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Box building software...

#1
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6/7/09 at 1:24pm
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I am kind of stumped with this winisd program. Been playing around with it for a month or two, and I felt like I knew what I was doing. I know it's not perfect, but it is close......except now am I doing something wrong?.....
I keep getting the same results for the woofers I choose. Sealed box the line is flat and slopes off normal. Ported box always sets the box cf at like .01 and the line is perfect, the woofers get lower and slope off nice.....But when I up the cf to 1 it spikes up like 9 dbs, I tried changing the frequency it's set at but the spike never goes away. I know it's not good, but what exactlly does the spike like that mean?

Also what other programs are there for an aspiring audiophile.
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#2
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6/7/09 at 3:28pm
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Re: Box building software...

Example......




If I leave the cf as it starts at (.06) it is same as the sealed box, but the slope starts alot low before it falls off. Don't understand why when I bring the cf up to 1, the big spike?
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#3
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6/7/09 at 4:49pm
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Re: Box building software...

I haven't played with WinISD in years. Post the T/S parameters and I'll see what I get in Unibox.

-Robert
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#4
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6/7/09 at 5:07pm
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Re: Box building software...

Quote:
Originally Posted by Robert_J
I haven't played with WinISD in years. Post the T/S parameters and I'll see what I get in Unibox.

-Robert
*Power handling: 60 watts RMS/110 watts max *VCdia: 1" *Le: 1.2 mH *Impedance: 8 ohms *Re: 6.1 ohms *Frequency response: 57-10,000 Hz *Fs: 57.3 Hz *SPL: 88 dB 1W/1m *Vas: 0.37 cu. ft. *Qms: 2.69 *Qes: 0.49 *Qts: 0.41 *Xmax: 3.5 mm *Dimensions: A: 6"

Using 2 of them in a total of 1.1 cf sealed, not too concerned about porting unless it is a considerable difference because it's just the center channel box going under the TV. And got an idea for a set of towers with an 8" for some nice front lows.

Appreciate the help. Gonna draw up the idea I have for the towers in paint and see what yall think is wrong with my idea, and give me any direction or help......cause I am sure something could be better and tweeked.
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#5
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6/7/09 at 5:33pm
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Re: Box building software...



I started by finding where I wanted these speakers and then rough measured. Then got some graph paper and went to scriblin, and came up with these towers that were 4 cf. By chance when I entered all the info into winisd 4 cf was the perfect volume tuned @ 30 hertz. The sub shows the flat all the way down to 30 then falls off slowly. Am I worng but this seems pretty good right?

Also any comments on the box? Let me know if you see anything obvioulsy wrong, or even personal opinions. Any input would be good. Like speaker placement? I like the look of the setup I have drawn, but what affect will it make elsewhere?

EDIT....Well just kinda pissed on my whole parade here with these towers....Just realized the sub is rated from 30-500 hertz, kinda leaves a gap to reach to get to a tweeter huh? But I guess I could use a full range speaker I guess.
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#6
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6/8/09 at 8:09am
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Re: Box building software...

WinISD is correct on the Peerless. Unibox recommens 1L for a pair. When I put them in a 1cf box, there is a huge hump in the response. You will have to build a smaller enclosure or chamber off the enclosure on the inside.

As for your idea for an 8" full range, look at the D8 I linked to in one of your other threads. It will give you a chance to build a crossover instead of buying a pre-made one. The reviews on that speaker are excellent.

-Robert
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#7
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6/8/09 at 5:10pm
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Re: Box building software...

Thanks man.

As for the peerless woofers, I guess I will see if I can find a different woofer. Did you look at them in a sealed box? The winisd showed them with a nice flat line, it did fall off alittle high I thought (around 200) but according to the Vas of almost .4 the 1 cf is pretty close for two of them........or would it change having two of them in the same box?
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#8
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6/8/09 at 7:22pm
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Re: Box building software...

