Data-Bass version 2 is live

Good day. After a very long delay and a TON of work Data-Bass version 2 is up (Virtually everything has been overhauled though it may look like it on the surface ). We have added a lot of systems, some drivers and quite a few articles. We also have a lot of added pictures and for a few of the passive systems we have done high power impedance testing. We still have a few minor things left to update and a couple of systems to add as well. Additional tests and articles will be able to be added much faster now and will be.

Those of you that have supported us, we thank you and apologize for the delays. Enjoy.

Data-Bass

I probably won't go into the same amount of detail in the reviews. The issue is simply time. Since I am doing reviews for AH those take a lot of time and effort. I am not allowed to repost those word for word at DB since it is property of AH so we are simply linking to them, which works pretty well all around. The DIY stuff will just have commentary on the measurements and the drivers, etc. The stuff on DB will be more to the point and straight up technical. Sorry. This stuff takes so much time that I cannot rewrite reviews twice or do them for DIY type stuff. The raw drivers and passive systems take way more effort and time to fully test to begin with. Any commercial subs going forward will probably have an official review at AH that will be linked to so those will have a full write up.

Hey Fatawan.

The 5100 models "ok" in the cab as does the 21SW152 but neither quite as good as the 5400. They give up some max output due to having less displacement . The Pi-18 models well in it as well but gives up a couple of db in max output and probably a little in some other areas. Haven't actually tried that driver though so...

Anybody check out the ported 21sw152 ? Its pretty viscous.

Btw I still need to redo 5 of the subs from the original tests to get them up to date. That includes the LMS and xxx stuff.

Exojam,
I don't believe you can know how much gain without doing some sort of outdoor or anechoic test at a known drive level. How do you know where the curves match up otherwise? At least in my case there was no logical point where it would be easy to say "There...at 70hz" is where the 2 curves line up otherwise. What frequency do you pick? It's a pure guess and it could be off quite a bit easily.

You can figure out what the effect on the response is though if not the absolute gain. That is still far far better than nothing.

I suppose that you could take a close mic at a known drive level at say 1.25" from the cone and calculate back to 1m output (39.6" = close enough to 40" here) by subtracting 30dB. Only problem is even if you pull the sub out into the room there may be some boost from the floor, measuring at such close range distances may have some extra proximity effect, errors in distance at such small sizes as 1.25" can produce large variations in output. What if the sub is dual opposed? You need to use a generous output level to get the deep bass up out of the noise floor and maintain as much accuracy as possible. Keeping freedom from clipping and issues with gain structure may be an issue doing such a close mic and then switching to a much lower volume level with the mic at the listening position far removed from the sub too. I wouldn't use vented, horn, or anything other than sealed for this also. You also should defeat any processing of any kind and try to maintain as deep , predictable and extended a response as possible again for SNR issues, hence why sealed is best.

Thanks for the kind words FOH (Everyone else too for that matter.)

Yes. Busy does not begin to describe it. My plate is full. Data-Bass is basically myself and Kyle. I do the tests and he designs and maintains the site which has also been a ton of work. There is nothing that says it must only be us doing all of the work. We have talked about having others contribute. If someone wanted to step forward and contribute some articles, measurements, pictures or whatever on any of the subjects you mentioned or a number of others that would be great. (Not necessarily outdoor testing which takes a lot of work, software, know how and equipment to get right.) We even thought about having someone do subjective reviews of some products. (That is really not my forte or preference of focus for myself personally). I personally would love to see some further research into room acoustics and PVG myself. It would be amazing to get information on 10 to 20 different spaces of different shapes sizes and constructions. It would be amazing for someone to take a small sealed 12" and do something like that. Bosso mentioned something like that a while back and I've been thinking about it ever since. That same thing could be done for different vehicles for the car audio crowd. How cool would it be to be able to go to Data-Bass and go to the vehicle gain chart and pull up 2008 Chevy Silverado regular cab and have the gain profile pop up?

Kyle's site he has built really is amazing with a very good interface to upload new content. Unfortunately there really is no money in DB right now. It is done out of love for the game so to speak. Anyone that did want to contribute would have to have a certain prefessionality and technical / knowledge level too. We have had plenty of offers to loan subs and drivers to get tested but I'm just one very busy guy and I can't handle what I have now let alone start working in these other areas.

Scott. Short answer is yes. Don't hold your breath though. I already did high power impedance testing on a dual 2226J cab from the JBL 4675C though. Output= Not much going on below 30Hz (Tuned to 40hz) but above there look out... it's LOUD.

I can only report what LIMP tells me. Seems like my driver parameters come out with a little more BL and hence slightly lower Q values than factory. not sure why. It's all relative though. Some parameters directly affect others and a lot of them are calculated so the programs that typically measure this stuff may report slightly different results but the modeling will be very close between the parameter sets.

Kyle could probably explain this better.

That has been planned for a long time. I have already put the sub back together. While I am at it I am going to do a test with the drivers push / pull to see if it lowers distortion compared to push / push.