The Great Isolation Cabinet Project

Discussion in 'Amps & Cabs' started by smitty_p, Sep 2, 2013.

  1. Dorian

    Dorian Active Member

    Joined:
    May 8, 2005
    Messages:
    650
    Likes Received:
    188
    Location:
    LA area
    I hadn't thought about that, but it makes a lot of sense.

    I'm glad it has proven so valuable.
     
  2. chilipeppermaniac

    chilipeppermaniac Well-Known Member

    Joined:
    Jan 1, 2012
    Messages:
    5,959
    Likes Received:
    3,179
    Location:
    Maryland

    I was thinking along the lines of a young Barbara Eden inside. MMMMM
     
  3. smitty_p

    smitty_p Well-Known Member

    Joined:
    Mar 20, 2012
    Messages:
    4,836
    Likes Received:
    3,466
    Howdy all.

    Well, I've posted on My Les Paul a few times over the last few days.

    Today, I ran across an isolation cabinet thread over there and decided to link back to this thread here, detailing my own iso-cab build.

    Before long, a member there rather adamantly voiced his concerns, mostly from the perspective of heat. As ya'll may recall, those concerns were also addressed here on this thread, and my experience with its performance has been very favorable. I've been using it for months with no ill effects. Of course, I'm using very small amps, all in the 5 watt range.

    Nevertheless, in the interest of openness, fairness, transparency, and full-disclosure, here's a link back to my post on MLP where ya'll can read the comments.

    Isolation Cabinets - MyLesPaul.com

    In the mean time, I need to go play my guitar!
     
  4. smitty_p

    smitty_p Well-Known Member

    Joined:
    Mar 20, 2012
    Messages:
    4,836
    Likes Received:
    3,466
    Update to my isolation cabinet.

    I found one drawback. By having an isolation cabinet for my amp, my amplifier is...well...isolated! If I need to adjust controls it can be problematic. Usually this is not an issue for the way I play. I usually can just set it and forget it, but sometimes I have wanted to make a minor adjustment.

    One other item, which is not so much a matter of using an isolation cabinet, is the matter of plugging into outlets. The way my system was set up, my amp was in the isolation cabinet in another room and required the amp to be plugged into a separate circuit from my effects. Well, this set up an AC ground loop. So, to address this, I made a speaker cabinet and have placed it into the isolation cabinet. I now have my amp on stage with me, plugged into the same circuit as my effects, but I am using the external speaker jack on the amp and am connected to the speaker in my isolation cabinet.

    Doing this has addressed two issues. First, if I need to adjust the settings on the amp, it's right there with me. Second, by having it on stage with me I can plug into the same circuit as my effects, eliminating ground loops. Again, the ground loop issue has nothing to do with the iso-cab, per se. But, by having the actual amp nearer to me, it helps ensure I will be able to use the same circuit as my effects.

    Here's a pic of the speaker in the isolation cabinet. It's not really visible but there is a thin grill cloth in front of the speaker to provide some protection.

    [​IMG]

    I'm still quite pleased with my isolation cabinet, but thought I'd share these observations.

    BTW, it's been in use for about a year and until today, I'd run my amps for hours at a time in it and have never had heat issues.
     
  5. Dorian

    Dorian Active Member

    Joined:
    May 8, 2005
    Messages:
    650
    Likes Received:
    188
    Location:
    LA area
    Smitty_p -- Well, that's a good point. Adjusting knobs inside a cabinet is obviously less convenient. Of course I didn't think of that, either. Your heat "issues", if any, ought to be less significant now that the electronics are on the outside. Even the My Les Paul folks ought to like you now. :)

    I am still curious to know what you think about the voice of the amp through the PA system versus the amp standing alone. Is the frequency response similar, for example? I often find that setting up in a different room causes huge differences in my tone, so perhaps the differences are not significant on the usual scale of playing live. Just curious.
     
  6. smitty_p

    smitty_p Well-Known Member

    Joined:
    Mar 20, 2012
    Messages:
    4,836
    Likes Received:
    3,466
    Dorian,

    My need to adjust controls actually was really minor, though, on occasion I had wanted to do some minor tweaks. The biggest issue was that I needed to fix a ground loop. This was actually noticed by the sound guy. It was a minor 60 Hz hum that was only really audible in headphones, but I recognized as a ground loop when he had me listen to it. So, the only way to get my effects and amp on the same circuit was to do what I did, or to run the power cord for my amp through holes I drilled in a wall and the stage. This can run afoul of some electrical codes, so I opted for the external speaker. I already had the speaker, so it was a fun little project.

    As for the heat issue, I was beset upon by one of the stalwarts at MLP who thought putting my amp in a cabinet was a really bad idea. I respect his opinion and his concern is not foolish. He is an amp builder and has respect on the forum, as well. Even though I did my homework and knew I had plenty of ventilation (which my experience has since supported), I opted not to get into it, especially as a relative newbie on that forum. So, I just attempted to politely add a disclaimer or two and quietly just disappear. No harm, no foul.

    The voicing. You are very correct. It does sound different through a PA than it does by itself. The nice thing about an iso-cab is that the acoustic environment of the speaker and microphone is pretty much constant, regardless of the venue, as they are both enclosed in the cabinet. This helps to minimize that variable. But, each venue has its own acoustics relative to the PA. So, you don't get entirely away from the need to tweak EQs at the mix. Generally, I have found that the sound through the PA is not as bright as listening to the amp by itself, not dull or muddy, just not as bright. Frankly, I attribute this to the, often, long cable runs that occur from the microphone to the snake head, and then from the snake head back to the mix. The highs will be the first to suffer.

    Another thing is that a microphone "listening" to the amplifier speaker from a few inches is much different than your ear listening from many feet. Even though the sound absorption nearly eliminates reflections, the enclosure is still filled with sound. I continue to be amazed at just how "big" a 10" speaker can sound in an iso-cab with a mic. Even the 8" speaker on my Fender Champ sounds like a much larger amp through the PA.

    A year or two ago, I ran into an interesting article describing how Yngwie Malmsteen works with his system in his studio. Unfortunately, I cannot find the link. Anyway, regardless of your thoughts about Yngwie, he does do some interesting things. This article described how he has his guitar, effects, amp head, and mixer in his studio. However, his speaker cabinet is in another, sound-proofed room. He mics his cabinet and runs it back to the mixer in his studio, which then feeds his monitor amps and speakers. He then works on his sound in this environment.

    Now, obviously, the "PA" in his studio is different from what will be used in a venue, but this setup in his studio is more analogous to what the audience will really hear and makes things a little more predictable.

    Anyway, thanks for the questions and insights, Dorian.
     
    Dorian likes this.
  7. LeadFinger

    LeadFinger Well-Known Member

    Joined:
    Jan 10, 2014
    Messages:
    2,778
    Likes Received:
    2,291
    Location:
    Los Angeles
    Thanks, smitty_p! I've been wondering about these types of cabinets.

    Some guy on the local cl was selling one, but warned that you'd need three strong guys to move it.
     
    smitty_p and 58pit like this.
  8. 58pit

    58pit Well-Known Member

    Joined:
    Jan 14, 2014
    Messages:
    1,712
    Likes Received:
    2,083
    Location:
    EARTH
    I'd go with the gorilla.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice