Dual Polk Audio Sr124 enclosure recomendation?

moreyb22 · November 2007

I have two SR124 subs and I had them in a 1.0 cu.ft. enclosure and they were loud even setting off my first car alarm but it wasn't enough. I want them to hit lower and harder. I am guessing I should go with a low tuned ported box. I checked the Sub box info section and it gives you basic dimensions but it doesn't tell me the tuning frequency, if it is a slot port or square, where to put the port. So if anyone has any suggestion that would be good.

System:
Pioneer 5900iB cd player w/ iPod hookup
Jl Audio XR650 components
Jl Audio XR650 rear coaxials
JBL GTO 75.4 at 100rms x 4
2 Polk Sr124 subs
Rockford Fosgate t1500bd

MacLeod · November 2007

A ported box wont hit as low as a sealed box, and it wont hit any harder. It may be louder in the upper end but thats it.

If you want more impact than a pair of powerhouse 12's and 1500 watts can deliver, youre going to have to move up to an SPL sub, bu another SR12 or get a 2000 watt amp.

Bruizer · November 2007

Is that 1.0cft before displacement? If thats the case that enclosure is a little small. The minimum for a single sub is suppose to be .88cft after displacement. Personally, I'd stick with sealed and go with something between 1.34cft-1.20cft before displacement. The box I'm putting my 2 SR124-DVC subs in is about 2.4cft total so each sub will have about 1.2cft in its own chamber which after displacement would be 1.06cft. The box is 14x28x14 but of course I had to take into account thickness of the wood (.75") and subtracted that.

rz22g · December 2007

moreyb22 wrote: »

I have two SR124 subs and I had them in a 1.0 cu.ft. enclosure and they were loud even setting off my first car alarm but it wasn't enough. I want them to hit lower and harder. I am guessing I should go with a low tuned ported box. I checked the Sub box info section and it gives you basic dimensions but it doesn't tell me the tuning frequency, if it is a slot port or square, where to put the port. So if anyone has any suggestion that would be good.

System:
Pioneer 5900iB cd player w/ iPod hookup
Jl Audio XR650 components
Jl Audio XR650 rear coaxials
JBL GTO 75.4 at 100rms x 4
2 Polk Sr124 subs
Rockford Fosgate t1500bd

I built a 3/4" MDF, Dual Sealed for my SR124 DVC's. I went with the 1.2 final volume for each side, (1.4 before displacement). Each is being pushed by a Polk 500 monoblock at 2 ohm each. I was not at all happy with how hard they hit. Maybe more power would have made a difference. I ended up having to go smaller on my enclosure and ended up with 1.06 final in order to get them to hit nearly as hard as my MM12 subs at 2 ohm on a single 500.1.

GLN305 · December 2007

To get what you want, you were correct in saying that you need a low tuned ported enclosure. I would say tune to 25-30 Hz and go with a volume of 2 cubid feet or larger. I'll throw the specs into Win ISD and see what I come up with for ya.

EDIT:

Enclosure info for ya:

2 cubic feet NET volume
4" vent 20" long (tunes to 27Hz)

or

2.5 cubic feet NET volume
5" vent 20" long (tunes to 30HZ)

Those are just two random box volumes, but they model up great. You are going to see increased low frequency output as well as more across the entire sub range. Keep in mind a subsonic filter is a must just set it to 20-25 Hz or so and you'll be good. I would personally go with the larger of the two.

moreyb22 · December 2007

I found a site that is building me a custom enclosure for them. I told what I wanted and gave them the specs and had the guy play around with it in the software. He came up with a 3.4 cu.ft. dual enclosure tuned to 30hz. I am still waiting for its completion but he is going to send me some pics as soon as its done so I will keep you posted.

