ahl395

Hey guys, just for anyone searching in the future or anyone curious. I contacted Fi directly and asked them if a High QTS Q12 could be used in a ported environment, the short answer is yes. My Message: Fi's Reply:

Hey everyone I made a similar thread some time ago, but it seems to have died and my question today is a bit different. I know it is not designed for it, but I am determined to try my Q12 in a ported box. If it doesnt sound good, I can always put it back in my sealed box. Anyway, since I do have a high QTS version, should any of the suggested box parameters be changed? Say a smaller/larger enclosure or a higher/lower tuning frequency? I should be able to go up to 2.1-2.3 cu.ft after the sub's displacement. And I was planning on tuning to 32hz as that's whats recommended. Also, would polyfill be beneficial, or not? Any thoughts are greatly appreciated.

Sorry for the big gap in response time. I've been quite busy recently and between jobs. Ah, I figured. I am using a Hifonics Mt. Olympus Hercules 4K: http://www.hifonics.com/hifonics_mtolympus_amplifiers.html and http://www.sonicelectronix.com/item_32988_Hifonics-Hercules.html X-Over set at 80-100Hz Subsonic set at about 20hz Boost is off Gain has been set both by a DMM and by ear. With my setup its hard to do that. I have my second battery and a board with all my amps on it behind the sub box at the back of the trunk. I'm not sure if I can swap the places without "remodeling" quite a bit of it. But I am going to try turning the sub around and facing it toward the rear at least. Alright, I'll have to lose that idea

moving the enclosure around in the trunk. for example, move it all the way to rear of the trunk, firing towards the license plate. - This is one thing I haven't done. Currently I have the sub facing forward with the back seats down. I'll have to get a grill to protect the woofer and try facing it towards the rear. reset the gain - This I've done a few times change xover points - I usually go between 80hz and 100hz eq the response (no boost. eq down the high end) - I have tried this, the amp unfortunately starts clipping though or it gets distorted before it reaches the output I'm looking for. add polyfill if you haven't already - I do have polyfill in my current enclosure. Thanks for your response. I'll try those couple things I haven't and see how it reacts.

I had a thread here which pretty much sums it up: http://www.soundsolutionsaudio.com/forum/topic/62125-low-output-below-35-40hz-and-high-qts-in-a-ported-enclosure/ Basically, not enough output. And not enough low-end bass. Originally my enclosure was too small, I fixed that, but still doesn't seem to be as good as I expected. Which is why im interested in trying a ported box. Would a recone be able to change it to low QTS, or is it part of the motor? Also, is there any chance it could be the amp? I think I would see other problems or it just wouldn't work, but who knows.

The sub amp is a Hifonics Mt. Olympus Hercules. (Top tier amp they have)http://www.hifonics.com/hifonics_mtolympus_amplifiers.html Electrical: Big 3, XS Power D1200 second battery, stock alternator, all 1/0 AWG OFC. Voltage monitoring: I have a voltage monitor mounted right in my dash that is wired directly to the battery in the back. Voltage never drops below 13.5V when above idle. When at idle it usually stays in the 13-13.5V range. Extreme bass heavy songs can put it down to 12.4V at idle though. Above idle never drops below 13.5V though. These are pretty good numbers considering I have a stock alt, I couldn't be happier with the battery. But I wouldn't point the finger at voltage issues, even though can dip down pretty low at idle, it sounds no better at normal voltage above idle.

Hi everyone, first post here. I have an Fi Q 12, I ordered it fully loaded with the high QTS option with the intention to use it in a sealed enclosure. I currently have it in a 1cu ft box. Unfortunately the sub response really rolls off below 35-40hz, which is very disappointing. I have had much lower end subwoofers in sealed boxes that were actually much better on the low end frequencies. So my thoughts are to try it in a ported enclosure and see how it responds. Problem is I have High QTS. What will happen and how will the sub react to a ported enclosure? If anyone has any input on how else to solve my issue or any ideas about the enclosure let me know, it's greatly appreciated.

