Open source speaker project - Part II

Design Goal

  • Classic -Amp Friendly- Hi Sensitivity (92db+), Higher Bass Ext (f3 40-45Hz), Cabinet Size 60-80

    Votes: 18 17.8%
  • Classic -Bass Friendly- Deep Bass (f3 35-40Hz), Lower Sensitivity (88db+), Cabinet Size 80-110

    Votes: 10 9.9%
  • Classic XL -Amp and Bass Friendly- Hi Sensitivity (92db+), Deep Bass (f3 35-40Hz), Cabinet size 100+

    Votes: 12 11.9%
  • Tower -Amp Friendly- Hi Sensitivity (92db+), Higher Bass Ext (f3 40-45Hz), Cabinet Size 60-80

    Votes: 13 12.9%
  • Tower -Bass Friendly- Deep Bass (f3 35-40Hz), Lower Sensitivity (88db+) , Cabinet Size 80-110

    Votes: 21 20.8%
  • Tower XL -Amp and Bass Friendly- Hi Sensitivity (92db+), Deep Bass (f3 35-40Hz), Cabinet size 100+

    Votes: 27 26.7%

  • Total voters
    101
  • Poll closed .
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Ok, Here we will continue from where we left off from previous thread - Open source speaker project?.
First poll result was for a 3 way classic speaker (no horn), the budget is 500-1000$ for drivers only (excluding the crossover parts and cabinet).

EDIT 9-20-18 :
Tower XL discussions and development will be continued here :
Open Source "Tower XL"
 

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The new poll is to set the goals for the selected design.
Poll options are pretty much self explanatory, please keep in mind that these numbers are not the final numbers and are flexible, but the poll result will set the goal for the design.
Please leave any questions you might have about the poll options.

Edit:
I had to shorten the options so it will fit the box:
1-Classic Look- Amp Friendly - High Sensitivity (92db+), Higher Bass Extension (f3 of 40-45Hz), Cabinet Size of 60-80 Liter.
2-Classic Look- Bass Friendly - Deep Bass Extension (f3 of 35-40Hz), Lower Sensitivity (~88-90db) , Cabinet Size of 80-110 Liter.
3-Classic Look XL- Amp and Bass Friendly - High Sensitivity (92db+), Deep Bass Extension (f3 of 35-40Hz), Cabinet size of 100-150 Liter.
4-Tower/Floor Standing- Amp Friendly - High Sensitivity (92db+), Higher Bass Extension (f3 of 40-45Hz), Cabinet Size of 60-80 Liter.
5-Tower/Floor Standing - Bass Friendly - Deep Bass Extension (f3 of 35-40Hz), Lower Sensitivity (~88-90db) , Cabinet Size of 80-110 Liter.
6-Tower/Floor Standing XL- Amp and Bass Friendly - High Sensitivity (92db+), Deep Bass Extension (f3 of 35-40Hz), Cabinet size of 100-150 Liter.
 
Why no OB option? Just genuinely curious.
Wtf!
Because we've got to narrow it down, geez!
Why not a tiny desktop? Good lord!!
Why not a fullrange in a 40cu ft backloaded horn? My goodness!!
:)

In all seriousness we've got to hone in on something that atleast a few people will build.
I love OB, but if you want an OB project at this point you need to start a new thread.

I have one question before I vote. What is the difference between the two xl options? It seems that once you get to a certain size the monkey coffin gets so big that the tweeter is at ear level. Is the woofer side mounted on the tower?
 
I have one question before I vote. What is the difference between the two xl options? It seems that once you get to a certain size the monkey coffin gets so big that the tweeter is at ear level. Is the woofer side mounted on the tower?
I cannot comment on the intention but my interpretation would be a tower is deep with a narrow baffle and possibly multiple woofers or woofers on the side. A classic cabinet would be shallow with a wide baffle and usually a single woofer. Something like Zaph's SB12.3 would be somewhere in the middle and difficult to categorise.
 
I voted before I got any feed back for the xl tower. I was thinking of Zaphs sb12.3 as a large tower. Any how I'm hoping for the largest woofer, largest box, most sensitivity and lowest extension and easiest load. I like the idea of a larger version of the Zaph tower but with a single mid, kinda like Troels fusion but larger.
 
Why no OB option? Just genuinely curious.

My own suggestion was an open baffle, but with too many options we had to narrow it down based on feed backs and what been discussed, hopefully later projects will include one :) there are pretty good open baffle projects suggested by members in previous thread if you are interested ;)

...I have one question before I vote. What is the difference between the two xl options? It seems that once you get to a certain size the monkey coffin gets so big that the tweeter is at ear level. Is the woofer side mounted on the tower?
I guess Andy covered it pretty well :)
 
I voted before I got any feed back for the xl tower. I was thinking of Zaphs sb12.3 as a large tower. Any how I'm hoping for the largest woofer, largest box, most sensitivity and lowest extension and easiest load. I like the idea of a larger version of the Zaph tower but with a single mid, kinda like Troels fusion but larger.

cool, I have to say i m kinda surprised that XLs have a lot of interests ;) if that's the chosen plan I personally like the two woofers version facing front, but that's something to be discussed later.
 
