Before I start out, I need some direction

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I need some advice so that I know which direction to take with my project (my first).

1. CAE software: I know, I guess this has been up many, many times but my searches came up with nothing about SPEAK. The only alternative that is reasonably cheap that can handle 5 drivers on the baffle is SPEAK, as far as I know. I don't know about lspCAD Stnd, but lspCAD Stnd seems to be too limited in features. Anyone who has used SPEAK? Is it any good? What about support, I sent an enquiring e-mail some weeks ago, still no reply? Speaker Workshop is not an option. Maybe I want too much?

2. What is the easiest to implement, a three-way speaker or a two-box solution with a sub unit that has a two-way on top of it? I was thinking the two-box, then it will be easier to do changes/upgrades in the future?

My plan is using four, or maybe two 10" or 9" woofers in isobaric configuration coupled in push/pull. Any reason to have one vs. two chambers in the sub-box?

3. Can I concentrate on the sub-box and leave the two-way for later?

4. I have considered the following woofers:
Dayton RSS265HF-4
Scan-Speak 23W/4557T00 9"
SEAS Excel W26FX001 E0026
SEAS Prestige L26RFX/P H1209
because: Fs lower than 25 Hz, no PP-cone, no foam surround, EBP not much higher than 50.

5. The room is 30-35 m^2 and 2.26 m high, and opens up to an additional 10 m^2.

6. The test box, what is mandatory of a test box, that is, how close to the final box does it have to be? Which factors are of importance?
 
Hi,

In a 2 way + sub all BSC correction is done in the 2-way.

In a 3 way the options for BSC implementation are numerous, most
of these options are not understood (e.g. partial BSC in the mid
driver + some back up from the bass unit), depends on the drivers
used and are impossible to design without decent simulation before
the drivers are chosen (IMO).

:)/sreten.
 
So I guess that I will stick with a sub + a two-way system.

For the sub section, any advantage/disadvantage to have one large chamber for all four drivers, or two chambers for each pair? (If I will need all four drivers for desired response, output etc)

I really would like some input about CAE software an in 1. Especially if anyone have had experience with SPEAK. Sure, I can use it in demo mode, but I would like some input from someone knowledgable that has had experience with it. Now that I have decided on the major design of my project, I need to decide on which software to use, so that I can start some simulations to pick the drivers.

For now, I plan to go active all the way.

I have started to collect info about what other DIY folks say are nice tweeters and midwoofers. What are you to look for when matching a tweeter to a midwoofer, more than that they have some overlapping frequency responses?

sreten,
what is BSC standing for? Audio lingo can be hard as it is, abbrivations even harder..........
 
frugal-phile™
Joined 2001
Paid Member
buggsson said:
For the sub section, any advantage/disadvantage to have one large chamber for all four drivers, or two chambers for each pair? (If I will need all four drivers for desired response, output etc)

Build 2 push-push subs. Stereo woofers have big advantages over a single woofer. And push-push is even more advantageous.

really would like some input about CAE software an in 1. Especially if anyone have had experience with SPEAK.

I can't recall ever running into anyone using SPEAK... the high price is a deterent for most diyers.

what is BSC standing for?

Baffle Step Compensation

http://www.t-linespeakers.org/tech/bafflestep/intro-bds.html

dave
 
Hi,

Attached are basic sims of two Daytons in a box.

Due to your driver selection criteria vent tuning frequency is low.

If the boxes are too big you could consider one driver with 1 or
2 passive radiators per box. Note that a mono sub amp driving
two seperate boxes gives better room drive than one box.
Its very arguable about having "stereo" low bass.

Personally I'd go sealed two box push push with those sort of drivers.
Sub amplifier with adjustable low bass boost would be a good idea.

:)sreten.
 

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I don't know if I wasn't clear enough initially, but my plan was/is to build two sealed subs, isobaric and coupled in push/pull, using either two or four drivers per sub.

I am mearly brainstorming at the moment and the knowledge is scarce, so my view was that going with the rather smallish 9" or 10" drivers, I might be able to get a desired SPL or whatever, using four drivers rather than two per sub. I really do not know what I need in my room, I just felt that I had to start somewhere.

Would four drivers per sub be overkill?

