Emerald Physics CS-2, Opinions Please

Tvad makes a very good point.

The CS2's right now have a lot of buzz and much of it stemming from a very good showing at this year's CES. I had one friend, a dealer, who picked up the line after the show. However, I'm not sure they are worthy of the hype.

I think the CS2's are an ok pair of speakers and the price is pretty fair given the usual difference between cost of manufacturing and final dealer price. I estimated that I could build a pair for about $1200 so the $3.5K is about right.

Except for using the DSP on the Behringer for fixing the bass problem, the CS2's break absolutely no new ground(and even that is not new in DIY circles). A two way speaker using a compression driver and a horn for the mids and highs and an open baffle for the bass goes back over 70 years. (let's avoid an argument over the semantics about whether a waveguide is a horn or not) Do a search for the old Western Electric 'Wide Range' speakers designed in 1931. Altec and JBL made their reputations on similar designs (albeit with bass reflex enclosures for bass and not open baffles).

I do find that speakers using this geometry when done right are very dynamic with smooth sound through the mids and highs. Of course, most horn fans will say I told you so. Compression drivers are incredibly linear and sound unbelievable when coupled with a properly designed and implemented horn.

The CS2's try very hard to cheat the laws of physics. As I said, open baffle bass go way back. They were used before bass reflex enclosures and certainly way before sealed enclosures. However, the drawback to an open baffle is the cancellation due to the rear wave. The way to defeat this naturally is to use a wide baffle. Check out the JElabs page about open baffle speakers. http://members.myactv.net/~je2a3/open.htm

But people want bass below 40 Hz and want their speakers small at the same time. i.e. trying to beat the laws of physics. Hence the use of equalization. DSP is essentially advanced (or not) equalization in the digital domain. One of the main problems I have with the CS2's is that I hear the digital artifacts introduced on the sound by the crossover. Several of my friends hear the same thing. Of course, everyone hears and likes different things so YMMV. The benefits from an open baffle hardly outweigh the negatives from a digital crossover especially if you listen to vinyl.

In my experience with the CS2's, I found the sound very odd and unnatural. My dealer friend gave me a frantic call one day because he received his speakers but they sounded very bad using the stock programs from the factory. Very different than at the CES show he told me. I went to his store to help set them up. With his electronics, I had to use a very different crossover program to get them to sound right. The stock programs did not work at all. Another friend did like them at another dealer but the other dealer also tweaked the stock crossover program. Maybe the pair I heard was just not set-up right. Still no amount of set-up was going to fix the vibrations from the plastic waveguide (aka horn).

I would suggest listening to other speakers that use a horn mid/high and a dynamic cone for a bass before buying the CS2's. In my opinion, the CS2's are not bad but other speakers using a similar geometry sound far better and use much better quality drivers. The CS2's are a good buy money wise because they use pro audio compression drivers and bass drivers. Effective and cheap but you can do much better. A JElab style open baffle using Great Plains Audio 604H-II drivers cost about half the price of the CS2's and sound much better and only need one amp. $3500 is not a bad price but you do need to factor in the cost of a second amp. You could buy a used pair of Altec Valecians, Altec model 19, JBL 4330 monitors, etc. for less than the CS2's.

If you are interested in open baffle speakers, check out speakers based on PHY-HP drivers which are designed for open baffle use. (Ocellia, Auditorium23, Musical Affairs) If these are a bit pricy check out the offerings from Hawthorne Audio (http://www.hawthorneaudio.com/index.html).

It is better to do a bit of homework before putting down the cash. Of course, if you really like them then get them. Utimately, each person has to decide what they really want.

The link for Hawthorne Audio is http://www.hawthorneaudio.com/.

The Altec 19 is a classic and unfortunately rather large. The JElabs open baffle is rather large width wise too. Hard to beat the laws of physics. The bass from the old Altec speakers are phenomenal but you do pay a price in size.

If you haven't figured it out, I'm a physicist by trade so I do view things a bit from the science standpoint. Hard habit to break. BTW-I use DSP in some of my data analysis so I know full well the advantages and disadvantages.

