(Poll) Next Upgrade: Door Panels or Sub Box?

[gckless 5,000+ posts]

Alright, so I'm hoping to get down to Heatwave in October, and looking to see what I should do this month. Budget is only allowing on or the other.

My front doors currently look like this:





My first option is to get them fiberglassed. They would get a lower half fiberglass treatment. Woofers would be flush mounted, covered and protected, and also in sealed chambers.

If I don't choose to get them redone I would just cut out some rings to cover the woofers and cover all that in grill cloth. Would make it look the best I could.

Or,

I could redo my substage. The ass end of my truck looks like this right now:



A pair of 15's with 18" passive radiators.

I would build this box instead:





Tuned at 28Hz, group delay is very low, should be a great sounding box.

So, which should I get done in September?

Click to read more...

 

[T3mpest 10+ year member]

Not seeing the advantage of the sub box change? You may get more output around 60hz firing the woofers that way, most vehicles have a sharp null when the woofers are up like that. Other than that, what's the difference between going to the slot port. You have adjustable radiators right? If so throw a bit of weight on them if you want a 28hz tune. If the box is too big add something inside it to take up some space.. Retuning a passive radiator setup is easy. Given that I'd do the doors, it's an eyesore for sure lol.

 

[Silverado SS 10+ year member]

Defiantly do the door panels, how do you like those exodus? I'm waiting on my 4ohmers

 

[murph 10+ year member]

I'd do the box. You will get louder than your passive setup.

 

[gckless 5,000+ posts]

Just so everyone knows, door panels are being sent off as soon as I get a shipping label. I'll be keeping the PRs.....for now.

Not seeing the advantage of the sub box change? You may get more output around 60hz firing the woofers that way, most vehicles have a sharp null when the woofers are up like that. Other than that, what's the difference between going to the slot port. You have adjustable radiators right? If so throw a bit of weight on them if you want a 28hz tune. If the box is too big add something inside it to take up some space.. Retuning a passive radiator setup is easy. Given that I'd do the doors, it's an eyesore for sure lol.

Original goal was to be louder, and also hopefully alleviate some pressure on my rear glass. But, found out that I'm reaching thermal limit on these subs, so I'm not getting a whole lot louder with them anyway. I'm just going to keep them and get it sounding as good as I can. Once the Levi gets back I can actually focus on my front stage, and I won't be as concerned with just getting the subs loud. And yeah, being able to adjust my tuning is awesome. Love it. I'm at 30Hz right now, I was at 27Hz before, but honestly didn't notice a huge difference between the two.

I haven't noticed the lull around 60Hz. Then again, I am crossed at 63Hz, so that might be a part of it lol.

Defiantly do the door panels, how do you like those exodus? I'm waiting on my 4ohmers

Well, my Levi died (and was sent back and is with Mr. Mantz right now), so they are only being pushed with a small MTX amp with about 30W a piece, so I can't really tell you. They're nothing special right now. I'm getting sealed chambers done on the door panels, so I should be able to smack the Anarchy's with about 175W or more once everything gets back //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I'll let you know then.

You bought into the pre-order? Mine are the 8 ohm versions, and I have a spare set. 8 ohm FTW bro!

I'd do the box. You will get louder than your passive setup.

I would get louder. Problem is, I found thermal limit with these subs, and it's about 1800W a piece with a 0dB tone. I'm not going to try to get as loud as possible, not with these subs. These are built to sound good //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Once I get the Leviathan back I won't be worried about being loud so much, I'll be tuning for dat SQ(L, if you will), yo!

So the plan is to sell these in another month or two if I'm still unhappy, get some Tantric HDD's, and build a regular ported box.

 

[T3mpest 10+ year member]

Why do you guys think you'll be louder going ported over passives? Your going to be losing box volume/effeciency and lose the ability to fine tune the tuning. Plus, ports are ALWAYS more lossy than a passive. With passives their is no airspeed inside the port do deal with and assuming the suspension is good, it will behave the same at high and low volumes. I don't see where that would be a gain, especially an audible one. I know of a few HT guys who tested this, where PR's are alot more common. There was NO SPL advantage either way, until the ports began to compress that is.

I guess in an SPL setup, you could aim the pressure with a port easier to the spot where the sensor is. Plus when pushing things to edge, the port will compress vs breaking your passives so that's cheaper. Running enough passives to not have to worry about that would be hard to fit on the same plane of the box too, again effecting where it's aimed. In that way, I can see where the port is "louder", but for a daily setup I just dont' see it. Low level port compression will be a limiter for daily just as at high level burping it's be safer to just have a port compress vs passives break.

