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Double Bass An Ehrlund blog, sort of

Hi drurb,

I'm not sure if it is a kind of mic reacting on air pressure or rather a contact sensor reacting on (relative) mass movement. (I assume it is the second one.)
In the second case, the contact points with the top transfer the vibrational energy to the pickup, so I think in that case it does matter where on a certain area the contact points are placed.
In the first case it (almost) doesn't matter.
 
Hi drurb,

I'm not sure if it is a kind of mic reacting on air pressure or rather a contact sensor reacting on (relative) mass movement. (I assume it is the second one.)
In the second case, the contact points with the top transfer the vibrational energy to the pickup, so I think in that case it does matter where on a certain area the contact points are placed.
In the first case it (almost) doesn't matter.

Well, that's not a reasonable assumption as I see it because it assumes that there is varying sensitivity along the surface of the transducer relative to the wavelengths of the vibration and the likely size of the nodes and anti-nodes. Not likely at all, as I see it. Again, empiricism is best. Give it a try. :)
 
I meant where on a certain area of the top the contact points are placed, not where the putty is placed on the transducer.
I think that the corners of the transducer are the intended and best place for a triangular membrane.
So, I was thinking about rotating the transducer (with putty fixed at its corners)over the same area of the top. (Probably by a maximum of 60° DEG.) I hope I made it more clear what I meant this time.

Different positions have different amounts of partials, so it should matter where the contact points are.
(I wrote my CS diploma thesis on different methods of simulation of the acoustic of musical instruments, so I know a bit about the acoustics of musical instruments.)

But you are right that some pure theory often enough is not complete and experiments will show something different than expected.
So let's experiment...
 
I meant where on a certain area of the top the contact points are placed, not where the putty is placed on the transducer.
I think that the corners of the transducer are the intended and best place for a triangular membrane.
So, I was thinking about rotating the transducer (with putty fixed at its corners)over the same area of the top. (Probably by a maximum of 60° DEG.) I hope I made it more clear what I meant this time.

I knew that's what you meant so my opinion remains.

Different positions have different amounts of partials, so it should matter where the contact points are.

Yes, they do but not expected to be rotationally dependent for a single position given the transducer we're discussing.

(I wrote my CS diploma thesis on different methods of simulation of the acoustic of musical instruments, so I know a bit about the acoustics of musical instruments.)

As do I, but I'm not going to trade credentials in this thread. :) Would that be CS as in computer science? Simulating the acoustics of instruments via computer is, of course, quite apart from the physical acoustics of vibrational modes and transmission of energy.

But you are right that some pure theory often enough is not complete and experiments will show something different than expected.
So let's experiment...

Well, I have the pickup and am quite happy with where I have it placed.
 
Hi Les,
do you and other owners feel confident enough to take the Ehrlund out without a back up piezo pickup?

Geoff

I have used it without a backup for the last year. I actually did dig up my Bassmax a month or two ago and keep in my case for emergencies, but if it wasn't there, I wouldn't be worried. The Ehrlund has delivered flawlessly in every gig I have done, which has included a lot of outdoor, and some ballroom and banquet type.
 
Hi Les,
do you and other owners feel confident enough to take the Ehrlund out without a back up piezo pickup?

Geoff

I never go without a backup, so I will have one in my gig bag. From all I can tell, however, the backup is not needed because of any liklihood that the Ehrlund will not work in some venue. I have the backup in case something just outright fails. It's the same reason my BassMax served as a backup to my Rev Solo, which is now the backup to my Ehrlund. :)
 
How do You set up the preamp? Switch and volume? In my case, I have to put the switch on high. When i set it on low, I dont get to much sound from the pickup.

Bassdane,
In my case, see picture below, I get a strong signal with plenty of bass, volume, and clarity in that specific spot. Goran Ehrlund maintains that the low position on the switch is the EQ he intended for bass whereas, the high was intended for guitar, violin, mandolin etc. I would surmise that the placement of your pickup isn't where it needs to be, but I could be incorrect. There are some basses where the EAP doesn't work. I do know that if I move the pickup ever so slightly of of that particular spot the sound changes quite dramatically.

Here's my suggestions from an earlier post to this thread

First of all, when installing an Ehrlund, it's best to move it around in very small increments, over the target area, and keep track of where you placed it, kind of like a submarine running a grid square.

Second, You really don't need a lot of putty, IME, although others have different opinions on this. The less the better IMHO.

Third, it doesn't really make full surface contact, like a piezo pickup does. All you have to do is mount the corners of the triangle.

Fourth, it's a linear device, so you'll never get the volume "bump" that a Realist or Full Circle has. I've noticed that when you increase the volume it comes up gradually, which in some playing environments can be deceptive. It's also actually blending with other instruments as it gets louder.

Fifth, the Pre Amp is mandatory, it increases the over all volume output of the pickup, enhances the midrange, and slightly boosts the bass response.