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what if ?

what if we can have a very high sensitivity driver in a smallish size cabinet with deep bass ?
BMS - 12N630
a very quick n dirty calculation shows very promising:
FB=0.39(FS/QTS)=0.39(28.6/0.33)=33.8Hz, with a small VAS of 85.5 and sensitivity of 96db(1w/1m).
another quick n dirty simulation in speaker builder pro shows the same results, w Fb of 33.8 in a 49.5 liter ported cab :
attachment.php

Troel used it in a ~63 liter cab in his fusion speaker. I m not saying to copy his design but we can have a similar cabinet which is floor standing monkey boxish/towerish design ! am I missing something here or this really can solve all above issues w no sacrifices ?
attachment.php
 

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what if we can have a very high sensitivity driver in a smallish size cabinet with deep bass ?

That would be cool. But we can't because phyisics do not allow it.

BMS - 12N630
a very quick n dirty calculation shows very promising:
FB=0.39(FS/QTS)=0.39(28.6/0.33)=33.8Hz, with a small VAS of 85.5 and sensitivity of 96db(1w/1m).

That sensitivity number is in the datasheet, but I honestly don't know what that is supposed to tell us. Max. sensitivity somewhere in the midrange? The bass sensitivity you get from the Thielle-Small parameters speaks a different language. Just take a look at Troels bass response simulations and you'll see that real-world efficiency in a real-world box is closer to 84 dB (1m,2.83V) into free space.

But yes, the 12N630 is a nice driver.
 
That would be cool. But we can't because phyisics do not allow it.



That sensitivity number is in the datasheet, but I honestly don't know what that is supposed to tell us. Max. sensitivity somewhere in the midrange? The bass sensitivity you get from the Thielle-Small parameters speaks a different language. Just take a look at Troels bass response simulations and you'll see that real-world efficiency in a real-world box is closer to 84 dB (1m,2.83V) into free space.

But yes, the 12N630 is a nice driver.

You are right, didn't read Troel's whole documentation, saw the numbers but assumed he lost some of the sensitivity due to ports facing backward to control directivity. Troel calculated to get around 89 dB/2.8V/1 meter in his which i can't ask for any better in a passive system :D. thanks for clearing that out :)

How about 12S330 version of it?
this has lower QTS of 0.24 which will bring fb to ~46Hz :)
 
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Aatto,

I find the same result, with the 12N630 in a basreflex of 50 - 55 L, F3 = 34Hz.

Regarding the sensitivity, in half space and calculated with TSP the sensitivity at 1m, 2.83Vrms is 90.7dB. That means, with the 12N630 you can make a flat SPL speaker in full space with a sensitivity equal to 84.7 dB maximum.
As Troels' Fusion is specified 89 - 90 dB, it cannot be a flat SPL speaker in full space.
I don't mind that it isn't flat, it is a design choice, but it has to be specified in a clear understandable way and IMO that is a SPL specification in full space.

To get the target of the XL tower you need minimum 2 of these 12N630 in parallel. It will become difficult to realize that XL with a driver set of 1000 $...

Anyway this BMS is an interesting driver.
 
very interesting driver indeed even the larger size drivers from the same series doesn't perform like this one and based on your simulations I would say it is still a good option ( we can always go half space ;))

GF is out visiting family so I had some time to check some drivers in this beautiful rainy day :D

anyhow, looks like Kappa-15LFA and SOVEREIGN 15-600LF are interesting as well. SOVEREIGN has a quite large VAS tho.
 

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looks like Kappa-15LFA and SOVEREIGN 15-600LF are interesting as well. SOVEREIGN has a quite large VAS tho.

Both drivers are intended to be used in a large cabinet. They have a large Vas and Qts and with these large volumes a high sensitivity.

The Kappa 15FLA in 160 L tuned at 39Hz, F3 = 39Hz. For a cabinet around 200 L, F3 = 35Hz. Sensitivity 91.4 dB full space.
The Sovereign 15-600LF in 225 L tuned at 37 Hz, F3 = 37Hz. Sensitivity is 92.3 dB full space.
 
Both drivers are intended to be used in a large cabinet. They have a large Vas and Qts and with these large volumes a high sensitivity.

The Kappa 15FLA in 160 L tuned at 39Hz, F3 = 39Hz. For a cabinet around 200 L, F3 = 35Hz. Sensitivity 91.4 dB full space.
The Sovereign 15-600LF in 225 L tuned at 37 Hz, F3 = 37Hz. Sensitivity is 92.3 dB full space.

yeah i noticed huge VAS, I ran it through simulation after I post them and i was like wtf, haha. a single driver, w flat full space SPL and low f3 is a tall order :D, still have a few days left on the poll tho.
 
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