Iso Cab Mic questions

kip4

kip4

Well-known member
So I'm going to make an Iso cab with a nice 6" Jenson speaker a fellow forumite donated to me.
And I got to thinking since space is at a premium in my little home recording studio. You gear heads know what i mean.
Is it a good bad idea first off to be thinking I could maybe make a small footprint condensor mic to go inside the cab rather than use the traditional Sm57 on a gooseneck.
I was wondering about using one of those tine condensor capsules used in some of the Niaint mics/ shotgun cartridge mics and making a pcb for the mic pre.
But heres the rub I'd prefer to make it with through the hole componants.
So Is it a good/bad Idea?
If you think its ok please could you point me in the right direction for a schematic or site that might suit my needs for tne TTH idea
thanks
Rich
 
Electret Microphone Element with Leads : Microphones | RadioShack.com

Can't see much point in a better mic cell than that ^? I would also use a cheap ass dynamic capsule which I am sure Rshack have as well.

Greg, I understand your dismay but the whole concept of putting a speaker in an airtight, largely noise tight box flies in the face of so much that we know about good sound that it hardly matters.

I will look it up and see if the Axtrak (I think it was called) is still available. They had a good following and were pretty expensive so I would think a lot of time and work went into making them sound decent?

Dave.
 
ecc83 said:
Electret Microphone Element with Leads : Microphones | RadioShack.com

Can't see much point in a better mic cell than that ^? I would also use a cheap ass dynamic capsule which I am sure Rshack have as well.

Greg, I understand your dismay but the whole concept of putting a speaker in an airtight, largely noise tight box flies in the face of so much that we know about good sound that it hardly matters.

I will look it up and see if the Axtrak (I think it was called) is still available. They had a good following and were pretty expensive so I would think a lot of time and work went into making them sound decent?

Dave.
Click to expand...

Wouldn't an omni mic probably be a bad idea? Think about it, you'd be recording a tiny speaker and picking up a ton of the iso-box. I can't imagine that sounding good.
 
Why don't you just take a 57 apart and get rid of the body? Iirc, the only thing in the body is a transformer, which can be put anywhere, or even discarded. problem solved, without resorting to omni condensers.
 
Unless the internal dimensions are much bigger than a wavelength at guitar frequencies, say <3kHz, any mic you put in there is going to be an "Omni"!

All the normal rules are out of the window, just cut and try.

Dave.
 
I'm with you on the real speaker thing. You cant beat a speaker pushing air and a good ol 57.
But the iso cab will allow me to work in the middle of the night when everyone else is asleep or the wifes trying to watch tv in the next room and I'll be able to push the amp nearer to break up without next doors calling the fuzz.
Then when possible I can rerecord with the amp.
Some fair points here.
Cheers guys
 
kip4 said:
I'm with you on the real speaker thing. You cant beat a speaker pushing air and a good ol 57.
But the iso cab will allow me to work in the middle of the night when everyone else is asleep or the wifes trying to watch tv in the next room and I'll be able to push the amp nearer to break up without next doors calling the fuzz.
Then when possible I can rerecord with the amp.
Some fair points here.
Cheers guys
Click to expand...

What is the rating of the amp and what is the rating of that poor wee speaker?!

Dave.
 
Greg_L said:
Sims. That's the one time an amp sim is truly useful.
Click to expand...
One other use is doing tours of Europe where you have to use rented backline. The guitar amps can range anywhere from a faltering Marshall to a solid state Peavey to a Roland Jazz Chorus. It's so much less of a headache to just have a 4 space rack with a sim and a tuner that can be plugged directly into the PA, if it comes to that.
 
15watt and 15 watt Dave.
I wished the speaker was at least 25-30 but I'm going with Keens second law.
 
kip4 said:
15watt and 15 watt Dave.
I wished the speaker was at least 25-30 but I'm going with Keens second law.
Click to expand...

Hmm, I'd say there is a fair chance you could burn that voice coil out since you will not hear the speaker's "distress".

Best bet is to shunt the speaker with a resistor (22W) equal to the speaker's impedance and adjust the amplifier's output tap accordingly. Still a chance of blowing it but at least there will still be a load on the amp.

Dave.
 
kip4 said:
15watt and 15 watt Dave.
I wished the speaker was at least 25-30 but I'm going with Keens second law.
Click to expand...

Hey Rich! Did you try that little speaker with the Deacy project, or any other amp?
What does it sound like? Useful?

Is it loud enough to really need an iso box?

I get a lot of use out of mine and I'm very glad of it, but If I was making it again I'd make it bigger and dampen the inside more.
To be fair, that was the advice at the time, but you work with what you've got, right?
 
Steenamaroo said:
Hey Rich! Did you try that little speaker with the Deacy project, or any other amp?
What does it sound like? Useful?

Is it loud enough to really need an iso box?

I get a lot of use out of mine and I'm very glad of it, but If I was making it again I'd make it bigger and dampen the inside more.
To be fair, that was the advice at the time, but you work with what you've got, right?
Click to expand...

I sure did try it with the deacy and my fender pj it sounds good mate thanks.
I'm certain it will be loud enough for a smallish iso box.
I have plenty of rockwool left over so no problem there. I really want to build this thing before summer, but I don't want to blow the PJ. Just trying to cover any potential accidents.

When you say put a shunt on it Dave did you mean put a 22w 8 0hm resistor in parallel with the speaker so if the voice coil breaks down at least the amp will see a load and i will get a chance to turn it off and possibly salvage the amp?
 
"When you say put a shunt on it Dave did you mean put a 22w 8 0hm resistor in parallel with the speaker so if the voice coil breaks down at least the amp will see a load and i will get a chance to turn it off and possibly salvage the amp?"

Yes, exactly that. Also the power into the speaker will be about halved so the amp will be getting dirty but with less stress on the speaker.

For those contemplating a bigger, 12" more expensive speaker in an iso-box and hitting it with a Greg-o-masher 100watter I would advise some form of LED power indicator.

Dave.
 
Thanks Dave.

---------- Update ----------

You must spread some Reputation around before giving it to ecc83 again
 
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