of the speakers on this board).  I also agree that there is no perfect speaker, although I think that new technology and understanding of both speakers and human hearing will continue to improve speaker design.

[Daedalus Audio]

Bob,  I totally agree with you.  
Believe me, a lot of science goes into my speakers and the drivers I have made for my systems.  I APPRECIATE  that... but I don't lose sight of the original source...Music. Science makes what we do possible and goes a long way to helping us reproduce music, but we're not there. Just like we're not beeming up to starships.
Anyhow, enough of this. Bob, I think you just summed up the science argument., can we drop it now.  ; )  

Frank, A few people have recommended my speakers to you, I can see that since they are extremely revealing of the equipment in front of them and of the source. (There is a difference between speakers which are revealing and those which are analytical. Please lets not launch into that one.)  The problem for your purpose would be that being a multiple driver system they do like current, so I can't say that they would be the best choice for all your designs. In any case there are many excellent systems and I'm sure you'll find one that will not be a bottleneck in your evaluations. Good luck with your search.

Lou

[alpha_03]

I have a novel Idea- build them yourself!!!!

I did.

Yes it is painstaking work, but- the rewards when finished are fruitful to say the least.

I would highly advise one of three tweeters:

Morel 33's (excellant), Hi-Vi Planer RT8 (revealing) these I believe would really shine with an all tube system, or, Viva's new concentric dome (great all around driver, and very forgiving), it is an amazing tweeter, lastly the dynaudio d-28 or focal inverted dome(s) if you can lay hands on such items- all be it they are demanding with concern to your crossover point(s).

And BTW, Legacy audio produces the best sounding speaker I have ever heard, check out their Focus Line- they are truely amazing speakers, all be it, a tad pricey, very, very good for the money.

[alpha_03]

Interesting,

I have read the last few pages from with in this posting and I find it odd that an audio manufacture'r would want to design speakers in a near perfect room?????????

Let me ask you one very, very important question, whom else do you know of,  from with in an average crowd, that has such a room- so as to duplicate such accoustic perfection?

Very, very few, to say the least.

One must also ask, what type of music do you prefer, how much power are you intending to drive the speakers with, how big is the room in which you would desire to place any potential speaker system?

Advice on speakers, over all, is pointless- HUMAN EARS, decide what is sonically correct, not sources, speaker brand or anything else for that matter.

And BTW, for those of you over age 50, you can generally count on a 20% hearing degradation (or greater) compared to some one of lesser ...... expierence, simply due to age and enviroment.

[Russell Dawkins]

Let me ask you a very, very important question, Aplha_03:
Given that all rooms are imperfect in various ways, which particular brand of imperfection would you design a speaker for? And if you are designing a speaker to, in effect, compensate for the particular imperfections of the room you designed in would it not work as designed only in a room with the same "imperfections".

If you read all the pages in this thread, most of your other questions have been answered.

[alpha_03]

Thank you for your question,

However, your question is a loaded question and you know it, there fore it is not a question ANY person (or engineer) can answer with any truth.

Hence my previous question, research dictates that a given average number of listeners will listen to their given choice of audio in a given room size, which contains X principle(s), and is constructed with X principles of materials. Certainly not cork, concrete (unless you live in your basement- or a millitary compound), and wall baffles, that by design, are constructed to reinforce a particular speaker design for a given listeners preferance.

It would be very wrong to design a speker in such a way, why? For the obvious reasoning that you say I have missed from with in this thread, for which, I have to say, I believe the majority here to be in error- considering certain speaker designs considered here-in.

Since we know that the average listening room is X, and a given speaker (designed correctly) will perform with X parameters in said given room size, then the equation dictates that a designer produces a speaker in "X" manner, this to best suite it's particular average customer- no? Or, should the designer simply build a speaker that sounds good in his/her room of choice?

Mind you we are speaking in terms of ecconomics, not custom design principles.

