Post Pics Of Your Trunks (Systems)
Team Owner
Joined: Mar 2006
Posts: 20,172
Likes: 1,818
From: Bakersfield
I found this quote by Lycan on DIYMA and thought it would be relevant. It's from the "Quick bass, slow bass" and transient response thread.
"The fact is, the COMPLETE time-domain transient response is DOMINATED by overshoot & ringing ... which are controlled by the driver's (plus enclosure) high-pass T/S parameters, and NOT the low-pass dynamics (including inductance and low-pass crossover filters)."
This quote was originally talking about Qts.
Anyway, peak output is determined by excursion. Most I have talked to about the peak in SPL by a sub in a very small box with a high Qtc is cone overshoot and ringing which is basically distortion since it's not a part of the original signal.
I found a bunch of stuff on the HT forums about damping and impact and transient response. Most agreed that critically damped sounded like it had the best transient response and overall sounded "quicker" than the high Q system. I should have bookmarked them last night.
I guess the way I look at it is if you start with a low Qts sub, you can always raise the Qtc of the system by installing multiple subs or by reducing the size of the enclosure. If you start with a high Qts sub, the best you can hope for is Qts=Qtc in an IB application and even then the trunk is going to drive up the Qtc a little.
I was a little worried about the Dyn 182 with something like a .65 Qts in my doors which are not quite IB for this speaker but with the low Fs and considering the frequency range, all seems well. I was ready to vent the door into the door sill if needed.
I believe my system modeled with a Qtc of around .6 with the pair of .45 subs and their Vas. When I open the trunk, the response sounds a little smoother and geared a little more toward the low end. I lose a little volume but not much at all.
I think that if you get a driver with the right Fs and Qts for your application that will require the least EQ to make it sound right, that's probably going to be the most power efficient way to implement it. I say probably because I'm definitely not sure.
This stuff makes my head hurt, I definitely do not have it figured out, not by a long shot so a lot of this stuff I'm throwing out there could or should be in the form of a question.
Jerry, I'll call you very soon. I'm in the doghouse right now, sneaking off and posting on here when I have a minute but my sentence is a weekend of chick flicks and no friends lol. I've been needing to talk to you about a lot of things lately from car audio products to retards on DIYMA lol. Also had a talk with Jon W on the E1200. I'm sure anything he's told me, he's told you already but it's pretty interesting.
A little off topic but the thing that really has my head spinning is it seems like larger speakers are less likely to cause vibrations at a given SPL. I've always assumed SPL is SPL but after my experience with the 12"-dual 15s and 6.5s to 10s along with reading others' similar experiences I'm having to rethink everything I thought I knew.
Mojofo- Have you seen what some passive filters go for? Especially the custom ones? That might not be a bad side job. Or even a super basic active crossover network that does filtering and time alignment. If I had the skills and the knowledge, this is always something I thought of as a way to make a little side money. Or maybe a lot of side money.
"The fact is, the COMPLETE time-domain transient response is DOMINATED by overshoot & ringing ... which are controlled by the driver's (plus enclosure) high-pass T/S parameters, and NOT the low-pass dynamics (including inductance and low-pass crossover filters)."
This quote was originally talking about Qts.
Anyway, peak output is determined by excursion. Most I have talked to about the peak in SPL by a sub in a very small box with a high Qtc is cone overshoot and ringing which is basically distortion since it's not a part of the original signal.
I found a bunch of stuff on the HT forums about damping and impact and transient response. Most agreed that critically damped sounded like it had the best transient response and overall sounded "quicker" than the high Q system. I should have bookmarked them last night.
I guess the way I look at it is if you start with a low Qts sub, you can always raise the Qtc of the system by installing multiple subs or by reducing the size of the enclosure. If you start with a high Qts sub, the best you can hope for is Qts=Qtc in an IB application and even then the trunk is going to drive up the Qtc a little.
I was a little worried about the Dyn 182 with something like a .65 Qts in my doors which are not quite IB for this speaker but with the low Fs and considering the frequency range, all seems well. I was ready to vent the door into the door sill if needed.
