Visaton W200S + TW70

[gfiandy]

To input data from data sheets Virtuix includes a graph trace utility that converts images to frequency and impedance data. I use the windows snipe program to capture the graph from the data sheet and convert it to a PNG file then open the PGN file in the SPL Trace tool. You set up the limits then tell the trace where the line starts and it tracks along it creating SPL data based on where you have told it the upper and lower limits are. If it gets lost which it sometimes does you just click on the line to redirect it.


See the attached example - Just noticed I didn't set the lower frequency limit it should read 20 not 400 (the 400 is from capturing a tweeter response) and I haven't set the top limit at all it should be on the 20KHz line and the box should read 20000. I didn't use this data I just set it up so you could see how it works.

[giralfino]

The problem in simulating Visaton drivers in a simulator different than boxsim is that Visaton provides only on axis FR, and moreover they are plotted as SPL for 1W and not the correct 2.83V.

Ralf

[gfiandy]

Well that is very annoying, so I simulated their W200S-4 in an infinite baffle at 2.83V and captured the data with the polar responses. I have also captured the impedance is a separate image. You should be able to use these to enter the data if you want to.

[gfiandy]

I have also extracted the HT22 data from the data sheet. This has no off axis response so if you want to simulate the mid range off axis you will need to copy the data to files with 30 deg and 60 deg in the file name, The cad package will then pick them up as off axis responses so you can at least see what the mid range is doing. The tweeter should be fairly close to an Omni at the crossover anyway.

[robert1111]

Woah. Thanks a lot. Now lets slow things down a bit. It will probably take me quite some time to get a grip with the VituixCAD.
Will see how it turns out. Right now I´m not sure if the W200S is up for the task. With boxsim I´m having hard time to simulate the result I would like to see. Maybe the ht-22 is the answer. Or maybe other woofer. I managed to combine w170s quite nicely.

[gfiandy]

Its OK, I had some spare time and enjoy messing about with speaker projects. I have no expectation that you will use the data.

The advantage of a smaller speaker like the 170 is the off axis response is better to higher frequencies and the breakup is usually a bit higher as well making the crossover somewhat easier.

[robert1111]

I did fiddle around with the VituixCAD. That damn thing is difficult. I quess it only makes sense if I measure the drivers myself in ready made box and insert frequency graphs. Or maybe copy Boxsim graphs without crossover. Right now it is just impossible. But I did like the frequency and phase drawing software.

I simulated a bit more with Boxsim. Pictures as results. Tell me what you guys think. I also pulled the tweter 5 mm forward.

[system7]

I can't see a good reason NOT to use Boxsim.

With the nominally 4 ohm W200S, the series filter looks promising. I happen to have the 8 ohm version (6 ohms DCR).

A fourth order filter on the 7 ohm TW70 tweeter and some impedance correction on a second order bass looks good too. I have built something close to this circuit and it sounds very good. Substituting the 6 ohm Monacor HT-22, which is a better sounding tweeter IMO, hardly needs any adjustment. You might give it a slightly more rising top end to allow for the fact it is flatter than the TW70.

[robert1111]

Little update. Not sure if that is anything to consider, but it turned me off from the w200s idea. I got my hands on a Visaton Alto II, that my friend just finished. I know it is different woofer, but I imagine it sounds similar.
I tested the speaker against my Classix II's.
The bass of the Alto was slow, and lacking the kick. Midrange was weak, I could not hear important sounds, so the detail was all gone. Not sure how english guys call it, maybe mash up? This is the biggest dissapoimtment.
And the sound was more like a big area around the speaker, not very direct. So I could not find the sweet spot for listening. I quess it is called weak stage. Cant pintpoint sound location? Beaming sound source maybe? Not sure what is causing that. Poor crossover?

It did handle more power, and maybe something in the frequency range was tonally more pleasing. But I did not enjoy it, if it had proper midrange, it would be okey for backround music. But definately not good for sitting down and enjoying music. And that is compared to a speaker, that also does not shine in the midrange.

[Lojzek]

All Visaton W---S drivers are a solid foundation for good SQ, you just have to put some effort into designing an appropriate crossover. Visaton kit ALTO II is very likely not optimized. W170S is best used sealed and in a larger enclosure volume.