So tell me, please, what is wrong with my previous posting? That you did not like my truths, or that you disagree with my principles? Either way, it really doesnt matter, listener preference and good - sound-  engineering principles from the get go are what matter, not esoteric designs that only work correctly in a "given" room.

[alpha_03]

I would like to also add a few things, that is if I can bend your ear a bit.

The first and primary design of a speaker is contained with in it's musical preferance via a given design goal, that is, this should be the case when one considers the majority of designers.

One whom listens to Metallica certainly will not purchase a speaker designed around classical music parameters, and, visa versa. Nor should they.

What saddens me is that this very premise is wrong, Big speakers sound better- period (if designed correctly). Small drivers produce small sonic signatures when compared to an equally designed larger speaker, yet are they only only larger in stature? I dont belive so. Why have all those WPC if SPL is not the end result one seeks?

Tell me then, why is it all the craze to design speakers with smallish drivers that, at best, produce music from 60Hz and above (real world and on a good day). For if you attempt to inflate a design with 6.5" bass drivers to say a 20-30Hz real world output levels your stealing from your customer- IMHO. Express this same impact via comparrison to a much larger speaker with the same gear, the larger speaker will sound much better.

No amount of x-over design can make up for shear driver mass, excursion and volume of air movement- which produces the sound waves that we as humans hear. No cabnient design can either (nice try Bose- you call that bass?) Speaker size and placement is all important, and yet the room can also add it's particular signiture & color, hence the many, many audio companies spanning the globe, that design with this very fact in mind. Speakers are generally  "lived with"- good or bad, audio gear is easily replaced, and usually replace first- that is for most consumers.

Tell me sir, do you know of a 6.5" or 8" driver that can reproduce a 16Hz to 20Hz note at 120dB? Or, the low level "real world" passages of a classical , or, heavy metal rock concert, at levels that inspire one to actually use all those watts many of us have paid for that in turn do not make boat anchors of a particular amplifier at some point?

I think not. But then, I am efficentcy bound by my nature, esp. when it concerns the use of electricity, and, the wattts of music I prefer to listen to.

That is to say, the average consumer has been categorized into segments, and these segments dicatate the speaker and gear you will purchase. This is where I speak from.

A good speker will play ALL music equally well, not just a given type- in a given room.

[bhobba]

One whom listens to Metallica certainly will not purchase a speaker designed around classical music parameters, and, visa versa. Nor should they.

IMHO your premise is not correct.  One should never buy a speaker designed around classical music or metalica or anything except the premise of faithfully reproducing what it is fed.  That is not just my view either:
http://www.linkwitzlab.com/reproduction.htm
'My goal is to design transducers that convert electrical signals into sound without adding or deleting information, with minimum masking by the listening environment and based upon what is perceptibly significant. The loudspeaker is only one element in the reproduction chain of tools, but it is the weakest link and determines ultimately what you will hear and experience.'

What saddens me is that this very premise is wrong, Big speakers sound better- period (if designed correctly).

That depends on what one means by big and better.  I have listened to big speakers, small speakers, eltrostatics, ribbons and all sorts of things.  Sound quality has nothing to do with speaker size.  The only thing the laws of physics prevent is a 5 inch driver from producing 30hz well.  But that is what subwoofers are for.  SP Timepieces, for example, while not a mini monitor, are not big under most peoples usual conception of the term as it relates to speakers either, and they are 3 db down at 28hz.  Bass that low combined with the usual room gain one finds in trying to reproduce wavelengths greater than its size is more than enough.  And except for bass small speakers can do anything large ones can.  And another thing I recently learnt is not is not possible to even hear 25hz unless it is at least 85db - the level you need to wear protective gear.

Tell me sir, do you know of a 6.5" or 8" driver that can reproduce a 16Hz to 20Hz note at 120dB?

No I don't - but then again I do not know of many rooms that can reproduce bass that low either.  I had an Richter Evictor that could go that low.  What it produced was pretty close to inaudible in my listening room.  People commented you felt in the dunny more than heard it.

Thanks
Bill