I believe my system modeled with a Qtc of around .6 with the pair of .45 subs and their Vas. When I open the trunk, the response sounds a little smoother and geared a little more toward the low end. I lose a little volume but not much at all.
I think that if you get a driver with the right Fs and Qts for your application that will require the least EQ to make it sound right, that's probably going to be the most power efficient way to implement it. I say probably because I'm definitely not sure.
This stuff makes my head hurt, I definitely do not have it figured out, not by a long shot so a lot of this stuff I'm throwing out there could or should be in the form of a question.
Jerry, I'll call you very soon. I'm in the doghouse right now, sneaking off and posting on here when I have a minute but my sentence is a weekend of chick flicks and no friends lol. I've been needing to talk to you about a lot of things lately from car audio products to retards on DIYMA lol. Also had a talk with Jon W on the E1200. I'm sure anything he's told me, he's told you already but it's pretty interesting.
A little off topic but the thing that really has my head spinning is it seems like larger speakers are less likely to cause vibrations at a given SPL. I've always assumed SPL is SPL but after my experience with the 12"-dual 15s and 6.5s to 10s along with reading others' similar experiences I'm having to rethink everything I thought I knew.
Mojofo- Have you seen what some passive filters go for? Especially the custom ones? That might not be a bad side job. Or even a super basic active crossover network that does filtering and time alignment. If I had the skills and the knowledge, this is always something I thought of as a way to make a little side money. Or maybe a lot of side money.
Chapter Leader (Southern Region)
Joined: Sep 2008
Posts: 88,888
Likes: 11,846
From: Waffles, BU
Mojofo- Have you seen what some passive filters go for? Especially the custom ones? That might not be a bad side job. Or even a super basic active crossover network that does filtering and time alignment. If I had the skills and the knowledge, this is always something I thought of as a way to make a little side money. Or maybe a lot of side money.
Team Owner
Joined: Mar 2006
Posts: 20,172
Likes: 1,818
From: Bakersfield
No, I haven't. I helped a friend design a butterworth LPF for a sub application. He's a manager at a shop that makes competition subs in vegas.. he said he'd build me a system.. but never took him up on it. If you think this is something worth investigating, I don't mind following up. Give me some specs and I'll see what I can do.
My idea was always to design something similar to the Focal crossblock or whatever it's called but add time alignment. However, the 4-6 years of school required to even begin understanding that stuff would not be cost effective for a lot of years.
Chapter Leader (Southern Region)
Joined: Sep 2008
Posts: 88,888
Likes: 11,846
From: Waffles, BU
I'll dig up some threads and links to what people are paying for basic passive networks and the specs.
My idea was always to design something similar to the Focal crossblock or whatever it's called but add time alignment. However, the 4-6 years of school required to even begin understanding that stuff would not be cost effective for a lot of years.
My idea was always to design something similar to the Focal crossblock or whatever it's called but add time alignment. However, the 4-6 years of school required to even begin understanding that stuff would not be cost effective for a lot of years.
Advanced
Joined: Oct 2011
Posts: 63
Likes: 1
From: Louisville, KY
Niebur3: It was actually the recommended tuning frequency for the subs in that size box (well for a 5CF box, so close). I'm sure to turn it down before I get into the neighborhood, but it works great for when some idiot cuts me off in traffic. Front windows halfway down, sunroof open, and volume at 35 with a bass tester CD. If I have to slam on my brakes, your gonna have to listen to it until the light turns green.
TrunkMonkey: It's not as big as it looks in that pic, I just have it moved all the way to the back because I've found it's much louder there than it was on the opposite side of the trunk (facing towards the back anyway) I'm gonna turn it around to where the port tubes are going right into the backseat armrest hole and see what it sounds like.
Eggy: Sounds loud and obnoxious. Definitely not for SQ. I'm only using it for 38-80hz. As far as the box goes, I built it for my Firebird. It's a strange design but utilized every inch of the Bird's hatch. Here's a pic from another angle:
TrunkMonkey: It's not as big as it looks in that pic, I just have it moved all the way to the back because I've found it's much louder there than it was on the opposite side of the trunk (facing towards the back anyway) I'm gonna turn it around to where the port tubes are going right into the backseat armrest hole and see what it sounds like.
