Thinkin on doing a 3 18" setup SEALED. How would that sound?

[terra 5,000+ posts]

orly

rly...

 

[Parker G 10+ year member]

you can tune a ported box to sound good too ya know.

 

[iamamp3pimp 5,000+ posts]

mine has that kick you in the chest punch too...

maybe its just the AQ's

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[galacticmonkey 5,000+ posts]

I wouldnt doubt it. Ive never liked the sound of DD/AQ subs.

 

[Skip01 5,000+ posts]

I wouldnt doubt it. Ive never liked the sound of DD/AQ subs.

Wish I still had my 4 12 HDCs and 500.1s , I'd change that mind of urs.

But it may be the sub honestly like said ha, I never liked them in a low tuned box myself

 

[cx-7heaven 10+ year member]

I had 2 Ascendant Audio Havoc 18's sealed off 3kw, it was truly amazing. Those particular subs only need 4 cubes each sealed to really get nasty, so 12 total. 3 of them on 2500 watts would be truly awesome. A bit pricey though, you will proly spend around 1000 on the 3 brand new, there is at least 1 used in the classifieds right now though.

 

[galacticmonkey 5,000+ posts]

Wish I still had my 4 12 HDCs and 500.1s , I'd change that mind of urs.
But it may be the sub honestly like said ha, I never liked them in a low tuned box myself

Ive heard lots of loud DD setups. They all meter pretty well, but Ive never heard a single DD setup that had that solid umph that feels like its pressurizing your body before.

 

[WOT]

Cool, some opinions!!

Im definetely still "open' to porting them, but I dont have much room for port area in a wall. I think I would prefer to seal them. AFAIK they only make IXL's upto 15", unless they released something that isnt listed on there site

Im still waiting on a reply form them on whether or not Im gonna go ahead with it.

I like the inspiration of someone saying an 18 can still be tight sealed though.

So sealed is probably what Im looking for with my music preference though right?

 

[galacticmonkey 5,000+ posts]

How much space and power do you have?

 

[Parker G 10+ year member]

Cool, some opinions!!
Im definetely still "open' to porting them, but I dont have much room for port area in a wall. I think I would prefer to seal them. AFAIK they only make IXL's upto 15", unless they released something that isnt listed on there site

Im still waiting on a reply form them on whether or not Im gonna go ahead with it.

I like the inspiration of someone saying an 18 can still be tight sealed though.

So sealed is probably what Im looking for with my music preference though right?

Sealed systems have several advantages, they are typically the smallest type of system you can build, easiest, have the least group delay (change of phase with respect to frequency), naturally protect the driver at lower frequencies, have a tame 2nd order roll-off characteristic, and they are the least temperamental when it comes it linear response. While all this sounds lovely, they also have one big shortcoming: They are the least efficient system, especially for low frequencies, so they can quite easily have the most non-linear distortion because the driver(s) has to rely exclusively on their own linear displacement to produce SPL for the entire spectrum. Compared to un-EQ’ed sealed systems, 4th order (vented) systems can have upwards of 6 to 9dB more SPL at tuning (usually below 40Hz) which translates in a 2 to 3 fold advantage. At higher frequencies, sealed sysetms and ported systems with the same driver and power produce similar SPL levels.

Sealed systems are often considered ideal if your purpose is “SQ” (Sound quality). This is probably the wrong reason to do a sealed system. Sealed systems should be used if space is a consideration or if the driver you’re using has a high Qts (above 0.5) then it probably should only be used in a sealed box to prevent unwanted ringing at Fb. Low Qts drivers don’t often benefit from being used in a sealed box and can quite literally be anemic in the low end response because of the high electromotive damping factor. EQ boosts are necessary to bring up the low end response if the driver’s Qts is too low. Higher Qts drivers tend to balance nicely in a sealed box and can have great low end response without Eq in the right volume. If the drivers Qts is high, larger volumes are needed otherwise ringing could occur, while low Qts drivers generally need a only small sealed box, but will still require EQ. If your goal is a very small sealed box, you’ll likely still need to use a low Qts driver and then EQ it.

