Help pls .... Spl tracer and vituix

[3rutu5]

Guys, im having my first go at trying to design a crossover, watched a few videos but considering the age of the video i'm having a hard time here. im need some confirmation on my FRD/ZMAs look right as i traced them from the SPL graphs for the respective drivers.

on the assumption that i actually traced the right things, i couldnt help but notice that just linking up the two drivers that the 5 inch visaton is hovering around the 60-65db and the peerless is 80-90+. The cyan is the W130x 2X4 woofer and the rainbow up the top is the various responses for the peerless 830985 full range. I was wanting to try get these to cross around the 200hz mark but just looking at the SPL i can see that this appears to not cross at all?

[3rutu5]

I've been afraid and quite intimidated by the idea of building a crossover, let alone designing one, but i'm keen to have a go and post the outcome for a peer review. I'm confident that due to a lack of knowledge in this field that what im experiencing is user error, but i would have throught that if the 5inch woofer had a SPL rating of 78db and the peerless was 82db, that they should be a bit closer graph than what im seeing (or am i looking at the wrong graph).

[Jicafold]

Well, the Peerless is a fulll range driver like it says so it would, or should maintain a higher SPL throughout the frequency range and would therefore not likely cross with a woofer on a graph. So I believe the tracing is accurate. I'm curious as to what you are trying to create with the choice of these 2 drivers.

[3rutu5]

Well, the Peerless is a fulll range driver like it says so it would, or should maintain a higher SPL throughout the frequency range and would therefore not likely cross with a woofer on a graph. So I believe the tracing is accurate. I'm curious as to what you are trying to create with the choice of these 2 drivers.

oh ok, i guess i was just assuming that the woofer would have been higher.

what i was thinking was something similar to this. Originally i was going the ND65 with a ND140 PR....but the smaller FR driver just didnt do it for me in the application i was going for (at my pc), so i needed something with better off axis response. So back to the original question, i was going to side mount the W130x, provide a vent out the rear and use the Peerless in a sealed enclosure and just try to cross it around 200hz. I've modelled these both at know i can do the peerless in a 0.01cuft box @ 150hz and the larger W130x in a 0.07cuft box @ F3 60ish.

i thought if i could work out the fast crossover i could 3d print one side to see how it sounds as a tester. Basically im thinking something that looks similar to the Boenicke W5 but just 1/2-1/3rd the size. The other thing is i have the drivers already so just looking to upcycle.

[ernperkins]

To accurately simulate a crossover using copied frd/zma graphs requires multiple steps. Paul Carmody has an excellent step-by-step write up on how to do it here: https://sites.google.com/site/undefi...d-measurements

[3rutu5]

Fantastic, im going to have a read of that, hopefully it sinks it.

[a4eaudio]

...on the assumption that i actually traced the right things, i couldnt help but notice that just linking up the two drivers that the 5 inch visaton is hovering around the 60-65db and the peerless is 80-90+.

Well, I think you had to have traced things wrong. (1) the SPL is stated in the T/S parameters so you should have a pretty good idea to begin with what the average SPL in the useable frequency is going to be. (2) The manufactured specs have the frequency plot which presumably you traced, when put into Vituix or whatever it should look pretty much like the mfg specs. All the trace program is doing is creating a bunch of points for you so that you don't have to eye-ball it and manually guess at a few hundred points from the mfg specs.

Which woofer are you using, 4 ohm or 8 ohm? If the mfg specs were at 1 meter @ 2.83 volts you wouldn't need to do anything extra. The Peerless is at 1m/2.83v. BUT...the Visaton graphs are at 1m/1w. If you are using the 8 ohm version, then 1w is 2.83v and you are fine. If you are using the 4 ohm then you need to either (1) adjust the spl limits so that the tracing program thinks everything is about 3db higher or (2) trace it as is and go into a spreadsheet like excel and add 3db to everything. (If I remember correctly, it is not EXACTLY 3db but since you are just simulating for now, that probably is close enough.)

From what I can tell the Peerless is 85.4db and the Visaton is either 87 or 90db depending on which one you are using, so they should be very close to each other.

[a4eaudio]

3rutu5 - by the way, your first crossover will be an extremely frustrating and humbling experience. But in the end, it will be worth it and having created your first design I expect you will have a great sense of satisfaction.