 

[gckless 5,000+ posts]

Why do you guys think you'll be louder going ported over passives? Your going to be losing box volume/effeciency and lose the ability to fine tune the tuning. Plus, ports are ALWAYS more lossy than a passive. With passives their is no airspeed inside the port do deal with and assuming the suspension is good, it will behave the same at high and low volumes. I don't see where that would be a gain, especially an audible one. I know of a few HT guys who tested this, where PR's are alot more common. There was NO SPL advantage either way, until the ports began to compress that is.
I guess in an SPL setup, you could aim the pressure with a port easier to the spot where the sensor is. Plus when pushing things to edge, the port will compress vs breaking your passives so that's cheaper. Running enough passives to not have to worry about that would be hard to fit on the same plane of the box too, again effecting where it's aimed. In that way, I can see where the port is "louder", but for a daily setup I just dont' see it. Low level port compression will be a limiter for daily just as at high level burping it's be safer to just have a port compress vs passives break.

You have a link to those tests? I haven't tested it yet, but from what I have seen it's around a -3dB loss with passives because of the added resistance of the PR's. Yeah, it should be the same weight as the air in the port, but that's theoretical, and doesn't account for the stiffness of the suspension of the PRs, especially in a higher power build like this. But again, just kinda regurgitating what I've read on that one. PRs don't have to deal with the friction of the sidewalls of a port, and they also don't have any turbulence issues. There's so many variables, that it's hard to nail down exactly.

The ported box would be the same volume, so would be no efficiency loss going to that.

But I do agree with you, they are very linear, both in frequency and low vs. high volumes. I LOVE being able to change tuning, hell I love them overall for the most part. My subs getting hot is a different problem that I need to figure out first.

 

[T3mpest 10+ year member]

3db loss, who's test was that? Like I said I can't see that happening. There is no real resistantance to a passive. Maybe your are slightly different since they were built with stiffer suspensions, but most passives are built with the stiffness to more or less mimic the resistance of air give or take a bit. With some mass you can actually calculate the overall displacement of a port vs a passive. I don't know if I can find links, I'll check as I do this post lol. Generally though, especially for lower tunings, it ends up being some ridiculous value. What you doing when you tune a PR is adding weight to equal the volume of air that a regular port that size would need. So if you have X amount of surface area on your passives, whatever length a regular port of the same area would need to be is the weight you add, that's why they get so heavy, the port size is crazy.

To find the effective surface area of the port you'd take the SD and calculate backwards to get your port area. it would be 2 x (Sd/pi)^0.5 so you have a port of round port of 25 square, that's one big freaking aero!

Excursion of the passives does limit it, so that it won't behave like a port THAT big, which is good since few speakers could drive a port as large as that. To get your 27hz tune you'd need a port that is 133inches long, I assumed your box was around 12cubic feet I found another link that said 2 12's acted like 2 5" round ports when they had 30mm of excursion. So your 2 18's with 30mm should have more effective displacment than at pair of 8"probably even 10" rounds ports.

Anyway here's a fewlink guy says he gained 3db's using passives, my guess is an undersized port in the first place

Here is the link where each 12 was about a 5inch port

Passive Perfection

Link to SD formula

Audio Innovation - by Dan Marx www.danmarx.org

Passive Radiators for SPL?

TC sounds gives a 1-2db advantage to the ports, but they don't specify how big the port needs to be

FAQ | TC Sounds

All and all seems like it will be close, but you have so much versatility right now I can't see switching back. If you really want to have fun with those subs, use the PR's to do a 6th order, or even a 4th, IDK the T/S to see what works better. Your box can be alot smaller since you get rid of the labyrinth of ports that eats up most bandpass designs.

Anyway if you rmore into musical and loud, passives are pretty much the holy grail in a car. You can tune as low or high as you want, tweak things as you go and really dial it in. Your giving up a db or 2 MAYBE, depending if you could even get a box of the tuning you really want into your car, without having the port compress before the PR's would have run out of excursion. The passives I'm using right now are even front loaded, I can literally change tuning from sub 20hz up to 42hz in around 1 minute using no tools, don't have to remove anything from the box.

 

[murph 10+ year member]

3db loss, who's test was that? Like I said I can't see that happening. There is no real resistantance to a passive. Maybe your are slightly different since they were built with stiffer suspensions, but most passives are built with the stiffness to more or less mimic the resistance of air give or take a bit. With some mass you can actually calculate the overall displacement of a port vs a passive. I don't know if I can find links, I'll check as I do this post lol. Generally though, especially for lower tunings, it ends up being some ridiculous value. What you doing when you tune a PR is adding weight to equal the volume of air that a regular port that size would need. So if you have X amount of surface area on your passives, whatever length a regular port of the same area would need to be is the weight you add, that's why they get so heavy, the port size is crazy.
To find the effective surface area of the port you'd take the SD and calculate backwards to get your port area. it would be 2 x (Sd/pi)^0.5 so you have a port of round port of 25 square, that's one big freaking aero!

