SR124-DVC Enclosure

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Comments

  • rz22grz22g Posts: 70
    edited October 2007
    Your volume would be 1.14 if you reversed. I am mounting mine back normal because I can hear a distinct difference in sound quality. I tried the phase both ways and finally figured out its just mechanical noise from the sub that I guess is muted out when mounted normal.

    Its a shame because I had planned on going reverse mount. They wasted their time making this sub look so good... unless you use a plexiglas enclosure.
  • rz22grz22g Posts: 70
    edited October 2007
    What am I missing here? I was running two polk MOMO MM12's on one C500.1 at 2 ohm in enclosure of recommended volume. Now two SR124 DVC, each on its own C500.1 at 2 ohm and enclosure is recommended volume.

    Im not going to push these new subs because Im still in the break in period but I can already tell a distinct difference between the two setups. Listening at my normal listening level, the new setup is not delivery nearly same level of bass or hit as compared to the older. Amp gains and frequency are the same as before. Will these supposedly get better after break in? I certainly hope so.
  • 1996blackmax1996blackmax Posts: 2,436
    edited October 2007
    The SR's performance will get better after the break in period. The suspension has to loosen up and reach its happy place. I remember when I first bought my 12" Alpine Type-X. That thing already has a stiff suspension in its happy place, imagine how it was when it was new. After a while though that thing sounded very nice. No sub I've had has hit the really low stuff like that sub.
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  • rz22grz22g Posts: 70
    edited October 2007
    Its going to have to be a major improvement. I had my momo 12's sold but called it off until after I break these things in.

    Also did anyone ever find an answer to the two conflicting enclosure volumes for the SR124 DVC's?
    The manual says .88 (1.02 with displacement) and the site shows an enclosure of 1.20, which I assume is with displacement because the box dimensions they show is 1.34.
  • Greg PetersGreg Peters Posts: 608
    edited October 2007
    rz22g wrote: »
    Amp gains and frequency are the same as before. Will these supposedly get better after break in? I certainly hope so.

    I'd go through the gain setting procedure again with the new subs- the point which distortion sets in with the Momos may be different with the SRs.

  • rz22grz22g Posts: 70
    edited October 2007
    I'd go through the gain setting procedure again with the new subs- the point which distortion sets in with the Momos may be different with the SRs.

    Good call Greg. Im assuming I need to wait till after break in since that would require me to push the subs.

    How do you know your correctly breaking in your subs? What if Im taking it to easy on them?


    ANY POLK REPS OR TECHS WATCHING!!! Your manual for the SR124 states .88 volume for this sub and the site shows a 1.20 enclosure for this sub.... which is it?
  • rz22grz22g Posts: 70
    edited October 2007
    Someone please look at the instructions for the SR124 DVC and tell me Im doing something wrong. http://www.polkaudio.com/downloads/manuals/car/SRSubwoofersManual.pdf

    Page5, wired in 2ohm parallel (factory setting)... I have each one wired this way and on its own amp. Enclosure is dual sealed, 1.20 each including displacement and sealed very well. Im no audio expert but have had quite a few systems and I can tell these are not going to improve to the level Im expecting even after break in.


    Ok I have to move this break in into high gear. My in car time per day is an hour at best. 7 hours per week puts me 3 months before these things are broken in. What exactly do I need to play to break these in? Is there an MP3 available with the appropriate frequency that I could let play in the car through the day? I would have it hooked to a seperate power source of course. Can I remove the subs from the enclosure during this time so I dont have to worry about bass bothering everyone?
  • Greg PetersGreg Peters Posts: 608
    edited October 2007
    rz22g wrote: »
    How do you know your correctly breaking in your subs? What if Im taking it to easy on them?

    If you're not running them flat-out, you're probably OK.

    If you play a variety of music (some of which may be bass-heavy) through them at reasonable volume levels, the sub's suspension, surround and motor assembly will be well on their way to softening up in a matter of minutes, and after a week or two of usage, playing at higher volumes won't be a problem, won't subject a suspension fresh out of the box to undue stresses which could cause damage.
    rz22g wrote: »
    ANY POLK REPS OR TECHS WATCHING!!! Your manual for the SR124 states .88 volume for this sub and the site shows a 1.20 enclosure for this sub.... which is it?

    I'm not a tech, but it's been gone over on the site before.

    .88 cubic feet would be the minimum recommended airspace for internal enclosure volume. Factor in the displacement of the woofer (.14) and you'll be looking at a total enclosure volume of 1.02 cubic feet to meet that recommended enclosure volume.

