OK, for about 8 yrs now ive been serious about car audio, im not saying im a genious but i feel im stumped in a position that i just cant seem to completely figure out.
some people probably wouldnt like my taste of bass but i like my bass ridiculously loud and very low in freq. but besides that ive owned many different HIGH END subwoofers and im going to list them so you wont suggest i get another SUPPOSEDLY great sub to perform like i like
:12w7 mtx9500 jlw0 jlw6 jlw3 RF-h-series punch15 audiobahnAW1805q SPL15W audioqueH3CA-18 and many others
now. the problem, im a big fan of ported and sealed enclosures but ive experienced that although the ported enclosure does give you more DB and also less strain on the amp, it just dont let the subs drop as low in freq. as a sealed. and that is what im looking for. and i know you are probably saying to yourself (why dont u just use a sealed enclosure) well my answer is to get the low gut busting freq. out of a ported enclosure that everyone keeps talking about. now lets use my 12w7s for example. the FS on those is 27hz. so if i tune the box to say 28 to be on the safe side, it sounds like sh1t at that freq. also the same with my audioque 18 which its FS is 31hz. and again i tune it to 33hz. to give the sub less strain on itself and still sounded like sh1t. yes, in know how to tune a ported enclosure. if u dont believe me then go to (clubknowledge.com)
so if anyone out there can help me then make my day because all these companies bullst1n is over about telling me that the ported enclosure is the best for ultra low freq. and yes my amplifier subsonic filter and on some infrasonic filter is set correctly. and no the gain is not set on full like some dumb @$$ does that doesnt know about clipping and distortion
so mainly my ? is. do i keep on trying to find that right ported enclosure or stick with sealed for those very low freq. also i really dont care for the higher freq. just to help u out w/ your answer
your problem will be fixed when you get the correct sub on the right power, in the correct ported enclosure. My guess(by looking at previous subs owned)is you have not made the correct decisions in sub choice to fit your preformance desires. A couple sound splinter RL-s and run em sealed.. They LOVE sealed boxes. "nly problem is they take a HUGE box. 15" RL-s need 4.5-5 cu ft sealed. One of my dream setups.
You're not going to get a ported enclosure to hit hard below the tuned frequency of the enclosure, and since the Fs of subs tends to be in the 27-33Hz range, and if you tune below that you get no real gair or the strong chance of the sub unloading, you wouldn't want to tune that low, a ported enclosure is out. This leaves us with the other options for low, lod bass. surface area, excursion, and power.
Look at a large enclosure (upper end of volume recommended for sealed for the sub)
use a lot of clean power. probably more than the sub is rated to handle, as you won't actually be using the full output of the amp anyway (inductive load, dynamic audio source etc)
Use a single 18" sub, or a pair of them depending on space available, and get a GOOD sub this time.. the W7 isn't bad, but stops at 13". I'd say if you want SQ go with something like the Fi Q 18. If you really want it to blow you out of the cat, look at the Fi BTL, but be ready to feed it massive power.. in the several kilowatt range.
That is your solution. If you want credentials, you can look at my abbreviated resume in my profile on here.
I don't completely understand why people insist on implying DD's don't "go low". That statement to me is absolutely ridiculous. but anywho....
The standard rule I've always followed when building systems for customers who want extremely low bass starts with a gigantic enclosure.
Going with 15 or 18" woofers always helps but not necessarily essential. However, as Glass mentioned it is important to have a woofer that can handle an immense amount of power. The lower the frequency the closer this is to direct current, which we all know, fries coils.
A typical set up for extremely low bass I've built in the past would include a pair of high output 15's. I primarily push DD because I'm a dealer but theres plenty of other subs out there that perform just as well. Starting with a pair of DD3515's and a good 2500-3000rms should be more than plenty for anybodies listening standards. The enclosure should be 10cuft, 148sqin of port with a length of 17". This system will rumble you to the bones.
What I'm getting at is the bigger the better for "loud" low bass.
the main reason behind my suggestion of the 18 was due to the typically lower Fs of the sub. That waqs about it. You can always go with a greater number of smaller diameter drivers, too. Simplicity is another reason.. I like to keep it simple. I used a single 18 in a sealed box for my car. Just easier really. I won't even get into the whole psychological arguments about phase and multiple point sources and alignment blah blah blah because I don't think you can actually hear those differences, particularly in a car.
get box enclosure software/freeware, then you will be able to build a box exactly for what you want and have all sorts of graphs telling you anything you want to know about how it will sound. im using bass box pro 6 and plan on building my box next week.
make sure the osftware gives a response based on your vehicle cabin and not an anechoic graph. Otherwise the data is mostly useless. One reason I don't rely solely on software for box building.
Get some AudipPulse LMS Ultra.. you seem to have had a lot of subs you gotta have some money.. People here will agree they get really low.. And you can give them 5000 watts rms easily. that should shatter ur brain
"you do realize when you tune the enclosure to 28hz its going to peak 8-10hz higher than that right?"
While this is typically true its not always true. For example we had a vehicle that peaked at 54 hz while the box was tuned at 35 hz ported. What im saying is you have to get a reference point of what frequencies your vehicle peaks at and build around that. For example my vehicle is a trunk car that the seat doesnt fold down and peaks at 41 to 45 hz so i could run a sealed box and have it center at say 46 hz and peak in the mid 50's but still only loose 12 db per octave below that tuning where a ported box would be 24 db per octave.
nly problem is they take a HUGE box. 15" RL-s need 4.5-5 cu ft sealed.