Hi, my first post on here as I'm really new to DIY speakers despite building my first pair about 8 years ago (haven't built anything since).
I have however slowly accumulated a collection of drive units with the plans of building some more speakers as I thoroughly enjoy the first set I built.
As far as I can tell the normal process is: plan, buy, build...
I've gone a bit backwards (budget constraints and taking advantage of good second hand deals) in that I have bought, need to plan and then build
In summary I have:
3* seas excel w18nx001 8 ohm
5* vifa m22wr-07 6 ohm
4* peerless 830493 HDS
& 9* vifa dx25tg-05
Many of the drivers I don't have any TS for, so I have invested in a dats V3.
My loose plans are 2* 3way pairs 1* 2way bookshelf pair and a 3way centre style but any advice or suggestions would be greatly appreciated. I also had a play with the Dats v3 on my first builds (2way sealed cabinets) with the impedance sweep (attached). I would appreciate it if someone could point me in the right direction where to learn how to interpret this.
Many thanks in advance
I have however slowly accumulated a collection of drive units with the plans of building some more speakers as I thoroughly enjoy the first set I built.
As far as I can tell the normal process is: plan, buy, build...
I've gone a bit backwards (budget constraints and taking advantage of good second hand deals) in that I have bought, need to plan and then build
In summary I have:
3* seas excel w18nx001 8 ohm
5* vifa m22wr-07 6 ohm
4* peerless 830493 HDS
& 9* vifa dx25tg-05
Many of the drivers I don't have any TS for, so I have invested in a dats V3.
My loose plans are 2* 3way pairs 1* 2way bookshelf pair and a 3way centre style but any advice or suggestions would be greatly appreciated. I also had a play with the Dats v3 on my first builds (2way sealed cabinets) with the impedance sweep (attached). I would appreciate it if someone could point me in the right direction where to learn how to interpret this.
Many thanks in advance
Attachments
In general you don't want to try to use the driver where the big impedance rise is, 50 hz in your chart.
If by "TS" you mean the theil/small parameters, you can measure them with free software, a non-inductive resistor, some aligator clip lead adapters & a sound card or stereo line level input & earphone output of a PC. See post 206 of the thread https://www.diyaudio.com/community/...a-16uf-cap-that-is-really-18uf.387658/page-11 particularly the "read this thread" link to measuring with REW free software. I would guess a datsV3 is some kind of sound card.
Qt of your woofer will tell you if you want to build a sealed or ported bass reflex enclosure. Qt <.4 means ported. Other kinds of enclosure are available, like bass horns, transmission lines, open baffle etc . I'm no expert on the exotics. Special room features may be necessary for some of them.
If by "TS" you mean the theil/small parameters, you can measure them with free software, a non-inductive resistor, some aligator clip lead adapters & a sound card or stereo line level input & earphone output of a PC. See post 206 of the thread https://www.diyaudio.com/community/...a-16uf-cap-that-is-really-18uf.387658/page-11 particularly the "read this thread" link to measuring with REW free software. I would guess a datsV3 is some kind of sound card.
Qt of your woofer will tell you if you want to build a sealed or ported bass reflex enclosure. Qt <.4 means ported. Other kinds of enclosure are available, like bass horns, transmission lines, open baffle etc . I'm no expert on the exotics. Special room features may be necessary for some of them.
This article would be a quick start:
https://speakermakersjourney.blogspot.com/2016/12/crossover-basics-impedance.html
The single low frequency impedance peak in a sealed enclosure will always be higher than the driver's Fs, (free-air resonance). Your chart indicates a 50Hz low frequency impedance peak, so we can assume the LF driver(s) Fs is below 50Hz.
The upper peak is indicative of the crossover used on the HF driver(s).
Why didn't you just look them up? Just use Google and the datasheets will jump at you.
Thank you for your response, you are correct in that the Dats v3 is essentially just a sound card but it comes with the resistor built in, the test leads and software to test the components. Yes by TS I was referring to theile small parameters.
With the big spike in impedance at 50hz I've been using the speakers (2way, first order crossover at 1khz) for ~8 years would you suggest adding some kind of filter to the crossover to mitigate this impedance spike? Or do I need to address the cabinet volume?
I'll have a read through the thread you mentioned and get a collection of ideas before starting the next builds.
Many thanks
Thank you for your response, that article is brilliant. I'm now speculating that although I calculated to crossover frequency to be 1khz the second peak is at 600hz so I likely got some of my mathematics wrong.
Many thanks
Thanks, the vifa and peerless woofers are older and more obscure models so nothing comes up on the Google search for data sheets.