I truly hope this helps.

Ric
 

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  • Mireourt Bass Ehrlund Location 2.jpg
    Mireourt Bass Ehrlund Location 2.jpg
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I agree with Ric. When I first started placing the Ehrlund, the "low" setting just wasn't doing it. Knowing that is the "proper" setting, I kept trying. Once I decreased the amount of putty and achieved a fitting close to the top, it all fell into place.
 
A member on the Basschat forum is selling Ehrlund gear in the UK and he said on that forum that the 'low' position on the switch is just a pad - there's no EQ difference between the two. I have never tried the 'high' position myself though.
 
A member on the Basschat forum is selling Ehrlund gear in the UK and he said on that forum that the 'low' position on the switch is just a pad - there's no EQ difference between the two. I have never tried the 'high' position myself though.

If you try them both, I think you'll hear a distinct difference between the two. Moving the switch to the "High" position emphasizes the highs and reduces the lows. Goran Ehrlund recommends the "Low" position for bass. Regardless of what it does and how it does it, the end result is that the Low setting goes better with bass, IME, IMHO.

Ric
 
What is weird, is I have lately been using the Erhlund on the HI position, going into the effects channel of my amp, thus bypassing the mid-rangey preamp of the Aguilar Tonehammer 500. This has worked surprisingly well, and I have had NO loss of bass frequency. It is a surprisingly balanced tone, considering I am using 0 EQ. This is only for outdoor gigs so far, not weird rooms that require all kinds of crazy eq. I don't think the TH500 is the ideal amp for upright, but it is what I have until I can get my old Iamp500 (the white faced and coolest one) fixed.
 
My amp couldn't handle the Erhlund set on hi without instant feedback, but it sounds great through the effects loop!

I guess that was what I was alluding to. If I run the Ehrlund Pre into the inputs of either Walter Woods amps, it will generally feed back in short order. Possibly the bass doesn't drop of a whole lot but the emphasis the Hi position puts on treble will override the bass, at least on a Walter Woods MI-400-8 or even the Walter Woods Electroacoustic Ultra.

Walter 's amps do not have the low frequency boost that other newer amps seem to have now. Incidentally, that White Faced iAMP 500 is the real deal, the best one they ever built, as it's mostly an analog amp. I just bet you'll be diggin' it when you get it back.

Ric
 
I guess that was what I was alluding to. If I run the Ehrlund Pre into the inputs of either Walter Woods amps, it will generally feed back in short order. Possibly the bass doesn't drop of a whole lot but the emphasis the Hi position puts on treble will override the bass, at least on a Walter Woods MI-400-8 or even the Walter Woods Electroacoustic Ultra.

Walter 's amps do not have the low frequency boost that other newer amps seem to have now. Incidentally, that White Faced iAMP 500 is the real deal, the best one they ever built, as it's mostly an analog amp. I just bet you'll be diggin' it when you get it back.

Ric
Great points Ric. I do miss that White Faced Iamp500. It had serious bottom to the tone that just killed for EB. I never did get to use it on upright. It is not an ideal situation going through the effects loop, as I can't dial out any bass, which I would like to do-just a little bit. However, the Aggie is very midrange colored, which rules for EB, but always had a little weird honk I couldn't dial out. I am thinking with my old school Iamp500 I will have a flatter response to start from, and each eq band is semi parametric, so I should be able to hand any room. EA has quoted me 2 months and $200 for the repair, since they will have to order a new power section from Ashdown in England. What they want me to do is buy a new doubler, but I really like this one, and want it back! :crying:
 
Hi! I founded a spot that was pretty similar to Ric Vice´s. In my case, I get a ok overall sound, but with very little bass. On my AI coda r, I have to have the basscontrol set to 3 o´clock, and turn down mid and treble to a very low level. The preamp is set to low as recommended.
 
Hi! I founded a spot that was pretty similar to Ric Vice´s. In my case, I get a ok overall sound, but with very little bass. On my AI coda r, I have to have the basscontrol set to 3 o´clock, and turn down mid and treble to a very low level. The preamp is set to low as recommended.

Interesting. I have my Ehrlund at almost the same spot, and have to dial the bass down to 9 oclock on my Aguilar (unless I am using the FX loop)
 
Hi! I founded a spot that was pretty similar to Ric Vice´s. In my case, I get a ok overall sound, but with very little bass. On my AI coda r, I have to have the basscontrol set to 3 o´clock, and turn down mid and treble to a very low level. The preamp is set to low as recommended.

Bass Dane,
I was wondering, it you still have you're Schertler DYN-B?
If that's the case, I'd be curious if you put it over the same spot, what the bass response would be like? Might be worth trying, I know the the optimal location of the DYN-B is over on the side of the G foot of the bass bridge, but they're both contact microphones, so it might tell you what the bass response is in that location. Just a thought.
That might tell you if it's only the Ehrlund doing that or if that location is bass deficient.

Ric