I modeled the Peerless with 2 in the cabinet. Unibox recommended .1L. The Vas parameter of .4 is in L not cubic feet.

Putting them in a 1cf sealed box is almost like having them run infinite baffle. There is no air suspension inside the box to help. They will either need a high crossover point and use a sub or the mechanical power handling will be about 10 watts.

-Robert
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#9
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6/8/09 at 9:18pm
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Re: Box building software...

Quote:
Originally Posted by Robert_J
I modeled the Peerless with 2 in the cabinet. Unibox recommended .1L. The Vas parameter of .4 is in L not cubic feet.

Putting them in a 1cf sealed box is almost like having them run infinite baffle. There is no air suspension inside the box to help. They will either need a high crossover point and use a sub or the mechanical power handling will be about 10 watts.

-Robert
It says .37 cf for the Vas, not L. So I am actually not far off from the vas for 2, I can just block off part and get closer to .74 I am at 1.1 right now.

With winisd it says I need the box to be .01 cf to port it correctly, lol.....Put a suction cup around the back of the woofer and a straw for a port? lol

Anyway...Just gonna go sealed and I can just drop the cf down inside, because I need the whole box as a TV base. I think I was expecting lower out of the 5.25's....It starts sloping off around 300 slowly, thats not bad. And with a nice clean tweeter, should be a nice budget center channel.
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#10
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6/9/09 at 4:37am
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Re: Box building software...

Quote:
Originally Posted by MarvinJr
It says .37 cf for the Vas, not L. So I am actually not far off from the vas for 2, I can just block off part and get closer to .74 I am at 1.1 right now.

With winisd it says I need the box to be .01 cf to port it correctly, lol.....Put a suction cup around the back of the woofer and a straw for a port? lol

Anyway...Just gonna go sealed and I can just drop the cf down inside, because I need the whole box as a TV base. I think I was expecting lower out of the 5.25's....It starts sloping off around 300 slowly, thats not bad. And with a nice clean tweeter, should be a nice budget center channel.
My mistake. I re-ran the simulation with a Vas of 10.47L and instead of 1L as the recommended enclosure size, it is now 11L for a pair of woofers. For the sealed box of 1cf (28.3L) the Qtc is .54 (great). The only problem I see is power handling. Each driver can only handle 5w across the low end of the frequency range. If you want to use a sub, you must cross over at 100hz. That will raise the power handling to 20w each.

Quote:
Originally Posted by VivekJust
I am kind of stumped with this winisd program.
[img]http://www.*******************************************[/img]
If you have any specific questions, please start a new thread.

-Robert
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#11
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6/9/09 at 4:37pm
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Re: Box building software...

Boy oh boy......I need to study up more, lol.

The problem with winisd was really the fact that the woofers I chose didn't need as much cf as I was thinking.

I really do appreciate the help man.
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#12
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6/10/09 at 6:24pm
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Re: Box building software...

I think I am gonna go with 2 of the 5.25 peerless, and the Dayton tweeter. The box is going to be .8 cf sealed......which is almost dead on the vas. Going by winisd it shows the hertz sloping off around 300. I tried using a smaller cf, but it didn't change a whole lot.

Just wondering what affect that size will have.
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#13
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6/11/09 at 4:30am
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Re: Box building software...

You have a low Qtc which I like. I don't like the boominess of a high Qtc speaker.

-Robert
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#14
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6/14/09 at 4:55pm
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Re: Box building software...

That box I drew up there is actually 2 cf per tower.

Kinda stumped again with what woofer to use. The tweeter goes down to 1300, and the sub I had in mind only goes up to 500. So I decided to try the specs for the Dayton classic 8" and it says ported I need .061 cf lol. I think I went thru this before.
Could someone point me in the direction of a sub/woofer for this size box. I can partition off and make the cf smaller, but not .061 lol. A sub that works well ported. Really just need some direction because the ones I find don't work. Also not looking to spend over 70 bucks or somaybe 100 per 8"
And I think I asked before.....like the chart above, the big spike before it drops off.....what exactly does that mean? Distortion? And you want to stay flat on that chart right? What about a small jump before it slopes off?
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#15
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6/15/09 at 12:00pm
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Re: Box building software...