Regarding SPEAK, as far as cost is a consideration, it is, but it is the least expensive software I have encounterd that can handle 5 drivers on the baffle, which is where I want to go, eventually.

I have read the link about BSC and it was interesting reading, but digesting it will be a while. I'll learn as I go along.

Box size is certainly an issue, so they cannot be to large, the dreadful WAF is a powerful force, and I am surprised that I got the OK for this project. My former speakers was a pair of Totem "Sttaf" and they were rather large, I was told. I would guess 50-60 litres for the subs would max it.

sreten, thanks for the graph. Is the different Qtc values due to varying box volumes? Is the responses to strive for, similar to the green response? Name of the software?

After all this time, it feels like I have finally begun. Software next so that I can mess around myself a bit.

What determines how low your speakers will go? I mean, I have a couple of 12" drivers I've been looking at, but they do not have much different Fs values, all else the same, would they by any reason what so ever, go lower than the 9" and 10"? If not, the smaller drivers will give a smaller box, and therefore higher WAF.
 
Hi,

Going isobaric halves box volumes and doubles amplifier power and driver costs.
Basically will not do anything for bass extension or maximum levels.
Given the sort of drivers your considering, isobaric is not a good idea.

Push Push in force cancelling mode is your best bet, 50 to 60L per pair.

Qtc depends on box volume and stuffing, target 0.6 to 0.7 IMO.

Green is not the target, red is better but these are vented, not sealed.

Basically the bigger drivers in bigger boxes will go louder, with similar
parameters the smaller will go as low in smaller boxes but with lower
efficiency.

Sub amplifier with adjustable low bass boost would be a good idea.
This will determine "how low they go".

Try Win ISD PRo or some other sub simulator.

:)/sreten.
 
Given the sort of drivers your considering, isobaric is not a good idea.

What have I missed? I hadn't the slightest idea that was so. What kind of drivers then is good for isobaric, just so I know? I have a couple of 12" drivers that I am considering as well, and I might get away with the larger box, but then size with will increase a lot, I fear.

I guess it is time to get some software going so I can do my own simulations. How nice it would be if size restrictions were non existent.

I saw in the latest TAS that they wrote that BB was the same as marine ply, that isn't so, or is it? I thought they were totally different.

Now I am gonna have a look at Win ISD Pro to start with.
 
I hope it's OK to bump my own thread, even though it was close to three years ago the last post was written?

I've finally, for some time now, decided that I will push this project to its finish. I have tried to inform me some more, and lately I've been trying to find some suitable drivers.

My game plan for now is:

Two-way box atop a sealed sub-box containing two 10" drivers. (For a push-push config, I would need some additional info about box placement. For both front-back or side-firing woofers, I guess there aught to be a minimum clear distance to walls, furniture etc, how much approx.?)

Active crossover for all registers. I want to cross at around 200-300 Hz between subs and mid, and around 5000 Hz between mid and tweeter. And yes, I know crossing that high (5000 Hz) can involve some problems, but I want to start there and if it goes bad, my plan is to start going down until problems become manageable again.

For subs I only have two contenders left, the SEAS Prestige L26RFX/P and SB Acoustics SB29NRX75-6.

For the mids however, I would appreciate all help I can get in reducing the number to a for me a more manageable number. (I've Googled and looked at company product data sheets as best as I can)
The mid-contenders are:
Aurum Cantus AC-130F1
Aurum Cantus AC-165 (here the response peak between approx 3-5 kHz worries me)
Peerless 830991
Peerless 830860
Tang Band WF W6-1721
Tang Band WF W5-1685
Visaton AL 130M

If you have opinions about driving the mids sealed or ported, I'm interested.

Tweeters, I planned to get to them last.

While the suggestions are bogging down the forum servers, I will get started about baffle step and diffraction.
 
re:' I want to cross at around ..." I think you're putting the cart before the horse, select drivers first, then cabinet width, THEN your crossover freqs
Go sealed with the mids, and ported with the bass drivers
links to the specs of the mids would help, go for the one that has the smoothest freq response, & if you can find it, lowest distortion profile
 
re:' I want to cross at around ..." I think you're putting the cart before the horse, select drivers first, then cabinet width, THEN your crossover freqs
Go sealed with the mids, and ported with the bass drivers
links to the specs of the mids would help, go for the one that has the smoothest freq response, & if you can find it, lowest distortion profile

Yes, I might have put the cart before the horse, but that's due to a reason, correct or not, I don't initially want to cross over, in for the ear, the most sensitive frequency range. If it goes bad, I thought that I just have to lower the crossover point. I know that you can cross much lower and get good results, it is just me, sometimes I just want to do it my way, and this is where I want to start, for now.

