Watts per channel question.

[MidnightSensi]

Again, how many ohms (impedance) are those speakers?

Their website (under FAQ) seems to imply that they are generally 4-ohm minimum.

They probably don't publish their nominal impedance because of people worried about blowing their receivers.

Actual impedance varies with frequency. The impedance listed by manufacturers is generally nominal, not minimum, and is sort of arbitrary without seeing the impedance curve itself. Phase angle is also important, which indicate how inductive or capacitative the loudspeaker looks to the amp. Sever phase angle swings will be more demanding to the amp.

They should post these things, but, don't. :/

I say that to say this: In my experience, Vegas are pretty easy speakers to drive. High sensitivity and average impedance being pretty mild. They are designed to be used with budget stereos, college rigs and so forth... these aren't my Dynaudio amp killers or anything.

 

[lsiberian]

Their website (under FAQ) seems to imply that they are generally 4-ohm minimum.

They probably don't publish their nominal impedance because of people worried about blowing their receivers.

Actual impedance varies with frequency. The impedance listed by manufacturers is generally nominal, not minimum, and is sort of arbitrary without seeing the impedance curve itself. Phase angle is also important, which indicate how inductive or capacitative the loudspeaker looks to the amp. Sever phase angle swings will be more demanding to the amp.

They should post these things, but, don't. :/

I say that to say this: In my experience, Vegas are pretty easy speakers to drive. High sensitivity and average impedance being pretty mild. They are designed to be used with budget stereos, college rigs and so forth... these aren't my Dynaudio amp killers or anything.

A single driver setup for the midrange would indicate it's likely closer to what an 8ohm nominal speaker would generate. Of course the driver may be lower, but I don't see this causing amp issues. Now I would be concerned about a lack of baffle step. Which is indicated by it's very high efficiency rating. I suspect this speaker is intended for small venue pro audio so near wall placement is presumed. I doubt it would take much power to push these, Just make sure you keep them close to a wall and out of the corner if you can. I suspect they rely on the wall reinforcement for bass.

 

[MidnightSensi]

A single driver setup for the midrange would indicate it's likely closer to what an 8ohm nominal speaker would generate. Of course the driver may be lower, but I don't see this causing amp issues. Now I would be concerned about a lack of baffle step. Which is indicated by it's very high efficiency rating. I suspect this speaker is intended for small venue pro audio so near wall placement is presumed. I doubt it would take much power to push these, Just make sure you keep them close to a wall and out of the corner if you can. I suspect they rely on the wall reinforcement for bass.

I just looked up baffle steps. Interesting!

How is that indicated by its very high efficiency rating?

Good stuff man, I'd love to see your bookmark file for some good reading.

 

[lsiberian]

I just looked up baffle steps. Interesting!

How is that indicated by its very high efficiency rating?

Good stuff man, I'd love to see your bookmark file for some good reading.

Well a Baffle Step circuit attenuates the tweeter to be in line with the mid range. Since the tweeter gets the boost of the front baffle we design a circuit that reduces the SPL of the tweeter in order to preserve an even F-R.

Higher efficiency usually indicates they left out a BSC. That is by no means full-proof since CV could have a very high efficiency midrange, but it's a hint to start the placement with.

It's really a logical deduction that can be helpful.

http://trueaudio.com/st_diff1.htm is a very good article on the subject.

Is his good example of a the circuit. As you can see it would reduce the efficiency of a loudspeaker by about 6 db. Which happens to be close to the distance between the CW and typical loudspeaker.

In a TM design 87 to 89 db/w is the usual of course. This is why MTM's are so popular. It really makes the speaker more efficient.

 

[Swerd]

Well a Baffle Step circuit attenuates the tweeter to be in line with the mid range. Since the tweeter gets the boost of the front baffle we design a circuit that reduces the SPL of the tweeter in order to preserve an even F-R.

I applaud the fact that you recognize the need for baffle step compensation because it is often ignored, but saying that a BSC circuit attenuates the tweeter is not correct.

If you look at a frequency response graph of a small 2-way speaker, you get a step up in loudness of about 4-6 dB, hence the name, baffle step response. In this example of an unidentified but well-known commercially available speaker, you can see the baffle step beginning between 500 and 1 kHz and ending with a dip just beyond 2 kHz. Attenuating the tweeter will not fix this. In this example, where the crossover point seems to be between 2 & 3 kHz, attenuating the tweeter might make it sound worse.

Our hearing is very sensitive in the 500-2000 Hz range. Depending on what you're listening to, this exaggerated midrange can sound too forward. Some people have described it as a nasal or honky sound. Voices and brass will be overemphasized in a way that smears the sound, loosing overall clarity and detail. I'm always surprised at how many commercially available speakers fail to deal with this.

It can easily be corrected in the crossover with BSC as explained in this article. There are simple to use online calculators that make the math easy.

Generally (but not always) baffle step is more of a problem with small narrow cabinets, as with 2-way bookshelf speakers. In larger speakers with wider cabinets, such as 3-ways with a large woofer, the baffle step shifts to lower frequencies where our hearing is less sensitive and we just don't notice it as a problem.

 

[jostenmeat]

I recognize that graph, Swerd. You've posted that on my behalf before.

 

[Swerd]

I recognize that graph, Swerd. You've posted that on my behalf before.

I rarely have anything new to say .

In fact, in the past several months, I've posted almost nothing. I've actually been busy at work .

Without lsiberian's hastily worded comment about BSC, I probably would have stayed silent a bit longer .

 

[c413]

Again, how many ohms (impedance) are those speakers?

im not sure how to measure ohms and it doesnt appear to be in the specs or anything?

 

[markw]

im not sure how to measure ohms and it doesnt appear to be in the specs or anything?

The discussion has progressed beyond my question since then and you were given an answer. See if you can find it by reading the responses.

(hint... read response 21 carefully)

 

[tesseract]

http://www.a1components.com/itemdisplayn.aspx?item=10985

I have owned that very sub (CLS-12S) recently. It only got down to around 35hz before starting to roll off, though the midbass slam was pretty good. The guy I sold it to loves the way it compliments his Bose speakers.

Just for reference, My current sub (MFW-15) gets down to 17hz sitting in the same place as the CW. That's a whole octave lower! I am NOT recommending the MFW-15, it is a great sub but..... just saying I would keep looking.

 

[tesseract]

Ooops, nevermind, I see you already bought the speakers. My sub tended to overheat. I put a small fan on it at low speed, that really helped a lot.

Really, these speakers will do just fine for the price of admission, enjoy.

 

[AJinFLA]

Since the tweeter gets the boost of the front baffle

Hi Siberian, that is incorrect. It is actually diffraction loss of the woofer as we transition from 2Pi to 4Pi space, which cause a drop (aka "Baffle Step") in the (free space/4pi) on-axis FR.

Higher efficiency usually indicates they left out a BSC. That is by no means full-proof since CV could have a very high efficiency midrange, but it's a hint to start the placement with.

It seems that CV might be overstating their sensitivity ratings, as noted in the Soundstage test of the CLS-215. I would be hesitant to allow sensitivity to dictate placement. Especially given the fact that his suggested receiver has a bass control .

Btw, I see absolutely no (technical) reason why he shouldn't buy the Sony he likes, to power these speakers.

cheers,

AJ