The Genesis Cabinets

[Abu]

I have Seas CA18RLY and Vifa DX25T tweeters for my 1st 2 way speaker build. It will be used mainly for fronts in my HT setup... but I do find myself listening to more stereo music lately

So some playing with winisd have yielded this :


The red and blue is my tweaking (at least what I'm thinking.. feel free to criticise). So it seems as if Blue is the the way to go as I can get an extra bit of bass out of it (not running a sub yet.. if this build is successfull then I might consider doing one of those too  )

Speakers will be close to the back wall so will probably run them front ported.

What do you guys think?  I'm going out to dinner now so want a full inbox by the time I return 

[JimGore]

Don't try to push the CA18RLY down too low - it is only a 6" driver after all. 

In my opinion the grey graph is the one to go for.

Ian.

[GearSlave]

You used the T&S specs from the Seas website? I remember there being an issue with them and it was quite a bit different to what I tested. There might still be a thread on here about that, many many years ago. From my experience, those woofers work best at between 25-32L enclosure, tuned to between 40-45Hz.

[alternativeroute]

See Troels design: http://www.troelsgravesen.dk/SEAS_CA18RLY-COMPACT.htm

[Abu]

Thanks for the advice guys.. will take it all into consideration.

I actually used the specs from WinISD Pro (it had CA18RLY already pre-loaded)

[Abu]

So if I stick to the vented solution and go by troels' 24l floorstander design, I get this :


I'm thinking I still like the grey one (the original UNtweaked one from above). It has a lower response and a more balanced wave across the freq range. Then again this is my 1st time using winisd so I could be severely misreading the information.

Which one will it be....  the grey pill or the blue pill?

[GearSlave]

I actually used the specs from WinISD Pro (it had CA18RLY already pre-loaded)

I suggest you rather not use the T&S from the CA18RLY loaded in WinISD. Grab the specs off the Seas (I think Rev6 already) website and plug those in. 44L for that driver is waaaay too much.

[Abu]

Cool.. I'm guessing you speak from experience? Forgive my ignorance, but how come the 44l enclosure looks so much smoother in WinISD... or am I reading it wrong? (completely possible seeing as I'm such a noob in this)

I want to understand but it's not making much sense at the moment.   

[GearSlave]

^^^ It looks smoother because the T&S Specs in WinISD is incorrect. When I used that driver for the first time, I used a previous version of the specs from Seas (for the same driver) and it also suggested I use such a large enclosure. When I went and measured the T&S specs for the drivers I had, they were very different than what I got off the Seas website. Subsequently I noticed that Seas posted a newer version of the T&S specs that was closer to what I measured.

So, I can only assume that the T&S Data loaded on WinISD is incorrect. You are basing your design on this incorrect data, giving you results that doesn't make sense from the experience I (and others) have had with these.

To summarise:
- Get the new data from the Seas website
- Plug the new data into WinISD
- Do your simulations again

You'll find that your enclosure is going to be more in the region of 20L than 44L. You'll also find that the ideal tuning fro this driver will be in the 40-50Hz range. This is based on my own experience with that driver after I also made my boxes too big as I based my design on flaky data at the time.

[Abu]

Thank you sir..   /me tips his hat

I've got the PDF spec off the website and trying to load it into WinISD  (not playing along).  Have found a youtube howto... lets see how it goes.

[Abu]

Eish.... I'm even more confused now... so I've plugged in the values from the website  http://www.seas.no/images/stories/prestige/pdfdatasheet/H1217_CA18RLY_Datasheet.pdf

And the red is what I get now... it looks even worse!?!?!

[GearSlave]

Is the gray line still with a volume of 44L?

[Abu]

Sorry yes... It is still 44l tuned to 35Hz

[GearSlave]

OK, lemme go back to my notes and see. But like I said before, 44L is just too much for that woofer. Maybe Ian can jump in here as well"?

[Abu]

Thanks GearSlave... really appreciate it. Will await further feedback befor I have everything cut.

Indeed... would appreciate comments from Ian and other master builders


Shaun