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Ampeg PF-210 is Sealed. DIY Port?

Discussion in 'Amps and Cabs [BG]' started by GGman, Dec 29, 2016.


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  1. GGman

    GGman

    Oct 17, 2008
    Hoping for a simple yes or no and how one might go about adding a port to the Ampeg PF 210HE sealed cab since I already know about the theories and math, and so on. Would you attempt to do this DIY port addition and would "any sort of port" help the bottom end on these cabs? Or, is the benefit so small it is not worth doing this. I do not have the cabinets here yet to look inside and see if it is possible.

    And a side note, I am also looking for two Ampeg covers that fit the PF-210HE cabs.
     
    Last edited: Dec 29, 2016
  2. Jim Carr

    Jim Carr Dr. Jim Gold Supporting Member

    Jan 21, 2006
    Denton, TX or Kailua, HI
    fEARful Kool-Aid dispensing liberal academic card-carrying union member Musicians Local 72-147
    IMHO, it is not a good idea.
    If you want lows, get a cabinet (with proper drivers) designed for it.
     
    Last edited: Dec 31, 2016
    DukeLeJeune, Mikeee71, NOVAX and 4 others like this.
  3. Well, one guy ported his PF-115he and seemed to enjoy the results. Porting, if and when done correctly, can up to double the low end displacement in some frequencies. In a lot of areas applicable to pro audio and live performance as far as bass guitar is concerned, porting can be very beneficial (though sealed cabinets can be equally valuable as well, and some enjoy using horns like BFM's stuff). While I would encourage learning through trial and error on, say, some speakers somebody tossed into a dumpster, I'd actually say that you could hinder the performance a perfectly good cab worth a good bit of cash. Of course, you could also improve the performance of the thing, but going about it without knowing which outcome could come out, I'd personally not do it.

    However, what you COULD do, is make an identical cabinet out of, say, particle board or whatever is cheapest, put the ampeg 10" drivers into it, and THEN experiment. But at that point, you might as well just buy some cheap drivers off of say MCM electronics, and do the same without nearly as much financial risk.
     
    GGman likes this.
  4. High Camp

    High Camp

    Oct 3, 2013
    Netherlands
    I think somebody else on Talkbass made a sealed cab ported (I have to go to work in a minute, so I can't search for you)

    There are several shops that sell the PF cover, this is one of them:

    Ampeg Cover PF-115HE/PF-210HE

    Hope this helps a bit! :)
     
    GGman likes this.
  5. GGman

    GGman

    Oct 17, 2008
    Thanx, good info.
     
  6. GGman

    GGman

    Oct 17, 2008
    Thanx, I would appreciate it if you can find it for me. I will try the two cabs with my pf 800 when they arrive and see how it goes. I was just wondering if it would be possible if I felt I needed more. That link is in Europe. Shipping would add too much unless they have a distributor over here.
     
  7. ScottTunes

    ScottTunes Gear-A-Holic

    Feb 7, 2011
    So Cal
    You could port the cab, and use port covers to compare (johnk_10 did something similar to his 2x15 cab) with and without. In my experience (and opinion), it isn't worth much to change from sealed to ported. As mentioned, you should probably just buy a ported cab. Although you gain a few db in the lower end of the spectrum, it may be detrimental to the driver, since it wasn't designed for that.

    I like the suggestion of building a test cab from cheap wood and compare how it sounds to the Ampeg. I think you'll find them so close (especially in a band setting) that it won't be worth wrecking the Ampeg by adding ports.

    The cheapest thing to do would be to use a speaker cabinet designer and see the differences between ported and sealed.

    The biggest advantage of the porting (if designed well), is a "louder" and "deeper" sound, compared to an equally sized sealed cab.

    Personally, I prefer sealed cabinets as they seem more forgiving, are easier to build and transport. I like the stronger mids and smoother low end roll-off. But I do have (and have built) and use ported cabinets of varying sizes.

    Just my 2 cents...
     
    Sartori and GGman like this.
  8. guy n. cognito

    guy n. cognito Secret Agent Member Supporting Member

    Dec 28, 2005
    Nashville, TN
    No
     
    Old Garage-Bander likes this.
  9. kpc

    kpc

    Apr 6, 2011
    I wouldn't advise it. The cab size isn't made for porting. Prolly won't sound good. Just my 2 cents.....
     
    Sartori likes this.
  10. 2saddleslab

    2saddleslab Supporting Member

    May 30, 2003
    Kentucky
    A well designed and tuned ported cab can enhance any setup. However, I don't think you will see appreciable difference vs the work and $$ invested, IMHO. I prefer sealed cabs.
     
  11. GGman

    GGman

    Oct 17, 2008
    Thanx for the good info. I was thinking it also might be possible to just take the flip top cover panel off and replace it with a temp panel that could have the port on it (the top). And trial and error the port size. Would that work to see and hear the difference? And if it was good, then add the port somehow to the front or back panel as usual with the original top panel back in place. I will see how the sealed cabs work out first at rehearsal, which is a pretty large room like a small gig would be.
     