Kinetic · December 2007

moreyb22 wrote: »

I found a site that is building me a custom enclosure for them. I told what I wanted and gave them the specs and had the guy play around with it in the software. He came up with a 3.4 cu.ft. dual enclosure tuned to 30hz. I am still waiting for its completion but he is going to send me some pics as soon as its done so I will keep you posted.

please keep us informed

im actually thinking in buy the second Sub, but im not sure, i will have to listen the one i recently buy first.

moreyb22 · December 2007

The guy building my box sent me a pic of the unfinished box so I could make sure I liked it. It shipped out tuesday and I am expecting friday. So I am pretty excited. I hope to have it in sometime during my christmas break.

Here is the pic:
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black magic · December 2007

Hope you enjoy it!

btw, I think you're picture's link is broken, I don't see anything

moreyb22 · January 2008

I have to say Mac and everyone you were right the ported was not any better. I decided to go back to my sealed box. The only problem is that before I blew both of my subs about a month or two in. I had them in a 1 cu.ft. box before displacement and someone had previously mentioned this might be to small. Could this be the reason for them blowing. I did noticed when I first got them that after a couple of hours of listening they would get really hot. Should I get a 1.2 cu.ft box because I noticed on the website it says a 1.2 give competition quality.

Kinetic · January 2008

moreyb22 wrote: »

I have to say Mac and everyone you were right the ported was not any better. I decided to go back to my sealed box. The only problem is that before I blew both of my subs about a month or two in. I had them in a 1 cu.ft. box before displacement and someone had previously mentioned this might be to small. Could this be the reason for them blowing. I did noticed when I first got them that after a couple of hours of listening they would get really hot. Should I get a 1.2 cu.ft box because I noticed on the website it says a 1.2 give competition quality.

check this:

http://www.polkaudio.com/downloads/whitepapers/SR_WhitePaper.pdf

On page 13 on the PDF (or 12 on the document)

the problem is that the website says one displacement, and then the white paper says another.

but its suppossed to be 1.3 or 1.4 for the best sound

for example i have the 1.4 Net, (1.56 without displacement)

And always remember to leave 2" or more of space between the rear end of the driver, and the backside of the enclosure for clearance, and to avoid over heating.

shawnberry45 · October 2008

i just put my sr124 sub in a ported box and it sounds way better than sealed. I guess it all depends on the car. Funny how everyones opinions of bass sounding good differs

eloplayspolo · October 2008

well... its a sound quality forum..... POLK is sound quality not SPL. ported is known to be more SPL. thats why when u read these forums just about everyone is gonna say go sealed.

pushkanak · August 2009

Hello,
I just purchased two SR124-DVC, and while I was thinking what kind of enclosure to use, this thread attracted my attention.

See, my main concern is SQ, but I'm willing to sacrifice some SQ for more SPL, only and only if the SPL gain is more than the loss in SQ. As you can see, I'm trying to find the optimal SQ&SPL combination.

So, I have seen many enclosure recommendations in this thread, but none seems to point to the best one for SQ. I see sealed recommendations totaling a range between 1 cu. ft. and 1.5 cu. ft. net of displacements, but no final conclusion was achieved regarding the best SQ enclosure internal volume. So this forces me to ask: what is finally the best internal volume net of displacement to use so as to achieve the best SQ setup?

Now, the optimality subject points me to the next question. Once the best SQ setup is defined, we must see if moving to a ported box actually adds total value: with this I mean, if it augments the total SQ&SPL value, maybe by sacrificing some SQ, but the SPL gain would be greater than the loss in SQ. So, the next question is: Is there any ported box setup such that the SPL gain more than offsets the loss in SQ? If so, which would it be?