Excursion of the passives does limit it, so that it won't behave like a port THAT big, which is good since few speakers could drive a port as large as that. To get your 27hz tune you'd need a port that is 133inches long, I assumed your box was around 12cubic feet I found another link that said 2 12's acted like 2 5" round ports when they had 30mm of excursion. So your 2 18's with 30mm should have more effective displacment than at pair of 8"probably even 10" rounds ports.

Anyway here's a fewlink guy says he gained 3db's using passives, my guess is an undersized port in the first place

Here is the link where each 12 was about a 5inch port

Passive Perfection

Link to SD formula

Audio Innovation - by Dan Marx www.danmarx.org

Passive Radiators for SPL?

TC sounds gives a 1-2db advantage to the ports, but they don't specify how big the port needs to be

FAQ | TC Sounds

All and all seems like it will be close, but you have so much versatility right now I can't see switching back.

Overall they would be pretty close. But, in the peak frequency range for the ported enclosure, I would almost guarantee at least a 2db gain.

 

[T3mpest 10+ year member]

Overall they would be pretty close. But, in the peak frequency range for the ported enclosure, I would almost guarantee at lest a 2db gain.

With boxes of equal volume probably, but how often does that happen? A port for 2 18's is going to take up a few cubic feet of space by itself, on equal power that's going to have a role to play as well. Again, in SPL balls to wall type I agree with you, daily with low tuning, I doubt it. Especially in cases where the passives save you enough box room to add an extra subwoofer in there. Lots of variables in this, jeez, lol.

Also, is that new box sub up port up? If so I'd put money on that not being much of gain, without loading the port off something I can't see that putting the pressure up front like the rear firing passives do. Although, I'm sure that is hell on your tailgate, my 15's rear firing do OK, but my caddy seems to really not have much of a flex issue, it's more rattle proof than alot of other mostly metal cars I've had.

Also, just I looked for that test, and I found the link but it was dead. I do remember they said they were very close though.

 

[gckless 5,000+ posts]

3db loss, who's test was that? Like I said I can't see that happening. There is no real resistantance to a passive. Maybe your are slightly different since they were built with stiffer suspensions, but most passives are built with the stiffness to more or less mimic the resistance of air give or take a bit. With some mass you can actually calculate the overall displacement of a port vs a passive. I don't know if I can find links, I'll check as I do this post lol. Generally though, especially for lower tunings, it ends up being some ridiculous value. What you doing when you tune a PR is adding weight to equal the volume of air that a regular port that size would need. So if you have X amount of surface area on your passives, whatever length a regular port of the same area would need to be is the weight you add, that's why they get so heavy, the port size is crazy.
To find the effective surface area of the port you'd take the SD and calculate backwards to get your port area. it would be 2 x (Sd/pi)^0.5 so you have a port of round port of 25 square, that's one big freaking aero!

Excursion of the passives does limit it, so that it won't behave like a port THAT big, which is good since few speakers could drive a port as large as that. To get your 27hz tune you'd need a port that is 133inches long, I assumed your box was around 12cubic feet I found another link that said 2 12's acted like 2 5" round ports when they had 30mm of excursion. So your 2 18's with 30mm should have more effective displacment than at pair of 8"probably even 10" rounds ports.

Anyway here's a fewlink guy says he gained 3db's using passives, my guess is an undersized port in the first place

Here is the link where each 12 was about a 5inch port

Passive Perfection

Link to SD formula

Audio Innovation - by Dan Marx www.danmarx.org

Passive Radiators for SPL?

TC sounds gives a 1-2db advantage to the ports, but they don't specify how big the port needs to be

FAQ | TC Sounds

All and all seems like it will be close, but you have so much versatility right now I can't see switching back. If you really want to have fun with those subs, use the PR's to do a 6th order, or even a 4th, IDK the T/S to see what works better. Your box can be alot smaller since you get rid of the labyrinth of ports that eats up most bandpass designs.

Anyway if you rmore into musical and loud, passives are pretty much the holy grail in a car. You can tune as low or high as you want, tweak things as you go and really dial it in. Your giving up a db or 2 MAYBE, depending if you could even get a box of the tuning you really want into your car, without having the port compress before the PR's would have run out of excursion. The passives I'm using right now are even front loaded, I can literally change tuning from sub 20hz up to 42hz in around 1 minute using no tools, don't have to remove anything from the box.

Good info here. Don't get me wrong, I love my PR's. They're sounding great as is. My frustration right now is with my subs themselves.

But what I think you're forgetting about is that the suspension on PRs are progressive. The more you push them the more they push back. Regular ported doesn't have this issue, it should be constant. This is assuming we are below compression on both.