Quote:
Originally Posted by MarvinJr
I think I asked before.....like the chart above, the big spike before it drops off.....what exactly does that mean? Distortion? And you want to stay flat on that chart right? What about a small jump before it slopes off?


The chart has two curves on it, blue for a sealed box, and green for a ported box.

The sealed box (blue) rolls off nice and evenly, just as you'd expect. The green curve has a major hump at 40 Hertz, then dives down like mad at lower frequencies. This is also exactly what you'd expect.

That big hump at 40 Hz is the tuning frequency of the port. In essence, the port "behaves like" an extra speaker, or more accurately, an acoustic amplifier with a narrow range. At and near (and most importantly below the tuning frequeny, the port is making almost all of the sound. An octave (double the frequency) above the tuning frequency the speaker is making most of the sound.

Designing a box involves playing tradeoffs to get the response of the speaker and box and port to play against one another, hopefully to make a flatter curve.

I can't say that I am familiar enough with it all to suggest drivers, but no matter what you select you'll be playing with the numbers until you get it right. The box design software can give you a real good idea of the correct dimensions quickly.

--ignore the man behind the curtain

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#16
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6/15/09 at 7:08pm
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Re: Box building software...

Wow that actually made sense to me, lol

Thanks

I think I have out grown this winisd. Do these other programs like bassbox allow you to more with home speakers, such as.....building mulitple way speakers, and just more options? From what I have searched it looks like it does alot more of what I have in mind.
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#17
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6/15/09 at 7:45pm
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Re: Box building software...





1st Pic is the comparison between ported vs sealed. I am correct in going with the ported box, right....seeing as how ported gets down to below 30 before it slopes off.

The second pic is the group delay? This don't look good does it?
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#18
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6/16/09 at 5:49am
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Re: Box building software...

Quote:
Originally Posted by MarvinJr
Wow that actually made sense to me, lol

Thanks

I think I have out grown this winisd. Do these other programs like bassbox allow you to more with home speakers, such as.....building mulitple way speakers, and just more options? From what I have searched it looks like it does alot more of what I have in mind.
WinISD and Unibox are great in what they do - model the speakers for the low end of the audio spectrum. Subs and bass only. Bassbox adds the ability to give you dimensions of a boxes. I'll stick with free programs and a pencil, paper and a calculator. I know that is so 'last century' but that's how I learned to do it.

Crossover Pro looks like the next step. I haven't heard much about this program though. The guys I read use the expensive stuff like I mentioned before. Or for a small fee ($30 or so) Madisound will design a crossover for you. I think Danny Ritchie of GR-Research will do the same. If you are going to hard core with this hobby, then Crossover Pro or another program will be a great addition.

-Robert
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#19
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6/20/09 at 11:24am
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Re: Box building software...

Quick question about winisd.......When I change the port # to 2 ports it gives me a single number. Is this number the length of each port? or both ports, and I cut it in half for each one?
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#20
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6/20/09 at 12:00pm
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Re: Box building software...

That is the length for each port. So if you have one 4" diameter port that is 18" long and it gives you an Fb of 25hz, then two 4" ports will need tobe 36" each to keep the same Fb. This is why you should learn the math of speaker building before jumping into the software - port math.

Also, the enclosure size is net. You have to account for the volume displaced by the port(s) (treat them as solid cylinders), braces and the driver.

-Robert
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#21
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6/20/09 at 12:14pm
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Re: Box building software...

I realize all that, but just wasn't sure about the dual ports. One 2" port I think was 5 or 6 inches, but two were 14 or 15 inches....it was more than double, almost 2.5 times.
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