Open Source "Tower XL"

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From what I can see/interpret ( from the referenced poll in thread #2 & then the info contained within the first post of this thread );

> you weren't handed a mandate to impose a "flattish 8-ohm" impedance curve.

I'm curious as to where you believe a"green-light" came from ?
- ( to limit the speaker to a "flattish 8 ohm impedance curve" )


:)
 
It's no biggie, I'm not trying to be an a..hole. The term amp friendly is the term being used for an easy 8ohm load with higher sensitivity. It came up a few times in the threads and if we're going large it's doable. It was in response to the popularity of small class A amps around here.
 
What about 4 x dayton RS 225P for the bass?

That should yield about 95db @ 8ohm and go in a tower box of mentioned and costs less than 50% of the budget.

On the top many alternatives can be had:

High effiency dome in a wageuide (2.5way)
Compression driver in a small horn (2.5 way)
Dedicated mid + tweeter (3-way)
Maybe an large AMT like Dayton AMTPRO-4 (2.5 way)
 
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Yeah I was looking at those too. I picked the aluminum version because the low frequency extension might be a little easier to work with and the breakup seemed a little more benign. Either would likely be a solid option though!

Also, the paper isn't going out of stock - that's just for the open box version.
 
What about the Selenium 15WS600 for $184.99

Is there SPL target? the Xmax might be low.

Sensitivity = 97 dB SPL
Fs = 35 Hz
Vas = 215 L
Qts = 0,35
BL = 19,1 Tm
Xmax = 3,75 (Xlim = 21)
Pe = 450W AES

Selenium 15WS600 15" 600W Woofer

Just one more proposal:

Dayton Audio PA380-8 for $75.77

Sensitivity = 96,1 dB SPL
Fs = 31,6 Hz
Vas = 175 L
Qts = 0,27
BL = 25,8 Tm
Xmax = 5 (Xlim = ??)
Pe = 500W AES

Dayton Audio PA380-8 15" Pro Woofer
 
From what I can see/interpret ( from the referenced poll in thread #2 & then the info contained within the first post of this thread );

> you weren't handed a mandate to impose a "flattish 8-ohm" impedance curve.

I'm curious as to where you believe a"green-light" came from ?
- ( to limit the speaker to a "flattish 8 ohm impedance curve" )


:)

yeah, as mordikai mentioned, we had long discussions over the types of speakers and specs in previous threads, and based on that and the feedbacks we included "amp friendly" options in last poll, 8 ohm and high sensitivity speaker options were targeted for people using tube and or Class A amps ;)
 
What about two of these wired in series? Only 91 dB, but close.

Dayton Audio RS225-4

What about 4 x dayton RS 225P for the bass?

That should yield about 95db @ 8ohm and go in a tower box of mentioned and costs less than 50% of the budget.

On the top many alternatives can be had:

High effiency dome in a wageuide (2.5way)
Compression driver in a small horn (2.5 way)
Dedicated mid + tweeter (3-way)
Maybe an large AMT like Dayton AMTPRO-4 (2.5 way)

Yeah I was looking at those too. I picked the aluminum version because the low frequency extension might be a little easier to work with and the breakup seemed a little more benign. Either would likely be a solid option though!

Also, the paper isn't going out of stock - that's just for the open box version.
4 of these will have enough efficiency, it is actually good idea but I m not sure how this will complicated the design (crossover wise) but I definitely prefer it over a 15 inch design.
lets see what others think.
 
What about the Selenium 15WS600 for $184.99

What about the Selenium 15WS600 for $184.99

Is there SPL target? the Xmax might be low.

Sensitivity = 97 dB SPL
Fs = 35 Hz
Vas = 215 L
Qts = 0,35
BL = 19,1 Tm
Xmax = 3,75 (Xlim = 21)
Pe = 450W AES

Selenium 15WS600 15" 600W Woofer

the sensitivity is not that great and it needs a quite large cabinet (200 liter +) but the price is good, lets keep an eye on this.

Just one more proposal:

Dayton Audio PA380-8 for $75.77

Sensitivity = 96,1 dB SPL
Fs = 31,6 Hz
Vas = 175 L
Qts = 0,27
BL = 25,8 Tm
Xmax = 5 (Xlim = ??)
Pe = 500W AES

Dayton Audio PA380-8 15" Pro Woofer

sensitivity is on low side (after baffle step) also it has low QTs & can't be tuned lower than ~45Hz.
 
