I finally got around to making a video comparing the volume levels (measured via decibel meter) from my Bassman RI with a Squeal Killer and a Kinder AFB+.
What I did was to plug the mic straight into the amp, then set it up for max volume and get a set of typical baseline max volume levels; then set it up for max volume with the SK and the AFB+ you can see how the volume levels compare.
With the amp turned up that high, the tone gets pretty distorted, and I actually prefer it cleaner.
How do they compare where the mic is just open - across the room and at full volume ...then turn up amp volume progressively till feedback starts....then try same with squeal killer and then with Kinder? Will the onset of feedback point be different?
So you're asking whether the antifeedback devices help prevent feedback from starting when you're not playing or cupping the mic? They definitely help in that situation - in fact, probably half the time I was tweaking the volume and tone knobs, I left the mic switched on (I use an on/off switch instead of a volume control...never liked the volume controls on a mic).
yes that's it exactly. I haven't seen anything definitive testing between the two antifeedback devices - seen the reports that they help but nothing definite like actual demo showing settings and volume setting achievable with mic at a set distance full volume with both comparing ...and then comparing to no device. It seems like from the readings you show so far the achievable db readings looked about the same on both devices and maybe a hair more than without the devices?
I see what you mean. If you're looking for a device that keeps the amp from feeding back when you're not playing, a noise gate would probably be the most effective device. And you can do the same thing with an on/off switch or volume control knob on the mic.
While the amp was noticeably louder with the antifeedback devices, it's not as if the amp will all of a sudden get twice as loud with them. It's more about a few key advantages in my opinion:
1) Being able to push the amp to just under the threshold of feedback without actually losing control and going over that edge;
2) The compression and punch that the devices seem to add to the attack of each note;
3) The changes to the tonal quality provided by each device. For the Squeal Killer, it seems to add bass response, which is nice for mid- and higher-key harps. For the AFB+, it can reduce bass, which provides better clarity and articulation, especially for lower-keyed harps.
I can't speak for the squeal killer since I don't have one, but with the Kinder AFB that I've used a lot, the more feedback your amp generates, the more you will have to turn up the right or left-hand controls to dial it out, unless you alter something else (like amp, mic, volume, cupping, etc.), depending upon whether it is a high or low harmonic squeal you are experiencing.
Dialing out feedback clips part of the wave form, which will make the sound seem more distorted and notes less sustained. To your ear, the notes may seem less articulate or less melodic. If you are fan of Rob Piazza, you may like that clipping. He may not use the pedal, but the Kinder mod is in the Kinder amps he uses.
However, the more you clip and flatten the wave form, the more distorted and unnatural your notes may sound. Consequently, there is a point of diminishing returns on the effect of the pedal, and it will vary, depending upon such factors as your amp, your mic and element, your cupping technique, and the presence of other pedals that may contribute to gain, just as it would without no Kinder AFB at all.
You can use the pedal initially to dial out feedback and avoid embarrassing and painful squeals. When you find you are able to obtain the tone you like, you can choose to use the pedal only as much as you need to enhance your tone, but not to compensate for an inadequate amp which may be useable with the AFB filter dialed high, but unpleasant sounding with highs and lows chopped.
Last Edited by PeterG on Jun 29, 2016 9:42 AM
rod uses one when necessary... he also said to me, you would be surprised how many harp players have them. if you don't see it.... its is because it is usually behind the amp.
From what I could see of the db meter there was not a big difference in volume. Does the meter favor certain frequencies in registering volume?
Another factor is input impedance for a crystal mic, with both devices having higher input impedance than a guitar amp, favoring more low freq from a crystal element.
"Does the meter favor certain frequencies in registering volume?"
Brilliant question! I looked into it, and yes, the sound meter does favor certain frequencies. I had the sound meter set for dBA, which seems to be the standard and supposedly was created to be indicative of how the human ear perceives noise levels. Looking at a chart of how the "A" weighting scale works, it appears to discount frequencies below 1,000 hz, so it could make a difference. The "C" weighting scale might be a better indicator because it is pretty flat over the range of harmonica frequencies.
I pulled out the sound meter again alongside my Bassman and found that for the 2 hole draw on my "A" harp, the dBC reading was 5 to 6 decibels higher than the dBA reading.
To check if there was a pronounced difference with the antifeedback devices, I plugged in the Squeal Killer and dialed up the volume same 2 hole draw dBA reading that I was getting without the squeal killer; then I switched over to the dBC reading, and it showed the same 5 to 6 dB increase, so I'm not sure it would have made any difference in the video comparison results.
I wish I had time to make another video doing the same thing with the meter set for dBC, but I don't have the time now...maybe sometime later!
