Distortion on lower notes on SWR LA10 !?!

Discussion in 'Amps and Cabs [BG]' started by Gintaras, Nov 25, 2005.

  1. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    Just got a LA10 for practice purposes. I am curious if the distortion on open 'E' and anything lower on the 5th string is typically the speaker?? I have not learned enough to know if the distortion I hear on the low notes is the speaker or can it be the amp and/or cab?

    I love to experiment with my gear and if I thought it was a speaker then I would experiment by putting in another one.

    Thanks...Gus :meh:

    My wife says that I need adult supervision.
  2. The speaker - cab combination will mostly determine distortion levels at lower notes. Please keep in mind that speakers need to be matched with the cab to get the proper performance. If you can measure the internal space of the cab and let us know how many and what size ports (if any) there are you will probably get a lot of suggestions for a speaker upgrade.
  3. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    Interior is 12"H, 11"W and 10.5" D
    It has a 2" port on lower front with no tube. It is lined with a white fiber material approximately an inch thick,
    The amp that intrudes into the interior space is screwed on the back with the knobs on top and takes up 7.5 X 10 inches of the back protruding 2 inches into the interior. Basically a transformer and a few cards.

    Thanks for your help :hyper:
  4. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    A cabinet that small just isn't capable of going below at best a low G cleanly, irrespective of the driver used. If you're going to go low and do it with any kind of volume the box has to be at least twice the size as this one.
  5. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    Bill thanks and I went to your website and was totally intriuged. I am in the midst of restoring a house and as soon as it is finished, the workshop will change duties and building an Omni 12 will be the next project. :hyper:
  6. Bill is certainly correct about the size of the cab and it's limitations. After all, he's a cab builder by trade. It would seem to me though that a better handling speaker made for smaller cabs would not distort even if it isn't producing the fundamental notes with high volume.

    The first thing I would consider doing is increasing port volume. You might be hearing chuffing sounds that could be interperated as distortion. 2 round ports that measure 2" in diameter and 2.5" in length would keep the box tuning relatevely the same but greatly improve port performance.

    I have done some research on some suitable drivers for your cab and here's what I came up with. All of these drivers have a similar F3 of about 80hz in your box. Prices range from about $90 to about $270. The overall tone of these speakers cannot be determined with the WinISD program I used. Only the low end extention can be simulated.

    Eminence Kappa Pro 10
    B&C 10 PS26
    Eminence Legend B102 (not BP102). This one has a whizzer cone for a higher frequency extension without a tweeter.
    Beyma 10G40
    EV EVM DLX. This one will have a very strong mid peak at around 600hz. Probably good for hard rock music.

    These drivers are listed in no particular order. They should all keep the sound clean even if you won't get earth shattering lows in your box. If you kept your original driver you could toy with the idea of building or buying a bigger box in the future. Anyway I think that tinkering is a great way of learning so good luck! :bassist:
  7. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    I can easily do the port enhancement. I was wondering what to use for the port tube? Will a piece of PVC pipe work?

    Also I can pick this Peavey speaker up for $45....will it work?

    I am especially interested in trying the port mod just to see what it does. I just want to make this a better practice amp not something it was not intended to be.
  8. PVC will work well. Just use the inside diameter for reference. You could get a cleaner look if you bought port tubes specifically made for this purpose. Ebay is a good source for this. They are cheap.

    The Sheffield speaker you refered to didn't have enough specs to make any determination on it's compatibility with your cab. The one spec that did jump out at me is sensitivity. The sheffield is 89db@1w/m. The drivers I suggested are on average 8db louder. That means it would take roughly 250watts to achieve the same volume level with the sheffield that you could with the other drivers with your 35watt amp. This translates to lower level on your amp to achieve the same volume level. That means the speaker will be pushed less and distortion will be down.

    If you e-mail Dave at avatarspeakers.com I think you will be pleasantly surprised on his price for the Eminence kappa pro 10.
  9. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    I just got a Delta lf from him today. I had bought a used tech soundsystems 212 that needed to have one speaker replaced. I emailed him about it and he had me a speaker out that afternoon. I will be getting a 2x10 NEO from him as soon as I sell my hartke xl 410
    I will check out his price on the 10"
    Now off to ebay in search of a port tube

    Thanks for all of the help
  10. No problem. Keep us posted! :D
  11. Funkateer


    Jul 5, 2002
    Los Gatos, CA
    I periodically forget this piece of advice and halfway convince myself that I've blown a speaker when the real problem is that bass notes suck too much power for a battery that is on its way out to handle.
  12. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    Hi Muzikman !!! I drilled a second port and put tubes in. I got the tubes as you recommended on ebay from Jam Music. The sound is clearer and punchier. The lows on the 5 string are still lacking but at least playable and not having that distorted farting sound. I was originally going to get rid of the amp but know it is a nice sounding practice amp and quite enjoyable to play. I still plan to take your advice on a Delta from Dave at Avatar.

    I am amazed that such as easy fix would have not been part of the design by SWR?!?!? It only cost $8 with shipping and 30 minutes in the shop.
  13. Glad it worked for you! Now if lack of low end is your only concern try placing it in a corner. You should pick up some free lows that way.
  14. BTW the Delta is not the right choice for a small cab like yours. The Kappa Pro would work much better. BUT..........none of these speakers are going to give you killer low end with such a small box. If it isn't distorted anymore I would leave well enough alone.
  15. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    I think your advice is sound and I will leave it alone. I will try the corner. The low does not distort just flat. Think I will use that money for something else (more stuff !!!) Really want to get an avatar 2x10 neo next. I have a 4x10 hartke XL that I bought for a song but did not realize how heavy this beast is...88 lbs.
  16. Hartke's sell well on the 'Bay! ;)
  17. LyleRyan

    LyleRyan Supporting Member

    Jun 20, 2006
    Berkeley, CA
    An interesting thread, since I just picked up an inexpensive LA10.

    Gintaras, any more specifics you can remember that might help me when adding a second port and port tubes to the LA10?

    Muzikman, when adding the second port, how do you think it would work if I put it on the rear of the LA10 (centered?) to get more of a omni-present sound, like a Hartke Kickback or my Bag Ends?

    Thanks for your help....Lyle
  18. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    It's been a while but I remember buying 2 ports on ebay and they were larger than the hole that was there. Used a hole saw that typically is used for cutting holes in doors for locks. Since then i have bought a Workingman 10 and put it a Eminence Deltalite 10. That really improved the tone. I would probably do that if I still had the LA10.