4th Order Ported SystemsPorted, or rather 4th order vented systems, are commonly stereotyped to have poorer sound quality then that of sealed systems. While this is far more myth than fact, it is true, that improperly ported systems are can devastate the frequency response, and while the driver may be producing very low distortion, the response curve can sound atrocious and affect the sound quality of the system. The fact is, ported systems are much more efficient than sealed systems and therefore can product more SPL with lower distortion especially in the lower frequencies. For full range bass, blind A/B tests suggest that ported systems (especially when passive radiators are used) are preferred to sealed systems and this is attributed to their dynamic headroom or rather ability to play louder with less distortion.

Not all mfr recommend enclosure specs are idea either. If you’re very serious about making your 4th order system linear, than proper modeling using accurate TS parameters will give you very good insight as to what you can expect from your system. We recommend that the ported box be made slightly larger than what you model unless the program accounts for non-linear thermal compression where BL lowers as a function of heat. Also remember that increasing the volume decreases tuning, so adjust for that if you need to by changing the port dimensions.

Port tuning is a function of the driver, the port dimensions and the box volume. Yes, we said driver! However the driver’s affect on the tuning is very slight and we can omit that safely and simply make tuning a function of purely the box and port dimensions. Longer ports and/or larger boxes decrease tuning, while the smaller boxes or shorter ports increase tuning. It is important that the port area is suffice the driver. High BL drivers with large cones and lots of power behind them needs lots of port area, while a lesser driver may not need quite as much. It can be difficult to fit ports in certain types of boxes with certain types of drivers at least if you’re attempting to maintain linear response so again, modeling software is critical. Multiple ports work the same as one port. It is simply a construction convenience; however, it is ideal to have the least amount of friction in a port so heavy flaring on both ends is ideal as well as using one port over more than one port to decrease the surface area of the port walls.

In a 4th order vented system, the driver does indeed roll off at 24dB per octave after tuning as the driver and port resonator’s energy cancel each other out as the system unloads. At tuning the port produces nearly all of the SPL of the system for a very short frequency range. As frequencies go higher, the active driver does more and more of the job. Because the system is vented, there is no air pressure to protect the driver as the port unloads. Also, unlike sealed systems, the driver’s excursion exponentially increases below tuning, so unless the driver is filtered, then mechanical damage can quite easily occur with surprisingly little power. This filter is often called a subsonic filter and should be set at or just below the tuning frequency so that the active drivers physically excursion reaches two maximum peaks, one before and one just after tuning. At tuning (Fc) the active driver will nearly stand still and the port does all the work. This is also the point where the system pulls the most current and power so if the amplifier is not up to the job, clipping is usually heard at Fc first.

 

[WOT]

How much space and power do you have?

Ive got about 16 cubes max, and 3000rms @ 2ohm for now

Ill have to read parkers HUGE post in a second, thanks for typing that. Looks like a good read

 

[G.W.Kush]

Wall of text.

You should quote your references.

Also, to the op, how do you have the subs wired? What are the coil configs of the woofers? I'm just questioning if that amp is not pushing them all that well. I would imagine it still getting low or being kicky or whatever you want out of them, could always try lowering the tuning.

3 18's isnt a bad option. It's all user preference in the end though.

 

[Parker G 10+ year member]

Ive got about 16 cubes max, and 3000rms @ 2ohm for now
Ill have to read parkers HUGE post in a second, thanks for typing that. Looks like a good read

I copy and pasted that. No way in hell i would type all that for you lol

 

[galacticmonkey 5,000+ posts]

Do 16 Image Dynamics 10s sealed. Would be perfect for the power and space. I bet it sound sound amazing for being a loud system too.

http://www.woofersetc.com/p7169/CTX104--Image-Dynamics-10"-CTX-4-ohm-Subwoofer.htm

 

[cx-7heaven 10+ year member]

Actually, on thinking about it, I would wait until FI comes out with the 22, then get a pair of those, that should be nasty