[srb]

I was looking at a pair of speakers, the CEntrance MasterClass 2504.  They are a small passive nearfield monitor with a 4" coaxial driver.  They started out as a $600 to $700 speaker and are being currently sold at a closeout price of $200.  Without getting into discussions about potential sound quality or what might be better for the price, it seems like a relative deal and would fit my desktop use.

Missing from the specifications was the sensitivity, so I inquired and was told "about 95dB".  My question is this - knowing what I do know about enclosure size, low frequency response, sensitivity and the design tradeoffs, how could it be possible that a small enclosure (~ 9" x 5.7" x 8.2"), a small driver (4") and relatively low frequency response (50Hz -1dB) could have such high sensitivity?

While a lowish sensitivity of 85dB would be entirely fine for my amplifier and nearfield desktop use, I would recommend this as a possibility in another topic where the OP is looking for a higher sensitivity desktop speaker for use with a low power amplifier, but I'm fairly skeptical of the quoted sensitivity.

Steve

[Wind Chaser]

Your skepticism is justified. You said sensitivity was missing from the specs, but someone gave you a number of about 95db? That's weird, but given the application and price, it's worth looking into.

[JohnR]

how could it be possible that a small enclosure (~ 9" x 5.7" x 8.2"), a small driver (4") and relatively low frequency response (50Hz -1dB) could have such high sensitivity?

It's a 4 ohm speaker, so sensitivity is (nominally) 3 dB higher than efficiency.

Manufacturers have been known to quote the speaker sensitivity as being the same as the driver's specified half-space sensitivity. That doesn't account for baffle step compensation (if there is any).

Driver manufacturers have been known to quote sensitivity based on peaky mid/treble response.

[JLM]

One of the reviews I found measured bass output as down 13 dB at 50 Hz and stated a specified bass limit of 63 Hz would be more reasonable.  It was bundled with a 25 wpc amp, but as JohnR and some of the related reviewers point toward, there appears to be more than the normal amount of liberties taken with their specifications.  So their "about 95 dB/w/m, could be very optimistic.  My guess is the amp is class T (most of these start to distort at 7 watts/8 ohms).  But one reviewer mentioned that it was adequate for (small) in-room use.  Again what adequate means is open to much interpretation. 

As you know there are very few standards in the industry for specifications and no one to enforce them.  It boils down to a matter of trusting the manufacturer and while I've read many good things about CEntrance, this dip into the 2504 speakers leaves me cold.

[apollophono]

It's funny that you ask.  I too was interested in their sensitivity and
did the same thing.  I was told the sensitivity was 85db.  That was
about 1 1/2 yrs ago. 

What you were told was wrong.  They are good speakers for near field.

As with all things everybody's tastes and needs vary and so it may
work for you or many not.  They are limited in the bass, but what
they have is good and clean.  I felt they lacked on the high end.  A
little to rolled of for my tastes. 

FYI, I don't use mine anymore and would be willing to sell them to
you for $100.  I have the original box and packing materials.  Just
PM if you're interested. 

[srb]

One of the reviews I found measured bass output as down 13 dB at 50 Hz and stated a specified bass limit of 63 Hz would be more reasonable.

While specs are most often only a starting guideline, there's a world of difference between 1dB and 13dB!

I too was interested in their sensitivity and did the same thing.  I was told the sensitivity was 85db.  That was about 1 1/2 yrs ago.

As the entire email reply consisted of "about 95 dB", it could have easily been a typo on a quickly dispatched response.

I felt they lacked on the high end.  A little to rolled of for my tastes.

While I expected limited bass response despite the specs, your subjective evaluation of high end response gives me pause.

I have two existing budget 2-way speakers that have both been used on the desktop with not unsatisfying results, KEF Cresta 1 and Pioneer SP-BS22-LR (stock), I just thought maybe a coaxial speaker might be a little better suited for ~ 24" nearfield listening as well as thinking I might also get a bit better and smoother sound in the process.

Thanks for the replies.

Steve