SB Acoustics SB20FRPC30-8 based desktop project

[ppataki]

Last year I did a project based on Markaudio CHR120 drivers in my home office

Then this year when I did my rear speaker project using the SB20FRPC30-8 drivers I really got astonished by these drivers so I have decided to replace my CHR120 desktop system with the SBs

I already have the SB drivers, they arrived yesterday:

Since I have already sold my CHR120 drivers the plan is to re-use their now empty sealed cabinets:

X-max limited max input power will be 45W:

At 45W I will get 85.6dB at 1 meter at 24Hz (=91.6dB for stereo + I will have considerable room gain too)
Listening distance will be approx. 70cm

Group delay:

Impedance:

I will keep on posting pictures and later on some measurements and videos
I will use Dirac Live 3.x for corrections

 

[ppataki]

I have made some progress, please see the pictures below:

Unfortunately one of the drivers is faulty, it makes a buzzing sound at low frequencies. I have a replacement driver arriving this week so hopefully I will have time to redo that cabinet and do some measurements.

 

[Noricha]

Hi, some information about standing waves will be useful to you

 

[ppataki]

The paint-job is still to be done, here is where I am now:

And the measurements:

Left channel, MLP measurement from approx. 75cm at 75dB

Corrected with Dirac Live 3.6 (highlighted) vs uncorrected

Distortion is room-driven due to the dips (I tried these drivers in my other room, distortion was really low there)

IR and SR

Waterfall:

Remember that the room is totally untreated!

Wavelet:

Typical to sealed sytems, there is close to zero delay in the low-end

Overall I am extremely satisfied with the sound subjectively speaking as well - typical full-range driver sound, totally holographic presentation, live sound!
Very strongly recommended!!

 

[ernestcarl]

Some deja vu feeling going on here… I remember your sold Morel speakers of similar design.

Unfortunately, one can no longer listen side-by-side. However, do you subjectively and objectively (from previous measurements) find this pair substantially better?

 

[ppataki]

Some deja vu feeling going on here… I remember your sold Morel speakers of similar design.

Unfortunately, one can no longer listen side-by-side. However, do you subjectively and objectively (from previous measurements) find this pair substantially better?

The Morels were by far the worst
The CHR120s were way better than the Morels and the SBs are so far the best
And price-wise we are going waaaay down
Apparently price has really nothing to do with quality here...

 

[ppataki]

Just realized that I forgot to add the phase graph:

 

[ppataki]

And with the paintjob done I consider this project to be finished:

 

[ppataki]

And finally, some videos:

3 new items by Peter Pataki

photos.app.goo.gl

Enjoy!

 

[shrub0]

Looks good ppataki,
What morel drivers did you compare them to and what didn't you like about the morels?

 

[jamescarter1982]

I'd just using these for Mt could the volume be reduced to very little ? would you think it would be realistic to wall mount some shallow versions of these if supported by a sub ? thanks

 

[kemmler3D]

Any off-axis measurements? Given the size it should be pretty easy to do. The on-axis looks dreamy, but as we all know things often fall apart at 30 degrees on out...

 

[ppataki]

Looks good ppataki,
What morel drivers did you compare them to and what didn't you like about the morels?

Thanks @shrub0

It was the Morel TSCM634.
First reason:

The SB provides 5dB more output at 24Hz

Second reason is that the SB costs exactly 10 times less....

 

[ppataki]

I'd just using these for Mt could the volume be reduced to very little ? would you think it would be realistic to wall mount some shallow versions of these if supported by a sub ? thanks

What do you mean by Mt?

You can put them in a sealed cabinet of 6 liters but then you will need more amp power to drive them - namely 150W max to reach xmax (if you have a sub this might be less relevant actually)
Whereas if you put them in 17 liters 25W will be the max power you will need to drive them to xmax

 

[ppataki]

Any off-axis measurements? Given the size it should be pretty easy to do. The on-axis looks dreamy, but as we all know things often fall apart at 30 degrees on out...

To be honest, no
I listen on-axis only and in one position only so I am focusing on optimizing the on-axis response only
I am sure the off-axis would look really bad, I can hear that when I move my head but that is totally normal for full range drivers of this size and I have no issues with that
The big advantage (for me it is an advantage) of this heavy beaming is that reflections are close to none (can be seen very clearly on the impulse response curve of full range drivers when measured in-room)

 

[ernestcarl]

Any off-axis measurements? Given the size it should be pretty easy to do. The on-axis looks dreamy, but as we all know things often fall apart at 30 degrees on out...

SB Acoustics does have a few off-axis curves already in their spec sheet:

https://sbacoustics.com/wp-content/uploads/2022/04/8in-SB20FRPC30-8.pdf

I would've loved to see 5-10 degree increments...

Like many "fullf-range" single drivers, if you flatten the HF direct on-axis too much, you will lose quite a bit of energy off-axis. For me personally, I would also try EQ'ing the driver (or make an extra DSP preset) so that it is not completely flat on-axis and listen to how that sounds as well -- if it's an acceptably better overall "compromise".

 

[ppataki]

if you flatten the HF direct on-axis too much, you will lose quite a bit of energy off-axis.

True!
What I do is that I compensate that with a high-shelf. Sometimes only on the Side channel (M/S processing) - that elevates the highs only on the sides but not on the phantom center
But I guess this is up to personal taste too (subjective)

 

[norman bates]

good work.
Here, there is not much love for full range drivers.

We would love to hear about your project over here.

Full Range

www.diyaudio.com

 

[ppataki]

Given that the cabinets are attached to the wall I got some complaints from the neighbor so I am now replacing the wall-mounted cabinets with desktop standing ones:

Will post some more pictures as I progress

 

[ppataki]

So here is some progress about the new cabinet: