I just finished building two sealed 15 inchers for my living room, and I love the sound so much I'm thinking about doing sealed again for my basement subs I'm going to build instead of ported. I currently have a huge Full Marty style sub (48x24x24) with an 18 inch driver and it's very good, but I'm not as impressed with it as I am with my two sealed 15 inchers (that have cheaper drivers in them to boot)
You may have seen my thread a few weeks ago about asking help with the port length for my basement subs, to be honest I was left with more questions than when I came in.
So I have an Eminence NSW4018-8 pro-audio driver, and a LaVoce SAF184.3 driver. Both really want to be in vented enclosures.
Eminence: Qts 0.36 EBP 92
LaVoce: Qts 0.32 EBP 88.
If I build a box the same size as I was planning (32 inches x 24 x 24) I get critically damped QTC 0.5 in WinISD. I could make them a bit smaller to get the QTC up slightly if I wanted to.
My question for you guys, can I make this work by brute forcing it with power? I have a Lab Gruppen clone FP14000 plugged into 220v. It has like 3000w or something stupid at 8 ohms and I can run it in bridge mode into less ohms if I need to. Edit- I also have a DDRC24 with Dirac for EQ.
This system is 98% used for music, and death metal is easily 70% of what I listen to. It demands extremely fast extremely tight bass. Once in a while I'll watch a movie while on the treadmill, or I'll listen to some electronic music with super deep bass, but it's not the norm. I'd like for those low notes to hit as hard as they can, considering it will be two 18 inch subs. If you don't feel the low notes with two 18 inch subs something is very wrong!
Attached WinISD, my living room setup (I'll make a post about the project soon enough) and current basement setup with the Full Marty (excuse the bad paint job, new ones will match the speakers)
Speakers in the basement are Crites model B CornScalas (Klipsch Cornwalls with the La Scala squawker, woofer crosses over at 500hz instead of 700hz)
Speakers in living room are Magnepan MMGs.
thanks!
Living room subs 15 inch Dayton MX 15-22
Basement sub, it's the Eminence NSW4018, TV is 85 inches for scale
You may have seen my thread a few weeks ago about asking help with the port length for my basement subs, to be honest I was left with more questions than when I came in.
So I have an Eminence NSW4018-8 pro-audio driver, and a LaVoce SAF184.3 driver. Both really want to be in vented enclosures.
Eminence: Qts 0.36 EBP 92
LaVoce: Qts 0.32 EBP 88.
If I build a box the same size as I was planning (32 inches x 24 x 24) I get critically damped QTC 0.5 in WinISD. I could make them a bit smaller to get the QTC up slightly if I wanted to.
My question for you guys, can I make this work by brute forcing it with power? I have a Lab Gruppen clone FP14000 plugged into 220v. It has like 3000w or something stupid at 8 ohms and I can run it in bridge mode into less ohms if I need to. Edit- I also have a DDRC24 with Dirac for EQ.
This system is 98% used for music, and death metal is easily 70% of what I listen to. It demands extremely fast extremely tight bass. Once in a while I'll watch a movie while on the treadmill, or I'll listen to some electronic music with super deep bass, but it's not the norm. I'd like for those low notes to hit as hard as they can, considering it will be two 18 inch subs. If you don't feel the low notes with two 18 inch subs something is very wrong!
Attached WinISD, my living room setup (I'll make a post about the project soon enough) and current basement setup with the Full Marty (excuse the bad paint job, new ones will match the speakers)
Speakers in the basement are Crites model B CornScalas (Klipsch Cornwalls with the La Scala squawker, woofer crosses over at 500hz instead of 700hz)
Speakers in living room are Magnepan MMGs.
thanks!
Living room subs 15 inch Dayton MX 15-22
Basement sub, it's the Eminence NSW4018, TV is 85 inches for scale
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As long as the box is not too small, you can usually employ a Linkwitz-Transform type EQ to extend the response another octave lower. Your plot shows F=50Hz and Q=0.5, and you could shoot for F=25Hz and Q=0.5 for some tight bass, or go for Fs=30 and Qts =0.7 for a more full sounding low end. The room gain will help you out below 20Hz - no need to go for ultra low corner frequencies. I think one octave of extension requires four times more power at low frequencies, but in any case you seem to have plenty of power available from your amp!
