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Bill Fitzmaurice

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Posts posted by Bill Fitzmaurice

  1. It's common for the low end of a speaker to be hard to hear when standing close to it. Reflections off nearby walls and the ceiling create low frequency null zones. If you're standing in one of those null zones the bass will disappear. When you move away from the null zone the true output of the cab will be heard. This effect gave rise to the myth of wave propagation, that it takes a minimum distance from a source for the bass wave to be heard. But if that was true headphones wouldn't work, nor would car subwoofers.

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  2. The US is having problems with the supply chain of everything from fuel to food for the lack of truck drivers. Many of those laid off during the height of the pandemic moved on to other higher paying jobs. One reason why ships can't off load their containers is the lack of trucks to transport them from the ports.

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  3. It mostly has to do with the Asian side of that other pond. Outsourcing just about everything to there made economic sense when it was done, but not so much when there are hundreds of cargo ships loaded with hundreds of thousands of containers anchored off the West Coats of the US unable to offload. I would imagine similar scenarios exist on your side of the pond.

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  4. 1 hour ago, BassYerbouti said:

    can anyone give me advice of anything I can check myself with a multi meter etc as I really hate spending money  if I can help it.

    If you have to ask then chances are slim that you'd have the chops to do it yourself. The good news is valve amps are easy to work on, if you know what you're doing, and parts are readily available, so it's worth having a tech look at it, if you can find one who works on valve amps. SS is a different story, and the newer they are the harder they are to repair, if it can be done at all for less than the price of a new amp.

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  5. Cabs don't create hiss. They reproduce hiss that amps create, so don't blame the cab on that. Why is everything at 12:00? That gives the same result as if those knobs weren't there. Use them. You should be getting 90dB with less than a watt, so some output voltage testing with a pink noise source is in order. However, I wouldn't put a lot of faith in phone app meters.

  6. Where what you're hearing is concerned the narrower vertical dispersion of two stacked cabs versus one on the floor is more than compensated for by the higher position of the upper cab.

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  7. That's not the one I recall. Mesa does call it a passive radiator, the one I can't remember didn't. In general PRs are smaller than ported cabs for the same result, because a PR takes up less space than a port.

  8. 56 minutes ago, Stub Mandrel said:

    Is there any strong reason why passive radiators aren't used for bass cabs?


    A passive radiator costs more than a port. 🙄


    I recall that someone made one, but I don't recall who. I also recall that they didn't call it a passive radiator, they used a different term that implied it was something new and unique, but it was a PR.

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  9. 2 hours ago, uk_lefty said:

     I played a function with the RM head and 1x15 cab only and I couldn't hear myself on stage though I think that's because I didn't elevate the cab.

    Elevate the cab, or at the very least tilt it back so you're on the driver axis. Adding a 410 to a 115 seldom works well, as most 115s can't keep up with a 410. 90% of the time you'll get the best results with two identical cabs.

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  10.  A tiny cab will have a tiny, as well as tinny, sound. It has nothing to do with power. In fact the less power you have the better result you'll get with a larger versus smaller cab. Google 'Hoffman's Iron Law'. Then have it tattooed on your arm. It is probably the single most important law of acoustics where bass players are concerned.

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  11. You don't need to use identical drivers, but they should be spec matched as close as possible, as should the enclosure. There's no need for a low pass filter in the extension, the woofers aren't doing much above 3.5kHz anyway. That's one reason why a 2kHz capable tweeter gives a better result.

    If you're going to run into problems it would be using an 8 ohm 210 along with the 8 ohm 110. That puts half the power into the 110, half into the 210. Doing that you might as well have the extension be a 110 as well.

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  12. 1 hour ago, Stub Mandrel said:


    Bass goes down to E so you can play in F without having uneven sounding open strings 😉

    I doubt that had anything to do with how standard orchestral tuning of the double bass was arrived at. How they decided on E I can't imagine, it's not an octave below the cello, which has a C as it's lowest note.

  13. 35 minutes ago, BassmanPaul said:

    What used to give me pause were the Guitar players who used 'curly' cables between their amps and speaker cabinets!

    It seems that one's IQ is inversely proportional to the number of strings on the instrument. I remember using those on my bass back in the day, and they were horrid in how they killed the mids and highs because of their capacitance and inductance, two terms not in the vocabulary of most six-stringers. 😊

  14. The only way they'd sound different direct versus daisy chained is if the cables are seriously undersized. All cables have some voltage drop, and when you daisy chain that drop is higher compared to when each speaker has its own lead to the amp. But with the length and gauge of correctly sized speaker cables the voltage drop in either configuration should be virtually unmeasurable, let alone audible.


    I keep seeing these references to getting more headroom with lower impedance loads. I imagine the reason for this notion is the higher power output into a lower impedance load. That notion should be divested. What happens with a lower impedance load is that for the same voltage output from the amp you get more SPL from the speaker. That's all well and good, but you also draw more current from the amp, so from the standpoint of current you don't have more headroom, you have less.

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  15. An eight foot ceiling won't provide a significant boost, if anything it will cause a null. This calculates floor and ceiling bounce:



    If you do a few calcs you'll see that the closer you are to the speaker the lower the cancellation frequencies. That's why you can't hear your lows on a small stage. Extend that distance to where the audience is and the reason why it's louder out there becomes clear. I always do my sound check from the dance floor, adjusting my volume and EQ for how it sounds there. Whatever that results in on stage I live with.


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  16. Definitions vary from person to person, but what most consider to be boom is a response peak in the midbass, from 80-120Hz. The usual cause of boom is an enclosure that's too small for the driver, especially when it's sealed.

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