Alright guys so I got my new enclosure built and my Q12 wired up. I ended up with about 1.25cu.ft. after the sub's displacement It definitely seems louder. I was able to turn the volume quite a bit higher without the clipping indicator coming on. Although I'm not sure if it actually sounds better or fixed my problem... The bass sounds more distorted now. Turning down the sub level on the head unit took some of that away but it seems like it doesnt sound as clear, for lack of a better term. Also, I didn't gain any low end response at all, in fact I think I even lost some more low end bass. The same goes for "higher" bass (meaning ~60-80hz) seems like it's much less pronounced. Meanwhile, the "mid" bass (around 40-50ish hz) is much louder and more pronounced. I'm pretty stumped, this isnt what I expected from the new box. I didnt get a whole lot of time to play with it because it was late by the time I finished working on it, but tomorrow I'm going to check the box for any air leaks, even though I used plenty of silicone and whatnot, to make sure that's not my problem.

Makes sense to me, thanks for the explanation.

Well I just measured how big a box I can fit in my car. I'll have about 1.3 - 1.4 cubes after displacement.

So your saying for the most part, I don't have to worry much about clipping unless it's audible distortion? From what I've read I thought clipping was usually not audible. Will do. Thanks! Do you suggest using a familiar song or test tones when setting gains by ear? I've read it's best to use tones since its very easy to hear distortion. As far as clipping on my sub goes, I can't hear distortion when the clipping indicator comes on, it just sounds louder. I've heard the indicators are pretty accurate though, because they measure the rail voltage in the amp or something along those lines. clipping is fine, its just distortion. distortion is only a problem when its audible. so the clipping light doesn't convey to the user anything significant. the light is just a gimmick. use a variety of songs. basically you're just trying to get close to some value that maximizes the output. so for songs that are recorded at a lower level you can increase the volume at the hu and match the output to songs recorded at a higher level. setting the gain is never foolproof, you should always be listen for distortion and speaker stress. +1 to you, probably the best way I've seen that said in awhile. Also, as Lithium pointed out if the box is 1 cu.ft. before you put the sub in it then the volume is all the way down at the low end for the sub. If you do as he said, turn the sub around in the box and add some polyfil I think you'll be very surprised at how much better it sounds and performs. I was going to unfortunately I realized I don't have the space my trunk to do so. So I'm going to work on building a 1.5 cube box.

Will do. Thanks! Do you suggest using a familiar song or test tones when setting gains by ear? I've read it's best to use tones since its very easy to hear distortion. As far as clipping on my sub goes, I can't hear distortion when the clipping indicator comes on, it just sounds louder. I've heard the indicators are pretty accurate though, because they measure the rail voltage in the amp or something along those lines.

Okay, sounds good. I'll work on that. Thanks everyone.

Okay. If i could fit 1.5, would I benefit from it?

Well Fi says .8-1.5 cu. ft. Would going from 1 cu. ft to 1.5 make much of a noticeable difference?

Bigger sealed, or bigger ported? 1cu. ft before the sub. I've had it for about two weeks now and I drive quite a bit so I think its almost done breaking in. But maybe some more time will help. By reversing you mean reversing the phase or mounting the subwoofer with the motor facing out and the cone facing into the box? Reversing the phase does help alot, if that tells you anything. All of this... If the first 2 things give you better sound then you should make a bigger enclosure. Did someone ask about ssf? You could turn it off The subsonic filter is set pretty low. I believe the amp starts at 15hz and its only turned up a hair from the minimum, so I'm guessing around 20hz, nowhere near 30hz.

I can fit a bigger box. I believe that the recommended ported enclosure by Fi is a bit too big though, but I need to measure to make sure. I will do that a bit later and post back. I'm using a Hifonics Mt. Olympus Hercules. It puts out 2000W x 1 @ 1 ohm. I have set the gains with a DMM and calculated for 1800W. Still waiting to get an oscilloscope to set them right. It has a clipping indicator that I watch like a hawk in the mean time