What are the 2 enclosures for testing 18's? Not the LMS ones? I think that the other 18's will be far from happy in 100L sealed and 200L tuned to 16hz. The generic, possibly interchangeable testing enclosure is a good idea though. 200L sealed and 400L vented would be better for the other 18's.Ilkka, you've got yourself an interesting setup for evaluating sub drivers. You currently have two enclosures that would be suitable for testing the 18s and I don't know about 12 or 15s. I guess you could easily fashion a front baffle to hold the smaller diameter drivers while mounted in/on the same enclosures. You could make the box's volume smaller by adding bricks on the inside. Plus you have a couple of the best amps to drive them with while testing.
Looks like you got yourself another round of very popular tests to accomplish.
Same here. I'm willing to donate 25$ for the acoupower.I'll pledge $15 minimum toward the Acoupower 18" driver.
I'm very curious how this driver will perform compared to the LMS driver. And for a very good reason... :devil:
Carlos and I have been working on the details, and at the moment it seems that the Acoupower 18" test will happen. :yes: We haven't agreed on the enclosure design though. Carlos is recommending a larg'ish sealed enclosure or a higher tuned (like around 30 Hz) ported box, but I said that it is probably not what most people want. I am suggesting something like around 400 liters tuned to 15 Hz with an 8" port. What do you think?Carlos replied to my e-mail and we are working on the details as we speak. I'll let you know asap as we agree on something concrete.
Excellent! Bump me up to $20 donation.Carlos and I have been working on the details, and at the moment it seems that the Acoupower 18" test will happen. :yes: We haven't agreed on the enclosure design though. Carlos is recommending a larg'ish sealed enclosure or a higher tuned (like around 30 Hz) ported box, but I said that it is probably not what most people want. I am suggesting something like around 400 liters tuned to 15 Hz with an 8" port. What do you think?
Is it really? For example 300 liters tuned to 15 Hz already starts to peak the tuning frequency area quite a bit.the problem with the acoupower 18 in a LLT is it's high Q and FS - more
suited for pro applications or Sealed box. the 15 is a lot more LLT friendly.
Although that's not a LLT it looks GR8 :T. however tuning such a high FS driverWhen it comes to the 18", IMO its sweet spot would be around 400 liters tuned to 20 Hz using that monster 10" port. Around 115 dB from 20 Hz and up with only 1000 watts. Power compression should be extremely low.
It's not just the Fs that dictates the best possible tuning frequency. You have to look the shape of the frequency response too. You don't want to create a recession just above the tuning or peak at the tuning.Itay is correct. The higher Fo of 28.2 Hz makes the porting favor an approx. 20 Hz tune. The 15 is a little lower at 24 Hz.
Yes, We want a copy of that. If you can't post it here, I'll PM my email address!The Acoupower 15" was measured in Voice Coil magazine a while back including Klippel data. I can dig it up and post it 9the Klippel data), if there is interest, or maybe Carlos has the reprint rights. In my experience, due to the statistical nature of the Klippel test and the limited number of data points at the extremes, the results need to be taken with a small grain of salt. At least the suspension and BL we well balanced (with neither being a huge limiting factor) and so the data is more "real" that it would be if that we're the case.
IIRC, Xmax was in the 28 mm range with near perfect suspension symmetry and centering. This is particularly impressive because of the spider being a 6" ID and 12" OD.
I completely agree with you on this one. Also, the Infinity Kappa Perfect/VQ series is a perfect high quality budget option for such a situation. Eventually I will have four of them in use for movies and two in stereo use for 2-channel listening.I know that drivers like this and the LMS TC sounds stuff capture the imagination of DIYers but I think that people are missing the point a bit. With the research that has been done by Harman and others showing how multiple LF sources having a very positive impact in smoothing rooms modal responses, the question isn't who can build the best $1k woofer, unless you have a lot of money to build 4 of them. Instead, four $250 woofers would be a better bet for that $1k budget. As engineering is really the art of doing the most with the least (and furthermore fits within the demands of the application from all other factors therein) these brute force approaches are not that interesting to me personally.