What do people think about this:

30 ~ 500Hz Dayton RS 225 x 4
500 ~ 3kHz B&C 5MDN38
3000 ~ 20kHz Fountek Neo 3.5h

Total = 760$
The left over in the budget could go to CNC machining of the enclosure which would be a large and difficult build for most people.
 
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4 of these will have enough efficiency, it is actually good idea but I m not sure how this will complicated the design (crossover wise) but I definitely prefer it over a 15 inch design.
lets see what others think.

Do not think it will be too hard making an xo for 4 vs 1 woofer, sure there are more things to consider, But the biggest problem with a Tower style enclosure with lots of drivers is that they excite a lot of different modes, in a box where a lot of modes can easily get out of hand.
Dampening material and bracing can only get you so far (and it's sometimes even wasteful if not properly implemented), one would have to make several internal volumes. It's not hard or impossible, but making a really GOOD tower solution that can really kick commercial design's ***** you really have to think about these things.
 
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And let's turn the calculation around:
If 1 "good enough" cast frame etc 15" costs 150$, it would mean that you are looking for 8" woofers costing less than 40$ each to make it comparable in terms of cost. I do not know what kind of quality 8" you can get for less than 40$ if cast frame is one of the criteria. The price for a cast frame 8" is quickly more like 60$ or more each, and more if you want to focus on mechanical loss (which will almost inevitably be completely different for a 8" than a 15", maybe unless it's a pro mid driver with high fs?)

Not trying to rain on anyones parade here, but please keep in mind that this was supposed to be a project that could be built by many. If the limit is supposed to be >500$ then I guess that's less than 750$ worth of xo and drivers per speaker for the people that where interested enough to vote.
 
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Do not think it will be too hard making an xo for 4 vs 1 woofer, sure there are more things to consider, But the biggest problem with a Tower style enclosure with lots of drivers is that they excite a lot of different modes, in a box where a lot of modes can easily get out of hand.
Dampening material and bracing can only get you so far (and it's sometimes even wasteful if not properly implemented), one would have to make several internal volumes. It's not hard or impossible, but making a really GOOD tower solution that can really kick commercial design's ***** you really have to think about these things.
Agree on that completely, especially in the case of a basreflex concept up to a few hundred Hz, because you cannot apply much dampening material.

Also a 4 woofer array will have some vertical beaming behavior at a few hundred Hz. It has to be combined correctly with an omnidirectional midrange, that will become more complex.

IMO the ATC SCM150 cabinet concept, apart from the midrange dimension at this time, is the most interesting for this project to get the targets.
 
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...the biggest problem with a Tower style enclosure with lots of drivers is that they excite a lot of different modes, in a box where a lot of modes can easily get out of hand.
Dampening material and bracing can only get you so far (and it's sometimes even wasteful if not properly implemented)...

Totally agree. How about internal Helmholtz absorbers? I have no hands-on experience with these, but they seem to do a good job if you need to fight a specific resonance/mode than you can't kill with a dampening material alone.
 
ok i m back, does everybody just quit ?
anyhow, making individual volumes inside the cab for each driver will complicate building process but it is doable, the problem is that the drivers need to have low VAS and also i m not big fan of rear firing ports, it needs better room treatments.
having 2 internal volumes (for each 2 drivers) is much easier of course but needs more prototyping ?
what about two 4 ohms woofers ? will not be easy to hit 92db full space but it can hit 90+ half space alright.
so looks like we need to do a pro and cons list here, I ll start

1- one 15"+ woofer.
Pros: easy to handle (crossover wise) and build. will be easier to reach 92db.
Cons: needs large cabinet (150-200 liter) and will be something between a classic and a tower design ( because of large front baffle). around 35-40Hz.
2- one BMS 12N630.
Pros: one behaved driver, less prototyping, can go really deep, does not need large cabinet (Vas: 85Liter). will look like a tower design (smaller baffle).
Cons: will not be able to achieve 92db+ in full space (maybe around 90 half space).
3- 4x 8inch woofers.
Pros: will be close to 92db full space target. can go deep.
Cons: Cabinet building can be complicated (separated internal volumes). total cost of 8 woofers will be expensive. needs more prototyping.
4- 2x 8 or 10" inch woofers per cabinet (4 ohms in series ).
Pros: ?
Cons: ?
 
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