    Last edited: Dec 30, 2016
  12. Rick James

    Rick James Banned

    Feb 24, 2007
    New Jersey
    This is how:
    1. Find all the T/S specs for the drivers.
    2. Load the specs into a speaker modeling program, like WinISD 0.7
    3. Model the speaker, entering the internal volume of your cab
    4. Determine the best tuning frequency, which usually is where the Maximum SPL is highest in the critical 50 to 70 hz range.
    5. Check the port velocity at the power level where the maximum power isn’t exceeded per the maximum power chart.
    6. Change the port area and length as required so that the port velocity doesn’t exceed 20m/s per the conditions in step 5.
    7. Recalculate the box size after deducting the volume taken up by the port.
    8. Perform steps 3-6 again, because everything will be different after performing step 7.
    9. Model the speaker as a sealed box, then compare the SPL and maximum SPL charts to the ported version, to make sure it’s worth porting.
    After you've done all that you can get into the particulars of adding the port, but chances are you won't get past step 1.
     
    BPhillips, LoDownSinner, ahc and 3 others like this.
  13. BadExample

    BadExample

    Jan 21, 2016
    Injiana
    No.

    No. Wrong drivers. Stuff the cab with polyfuzz stuff if you want more bass, or go to better drivers, or sell and replace.

    IMO/IME you don't really gain bass by porting, you just shift the frequency around. You may gain volume/Watts, but you can hit the sealed cab a lot harder before mechanical limits are reached. The problem you will have adding ports is the drivers in it are designed for sealed cabs and will not work well with porting. Drivers that work well ported don't do so well sealed either. There are mediocre drivers that work in either, but most are a compromise. I doubt if Ampeg would use such drivers in either sealed or ported cabs... but you never know until you know! IMO you have little to nothing to gain, and could well just end up with a cab that farts out too easily or damaged drivers. If you are going to try, I suggest making the modification fully reversible and test carefully in a quiet place (just you playing and no other music). If you do it, I hope you are lucky and get the results you seek.

    Follow @kringle77 around if you want to learn more about sealed cabs. I've gotten very good results, but consider myself more of a hack, and he's gigged his DIY sealed cabs with great results.
     
    Sartori likes this.
  14. You evidently want more low end than the stock cabs provide. You may or may not be able to get the low end you want by porting your cab, but you will need to go through the steps outlined in the Rick James post above. Even then, you must be prepared for an unsatisfactory result and a loss of resale value. That cab was optimized for sealed use. It offers good sealed cab tone. If you prefer a more bass-rich tone the best way forward is to sell your cab, audition cabs and purchase a cab that meets you tone preferences.
     
    DukeLeJeune and BadExample like this.
  15. InhumanResource

    InhumanResource

    Dec 28, 2012
    No!!! Get a 210 that is already ported and designed to be so.
     
    BadExample likes this.
  16. BadExample

    BadExample

    Jan 21, 2016
    Injiana
    Seriosly, if money is a concern, you risk less buying used and selling old.

    If money is not a concern, why waste your time on something that probably won't work? Buy new or do a DIY if you want a project.
     
    Sartori and agedhorse like this.
  17. Rick James

    Rick James Banned

    Feb 24, 2007
    New Jersey
    Probably true, it depends on the driver Q specs. Low Q is best ported, high Q is best sealed, but medium Q might go either way.
    False. Stuffing lowers the speaker Q, which can tame midbass boom, but the response doesn't go any lower. There's a long standing myth that stuffing gives the same results as a larger cab, but it's not true. That's why it's a myth.
    False. Porting can give 6dB or more higher efficiency in the lows than sealed, and lower f3 by as much as an octave compared to sealed.
    False. It takes a lot more power with sealed to reach the mechanical limits, but since the efficiency of sealed is lower you're much more likely to use enough power to hit xmech than you are with ported. Ported has minimum excursion at the tuning frequency, where the port provides some 90% of the output, so you hit the mechanical limits with sealed at a lot lower volume than you will with ported.
     
    Jim Carr and GGman like this.
  18. High Camp

    High Camp

    Oct 3, 2013
    Netherlands
    This is strangely enough (or not) the best suggestion, to be more specific, maybe you could change your PF210HE for the:

    Ampeg: Portaflex Series - PF-115LF

    It is Ampeg, Portaflex, same power, but ported.
    Voiced lower then the PF210HE and PF115HE, the PF115LF might just be your cab, @GGman ! :)
     
    BadExample likes this.
  19. Session1969

    Session1969

    Dec 2, 2010
    No.
     
    BadExample likes this.
  20. Session1969

    Session1969

    Dec 2, 2010
    Sounds like a real hoot.
     
    GGman and BadExample like this.

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