WinISD auto calculations w/ WR125

[edjosh23]

The other day when modeling different drivers for my next project I looked back and modeled the WR125. What I didn't realize is that winISD automatically calculates the best box size and tuning frequency, I'm not sure how I didn't realize that. But winISD recomended box size for the wr125 is 26.6 litres and tuned to 42hz. I tuned my box to 50hz (I think).

Why is winISD recomending tuning frequencies so much lower than the Fs?

I was thinking about building a pair of boxes this weekend using the recomended volume and tuning frequency. Would that be a wait of time?

Thanks,

Josh

 

[Audist]

WinISD can calculate the optimal box, but what the type of the box system that you choose?

BB4 / QB3 / C4 ... ?

I like use with BB4 tuning, for my opinion is the best sounding.

 

[planet10]

What I didn't realize is that winISD automatically calculates the best box size and tuning frequency,

It might be better to say that WinISD, calculates whatever the author used for his idea of what optimal is. I'd think that this would end up as a receipe for not very optimal most of the time.

I spent quite a bit of time playing with BR for the similar FR125 and ended up with 13 litres tuned to 52 Hz (true thou that i also intend to push it toward aperiodic)

dave

 

[edjosh23]

I've got I think 2 other software to help with box design, but I like winISD because it very user friendly and you can easily compare different drivers and different enclosures. The boxes that the wr125s are in now are poor quality, ugly, cheap ($15 of materials, I had a bit), and will never be finished.

I like the new FR125s, they would be great instead of this hi-vi tweeter, which I like just because it is an easy addition to any speaker to see how a little top end would sound. I haven't looked a the t/s parameters for the fs125 but I thought Tim said they were very similar, and if they are very close I'd love to drop them into these enclosures.

Well here is a graph comparing your box Dave to mine, from winISD and I might try to model the boxes in diffent software. I also have to try this out in MathCAD now that it is working on my computer .

I'm going to try out these boxes and if they don't sound as good as what they are in now I'll just have to rebuild them. But what you don't think I'll be waisting my time on these boxes?

Thanks,

Josh

An externally hosted image should be here but it was not working when we last tested it.

 

[edjosh23]

Dave,

I modeled both enclosures in unibox. Your enclosure is much smoother and doesn't really peak much, while mine peaks in the 40-45hz range and then levels out smooth, actually a bit smoother than yours. In yours from about 50hz -100hz the responce is +3db, similar to the plot from winISD. The unibox for my box is similar to the winISD plot, but when it peaks at 40hz it is +3db and then levels out at 50hz, in the winISD plot it peaks then decreases, which does not happen in unibox.

I think I'm going to buy some wood tomorrow and build myself some real boxes, finally. How does electric blue sound? I'm hoping the color will make it sound better

Thanks,

Josh

 

[Stocker]

If you have the time, supplies, money and motivation, go for the different boxes. You may be pleasantly surprised. Build just one and do a comparison with what you currently have. The +/- 1, 2, maybe 3dB differences, most people are pretty unlikely to hear, especially during actual music.

 

[planet10]

Your enclosure is much smoother and doesn't really peak much, while mine peaks in the 40-45hz range and then levels out smooth, actually a bit smoother than yours. In yours from about 50hz -100hz the responce is +3db,

And with my close to aperiodic ports -- inspired by the solo 103 -- i hope to convert that slight rise into a smooth fall-off and a bit slower dive as things reach cutoff. ie somewhere between the BR response & sealed response.

dave

 

[edjosh23]

Well I work 50 hours a week, but I'm hoping to build both boxes this weekend. Sanding and painting will end up taking a very long time, but I can handle that. I'm craving more bass.

Dave, I must say, my aperiodic boxes didn't sound the best, but they weren't bad, but I had no clue what I was doing. I'm sure you can make them work really well though.

I'll update tomorrow hopefully with pictures too.

Thanks,

Josh

 

[planet10]

my aperiodic boxes didn't sound the best, but they weren't bad, but I had no clue what I was doing. I'm sure you can make them work really well though.

At this point there isn't a whole lot of science behind the aperiodic box... experience, feel, cut & try are the tools... (i'm guessing the MJK model could be extended to model them, perhaps some day...)

dave

 

[edjosh23]

I've done a little work in MathCAD and I've figured out I need a lot of stuffing. The total length is 49.5" and the vent is 2x6 and is 15.84" long. The woofer is 6" from the top and the stuffing is going to be about a .5 lbs per foot thoughout the cabinet except in the vent. Does this sound like a good plan or should I change something?

Thanks,

Josh

 

[edjosh23]

Well I did a little work this weekend and got one box done, and the other is waiting on interior dampening and the last side pannel. The one this is working and ready sounds pretty good, but the woofer seems to stree on some bass notes at high volume. Could this be because of too much or too little stuffing? The bass is low, but I haven't had the time to really test it out because my mom is asleep.

My Dad took the digital camera so I had to use a friends and I didn't get a picture of the entire box front, sorry.

Josh

There are more pictures on my website, page 4

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[edjosh23]

Well I seemed to fix the streesing of the woofer. I came home after work, sanded the 1 finished box, use my new favorite router bit (the flush trim router bit), and took out some stuffing. The bass responce seems to be much better, clearer, and the speakers look great, just because the vent hole is so perfect. I need to finish the other enclosure, but I don't have much time during the week. I also need to use the round over bit on the front baffle which will hopefully make them look even better. These boxes are my first real example of how much better I've gotten with the router, although I'm not that good and am still learning. Unfortunately I have not calibrated the plunge base so that I can see how many inches I've plunged into the wood, so my woofers aren't perfectly flush mounted , but I can deal with that. My dad comes back on wednesday with the camera and I'll post some more pictures.

