AVS Forum banner

1 - 20 of 254 Posts

·
Registered
Joined
·
559 Posts
Discussion Starter #1 (Edited)
My new bass array is done!


It consists of 18 x Peerless XXLS12 each in about 65 l. A Sanway FP14000 provide the necessary electrical power to the drivers. Since the XXLS12 are not as power hungry as some of the bigger 18" one amplifier is enough to reach reference SPL at the very low end.







The room is made of stone and concrete. There is 60 cm rockwool at the back wall to absorb the length mode. The rest is killed by an equalizer (K+H Pro C 28). The signal chain is pretty flat to 3 Hz. So it was no problem to reach -3 dB @ 3,3 Hz. I already measured 115 dB at 4 Hz. So reference SPL is no problem here.



The three front speakers are self-made. I built them a few years ago. Back then the design goal already was in-wall usage and the target frequency range 100 - 20,000 Hz. The waveguides were designed to reach a near constant directivity. Finally these speakers got their suitable subwoofer system!


The rest of the room is not finished yet. So the measurements will change a bit when more absorbers and diffusers are placed on the walls.
 

Attachments

·
Registered
Joined
·
559 Posts
Discussion Starter #2
This is the design planned with a CAD software. The curved screen shall be in front of the baffle wall. Later everything will be covered and only a big picture will be left for the viewer.





Then I started the building. I used MDF for the enclosures. First step was the milling and sawing of the cutouts for the 18 drivers.






Then 144 holes had to be drilled and 144 drive-in nuts had to be inserted.






I needed 2 l of wood glue for the 4 enclosures.






The cables were fastened with hot-glue to avoid rattling.




The edges were milled to avoid MDF's destruction when the heavy enclosures got moved through the room.






Each box is damped with Iso Bond. I used Iso Bond, because I had much left from my experiments with metal pane absorbers (VPR).




The 4 mm² cables are soldered to the driver's terminals. There are 3 in parallel and 3 of those in series. First parallel, because this averages variations of impedance.









Since it is a cellar room, mold is always a problem. So I left air behind the front speakers. The baffle wall should be sealed though.


 

·
Registered
Joined
·
4,829 Posts
Wow, stunning!


XXLS12 superb stuff, well executed!


Textbook reference build here, is the rear wall damping spaced? Curious about the mid dome mfr,? What's your listening distance measurement, and what percentage that is of total length, from front wall.


Outstanding, this will be one for the ages
 

·
Registered
Joined
·
97 Posts
Very impressive FoLLgoTT! (But I am not surpised, judging from your previous posts) Will you hang up a cloud to cure the ceiling reflection or redirect it to the backwall?
 

·
Registered
Joined
·
559 Posts
Discussion Starter #9
@all

Thank you!

Quote:
Originally Posted by FOH  /t/1507428/follgotts-build-18-x-peerless-xxls12#post_24112681


Textbook reference build here, is the rear wall damping spaced?

It will be spaced by about 10 cm. The reason is only to avoid mold in this cellar room.
Quote:
Curious about the mid dome mfr,?

The mid dome a Tang Band 75-1558SE. The full documentation of my speakers is here . Sadly only in german right now. But maybe there is a online translator for PDF's out there?
Quote:
What's your listening distance measurement, and what percentage that is of total length, from front wall.

The microphone's position was 4 m distant to the front wall. Room is 6 x 4,8 x 2,2 m. So measurement was taken at 2/3 of room length.
 

·
Registered
Joined
·
5,207 Posts
What a well-executed room! Though the advertised subwoofers are not nearly as impressive as those mains.


Don't get me wrong, it's an impressive subwoofer setup, but those mains look fantastic. I love the mid/tweeter WG module. Overall everything is just as impressive as it gets in design and execution! When someone not only gets the big stuff - axial FR, polars, adequate dynamics, etc. - right but also thinks through things like "Sie unterscheiden sich nur durch die Position des speakON-Anschlusses an der Unterseite." - "One can distinguish the three speakers from one another by the placement of the SpeakOn connector on the underside [of the cabinet]" I'm impressed.


What program did you use to make the polar map on pg. 15?
 