Sorry it it's too large a post, but needed to do so since I really want to get the best from my new polks!

cadenceclipse · August 2009

spl gains don't offset sq losses, least not for me. what vehicle this going in? optimality speaking, over 1200wrms(at least, and 2400w of dynamic power{at least]) going into 2 12" SRs...how much more SPL u need? none if your serious about SQ. hell, all u really need is 1, specially with that amp(PA1200). i wouldn't even think about going ported...

pushkanak · August 2009

This system is going into a 2007 Jeep Liberty. I want sound quality, but it's not irrational to lose some SQ only if the gain in SPL is much more. I'm serious about SQ, but there could be times that I would want to explode some techno in open beach with friends, so it makes sense to change enclosure only if the gain in SPL offsets the lose in SQ.

cadenceclipse · August 2009

ok. yeah it would make sense if u were talkin 2 sony explodes or 1 SR running off a HU. but 2 SRs, talking at least 1200wrms, technos gonna b exploding any beach ur at. preference comes to play but...i think u may b happier with 1 SR, ported.. get a bomb box ****!(not refering to u, push, rhetorically speaking..get a bomb box ****!)
and if u do go dual ported SRs, pa1200 is more than enough. sealed, could def go w/ more..

pushkanak · August 2009

I'm not sure why you said I would be happier with 1 SR124-DVD in a ported box, and don't know what you meant by "box bomb ****", but thanks for your advices, though I still don't know what to conclude from them.

I still got doubts about what internal volume should I use for the sealed enclosure. The manual says 0.88 cu. ft. and 0.14 cu. ft. for displacement, giving a total of 1.02 cu. ft. But this thread has mentioned many different internal volume numbers, mostly greater than what the manual explains, saying that maybe more volume can reach better SQ levels. So I'm too confused: what is finally the optimal internal volume gross of woofer displacement to be used in a sealed enclosure with a Polk SR124-DVC?

cadenceclipse · August 2009

wellll u want sq hence same sub setup as sq champ macleod (1 sr12) but u want people in china 2 hear it (ported). didn't say box bomb, ****, said "bomb box" **** check it out think its perfect volume for SR also..

pushkanak · August 2009

I don't know what's that "bomb box ****", but really, I just got the two SR124-DVC here and I still don't know on what enclosure to put them into.

Please, someone, help me find the best internal volume gross of woofer displacement, for a sealed enclosure, such that the SQ is optimal.

Thanks.

Kinetic · August 2009

I have 1.25 cubic feet without the driver inside, its just for one driver..

you can do 2 separate enclosures, and then put them together..

Kinetic · August 2009

sounds hard in volume and low in frecuencies, I use to have it bigger enclosure, but this is the best one, and if you put a smaller one you can burn your sub..

check the white paper.. you have a minimum and a maximum

pushkanak · August 2009

Thanks Kinetic. Checking again its white paper, I figured out that the smaller the box the punchier the sound, while the larger the box the deeper the bass. This will be left then to ones personal preferences.

However, further ahead in the same page of the white paper, it says "If you are looking for the ultimate in loudness .... a ported enclosure may be the way to go." But it does not specify its required internal volume nor the port specs. Where can I find such official and optimal ported enclosure specs and comparisons in SQ vs. the sealed enclosure?

Kinetic · August 2009

the sealed its the way to go for this sub

pushkanak · August 2009

Thinking about this subject cautiously, I decided to better go sealed; this subs were optimized for a sealed environment and not for ported. I would then choose the middle of the recommended range for internal volume to strike a balance between "punchness" and deepness.

Thanks to all who helped me here.

pushkanak · August 2009

Kim wrote: »

If your goal is sound quality, then I would suggest installing each sub into a sealed enclosure volume that has a gross of 1.4 cubic feet. Driver displacement for this
sub is .14 cubic feet. The net volume needs to be at least 1.2 cubic feet.
This will result in a "QTC" of .707

A box volume of 1.0 cubic feet, minus driver displacement, is really too small for these subs. (.86 net)
It also restricts cone displacement "aka" excursion, and will produce a "harder" sounding bass. You also run the risk of damaging the voice coils when driving them hard due limiting the excursion of the smaller sealed enclosure volume.

Do I take into account the driver displacement simply by adding up 0.14 cu. ft. to the total enclosure volume? That's all? No internal additional manipulation needed nor anything special at all?

pushkanak · September 2009

^^^ No insights onto that?

Dual Polk Audio Sr124 enclosure recomendation?

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