Seemed to me that the peaks were 1 or 2 db higher. That's significant I think. But I also agree that the amp probably sounds better a bit quieter than that... I enjoyed the playing also.
Great discussion!I feel like we are sitting around the gear Having just listened to it. I have tried noise gate type but don't like the on-off nature of it. Not expecting massive volume increase just a bit more ... and with more reliable feedback edge control. Really leaning towards the squeal killer at the moment as best option in my particular circumstance and my particular amps.
@Bugfan: I like them both and use them both. The two devices may be similar in their overall ability to achieve high volume and feedback reduction, but they do have some differences.
For warm, beefy tone, I give the edge to the Squeal Killer; for cut, projection, and ability to dial in control of high-frequency feedback, I give the edge to the AFB+.
If possible, I would suggest you find a way to try out both devices before buying - that way you know you're getting the one that's best for you.
I never liked the sound I got through my AFB+. Sounded harsh to my ears. The SK I use now may or may not provide more volume before feedback; it's hard to tell without measurements. But what I do like is that when you do hit feedback, it's much more controllable. Just back off a bit and it's gone.
I have the Squeal Killer and the Mojo Pad from Lone Wolf. On their own I prefer the Squeal Killer. The Mojo Pad seems to work much like a tube swap in that it dramatically reduces volume, (so you have to turn up the amp quite a bit) and cuts the treble which I'm not a big fan of because I like the harp sound to cut through the rest of the band. However, when I tried them both together I swear I can get the amp (a baseman) louderand with more treble before feedback and I get that broken up sound I've been searching for. The amp is turned up to 9. If you already have a Squeal Killer then it might be worth trying it together with a mojo pad (which is really cheap). I plug my mic into the SK first.
I always love the playing in your demos harpoon_man.
Am I missing something though - there doesn't seem to be much difference in available volume between no pedal and either pedal. Aren't these boxes supposed to give you much more volume before feedback?
I thought from the OP that you set each test to the max volume on the edge of feedback?
@MTG Background- I have the Mojo Pad and the Boogieman (Harp Tone + circuitry) to get the job done. I was not looking to use them with my own amps as they are set up for harp anyway. What I need is an easy solution for amps that I am faced with at gigs/jams that are not harp-friendly.
The Mojo is very easy to use. No electricity needed. Plug and play. It works. It reduces the input signal getting to the amp. That means you have to turn the amp up way more than you usually can, say up to 8 instead of 4. Is it then louder than before ? Probably not but you get more USABLE volume. On 4 you might be on the edge of that painful, ear-splitting feedback that leads you to cupping hard when playing and praying you're ok when you remove your hands! Not with the Mojo on 8. That doesn't happen. It does alter the sound somewhat (for reasons others can probably explain) but that's easy to compensate for with dials or mic choice.
Same with the Boogieman. I have played through the Squeal Killer and it's basically the same deal. It wasn't worth the extra cash for me as I don't use it for my own amp. If I wanted to use it all the time I might go for the AFB or the SK, don't know. In fact, I'd probably just mod or exchange the amp to eliminate the problem!
I did a comparision between Kinder AFB, Squeal Killer, Harp shield, ART Noise Gate and a Lone Wolf mojo pad recently. All of them is great except the Art Noise gate. They have different ways to work and is good for different kind of amps and musicians. kinder is a great pedal to tame bassmans and super reverbs. But when you come to a Hot rod deville or even hotter amp they do not work. The same with Squeal killer and Harp shield. The only way to calm down such a amp is to take down the gain. The Mojo pad do that work very well. But most of those, modern, hi gain amps aint no good for harp anyway. They are stiff and don't sing in the right way. But the real adantage with the mojo pad was the way it work with other Lonewolf pedal and other guitar pedals. I discovered i get the same sound as a Kinder pedal and a better feedback resistance. A Mojo pad and Harp Octave give life to amps i hate. A original Blues junior come to be a great harp amp suddenly! With a AFB system at half price of a Kinder AFB pedal.
@MTG:. Thanks! I was surprised at how loud I was able to get the bassman with no antifeedback device, but it took probably 15 or 20 minutes of me experimenting with the settings to get it there.
And I agree, the difference in measured dB was not that dramatic, although it sounded noticeably louder in the room with the SK and AFB+. Also, the sound quality was different with the devices. When I get some free time, maybe I will go through the video in slow motion and calculate the average dB level for each clip.
From what I understand, the perception of loudness and the actual physical sound pressure can be quite different. Even though the dBA weighted measurement is intended to reflect the response of your ear, it's more subtle than that apparently. So I can believe that the effect of these pedals is to increase the perceived volume in the room.
An analogy would be the 'loudness' button on the old hifi units. That didn't increase the actual volume much, but boosted the frequencies that your ear becomes less sensitive to at low volumes.