    Car Audio and Electronics magazine reviewed the SR124 DVC, and in conversations with "Polk" Paul at head office, 1.25 was suggested to be the best internal volume for a sound quality application, while the magazine felt 1.5 cubic feet might have been even better.


    Polk recommends a range of enclosure volumes...for a higher resonant frequency and "punchier" response (along with highest power handling capability), you'd go with an enclosure closer to the 1.02 total volume. For maximizing low-end extension, you'd go with a volume on the larger end of the spectrum. Ideally, you tailor the response of the subs by placing them in an enclosure designed to bring out the traits most important to you in your application.



    If you want an idea of what enclosure volume does to the response of the sub, try to download some enclosure design software- you can "model" various sized enclosures and see the projected responses in graph form, without having to build enclosures of various sizes to see the fruits of the different volumes.

    If you have the desire to see firsthand how your subs respond in the smaller enclosure, you could take your dual enclosure and add an object that displaces .18 cubic feet to each side to reduce the airspace each sub "sees" to that of the minimum recommended. I'd suspect doing so pushes the resonant frequency upwards, gives you a peak in frequencies approaching your LPF setting, and reduces output in the lowest octave the subs can reproduce with the larger enclosure.

  • MacLeodMacLeod Posts: 14,365
    edited October 2007
    For a sealed box, the SR124 needs a 1.20 ft3 interior volume.
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  • Greg PetersGreg Peters Posts: 608
    edited October 2007
    rz22g wrote: »
    Someone please look at the instructions for the SR124 DVC and tell me Im doing something wrong. http://www.polkaudio.com/downloads/manuals/car/SRSubwoofersManual.pdf

    Page5, wired in 2ohm parallel (factory setting)... I have each one wired this way and on its own amp. Enclosure is dual sealed, 1.20 each including displacement and sealed very well. Im no audio expert but have had quite a few systems and I can tell these are not going to improve to the level Im expecting even after break in.

    While I'm not too familiar with your sub amps (I held one in my hands briefly, if that counts for anything :)), I suspect they're rated for around 600 watts RMS at 2 ohms on their birth sheets? You stated you were using the same gain settings as with your previous subs?

    http://www.resnet.trinity.edu/areynol1/gain.htm

    It may be worth going through the setup process again from scratch with your SRs connected.



    It may help to explain "the level I'm expecting" some, and also may help for troubleshooting purposes to describe the rest of your equipment, the vehicle, the direction your enclosure is aimed, as well as LPF settings from your amps and head unit (if applicable).

  • Installer4lifeInstaller4life Posts: 256
    edited October 2007
    rz22g wrote: »
    Its going to have to be a major improvement. I had my momo 12's sold but called it off until after I break these things in.

    Also did anyone ever find an answer to the two conflicting enclosure volumes for the SR124 DVC's?
    The manual says .88 (1.02 with displacement) and the site shows an enclosure of 1.20, which I assume is with displacement because the box dimensions they show is 1.34.

    In a nut shell all you have done is doubled your power. You went from two
    12" woofers with one amp to two 12" woofers with two amps. The most you can expect is a 3db increase in loudness. That is not that much. Second, the box you chose for these woofers is sound quality box. The subs will play louder in a different box. What you should notice is better sound coming from your subwoofers once they are broken in. You may not notice the difference in loudness. What type of car is your system in? As the enclosure gets larger to a certain point the subs ability to play lower is made easier. The power handling may go down but you are under powered anyway. I have used the subs in a 2 cubic foot enclosure per sub with a Alpine PDX1000 on them in a Chevy Equinox with very good results. It wasn't exactly what I wanted but the customer, who was much younger than I, was very happy. WE designed the box using box building software. We were considering going larger but the gain to size wasn't enough. They will work in a ported box if you choose and this will give you more output.
  • rz22grz22g Posts: 70
    edited October 2007
    Thanks for all the input everyone. Im definintely more into a hard hit rather than the lower bass so Im probably going to go with a smaller enclosure.

    As for the breaking in part, can I play something through them while they are out of the enclosure and break them in that way? I want to take them out of the enclosure so I canleave them hooked up overnight and not bother folks.
  • Greg PetersGreg Peters Posts: 608
    edited October 2007
    rz22g wrote: »
    As for the breaking in part, can I play something through them while they are out of the enclosure and break them in that way? I want to take them out of the enclosure so I canleave them hooked up overnight and not bother folks.

    Just normal usage (read as: no testing excursion limits @ 20hz) will do that, without all the fuss- not worth the trouble. When you read about a lab or reviewer breaking subs in free-air overnight with a "X" hz tone, they're trying to compare the tested T/S parameters against those published by the manufacturer for accuracy. If you won't be performing those tests, just play the subs until they're loosened up before unleashing the volume knob to max potential ;).

