Ampeg Isovent - Jack Plate Circuit Board.

[candiehappy]

Anyway I am fairly certain the F Bomb comes from the Cross Over circuit board since independently the F Bomb exists in the 210s and the 215s separately.

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Like the previous person said, the crossover could not possibly be the problem. It has ZERO effect at the frequency you are complaining about. It only affected the high end, read up on how crossovers work as low-pass/high-pass filters and you should be able understand the basic principals and understand and accept this explanation. It is not the electronics in the cross-over.

What you are experiencing comb filtering like phenomenon. That particular frequency and that particular speaker cone is making that frequency much louder than the others because of physics NOT electronics. If it is only happening in the cabinet, then the cabinet is causing it. If it is happening outside the cabinet then it is the speaker cones and the driver. If it happens only on a single bass it is a combination of the pickups in the bass and the speakers interacting.

I had a set of speaker cones that did this exact same thing, but on a different note and it was about 2 to 3 times louder than any other notes I played depending on how far up the neck I was playing. Higher frequency notes were much louder than the same notes that were lower. But the lower ones were still way louder than any other note. I gave that combo amp away on craigslist 14 years ago so I do not remember the specifics. It was a 1966 tube amp with no crossover electronics.

The real way to understand and "see" this is with a oscilloscope and waveform monitor and you can see what is getting boosted and figure out how to eq it out at the bass, amp or with a pedal.

 

[candiehappy]

Maybe you misunderstood me.
This is the common point is the Crossover Board and this means something ON the Crossover Board is Building UP F Frequencies causing the F Bomb.
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That is not how electronics like this work, especially the electronics you posted pictures of.

 

[agedhorse]

There isn't even any low pass filtering on the crossover!

 

[radiopicture]

I think the light bulb goes off when you close up the cabinet but no one knows for sure. I had the 2-12 Orange version of this. If did produce huge volume levels from a tiny cabinet, but required a boatload of power (which is no problem with modern class-D amps). There was a certain wonkiness to it that I couldn't quite figure out, but it had its merits. This seems like a physical / acoustical quirk in the case of the writer's IsoVent.

 

[candiehappy]

Both speakers work, they all work.

They fully understand what I have been saying to all of you and were are going to ReWire it with a much simpler Wiring Scheme WITHOUT the Crossover.

You do not fully understand that the crossover can not possibly be the problem.

 

[candiehappy]

Presumably you were able to diagnose tank problems because you had a great deal of training and experience that gave you a thorough understanding of the various systems involved. You have evidenced no such knowledge base about the subject of your initial inquiry...in fact, you have shown a considerable lack of it, all while asserting "I know things".

Dunning/Kruger Effect is a thing for a reason! It is on full display with the OP.

 

[NKBassman]

Dunning/Kruger Effect is a thing for a reason! It is on full display with the OP.

The DK Effect is my favorite thing that I learned last year.

 

[candiehappy]

The DK Effect is my favorite thing that I learned last year.

This is where we are all at on this thing!

 

[BassmanPaul]

I find this thread sad. A lot of us come here to help our fellow bassists get around problems they encounter. It's doubly sad that the OP will not listen to the good advise he has been given by very knowledgeable folk and is stuck in a rut about the crossover board. I guess we'll see how it goes without said board. <sigh>

 

[Jeff Scott]

Why do you (the OP) love this cab so much to invest in an additional EQ just to make it usable?

The OP mentioned in a post that his favorite band used these (like 30 years ago, or something). But, they (Metallica, IIRC) quickly moved onto better sounding gear once they realized their mistake.

 

[NKBassman]

The OP mentioned in a post that his favorite band used these (like 30 years ago, or something). But, they (Metallica, IIRC) quickly moved onto better sounding gear once they realized their mistake.

lol I’ve been suckered into the folly of buying the gear my favourite bands use(d) multiple times. Also similar to OP, I once even tried to rehab a new production “boutique” cabinet that turned out to be just a poorly designed shell of pretty plywood. For all my effort in trying to fix what was wrong with it, the Best thing I ever did was sell it and move on with my life. Absolutely no regrets.

Also, I learned a bit about cab design along the way, thanks in no small part to @agedhorse and many other helpful and knowledgeable TB members.