In the end, I don't really know man. I'm just testing and searching for results //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[T3mpest 10+ year member]

Good info here. Don't get me wrong, I love my PR's. They're sounding great as is. My frustration right now is with my subs themselves.
But what I think you're forgetting about is that the suspension on PRs are progressive. The more you push them the more they push back. Regular ported doesn't have this issue, it should be constant. This is assuming we are below compression on both.

In the end, I don't really know man. I'm just testing and searching for results //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Depends on the suspension. Generally PR's use very soft suspensions that aren't very progressive. I pushed mine by hand and they seem to be a pretty linear, very soft all things considered, especially vs my sub which you can press on pretty hard with no movement. Your PR's were built a bit sturdier for extra abuse, which probably effects your result some. That may have been a mistake, depending how you look at it. Regardless, that's also why your supposed to have enough cone area in PR's to never push them that hard. I'd bet with 2 18's your not at suspension limits at tuning.

There is no "compression" on a passive radiator, at least beyond the suspension's linearity. Again, that's why you generally use a very soft suspension and have more cone area than needed. Ports however, have compression as soon as air starts moving so really it's a similar mechanism in both. One is limited by friction and another by the suspension. As in the one link I posted, the 5" ports would begin to compress heavily around the same time the suspension of a 12 would run out of throw, different mechanism, similar effect.

If your subs are thermally limited in output, I'd start there. Is there any specific range that isn't loud enough for that gives you issues, or it it just all and all not loud enough?

 

[gckless 5,000+ posts]

Depends on the suspension. Generally PR's use very soft suspensions that aren't very progressive. I pushed mine by hand and they seem to be a pretty linear, very soft all things considered, especially vs my sub which you can press on pretty hard with no movement. Your PR's were built a bit sturdier for extra abuse, which probably effects your result some. That may have been a mistake, depending how you look at it. Regardless, that's also why your supposed to have enough cone area in PR's to never push them that hard. I'd bet with 2 18's your not at suspension limits at tuning.
There is no "compression" on a passive radiator, at least beyond the suspension's linearity. Again, that's why you generally use a very soft suspension and have more cone area than needed. Ports however, have compression as soon as air starts moving so really it's a similar mechanism in both. One is limited by friction and another by the suspension. As in the one link I posted, the 5" ports would begin to compress heavily around the same time the suspension of a 12 would run out of throw, different mechanism, similar effect.

If your subs are thermally limited in output, I'd start there. Is there any specific range that isn't loud enough for that gives you issues, or it it just all and all not loud enough?

The only reason I'm talking about getting louder is because demos, but more because I know there's plenty of suspension left on these. The box itself is pretty **** flat if I tune 30Hz or below, though my vehicle does add a hump centered around the mid to upper 40's. definitely cannot say it's one frequency, it's just overall. Honestly once I get my Levi back and start tuning my front stage I'm pretty sure it's gonna be more than enough.

Until I get used to it. Lol.

 

[T3mpest 10+ year member]

More suspension left on the subs or passives? I'd realy think hard about doing a 6th order. Since your crossed over at 60hz your really only looking at 1-1.5 octaves of response total and 6th orders will do that very well and pretty much up your output over the entire range. I'll give you extra output over most of your bandpass and extra impedence peaks are defintely going to help you from overdriving the woofers thermally.

 

[gckless 5,000+ posts]

More suspension left on the subs or passives? I'd realy think hard about doing a 6th order. Since your crossed over at 60hz your really only looking at 1-1.5 octaves of response total and 6th orders will do that very well and pretty much up your output over the entire range. I'll give you extra output over most of your bandpass and extra impedence peaks are defintely going to help you from overdriving the woofers thermally.

More suspension on both. Powered drivers are moving about 1.5" p-p around 35Hz where they move the most, and PR's are moving less than that at tuning (30Hz right now). But see, I don't know if what I am seeing is normal. The motors are getting warm and sometimes hot if I go above this power, but I don't know exactly how warm is normal. This is my first time with this sort of power. I know the motors are the heatsinks for the coils and all that, but not being able to touch inside the pole vent for more than 5 seconds scares me. I've smelled something before, but not sure if it's coil or my amp. Haven't smelled coil in a while, but I don't think it's that. My amp does smell a little funny, and I think it's that, but not sure right now. So I think I'm just gonna give them a few more hours to break in, and then slowly start turning up and see where I can get to.

I don't think I have the space for a 6th unfortunately. The regular ported box I had designed barely fits, and is taller than I would like in there. Although, with the PR's, I may have the room. But I definitely need to figure out the powered subs power issue before I do that, as they will be completely sealed. That's a bit unsettling to me.