Canton Reference 3K measurements

Me and my dad pondered if it's feasible to build a new crossover for the Reference 3K speakers, since we thought we might prefer a 2nd order XO over the stock 4th order XO.

So I opened up the speaker and made extension cables from the crossover outputs and driver inputs to be able to measure the drivers individually in the stock enclosure. For now all I have are 1m in-room measurements, with a 2nd microphone positioned closer to the speaker drivers, at ca 30cm from the tweeter. The resolution for the woofer measurements is thus very limited.

Spoiler: FREQUENCY RESPONSE MEASUREMENTS

All of the following measurements are with both the bass and midrange controls set to +1.5dB.

First, here's the in-room listening position response with the woofers bi-amped and EQd, mainly to combat a 42Hz room mode.


The following are the 1m measurements I took yesterday:

BLACK = DRIVER BY ITSELF
RED = DRIVER WITH CROSSOVER
DOTTED = 30cm closer mic position for some extra LF resolution. Merged nearfield measurements would've been better, but as is I won't be able to redo the measurements this week.

1" TWEETER FR:


7" MIDRANGE FR:


2x 9" WOOFERS FR:


WHOLE SPEAKER:

RED = midrange inverted

I haven't taken proper outdoor measurements, where I would normally measure at many angles from 0 to ±180° both vertically and horizontally. It would be interesting to see how a polar of a "normal" speaker like this would look, but I would estimate that it takes 2 whole days to do so.
The problem is currently I'm not sure it's worth it to do so, which I will explain in the next post.

 

Now, I knew that the 3K exhibits high-ish 3rd and 5th order distortion at lower SPLs. This 3rd order distortion does not seem to increase as much by the playback level resulting in okay distortion measurements at 90 or 100dB. But at 70 or 80dB the distortion is very high compared to other speakers.

I've seen the same pattern with the HEDD Type 07 and the DreiZwo. The midrange of the W8-2314 was the worst offender in this regard, with the sweep sounding very distorted, to the point where I questioned if the drivers were broken.
My 2021 distortion measurements of the Reference 3K (which are actually of a higher quality than the ones I took yesterday) also bear this out.

In these four cases the distortion was definitely audible with the sweep. Odd order distortion like that sticks out during the sweep.

Spoiler: DISTORTION MEASUREMENTS at 1V

These are all taken at the 1V measurement level. 1V is 9dB quieter than 2.83V, so my estimate of the sensitivity of the Reference 3K is actually only 88dB, not much better than my much smaller Hathor (85 to 86dB).

All of these measurements have an ugly rising distortion for higher frequencies. I'm hitting the SNR limit of my microphone here, so this can be ignored.

TWEETER DISTORTION


MIDRANGE DISTORTION


WOOFERS DISTORTION

(this looks particularly bad due to the limited bandwidth of the woofer FR I got at the micriphone position. But we can see the same pattern with high 3rd order distortion.

SPEAKER DISTORTION

I attached my 2021 distortion measurement for reference. Not too much of a difference, except that the older one was taken with the LCT550. These are taken with a SDC omni microphone and have about 15dB more noise.

So what does this mean? We listened to the midrange by itself and it just didn't sound very special. Sure, the bandwidth was good for a driver of this size (as can be seen from the FR), but it didn't seem to be very resolving to me. At least compared to the uber widebanders I'm used to.
I always wondered if this is a matter of the crossover limiting things and it probably does. But the baseline isn't as high as it could be. The tweeter seems to help out quite a bit. Overall I'm not sure it's worth making a new crossover for it, yet.

I don't mean to say that the Reference 3K sucks. I think it's a great speaker. Even for the price it seems to be one of the more resolving speakers I've heard. It stages quite well. The crossover components aren't bad for the price.

 

RESERVED FOR IMPEDANCE