It seems you have made up your mind so some of comments seems to have rubbed you the wrong way. I never intended to do so. As long as it makes you happy, it doesn't matter what I or anyone says. I was just expressing my opinions based on my experiences and my own personal preferences.

My main point was that many of the good qualities of the CS2's are due to the use of compression drivers, properly made horn, etc. and less to due with the DSP or open baffle nature of the CS2. So it is not a bad idea to listen to some other examples of speakers before you buy.

I do not own a pair of CS2's but my friend is a dealer and I hang out at the store most weekends so I get lots of listening time with the CS2's using a variety of electronics. He also asked me to him set-up the speakers so I did spend a fair amount of time playing with them.

I never dismissed pro drivers. They are very effective when used properly (operative word is properly). They have many key advantages like power handling and efficiency. I use Altec drivers which are essentially pro drivers. My point was that you could get a speaker with parts that have a better design for less. I did not intend to mean more expensive was better. Just that the component needs to be designed to do the intended job. The 'wall of sound' is very effective in creating a wall of sound just not music reproduction. Pro audio and home audio have different design criteria and needs.

That's why I suggested looking at Hawthorne Audio. Their drivers are made by Eminence, the same company that makes the bass drivers for the CS2s and the OEM for the drivers used Zu speakers. The main difference is that the drivers used by Hawthorne have a qts value optimized for open baffle operation so they don't need to use DSP to compensate for the bass. Same story with the PHY-HP drivers. They are designed for open baffle use and don't need equalization.

Since you have or are buying the CS2's, I do agree with using the digital input on the Behringer. The extra analog to digital stage really is a negative. Not sure what to do with vinyl playback other than an outboard A/D. One thought I had about the CS2 was to replace the Behringer crossover unit with the DEQX PDC2.6 (with or without preamp). The DEQX has a more flexible crossover and will also allow for room correction. If you are going to use this stick then you might as well get a bigger stick.

Matrix-In my original post, I refrained from giving the exact breakdown on the parts used in this speaker. You didn't pull any punches here. I was a bit more gracious in the $1200 estimate. :-)

Kehut-My experience with the CS2's seem very different from yours. The reason my dealer friend called me for help was that none of the presets worked at all in his room with his electronics. I painstakingly created a new setting for his set-up from scratch and it was very different (almost opposite) of the factory presets. Everyone who heard the comparison between my program and the factory program thought the factory program was a non-starter. I found that very odd given the very positive comments at CES.

Perhaps my listening preferences are very different than Clayton's because I was hearing both digital artifacts from the Behringer and acoustic artifacts from the plastic waveguide. The waveguide artifacts are not due to the DSP but from the waveguide interactions.

I do agree the concept of the CS2 has merit. It would be intersting to DIY a similar speaker using bass drivers meant for open baffle operations (say two PHY-HP H30LB15), making the baffle a bit wider, adding sides and a top along the lines of the A23 Solovox (the Solovox cabinet uses a neat trick to deal with the rear wave cancellation problem), a damped metal horn, and a compression driver designed for audio. Or you could just stick an Altec 604 in an open baffle and call it a day.

Wow, I seemed to have stirred the pot.

No point in attacking Tvad whom I hardly know. I'm the one who did not like the speaker.

Paul-If you want to know who my dealer friend is feel free to send me a PM. I have nothing to hide. I call it as I see it. The reason I didn't disclose the name here is that I'm basically saying something he used to sell is not that great. Although it wouldn't be the first time.

As for EP having only one dealer, that seems to be a more recent event. EP had a great showing at CES and a number of dealers picked up the line in January. My friend started carrying the line after the show. He was not the only one. I remember seeing several dealers advertising the CS2 after the CES including here at Audiogon. I first listened to the CS2's in mid February; the speakers arrive about a month after the CES. As I of my last visit to my friend's shop, he had sold his demo CS2 and he is not carrying EP anymore. Which is in agreement with the new single dealer policy. Dealers change lines all the time.