Josh

 

[edjosh23]

I have now completely finished the Construction of the speakers, I just have to put a finish on them. I'd like to try to veneer them instead of paint them electric blue. I'm afraid with the electric blue, if it turns out well it will show any flaws in my construction, which is not the best. They sound great and the bass is really good. I think they may be tuned a tad low, because the bass is not as prodominate as with the last boxes. I haven't modelled the last boxes in a while, but they might have peaked new the f3 so this actually might be right. The bass is tight and the tweeter looks much better now that it is actually attached to the enclosure rather than placed on top with the crossover sitting behind it.

Here are some pictures

Josh

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[edjosh23]

This morning I rounded over the front baffle and I would say I did a pretty good job, although I did make 2 very minor mistakes. I am planning on bringing my speakers to an home theater shop pretty soon, I know the guys there really well, and they sell Classe, McIntosh, and Rotel amps and I want to hear the speakers on some better amps just to try it out. So when I finished with the roundover I brought my speakers in, and I leave my integrated up plus 6db bass, because I like bass, and I decided what would the speakers sound like natural. I must say they are a little too bright now. The bass is still good when the eq is flat, but there is a little too much high, the over take the mids and lows. Should I try changing my crossover, add another .1uf and keep adding until I like it, or should I try putting a resistor, say 1ohm or .5ohm resistor paralell with the crossover caps? I'd rather not an a pad, its a little late in the game for that, well not really, but I'd rather add a resistor if needed then add a whole pad, especially since I can adjust the highs if need be on my amp.

What do you all think?

Josh

 

[planet10]

Should I try changing my crossover, add another .1uf and keep adding until I like it

Try decreasing the size of the cap 0.1 uF at a time (althou i find it easier to start with too small a cap & increase it a bit at a time until there is just a bit much & then back it off.

dave

 

[GM]

Greets!

Ideally you want an aneochoic (half space) flat response, then add some form of baffle step compensation (BSC) to flatten the rolled off bass as required to best blend with the room, either with digital EQ or passive LR network: http://www.quarter-wave.com/General/BSC_Sizing.pdf http://www.quarter-wave.com/General/BSC_Variable.pdf

If you're asking about adjusting the level of the tweeter, then yes, you can do it either way since an RC network will suffice when only doing super tweeter duty. Just hook a cheap pot in parallel, dial it in, then measure its resistance to get the desired fixed value if you don't want to spend a bunch of time swapping out caps.

BTW, in the future please shorten long links: http://snipurl.com/fj36

GM

 

[edjosh23]

This is my 3rd time trying to send in this reply. First time my Dad turned off my modem, and the 2nd time I finished typing it and I looked in my email and clicked onto a link and it changed this reply page.

Anyway..

I think that perhaps it is not that they are bright, but perhaps the Hi-vi is a bit more efficient that the wr125, especially with all the suffing in the enclosure. The other thing is the XO is only 1.2uf because I liked it there, although that is a very low xo frequency espcially for a helper tweeter. Perhaps the overlap in frequency range is adding the 3db boost to the responce and it is apparent to me, but why was it not before? I'm gonna try adding a few more .1uf caps and seeing what happens, but perhap the 6ohm TN28 is more efficient with the power than the heavily stuffed 8ohm wr125.

Dave, I orginally had 1uf and added .1uf and then I backed off at 1.3uf because I thought it was bright, but I was even more of a noob then than I am now so we will see.

What I would like to try is to simply add a 1ohm 5w resistor or something to the TN28 so it is not as efficient. I can also hear lost of static from the TN28s, dc offset maybe? Although it is from my Denon.

GM, I'll add baffle step, hopefull after MJK's site starts working again (is it not working for others or is it just me?) You think it would be an alright idea just to try adding the resistor? Should it put the resistor in a series or paralell with the caps?
And what is with the shorten link site? I didn't have any links.


Thanks,

Josh

 

[morbo]

I have the Hivi units here, and they are quite a bit more efficient than the WR, I never measured, but I would guess at least 6db louder.

Also, unless you are crossing over really low (which you shouldn't be with this tweeter), that is a very large center to center distance between the WR and the tweeter. I know there's not much you can do about it now, but be aware that it is not optimal and will result in lobing that gets worse the closer you are to the speaker.

As for the static from the tweeter, what is your crossover frequency? In my expereince, they sounded pretty bad crossed over lower than 3k 2nd order, if you are just using a cap I wouldn't want to cross them below 5 or 6k. The static may be the result of overdriving the tweeter by crossing it too low.

 

[edjosh23]

Well I used an excel sheet that I had and for 6db baffle step I'm gonna use but I don't know which type of resistors to use. I'm thinking about 1.5uf cap and 3.5ohm resistors. Any good?

Dave explained more to me about the xo
He is suggesting add a 2ohm reisistor and to try up to 2uf. But should I get a non-inductive resitor?

Dave says that with 1.2uf on 6ohms the xo frequency is close to 20khz. Since the tweeter is more effecient, when crossoved over higher the roll off will be closer to the spl of the wr125 (thanks Dave) I had no clue what the xo frequency was, I just added caps as Dave mentioned earlier, he told me to do that a couple months ago when I bought them and I found that 1.2uf was the best for me.

Its odd, with the bass +6db on my amp the highs don't seem too much, so with the 6db baffle step would the highs sound like they do when I change the eq on my amp?

Thanks,

Josh