5” Mid-woofer help

[GringoAudio]

Thank you Lojzek, I will try again tonight after work to put the FR and ZR files up.

 

[GringoAudio]

Yes the images with circuit diagrams on the left show the system response curves curves on the right.

So these attached files are the ZR and FR response curves as traced by me from ScanSpeak literature. As mentioned above I had to change the file extension name to .txt to be able to attach them to this forum. You will have to change them back to the extension names .FRD and .ZMA. I don't remember what I used to trace the curves. It's been awhile, a few years actually. I found it reading the X-Sim forum here though. It is mentioned somewhere there.

 

[verona]

Hi, I can't thank you guys enough!
I downloaded, renamed and read both files into x-Sim without any problems.
This has been a massive boost for me and I am really looking forward to doing some work on there.
I will look into tracing curves for my chosen tweeter and I will see if there is somewhere to post them on here when I have them finished.
Thanks again, Verona.

 

[schwantzi]

What is your baffle width? Paul's design uses an 8" W X 14" H baffle. If your width is close to 8" it should be OK.

Going from 0.5 ft3 to 0.38 ft3 doesn't make a lot of difference if you can handle a longer port. I used the 15W8530K00 T/S parameters from zaphaudio and used WinISD for modeling. I first modeled the 0.5 ft3 cab (red trace) which matched Paul's results (43 Hz tuning, 2" X 7" port) almost exactly. I then modeled a 0.38 ft3 cab (blue trace) with the same tuning of 43 Hz. The only real drawback is the port length increases to 10.5" which may be hard to fit in the cabinet.

One possible option is to use a 1.75" diameter port which reduces the port length from 10.5" to 8". This will increase the port velocity which may cause audible "chuffing". For a 100 dB output WinISD gives a max port speed of 27 m/sec for the 0.5 ft3 cab using a 2" port. For the 0.38 ft3 cab it gives a max speed of 23 m/sec for a 2" port and 30 m/sec for a 1.75" port. These are all pretty high values, but so is the 100 dB output.

Hello,
I came across this thread while essentially searching for the exact same issue with one caveat, I already had the Carrera build in mind. Baffle width will remain at 8" and I've got a vb of 0.385 ft3 and attempted modeling the 15W8530K00 in Winisd but my results suggest a much smaller enclosure. As such I'm convinced I'm doing something wrong. I was hoping you might be able to help me answer a couple questions:
1) Sticking with a 2" port would tuning to a higher frequency lower the port velocity? I was planning to try and tune to 45-48hz?
2) With this slightly smaller box volume would there be an ideal/better tuning frequency and what would my port length be?


I was ready to pull trigger on the Finalist Monitor speaker build, which is the size that fits my needs and I love the sound of Morels but then saw the Carrera, and well....I don't need to say anymore.
Any help you can offer would be greatly appreciated.
Thx
Phil-

 

[ernperkins]

I would guess you're using the Thiele/Small parameters published by Scan Speak and not the parameters from Zaph Audio. I've always had better results using his measured parameters than the manufacturer specs. And using Zaph's parameters matches the tuning frequency and port length from Paul's website.

Unless you already have the cabinets built I would recommend sticking with Paul's cabinet dimensions and volume. I have heard the Carreras and I would deviate as little as possible to keep that marvelous sound. YMMV.

 

[schwantzi]

Thanks. Yes I'm trying to work with the space and although the carreras are not huge by any means the smaller size was more appealing to me partner when I mocked up a cardboard box. Truthfully she didn't want any speakers.
I'm currently at about 0.44 ft3 but that is about as big as I can go. And the kit is on the way so it's going to have to work one way or another.
I took another crack at Winisd I get a 2x8" port tuned to 45hz although I will probably go to Zaphs site and use his values.
Thanks again