 

[farace]

OP is searching for an alchemy "lead into gold" solution. You guys keep giving him science. No wonder he's frustrated.

 

[NKBassman]

OP is searching for an alchemy "lead into gold" solution. You guys keep giving him science. No wonder he's frustrated.

OP has already made up his mind on what the problem is and he’s looking for validation. Clearly the circuit board must be the problem because the speakers are connected to the board. Meanwhile, what do Inductors and Capacitors do?

 

[farace]

Meanwhile, what do Inductors and Capacitors do?

Nothing at all when they've been taken out of the circuit by removing the horn. Nothing at all anyway, in this case, since they're operating far above the trouble frequency. It's like wondering why the blender on your kitchen counter is not working and trying to fix it by unplugging the food processor just because they're both plugged into the same outlet.

 

[NKBassman]

What do Inductors and Caps do?
Also do you see anything which could potentially Intensify the F frequencies?

Inductors are sometimes called coils or chokes, and capacitors are sometimes called caps or condensers. In this application, those components are what are used to allow certain frequencies to pass, and allow others to be blocked. It’s how crossovers are designed. It can be as simple as one cap or one coil, all the way to a board chock-full of components.
In simple terms, if you want to lo-pass a woofer, IOW, send only frequencies below a certain Hz thereby blocking everything above, a coil would do.
If you wanted to hi-pass a tweeter, IOW send only frequencies above a certain Hz thereby blocking everything below, a cap is used.

FYI Chokes are inductors AFAIK.

Okay sounds good, but what could ne Building Up an Intense F?
Something tells me that between Choking and Blocking is a Build Up of F Frequencies causing the F Bomb to Overload.

How can I improve this set up.
For example what would be a better way of protecting against the Slamming Overloading - besides using a light bulb?
How can I pass All Frequencies without building up the F Bomb?

Maybe you misunderstood me.
I am trying to get rid of the F Bomb which seems to be in common with both the 210s and the 215s, and this common point is the Crossover Circuit Board.
How about that?
There is something on the Crossover Circuit Board causing the Build Up and Intensification of the F frequencies thereby causing the F Bomb.
I am trying to get rid if the F Bomb.
The Crossover Circuit Board seems to be the Source of the F Bomb.
This is the common point is the Crossover Board and this means something ON the Crossover Board is Building UP F Frequencies causing the F Bomb.
Get It?
Now what is that something?

I'm starting to feel bad. I'm not intentionally trying to be mean or pick on the OP here, but this exchange is rather damning.

 

[NKBassman]

Nothing at all when they've been taken out of the circuit by removing the horn. Nothing at all anyway, in this case, since they're operating far above the trouble frequency. It's like wondering why the blender on your kitchen counter is not working and trying to fix it by unplugging the food processor just because they're both plugged into the same outlet.

I know what they do. I was paraphrasing.

 

[DJ Bebop]

Both speakers work, they all work.

All four speakers are 16 Ohms, a couple of friends are going to ReWirethe Isovent since I am a bit busy with work, and they have the Jack Plate minus the Crossover, I have fully put the Isovent back together, and later this week I will be taking it to their pllace.

They fully understand what I have been saying to all of you and were are going to ReWire it with a much simpler Wiring Scheme WITHOUT the Crossover.

When you 'test' the speakers outside the cabinet, are they still connected to the other speakers via the crossover you are not testing? And if so, are the other speakers still in the cabinet producing sound?
At the same time?
Ampeg Isovent - Jack Plate Circuit Board.

 

[DJ Bebop]

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And, your point?
Yes, these speakers are still used, just not for bass guitar. like the cabinet, you are trying to revive.

 

[DJ Bebop]

OP is searching for an alchemy "lead into gold" solution. You guys keep giving him science. No wonder he's frustrated.

 

[Jim C]

Every time I open this thread, all I can think of is "no good deed goes unpunished".

To the OP:
There are people here with more years of tech experience than could be learned in a single lifetime.
Why fight clear and logical trouble shooting techniques?
I think this is actually a very simple problem to diagnose yet very little tech advice has been taken seriously by people who design, build, and repair these devices as their profession.