HSU CCB-8 Speaker Review

[peniku8]

Wow what a piece of manufactured garbage! They quote Don Keele on their product page. He should be suing HSU for libel

As does csd/waterfall measurement:
View attachment 497431

That being said, an unnormalized waterfall/burst decay plot can be visually misleading, just like an unnormalized directivity plot can. I might've asked for this already but is it possible to export normalized decay plots from the Klippel software? Those would be a lot more interesting in extreme cases like this.

 

[kharan]

I am surprised by the positive words there, especially coming from James Larson.

It could be that his speaker is markedly different from yours. His can be barely fits within a +- 2 dB window from 200 Hz to 10 kHz, somewhat irregular but terrible. Yours shows + 4 dB peaks and a - 7 dB dip, which is actually terrible. Almost like two speakers with the same rough design but different components.

 

[wemist01]

I suspect it is supposed to read "wasn't very motivated" instead of "was".

Yours,
Editor

 

[Scrivs]

With a response like that, they should have called it the “Himalaya.”

 

[JayGilb]

Amir,

Thanks for the review.

 

[tw 2022]

Yikes! I've thought about trying these out a few times and was just looking at them again a few days ago.

Amir, thank you for saving me the trouble!!

my thoughts as well....

 

[Juhazi]

KEF Q350 price is now around 300$/speaker in USA, much wiser choice. Sensitivity just a tad lower

KEF Q350 Speaker Review

This is a review and detailed measurements of the KEF Q350 Bookshelf/stand-mount speaker. It was purchased new by a member and kindly drop shipped to me for testing. The Q350 costs US $700 on Amazon including prime shipping. As with other KEF coaxial speakers, the look is unique and quite...

www.audiosciencereview.com

Spl problems around 1kHz are common to almost every mid-size 2-way speaker! - BR resonance, driver sisize and baffle edges...

 

[Randolf]

Other external measurements (not with an NFS) show a similar story too;

To me the difference between Amir's and Audioholics measurement is to big to be explained by the measurment technique NFS vs. 9 feet high 14 ms gated free air. Even the impedance sweep is rather different. I used VituixCAD SPL Trace tool to quick an dirty digitze the data (not 100% accurate):

Even there are some similarities, to me the it looks like two different speaker versions (at least with different crossovers) had been measured, Audioholics measurement was from 2017.

 

[yo!]

To me the more accurate graph is questionable.

The result is somehow to be expected based on the construction.
A wide front panel is not a good idea and causes interference with the woofer in the midrange. Not nice to control, specially passive.
Then this type of 'horn' is more a tweeter behind a long waveguide through the magnet. No smooth function possible into the crossover region, nor even pressure level. Lot's of interference too.
Only 'benefit' is time alignment that makes it easier to drive both speakers ++. In this case not worth mentioning.

To be fair, it's not easy to get better results out of the given material.

 

[mlankton]

your first warning was the manufacturers recommendation to listen to them off axis, then seeing the tweeter buried inside a virtual tunnel.....it's too bad because low price, good quality build with high efficiency and big soundstage would be a win for so many people's living rooms, but this is not it and Hsu should have realized it and kept working on it instead of shipping this

 

[MZKM]

Preference Rating
SCORE: 1.9
SCORE w/sub: 4.3

Sensitivity: 90dB (300Hz-3kHz ; spec: 88dB (94dB half-space))
Frequency response: ±7.2dB 50Hz-20kHz ; ±6.5dB 80Hz-20kHz

 

[Hipster Doofus]

From the website: The CCB-8, a constant directivity horn made in collaboration with Don Keele, is one of the industry’s best performing speakers when it comes to smooth, musical, off-axis response.

• Point source ensures no lobing effects because you’re always the same distance from the woofer and tweeter
• True constant directivity (circular) horn allows for a smooth, musical, off axis response regardless of whether you’re vertically, horizontally, or even diagonally off axis
• Horn loaded coax gives increased efficiency in the higher frequencies
• Maintains linear responses even when 15 degrees off axis

CCB-8 Speaker

Status 01-16-2026: Out of stock - Current estimate is that we won't receive a new batch until early spring Order Note: Each order quantity contains ONE speaker. For a pair you would need to change the quantity to two The CCB-8, a constant directivity horn made in collaboration with Don Keele, is...

hsuresearch.com

one of the industry’s best performing speakers when it comes to smooth, musical, off-axis response.

Sound like anyone we know???
Create a problem that does not need fixing and make it worse.

