Welcome to
Doug’s Plugs
Hand made f-hole covers for the Jazz Guitar Industry
If you’ve experienced feedback on your expensive arch-top, you’ve come to the right place.
Ever have trouble hearing your guitar over the band because the gain you need causes your guitar to feedback? I make custom f-hole covers that virtually eliminate the feedback that keeps you from getting the tone you want, and allows you to increase your gain so you can hear.
Jazz Guitar Photo by Wade Rambo
Before and After
How Doug’s Plugs Work
The cause of the feedback is from high SPL (Sound Pressure Level) entering the guitar body. The sound vibration not only causes the top to vibrate WITH the surrounding air, but the SPL also enters the guitar body and bounces around inside, causing more vibration to the top (i.e. the guitar bridge and ultimately the strings).
This causes the string or strings to vibrate more, causing more sound out the amp. My Doug’s Plugs seal up the f-hole and stops the SPL from affecting the air inside the instrument.
Doug’s Plugs custom, hand-made f-hole / sound hole covers control and eliminate acoustic jazz guitar feedback on your archtop jazz guitar!
The plugs I make are made of very light weight high density foam, the same stuff sometimes used to make flip-flops. The main plug fits into the sound hole and a slightly larger top flap, made of the same material, keeps the plug from falling inside, and seals up the hole. The plugs will have a very slight dampening effect on the vibration of the top since they are not glued, screwed, or permanently attached to the top – much like a shock absorber. I have not noticed any effect on the sound on my guitar, nor have any of my customers. In fact, since the feedback is eliminated, you can actually add back some of the EQ you had to take out to eliminate the feedback, giving you the rich sound you have at lower volumes. Some purists may say that it affects the sound, but they don’t buy my product because they either don’t ever get that loud, or still prefer to use clear packing tape, or use balloons, which can still dampen the soundboard.
I would definitely say that my Doug’s Plugs will greatly reduce the feedback you have as long as it’s not microphonic feedback (high frequency feedback that squeals like a microphone). That type of feedback is caused by pickups that are not potted with wax or epoxy. The type of feedback most commonly experienced by owners of archtops is where one note in a chord will vibrate out of control, overshadowing the rest of the chord, or one note in a melody line runs out of control. In some styles of music like Blues or Rock, a small amount of feedback is probably ok, like the kind of feedback experienced by a solid body Les Paul – more of an effect rather than a hindrance.
Also, please understand there are always circumstances, such as room shape, overall SPL from PA systems, bass amps, drums, as well as use of effects pedals, which can contribute to feedback. I don’t guarantee that it will totally eliminate feedback given the above conditions, but I do honestly state that the feedback will be significantly reduced if not totally eliminated. After all, even a solid body guitar will feed back if the volume is high enough
Will it Change my Sound?
One of the most often asked questions I get about my plugs is “will it change my sound?” Until now the answer I always gave was “Yes, you’ll be able to dial in your EQ the way you want it and you’ll sound better since you won’t fight the feedback.”
However I recently acquired a digital recorder and thought it might be time to put the question to the test. This is not scientific by any stretch and no specialized test instruments or oscilloscopes were harmed in the process. It is simply one guitarist’s opinion about what I heard.
My recording was on a Fostex MR16-HD digital recorder with my Gibson L-5 direct to the board with some minor EQ. Both tracks used the same EQ setting, volume and guitar settings (Volume and tone on the guitar were set to 10). I played a simple jazz progression using chords up the neck to exploit the range of tones from the guitar. My playing was as consistent with regard to playing strength and attack as I could make it.
Both tracks seemed at first to be identical with regard to tone and clarity. I bounced the tracks back and forth listening to one pass, then the other, and sometimes bouncing the tracks within the phrase. Since this is my product, I guess I secretly wanted there to not be any difference at all. However, as I listened again and again, I began to notice something I hadn’t at first. The track using my Doug’s Plugs was actually a little clearer and more defined. Both tracks seemed to be identical as I said before, but I noticed that the track without the plugs was ever so slightly muddy. However with the plugs in place, the highs seemed to get ever so slightly crisper and more detailed.
I’m not a sound engineer and don’t have the “golden ears” needed to be one, however I did notice the plugs gave the guitar sound a clearer, more focused sound than without them. Of course, acoustically, the plugs reduce the sound of the guitar since the holes are blocked. However I was pleasantly surprised with the results I heard. Your mileage may vary depending on road conditions and weather….
I would welcome any of my customers to write in and let me know what experiences they have had with regards to recording. I can post it here on my site.
Testimonials
Doug,
I wish I could copy every hollow body guitar player with this message. The f-hole plugs you made for my Epiphone and two Gretsches are the best hollow body guitar accessories I have used in decades of playing. First, they fit perfectly. There was no need at all for the emery boards you kindly sent with the instructions. (I don’t like, and had already discarded, the pickguards, so I did not have to deal with that.) Second, the outside appearance of the plugs could not possibly match the look of the f-holes any better. They are, of course, a tiny bit larger than the actual hole, but the contours of the plugs are identical matches to the f-holes . Third and most important, they work.
Over the years, I have tried almost every electronic feedback device available. I have ruined a finish using tape, I’e tried to cut my own foam, and once out of desperation I resorted to stuffing socks into the guitar. Now, though, after spending a few days playing, the feedback problem that has always accompanied my hollow bodies is under control. It is obvious these plugs would not work so well or look so good without a great deal of extra effort and precision on your part.
Many, many thanks!
Hey Doug,
Just wanted to let you know I got the plugs in the mail Thursday and fitted them today (Saturday). Went as easy as you said, just takes a little patience. They look great and significantly cut the feedback. My L-5 tends to feedback on F, so I plugged in, cranked it, hit F and – no feedback. Plus it doesn’t seem to noticeably alter the tone of the guitar – still has that archtop sound and vibe.
I’ve have my L-5 for several years but wasn’t playing it all that much, mainly due to the feedback issue (also, my workhorse guitar has been a Howard Roberts Fusion). But now I’ll be getting more use out of it – in two big bands, accompanying a singer, and with my trio.
I’ve seen other people fill the box with rags or foam, or, even worse, tape over the F-holes (ouch!!!). This is a more elegant solution, and I will definitely recommend these.
Thanks again!