  • rz22grz22g Posts: 70
    edited October 2007
    It may be worth going through the setup process again from scratch with your SRs connected.

    Well at first I agreed with you on this but after thinking about it if you set your amp for its max safe output that would be independant of what sub you had connected. If the amps target output voltage is 31.6 for example, that would not change simply because you change subs.

    I went through the DMM process..
    Set all HU EQ levels flat
    Set all amp gains down
    Disabled any boost and LPF/HPF
    Disconnected speakers
    Set HU to 3/4 volume
    Put DMM at terminal on amp
    Played a 50hz tone
    Slowly turned up the gain until I reached 31.6

    I did this for each of the 500 amps. I did the same for my 4 channel but target voltage per channel was 17.3 if I recall correctly.


    Now what I don't understand is if you disable all these EQ's, filters, etc.. and get your target voltage that is of course going to change as soon as you enable these again and in my case this went up, especially when I enabled the 500's Pre EQ Switch. The reading went from target to 50's.

    Is that correct? Why wouldnt you set the voltage to target at your listening settings?
  • rz22grz22g Posts: 70
    edited October 2007
    I dropped the 124's into my old enclosure, which is probably about 1.02 per side not including displacement. I tried them reverse and normal mount and it sounds so much better than the 1.20 enclosure. I do not like the 1.20 volume at all. Perhaps with more power the outcome would be different.
  • RemyngtonRemyngton Posts: 18
    edited October 2007
    rz22g wrote: »
    I dropped the 124's into my old enclosure, which is probably about 1.02 per side not including displacement. I tried them reverse and normal mount and it sounds so much better than the 1.20 enclosure. I do not like the 1.20 volume at all. Perhaps with more power the outcome would be different.

    Thanks for the input on that, it's encouraging for my box size. Did you notice increase in output and a higher frequency response with the smaller enclosure? Did the sound quality decrease when you reversed the sub?
  • Greg PetersGreg Peters Posts: 608
    edited October 2007
    rz22g wrote: »
    Well at first I agreed with you on this but after thinking about it if you set your amp for its max safe output that would be independant of what sub you had connected. If the amps target output voltage is 31.6 for example, that would not change simply because you change subs.

    I went through the DMM process..
    Set all HU EQ levels flat
    Set all amp gains down
    Disabled any boost and LPF/HPF
    Disconnected speakers
    Set HU to 3/4 volume
    Put DMM at terminal on amp
    Played a 50hz tone
    Slowly turned up the gain until I reached 31.6

    I did this for each of the 500 amps. I did the same for my 4 channel but target voltage per channel was 17.3 if I recall correctly.


    Now what I don't understand is if you disable all these EQ's, filters, etc.. and get your target voltage that is of course going to change as soon as you enable these again and in my case this went up, especially when I enabled the 500's Pre EQ Switch. The reading went from target to 50's.

    Is that correct? Why wouldnt you set the voltage to target at your listening settings?


    That all sounds good to me- very comprehensive. You ARE correct, sir :).

    I was operating on the assumption you had a 500.1 powering Momo subs previously (and were using the same gain settings). My bad.

    Until I got my SR124, I had been typically over-powering my subs. I was coming from the perspective of setting gains not to reach maximum unclipped signal, but setting them to prevent my amplifier from reaching maximum power throughout the range of the volume dial so as to prevent thermal damage at maximum volume. When I switched to the SR, I found I could set the gain higher than with my previous setup (400 watts RMS sub powered by 600+ for headroom purposes).

    I suppose when I switch up to 1000 watts RMS (again, for some headroom) I'll have to revert to the conservative use of the gain knob. I prefer to run more than rated power rather than push an amp to it's jagged edge performance-wise...when I can afford to do so :).

  • rz22grz22g Posts: 70
    edited October 2007
    Well I chopped my enclosure from 1.36 to .90, both before displacement but I have reverse mounted the subs. Before I mentioned noise when reverse mounted but apparently that was due to the large volume. With the .90 it sounds very good. I can hear and feel an improvment over my single 500 on two MOMO's but from a cost perspective, I would have stuck with the MOMO's knowing what I know now.

