Schertler Jam 100: Is this amp idiot proofed?

[dannyg1]

Originally Posted by sdelsolray

Here are two points adding to this discussion:

1) I have a Jam 150. It's three band graphic EQ works quite well for that amp. I did connect the amp's line outputs to my full mini-PA back end (Bryston 3BST and a pair of Daedalus W823 speakers). It did quite well. I noticed the Jam 150's EQ was more noticeable (in terms on cuts and gains) with the larger system and less with the smaller power amp/speakers in the Jam 150 box. I've noticed this in the past with other gear. Less is noticeable with smaller speakers. For example, if I boost EQ at 1K HZ by 10 dB on dinky computer speakers I'm not going to hear much change. Contrast that with the same boost on a high end mini-PA system. The Jam 100 is closer to the former than the later. A Jam 150 or 200 is somewhere in the middle.

2) I've owned and used many different EQ units. While somewhat counter-intuitive, the higher quality EQ units (e.g., Millennia Media, Crane Song, Speck, among others) tend to be less obvious as you increase a boost or gain for any particular EQ filter, whether rolloff, bell, pass, for Q settings, etc.. Cheaper and more faulty EQ circuits tend to be quite obvious when employed, whether though distortion, phase issues or ringing.

On point one, what you’re describing is true for smaller cabinets with not-so-flat response and/or cabinets that are loaded to accentuate their bass response via the resonant response of the box itself. Truly flat speakers respond well to parametric EQ’s and, should the parametric EQ not have huge phase shifts and/or execessive gain problems in their sweeps they should sound similar as well.

On point two, having owned and used parametric EQ’s from Klark Teknik, Ashly, Focusrite all the way down to the lowly ART tube EQ, I can say that they do sound different but almost all of the differences are at the extremes of the sweep and at higher Q’s.

Might it be that you’re attempting to subtly cast doubt on what others have written by suggesting that they must not have yet heard the finer front end EQ’s and vocal channels?

[Cuki79]

I put my JAM 150+ through Room EQ. I used Low input and XLR line out so the speaker is not included in the measurement. Only the preamp and EQ are.



Here are the same measurement with a normalized data on the vertical coordinate (means centered on "zero" dB).



As Dannyg1 said, you don't reach 15dB.

* I read somewhere that the low EQ was more to protect the speaker than to shape tone. One can see it affects mostly ultra low frequencies where the Fishman mini Low EQ is centered on 80z.
* The mid resonance is around 500 Hz. It would be at 750Hz on a Fishman loudbox mini, 800 Hz on the AER compact 60 or around 2 KHz on any mixer. The Baggs PADI for example sweeps its mid from 400Hz to 1.6 kHz. so the JAM150 is like having the PADI mid frequency tuning pot turned to the extreme counterclockwise direction.

[varmonter]

Wow that's pretty impressive.. what does that
"Room eq " do for you? I can read the graph but
What does it do. Maybe I don't want to know.
One less thing to aquire. Ha

[Cuki79]

It's free. It just scans the frequency response of a room or speaker (or any electronic-audio device).

1) It is mainly there to help you adjust your room acoustic: like the Room tuning wizard from QSC touchmix mixer. The idea is too find the resonant frequencies of your room and tame them.

2) You can also capture the impulse response (IR) of a speaker for example and put the IR file in a IR pedal.

I use it only when I want to capture quickly the frequency response of an audio device.

https://www.roomeqwizard.com/

Cuki