 

[Maiky76]

Here is my take on the EQ.
Please report your findings, positive or negative!

For the score rational your journey starts here
Explanation for the sub score
The following EQs are “anechoic” EQs to get the speaker right before room integration.
If you able to implement these EQs you must add EQ at LF for room integration, that is usually not optional… see hints there.

The raw data with corrected ER and PIR:

Score no EQ: 1.9
With Sub: 4.3

Spinorama with no EQ:

• Very uneven response
• Major resonances
• Major directivity errors
• Where is the "constant directivity"?
• Port
• Can't see the point...

Directivity:
Better stay at tweeter height
Horizontally, better toe-in the speakers by 10/15deg and have the axis crossing in front of the listening location, might help dosing the upper range. explanation here

EQ design:
I have generated two EQs. The APO config files are attached.

• The first one, labelled, LW is targeted at making the LW flat
• The second, labelled Score, starts with the first one and adds the score as an optimization variable.
• The EQs are designed in the context of regular stereo use i.e. domestic environment, no warranty is provided for a near field use in a studio environment although the LW might be better suited for this purpose.

Score EQ LW: 4.9
with sub: 7.2

Score EQ Score: 5.3
with sub: 7.7

HSU CCB-8 APO LW EQ 96000Hz
December162025-005649

Preamp: -6.00 dB

Filter 1: ON HPQ Fc 40.9 Hz Gain 0.00 dB Q 0.98
Filter 2: ON PK Fc 159.5 Hz Gain -2.75 dB Q 1.38
Filter 3: ON PK Fc 637.1 Hz Gain -3.38 dB Q 5.82
Filter 4: ON PK Fc 1219.6 Hz Gain -7.11 dB Q 4.24
Filter 5: ON PK Fc 1762.1 Hz Gain 6.79 dB Q 2.34
Filter 6: ON PK Fc 4505.6 Hz Gain -2.64 dB Q 3.44
Filter 7: ON PK Fc 7102.7 Hz Gain -2.74 dB Q 6.00
Filter 8: ON PK Fc 11239.4 Hz Gain -4.21 dB Q 3.28

HSU CCB-8 APO Score EQ 96000Hz
December162025-005649

Preamp: -4.80 dB

Filter 1: ON HPQ Fc 44.4 Hz Gain 0.00 dB Q 1.00
Filter 2: ON PK Fc 153.4 Hz Gain -3.11 dB Q 1.28
Filter 3: ON PK Fc 632.0 Hz Gain -3.09 dB Q 5.73
Filter 4: ON PK Fc 1262.6 Hz Gain -9.22 dB Q 2.89
Filter 5: ON PK Fc 1631.5 Hz Gain 7.69 dB Q 2.00
Filter 6: ON PK Fc 4390.9 Hz Gain -3.52 dB Q 1.92
Filter 7: ON PK Fc 7109.8 Hz Gain -3.44 dB Q 6.00
Filter 8: ON PK Fc 11066.9 Hz Gain -5.77 dB Q 2.69

Spinorama EQ LW

Spinorama EQ Score

Zoom PIR-LW-ON

Regression - Tonal

Radar no EQ vs EQ score
Some improvements?

The rest of the plots is attached.

 

[dtaylo1066]

 

[Chanur]

Very disappointing. I had hoped these would be a bargain.

 

[MZKM]

I might've asked for this already but is it possible to export normalized decay plots from the Klippel software?

Decays should be linear across frequencies (to an extent), meaning the normalized decays of 2 different speakers housed be near identical. Active speakers with internal DSP could have some deviance.

For the most part, non-normalized versions of a waterfall plot are simply used to more easily see non-linearity in the response (such as resonances).

To my knowledge, at least.

 

[jkasch]

The HSU for ZU lovers.

 

[RogerSmith]

To call the response "uneven" is humor so dry, even a mixture of an english man with the Kalahari dessert doesn´t come close.

 

[HalSF]

Sometimes I’m mystified by the choice of components that are measured and reviewed here, and this is one of those cases. Perhaps a bit more information on the rationale would help — in this case, the context is a speaker that’s been in the audio marketplace for a decade or more and seems to have received a lot of subjective praise back in 2017-19. Is it stillpopular? Does it still sell?

I’m just trying to get a sense of the case for warning potential buyers off of this somewhat minor and long-in-the-tooth product at this late date.

 

[Rick63]

If all of a sudden a bunch of these show up on the used market we'll know why.