·
Registered
Joined
·
559 Posts
Discussion Starter #12

Quote:
Originally Posted by DS-21  /t/1507428/follgotts-build-18-x-peerless-xxls12#post_24115797


Don't get me wrong, it's an impressive subwoofer setup, but those mains look fantastic. I love the mid/tweeter WG module.

Thanks!



But the dual waveguide was not developed by myself. A friend of mine did it. He simulated it with ABEC and built several prototypes. He was so friendly to let me build my own speakers using his design. The rest is my own development, of course.

Quote:
What program did you use to make the polar map on pg. 15?

It was done in Excel. I exported several frequency responses from ARTA and made my own diagram. ARTA's directivity patterns are a bit ugly. Excel has more possibilities to make it look good.
 

·
Banned
Joined
·
8,743 Posts
What a terrific room. The speakers look like those Genelec 1000 series, is that their pedigree? If so, amazing, I have been salivating over those 1000s for awhile now. Real nice subs too, the XXLS are beautifully linear. I bet that whole system hardly needs any EQing at all, if any, which, to me, would be the ideal. A true reference system. Beautiful!
 

·
Registered
Joined
·
4,575 Posts
F,


Too cool.


I'll be interested to get your feedback on replay of the heavyweight soundtracks at reference level with 22L in 2200 cubes.



What the he!! does "Constant Directivity" mean?



Have you heard the TB mids yet, and, if so, how do you like them, subjectively, and do they handle reference playback in your space?


Thanks for consistently great info...
 

·
Registered
Joined
·
559 Posts
Discussion Starter #17

Quote:
Originally Posted by shadyJ  /t/1507428/follgotts-build-18-x-peerless-xxls12#post_24116107


What a terrific room. The speakers look like those Genelec 1000 series, is that their pedigree?

In fact the model was the Neumann O 410 . But Genelec has very similar models, that's right.




Quote:
Originally Posted by bossobass 

I'll be interested to get your feedback on replay of the heavyweight soundtracks at reference level with 22L in 2200 cubes.

At the moment the reverberation is just too high to enjoy reference SPL (about 500 ms). When the room is furnished and more absorbers are placed I'll catch it up.

Quote:
What the he!! does "Constant Directivity" mean?

It means that beam width is nearly constant at all frequencies. Every driver begins to beam at frequencies larger than its diameter. Because of this phenomenon typical 2- or 3-way systems without waveguides have jump discontinuities in their directivity patterns. They occur at the crossover frequencies. For example the woofer already beams at 2 kHz, but the tweeter acts like a sphere at this frequency. So the speaker beams much up to 2 kHz and when the tweeter comes into play it abruptly radiates in all directions. This leads to a colored diffuse sound field. Waveguides can greatly help to linearize the overall directivity.


I must admit that my speakers are not constant in this regard. But rather linear with a slight beaming toward higher frequencies.

Quote:
Have you heard the TB mids yet, and, if so, how do you like them, subjectively, and do they handle reference playback in your space?

Yes, I listen to my speakers a few years now and I really like the Tang Bands. They have low THD and very low K3. Even at higher SPL I never experienced any harshness. The sound is very clean and direct (because of the waveguide).
 

·
Premium Member
Joined
·
24,465 Posts
Extremely impressive, Nils!


The only thing I wonder about is the fairly sharp edge transitions on the WG's.


Are the CNC'd baffles available for purchase?


If not, is your friend willing to make the path programming available?


This would be a fantastic addition to Erich's range of kits.
 

·
Registered
Joined
·
559 Posts
Discussion Starter #20

Quote:
Originally Posted by ChopShop1  /t/1507428/follgotts-build-18-x-peerless-xxls12#post_24117236


The 60cm on the back wall seeming to do the job? What is your tie angle for those mains?

The absorber is not finished yet. But there is still something of the first-order length left that has to be equalized.


The mains are pointing toward my listening position which will be at about 4 m from the front wall. This is about 2/3 of room length.
Quote:
Originally Posted by noah katz  /t/1507428/follgotts-build-18-x-peerless-xxls12#post_24117274


Are the CNC'd baffles available for purchase?


If not, is your friend willing to make the path programming available?

Sadly not. He is working at Sennheiser now and he won't publish his waveguides nor sell it.
 
1 - 20 of 254 Posts
Top