I have done a similar thing with several sealed subs over the years.
I have done a similar thing with several sealed subs over the years.
@CharlieLaub That's encouraging! I have a MiniDSP DDRC24 with Dirac for EQ, I was planning on using that and playing around with different house curves (you get 4 presets on the minidsp remote).
I'm leaning towards sealed for sure at the moment
I'm leaning towards sealed for sure at the moment
What is not to like about a total Q close to 0.5, cannot get much better if if you like tight bass? When voicecoil heats up and Qes increases, fr goes down and Qts goes up and things get sloppy. Better run it cool, voicecoil Rdc increases 0.4%/C° and easely messes up big any artificial compensation.
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@gorgon53 how do I cool a driver inside a sealed enclosure filled with fiberglass? serious question
The reason I'm asking about 0.5 is because the curve in winisd has very little going on at low frequencies. I'm asking if brute power and EQ can make it work, so far Charlie says yes. I'm reading around, and other posts seem to agree with him.
The reason I'm asking about 0.5 is because the curve in winisd has very little going on at low frequencies. I'm asking if brute power and EQ can make it work, so far Charlie says yes. I'm reading around, and other posts seem to agree with him.
Box size, Xmax and voicecoil thermal conditions set the limit at what you can get at low f. Below fres the efficiance decreases sharply, more power, higher Q, endeffect heatmodulet speaker with questional qualities, if you find a. o .t., heat induced dynamic compression exiting, go for it, but If you like tight bass Qts should never be much higher than 0.6. When you make some artificial frequency respons lowering you need plenty of additiona power wich gets mostly converted into heat. The increase in temp will at 250 deg double rdc and Qes is far off. You can only compensate correctly for a known and stable Qes, not for a Qes wandering between 0.3 and the sky is the limit, in a unpredictable amount that is depending on what and how loud you play. The normal situation where, for example, Qes cold is 0.3 and hot wanders off to 0.4would be bad enough for me, but double and more, no, i would keep it cool unles you invent some cleve way to negiate that peski Rdc increase with neg. resistance somehow.
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@gorgon53 So it would be better to build a bigger empty box than a slightly smaller box full of fiberglass stuffing? Both are the same "size" on paper, but one has lots of empty air and the other has... well it has isolation made specifically to trap heat.
I don't listen at obscene volumes (it happens when my wife isn't home lol), and I only use the system while I workout in my basement so it's 2 hours max.
I don't listen at obscene volumes (it happens when my wife isn't home lol), and I only use the system while I workout in my basement so it's 2 hours max.
Run it in its normal state without any trickery and it will run the coolest.
Bigger box is always good, has also to be stuffed offcourse and need thicker panels, sturdier brazing to minimise case radiation wich is a prob getting bigger with the box
Bigger box is always good, has also to be stuffed offcourse and need thicker panels, sturdier brazing to minimise case radiation wich is a prob getting bigger with the box
Box adds a spring, you need a lossy spring just the rigth way, so, stuffing must be done to get Q adjusted. Stuffing also lowers f3 a bit.
Bit late here, but maybe tommorrow i can give you something exact so you can compare differences of closed box tuning
Bit late here, but maybe tommorrow i can give you something exact so you can compare differences of closed box tuning
For better bass just try 0.22 or 0.47 ohms 20watt in line with the woofer.
Can reduce distortion and sound better if it's overdamped .
I have put on my marble subwoofer 0.15 ohms in line and this made it sound better
https://www.diyaudio.com/community/...-concrete-loudspeaker-box.406856/post-7547864
Can reduce distortion and sound better if it's overdamped .
I have put on my marble subwoofer 0.15 ohms in line and this made it sound better
https://www.diyaudio.com/community/...-concrete-loudspeaker-box.406856/post-7547864
(my 2 cents)
Your first "eminence closed" frequency response really doesn't look too good for the start of a sub.
Before adding 'forced EQ power', I would improve the preliminary speaker/box response.
As mentioned, a larger box is probably the best 'first step'.
Tuning @ something like 25Hz is probably a good second step.
Adding series resistance (although minimal) would probably be a 'last step'. (it functions on impedance peaks)
For tight power, try to maintain your amplifiers Damping Factor.
Your first "eminence closed" frequency response really doesn't look too good for the start of a sub.
Before adding 'forced EQ power', I would improve the preliminary speaker/box response.
As mentioned, a larger box is probably the best 'first step'.
Tuning @ something like 25Hz is probably a good second step.
Adding series resistance (although minimal) would probably be a 'last step'. (it functions on impedance peaks)
For tight power, try to maintain your amplifiers Damping Factor.
If you have an overdamped system adjusting this can be done by
1 making the box smaller
2 closed sub converting to bass reflex
3 adding series resistance
If the system is less overdamped bass reproduction (impulse response) becomes better
Maybe point
4 putting closed box near room boundaries
Would help also
1 making the box smaller
2 closed sub converting to bass reflex
3 adding series resistance
If the system is less overdamped bass reproduction (impulse response) becomes better
Maybe point
4 putting closed box near room boundaries
Would help also
Actually the transfer function
looks fine. Typical sealed alignment
no strange responses you can see if box is too small.
Usually the problem is people want tiny little boxes.
You like building big boxes. Welcome to real bass.
You just bump the bass EQ knob and cone control
is good No port farting of high tune nonsense.
Sensitivity is high you wont need to throw much
power at it. Just turn the bass knob to your liking
depending on source material. And its that simple.
Could have fun shove it in that corner in your basement
pointing straight up and will be even deeper.
with corner loading.
Your on a good journey, my first sealed subs was a pair
of 12". Once you get use to the nice snap. Its hard
to care about a few dB of chuffy port. When a clean roll off
with a basic bass boost shelf filters can add way more than a purt.
The real trick is nice big boxes matching the speakers compliance.
So just quick sim to find volume for .5 to .7 Qtc and boop that is it, all done.
looks fine. Typical sealed alignment
no strange responses you can see if box is too small.
Usually the problem is people want tiny little boxes.
You like building big boxes. Welcome to real bass.
You just bump the bass EQ knob and cone control
is good No port farting of high tune nonsense.
Sensitivity is high you wont need to throw much
power at it. Just turn the bass knob to your liking
depending on source material. And its that simple.
Could have fun shove it in that corner in your basement
pointing straight up and will be even deeper.
with corner loading.
Your on a good journey, my first sealed subs was a pair
of 12". Once you get use to the nice snap. Its hard
to care about a few dB of chuffy port. When a clean roll off
with a basic bass boost shelf filters can add way more than a purt.
The real trick is nice big boxes matching the speakers compliance.
So just quick sim to find volume for .5 to .7 Qtc and boop that is it, all done.
Built six Qts 0.5 18" subs and never looked back. (Four 21" in the pipeline...).
The sound of sealed has spoiled me for ever, to the extent that every other type of enclosure has become obsolete to my ears and fatally flawed - I feel it has to do with energy storage. Oddy, I also noticed a profound subjective difference between cuboid and cylindrical/12-sided enclosures.
Simply accept the need for plenty of power and EQ - they are both dirt cheap these days!
The sound of sealed has spoiled me for ever, to the extent that every other type of enclosure has become obsolete to my ears and fatally flawed - I feel it has to do with energy storage. Oddy, I also noticed a profound subjective difference between cuboid and cylindrical/12-sided enclosures.
Simply accept the need for plenty of power and EQ - they are both dirt cheap these days!
I think you love them just because they are sealed. Never give up love...
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A couple of thoughts. As was mentioned a series resistor acts like increasing the Q. In effect it flattens out the response at the expense of sensitivity. Another easy and inexpensive trick to try is a series cap. In some cases it seems to produce what amounts to a ported EBS response. What I don't know is whether you get the same ported sound in exchange as I haven't tried it yet. As an example simulated in HR this is the Eminence 18 with 1.5 ohm in series with 800uF. Red line is with RC grey is just the driver. 300L sealed.
P.S. don't forget room gain.
P.S. don't forget room gain.
@mashaffer a few people have mentioned this, my question, is this different than just EQ? If I run Dirac and I tell it to flatten out the bass and add more low end, will I achieve the same thing? Or are these things different/complementary