BTW-when I say I hang out at the store, I really mean I hang out at the store. I have often referred to that place as an audio version of Cheers.

In my original post, another friend of mine did listen to the CS2 at another dealer I know in LA. That friend liked the CS2 and I do trust the dealer's taste since I used to hang out at that store when I lived in SoCal. It is ironic. Another of my friends listened to the pair at my friend's store and did not like the speaker. The three of us went through the exact same arguments in this thread via e-mail for several weeks. Feels like deja vu.

Paul-I never for a moment thought you were insinuating. I was just offering since you asked.

My parting commennts.

I do agree with all of the CS2 advocates here that the CS2 are not dynamically compressed. It is unfortunate that a lot of speakers these days are dynamically compressed.

My main point in my original post was that there are a whole class of speakers out there (many decades old) that have the same characteristics as the CS2s and it is worth taking a listen. Unfortunately, most of these speakers are not in the mainstream audiophile consciousness at least in this country or thought to be too old to be any good. A little education goes a long way.

Paul-your comments about your friend Duke's design is interesting. In my original post, I mentioned the old Western Electric 'wide range' speakers. I did not mentioned that they weren't actually that great. They had a variety of problems. This led to the famous Shearer horn, a two way speaker with a multicelluar horn on top and a folded bass horn driven by a dynamic cone driver. BTW-a waveguide is just another form of horn.

Philefreak

While, I'm a SET advocate, I agree completely that sticking a 3 W amp on even a 100 dB speaker may not always yield the best results. This depends somewhat on the speaker,amp, room combination.

However, I do disagree about your comment that SET amps having problems below 1000 Hz. I realize the 1000 Hz number comes from the crossover point of the CS2 so it was a number that was thrown out in discussion.

The modern pitch standard for music is 440 Hz, which is A4 (the A note above middle C) and the 49th key on a piano. This is right in the middle of the piano and hardly in the bass region nor difficult for a SET amp to reproduce. The normal frequency range for the average human voice in normal conversation is about 80 Hz to 1100 Hz. Obviously, talented individuals can go much higher or lower. However, the normal vocal range is below 1000 Hz. One traditional strength of SET amps is their presentation of human voice. A soprano is expected to cover from C4 (261.626 Hz) to C6 (1046.50 Hz). So saying SETs can't handle music below 1000 Hz is a bit off. Now, getting below 40-60 Hz becomes tricky. Certainly getting to 20 Hz is downright difficult without a gigantic bass horn.

A 500 Hz lower cutoff for a compression driver is a pretty severe requirement on both the driver and the horn/waveguide if you want the driver to cover 500 Hz to 20 kHz. 800 Hz is a more reasonable and achievable goal. There are compression drivers rated down to 500 Hz and go up to 20 kHz (usually a larger 2" driver). But, you do want some head room (say 1/2 octave) below the crossover point. 500 Hz is pretty hard to do and it is debatable whether there are any advantages. At that point, going to a three-way design may be a better option.

Philefreak-I get your point. I do understand what you mean when speakers don't play to realistic levels and seem to just run out of gas. But in my experience, this usually happens at frequencies below the midrange when the speaker impedance begins to dip.

I threw out the comments about the pitch scale because I get a sense that a lot of audiophiles cannot relate a frequency given in Hz to real life. Middle C is well within the midrange and that's at 261 Hz. Human hearing is not linear.

I think a lot of the attraction that the CS2 offers based on the comments in this thread really stems from the dynamics that the CS2's offer. I find that the majority of audiophile speakers these days do a very poor job in the dynamics area and when one does find a speaker that offers dynamics the experience is eye opening. It is an experience much like the first time one hears a SET amp.

One thing that the CS2's are doing is showing the mainstream audiophile the wonders of a speaker that is not dynamically compressed. And that is a good thing.

I just find, much like Undertow, that there are plenty of speakers out there that can offer the lifelike dynamics. You just have to look in the right places.