    On another note... I just got access to a nice Fluke Scopemeter. Unfortunately the knowledge to use it was not included :) So I am working on that part and will compare results of setting gain with it and a DMM.
  • rz22grz22g Posts: 70
    edited November 2007
    Enclosure is not covered yet... good thing since I had to whack about 3 inches off the back to get the sound I wanted. Excuse the cell phone pic. Leads are going to be routed into the enclosure and hooked to terminals. I just have them hanging temporary.
    sr.jpg
  • rz22grz22g Posts: 70
    edited November 2007
    Ok another update :) Luckily I have two enclosures so I am able to try different setups. My old enclosure is dual sealed at 1.08 per side so reverse mounted the volume is 1.08. I mounted the subs reverse today and like the sound much better than anything I have tried.. so...

    1.20 final volume = did not hit hard enough for my liking

    .90 final volume = hit like a **** but low end suffers and some of the hard hitting bass was a little pinging (best way I can describe it)

    1.08 final volume= better balance of hard hit and nice smooth lows.

    So it seems like the middle range of suggested enclosure volume is closer to my idea of a good balance of bass. I would test more but since I cut my large box down I do not have the option of actually increasing the volume again. Im happy with the setup as it is now but would like to try around 1.12 or so.

    Also all the above final volumes are with reverse mounted setup but unless there is a significant change in normal mounting the results should be similar.
  • Greg PetersGreg Peters Posts: 608
    edited November 2007
    ...so do you think you're gonna like (keep) them?

  • rz22grz22g Posts: 70
    edited November 2007
    ...so do you think you're gonna like (keep) them?

    Yes I will be keeping them. I will probably change amps later and get a single amp that will give them a bit more power.
  • RemyngtonRemyngton Posts: 18
    edited November 2007
    Well I finally got mine in and installed it in the 1.00 ft3 box. I am still breaking it in, but I think it sounds amazing in that enclosure. Because of my trunk space (RX-8) I can't really get a bigger box than that in the trunk. I could barely fit the 1.00 box in when the sub was installed, the lip of the sub rubbed against the trunk opening when I installed it. I guess the only options I have are to reverse mount or to add polyfil. I'll try them when I'm done breaking it in. The Apline V12 600W (655W) amp that I have installed seems like it is the perfect match for this sub.
  • rz22grz22g Posts: 70
    edited November 2007
    Remyngton wrote: »
    Well I finally got mine in and installed it in the 1.00 ft3 box. I am still breaking it in, but I think it sounds amazing in that enclosure. Because of my trunk space (RX-8) I can't really get a bigger box than that in the trunk. I could barely fit the 1.00 box in when the sub was installed, the lip of the sub rubbed against the trunk opening when I installed it. I guess the only options I have are to reverse mount or to add polyfil. I'll try them when I'm done breaking it in. The Apline V12 600W (655W) amp that I have installed seems like it is the perfect match for this sub.


    Is that 1.00 before displacement? If so that puts you below smallest recommended size.

    Everyone has different opinions of what sounds good, etc.. I did not like the .90 final volume because the hard hits sounded to hard and the lows were tightened up a bit to much as well. It may sound completely different in you car though.
  • RemyngtonRemyngton Posts: 18
    edited November 2007
    rz22g wrote: »
    Is that 1.00 before displacement? If so that puts you below smallest recommended size.

    Everyone has different opinions of what sounds good, etc.. I did not like the .90 final volume because the hard hits sounded to hard and the lows were tightened up a bit to much as well. It may sound completely different in you car though.

    It is 1.00 before displacement, putting it at .02 ft3 below the smallest recommended size. Like I said, this is probably the biggest box I could fit in the trunk of this vehicle. I think it sounds great, but yes, the real low doesn't sound as good as it could. Other than that, it is the best sound I could have hoped for.
  • 1996blackmax1996blackmax Posts: 2,436
    edited November 2007
    Some people actually like the more punchy type sound that sometimes comes from the smaller enclosures. If you like it, that's all that matters.
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  • RemyngtonRemyngton Posts: 18
    edited November 2007
    Ok, I think I have broken the subs in and they sound great, very accurate bass, just as I was hoping.

    In order to play with the sound a little, I flipped the sub facing in to increase the box volume. I noticed the lows were a little bit lower and deeper which was nice, but the sound wasn't as crisp and punchy as I prefer it so I turned it back.
    When I turned it back, I was planning on adding some polyfil that I had in a different enclosure but I forgot to do it. When I took the sub out originally, I put the screws back in the holes that I take them out of, but it wasn't as secure. Is there an easy way to fill those holes?
  • moreyb22moreyb22 Posts: 9
    edited January 2008
    I have two Polk Sr124's in a dual 1.0cu.ft. per side box and I also blew two subs. I think the box is to small because after about an hour of listening they get really hot. The only thing I can think of is that the box was to shallow to allow for proper cooling.
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