Eggy: Sounds loud and obnoxious. Definitely not for SQ. I'm only using it for 38-80hz. As far as the box goes, I built it for my Firebird. It's a strange design but utilized every inch of the Bird's hatch. Here's a pic from another angle:
Team Owner
Joined: Mar 2006
Posts: 20,172
Likes: 1,818
From: Bakersfield
Looks great, JayVee. The last few pages with all of the IB installs have been really neat. What a change from the first part of the thread!
You've inspired me to put my unused all weather mat in the trunk. I've never installed it but it came with the car when brand new. It would make the old carpet that was destroyed by the previous large box look so much nicer.
If anyone is interested in the cone control vs air spring vs Qtc debate, it's pretty much settled that a sealed box with the air spring reduces cone control and efficiency, it does not increase cone control. A low Qts sub is acceptable in IB and only effects the frequency response slightly. Too high of a Qtc will results in cone ringing. Too low of a Qtc will give more low, low end output but might be missing a little of the upper frequencies. You can change it with EQ but it's best to get one with the best response for your preferences before eq when possible.
You've inspired me to put my unused all weather mat in the trunk. I've never installed it but it came with the car when brand new. It would make the old carpet that was destroyed by the previous large box look so much nicer.
If anyone is interested in the cone control vs air spring vs Qtc debate, it's pretty much settled that a sealed box with the air spring reduces cone control and efficiency, it does not increase cone control. A low Qts sub is acceptable in IB and only effects the frequency response slightly. Too high of a Qtc will results in cone ringing. Too low of a Qtc will give more low, low end output but might be missing a little of the upper frequencies. You can change it with EQ but it's best to get one with the best response for your preferences before eq when possible.
Looks great, JayVee. The last few pages with all of the IB installs have been really neat. What a change from the first part of the thread!
You've inspired me to put my unused all weather mat in the trunk. I've never installed it but it came with the car when brand new. It would make the old carpet that was destroyed by the previous large box look so much nicer.
You've inspired me to put my unused all weather mat in the trunk. I've never installed it but it came with the car when brand new. It would make the old carpet that was destroyed by the previous large box look so much nicer.
Racer
Joined: Mar 2011
Posts: 419
Likes: 86
I have got to see this car in person when I go back home to visit.
Intermediate
Joined: Jul 2012
Posts: 34
Likes: 0
My New Alpine Install
Just installed this over the weekend.
Alpine MRP-M500 Amplifier (500 watts RMS @ 2-ohms)
Alpine SWS-12D4 (12 inch dual 4-ohm voice coils)
Just fine tuning everything to my liking.
It definitely plays louder and cleaner than the Infinity Basslink I had before.
The only problem I have now is that the Subwoofer box and amp are sliding around in my trunk because of the trunk tray that I have. How can I secure these so that they don`t move around? Thanks.
Alpine MRP-M500 Amplifier (500 watts RMS @ 2-ohms)
Alpine SWS-12D4 (12 inch dual 4-ohm voice coils)
Just fine tuning everything to my liking.
It definitely plays louder and cleaner than the Infinity Basslink I had before.
The only problem I have now is that the Subwoofer box and amp are sliding around in my trunk because of the trunk tray that I have. How can I secure these so that they don`t move around? Thanks.
Advanced
Joined: Feb 2012
Posts: 83
Likes: 11
From: Santo Domingo, Dominican Republic
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Instructor
Joined: Jun 2013
Posts: 164
Likes: 44
From: Mooresville/Charlotte, NC
Heres mine... JL 12W7v3 powered by a JL HD750/1... need to take better pics they're are from the day i got it put in
Bass knob
Old setup from my MDX.. 2 10w6v2's... loved that box.. sorry for the terrible iphone4 picture
Bass knob
Old setup from my MDX.. 2 10w6v2's... loved that box.. sorry for the terrible iphone4 picture
Instructor
Joined: Jun 2011
Posts: 105
Likes: 2
From: LA