I've seen some calculations/measurements that one can do to find the optimum cross over points, and I will certainly check those out in more detail before I settle on my final, first cross over points.

I've choose to go sealed because it is said to be the easiest way for a newbie like me, and are also said to have better transients (in general).

I will do the mids closed as well.

Distortion curves are very hard to come by, but I will select four of the mids that I contemplate and serve some numbers later.

And for the width of the box, I have to take it into consideration at the initial design stage, and it has all to do with WAF:D
 
So, here are some data for the for now chosen mids.

ScanSpeak 15W/4434G00
Cone: coated fiberglass
Nom. imp.: 4 ohm
DC res.: 3 ohm
Resonance freq.: 43 Hz
Qts: 0,21
VAS: 12,89 liters
Sensitivity (2.83V/1m): 89,7 dB
Powerhandling: 120 W
Xmax: 4.3 mm
http://scan-speak.dk/datasheet/pdf/15w-4434g00.pdf

Tang Band WF-Series W5-1685
Cone: paper
Nom. imp.: 4 ohm
DC res.: 3.6 ohm
Resonance freq.: 50 Hz
Qts: 0.46
VAS: 12.6 liter
Sensitivity (1W/1m): 86 dB
Powerhandling: 45 W
Xmax: 6.1 mm
http://www.tb-speaker.com/detail/1230_04/w5-1685.htm

Tang Band WF Series W6-1721
Cone: paper
Nom. imp.: 4 ohm
DC res.: 3.4 ohm
Resonance freq.: 40 Hz
Qts: 0.43
VAS: 29.38 liter
Sensitivity (1W/1m): 88 dB
Powerhandling: 50 W
Xmax: 8 mm
http://www.tb-speaker.com/detail/1230_04/w6-1721.htm

Visaton AL 130 M
Cone: Alu.
Nom. imp.: 8 ohm
DC res.: 5.4 ohm
Resonance freq.: 57 Hz
Qts: 0.46
VAS: 9.1 liter
Sensitivity (1W/1m): 90 dB
Powerhandling: 60 W
Xmax: 5.5 mm
Visaton - Lautsprecher und Zubehör, Loudspeakers and Accessories

I hope they will fit my plan.
 
Ex-Moderator R.I.P.
Joined 2005
My game plan for now is:

Two-way box atop a sealed sub-box containing two 10" drivers.

(For a push-push config, I would need some additional info about box placement. For both front-back or side-firing woofers, I guess there aught to be a minimum clear distance to walls, furniture etc, how much approx.?)

Active crossover for all registers. I want to cross at around 200-300 Hz between subs and mid, and around 5000 Hz between mid and tweeter.

Thats not a 2way with sub, but a regular 3way ;)

But I suppose you are in no hurry, and have plenty time to get it straight

I would choose a single 12" woofer, and go from there ... ehh, thats not true; it would be a 15" or 18" :p
 
Ex-Moderator R.I.P.
Joined 2005
I dont have much experience with classic active xo
But the general rules of passive xo still counts
With the exception that they(active) uasually do not have adjiustable slopes, which passives do

Thus I suggest to stay well clear of drivers own natural roll off
Which would mean that even as low as 2khz might be a better choise
But as said, its theoretical
 
Ex-Moderator R.I.P.
Joined 2005
None of those look like true mid-range drivers to me.

The SS discovery certainly shows all the virtues of a good midrange driver

Tho, I dont understand how they managed to get both relatively high Xmax AND high sensitivity, considering its a 5" with low Fs
Maybe too good to be true

Accuton drivers are interesting, but expencive

But I have a humble suggestion
If you use dsp Eq the very cheap 2" TB (W2-800SL) can be crossed lower than a tweeter, and opens a door to a different design; a 2.5way with subs
With those also cheap SS discovery drivers you could be in luck
 
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