Team Trace Elliot pt4.

[John D Harris]

The low frequency response will vary with the cabinet design, so the raw response plot is not indicative of how the driver performs in the ELF 2x8. AFAIK raw response curves are developed with the driver essentially mounted on a flat panel in an anechoic room.

Not sure if most companies use the same or similar procedure, but you may find this page informative.

What is a Frequency Response Chart? | Jensen Loudspeakers

www.jensentone.com

Here's an example using the Eminence 3015LF (for convenience). The charts are not scaled the same, so I aligned them at 100hz. The top chart is the raw response plot for the 3015LF. The bottom plot is the 3015LF in a 6.651 cu ft enclosure tuned to 38hz.
View attachment 7021549

I see what you mean.
I looked the driver up on parts-express DOT com and here's what they showed:

Parts Express Staff Recommended Enclosure Volume​
Sealed Volume	0.3ft³
Sealed F3	131.8Hz
Vented Volume	0.6ft³
Vented F3	55.8Hz

[~ Never mind the sealed data. ~]

So not too shabby for a small cab.
2x8 (and twice the cab volume) should go a bit lower.
Thank you again for going to the trouble to give me this information!

 

[JMX]

My new Tracey...

Great condition, still has the original tubes, which are supposed to be still good. Amazing Sound, but has quite some ground hum, unfortunately, but a recap after 32 years is inevitable, I guess.

 

[Wood and Wire]

View attachment 7086377

My new Tracey...

Great condition, still has the original tubes, which are supposed to be still good. Amazing Sound, but has quite some ground hum, unfortunately, but a recap after 32 years is inevitable, I guess.

Is the ground hum present at the speaker output, D.I. effects send, line out, and headphones out?

Checking where it is, and isn't present, should help you track it down.

This wouldn't apply to your amp, but I found that when I had a constant low frequency hum, it turned out to be because there was no bulb in the blacklight socket, and simply disconnect the flying lead from the quick connect at the starter, solved the problem - you may have an equally simple, non-invasive solution.

 

[B-string]

View attachment 7086377

My new Tracey...

Great condition, still has the original tubes, which are supposed to be still good. Amazing Sound, but has quite some ground hum, unfortunately, but a recap after 32 years is inevitable, I guess.

32 years on the caps is no guarantee, I've seen 98% of 60 year old caps just fine still. There is a procedure to "reform" caps if you are concerned. I am not comfortable posting it not knowing the expertise of everyone who may read it. The best I have found involved an inline component added temporarily. A browser search would be your friend. Lots of things to check and look at before you go dumping caps.

 

[JMX]

Thanks for the advice. I know a very good tech, I'll have him take a look at it.

 

[B-string]

Not saying this will apply to your amp, but as an example to impart to you. Before I moved and was still doing repairs a local Bassist I knew well finally bit the bullet on a 1972 Ampeg SVT. Sounded pretty good but it had this annoying hum. A local ripoff shop quoted almost a grand to do a full re-cap and misc new tubes. I had him bring it over, long story short , Hum Balance pot adjust, properly bias and the amp was healthy. Had a few cosmetic issues, but it was a player.
Sometimes it can be simple before someone actually makes it hard.