Question about Bass Cab Speaker Pairing / Dimension / math etc.

[raketenmann]

Deal Community

I know that probably a lot of you will argue that my plans are no good, but still I am trying to figure out if it could work or not

I am a guitar player that plays sometimes bass. I like old school sounds, nothing super deep modern. I like Ampeg or Orange Bass tones. So I have this old Carlsbro Cab fom the late 60ies that was built for guitar, a Tall 4x12 cab, which is oversized and way bigger than a regular Marshall 4x12. I would like to convert it to a bass cab - the speakers need to be replaced and I have no use for another guitar cab, but I love that cab for its style, therefore I would like to keep it and probably use it sometimes for bass tone. I know, it is likely not to be eathshaking and for most of modern bass players not satisfying - but as we all know Lemmy also played a 4x12 cab and had a tone that at least some bass players find adorable.
So I would liket to but in 4 Celestions Pulse 12, making the cab an 8 Ohm 800 watt cab.

I am just wondering if this will be a somewhat working pairing for my needs? I know some speakers are not made to be used in closed cabs, but I think the Pulse 12 can do that.

The inside dimensions of the cab would be 280mm deep, 725mm wide and 915mm high.

What are your thoughts? I am very curious!

 

[raketenmann]

Deal Community

I know that probably a lot of you will argue that my plans are no good, but still I am trying to figure out if it could work or not

I am a guitar player that plays sometimes bass. I like old school sounds, nothing super deep modern. I like Ampeg or Orange Bass tones. So I have this old Carlsbro Cab fom the late 60ies that was built for guitar, a Tall 4x12 cab, which is oversized and way bigger than a regular Marshall 4x12. I would like to convert it to a bass cab - the speakers need to be replaced and I have no use for another guitar cab, but I love that cab for its style, therefore I would like to keep it and probably use it sometimes for bass tone. I know, it is likely not to be eathshaking and for most of modern bass players not satisfying - but as we all know Lemmy also played a 4x12 cab and had a tone that at least some bass players find adorable.
So I would liket to put in 4 Celestions Pulse 12, making the cab an 8 Ohm 800 watt cab.

I am just wondering if this will be a somewhat working pairing for my needs? I know some speakers are not made to be used in closed cabs, but I think the Pulse 12 can do that.

The inside dimensions of the cab would be 280mm deep, 725mm wide and 915mm high.

What are your thoughts? I am very curious!

 

[KevInDaBassment]

You're going to get plenty of explanation as to why, but I'll keep it short and sweet....

- Don't do that
- Buy a bass cab that's already designed to work with bass amps
- NEVER buy a cab for (or start based on) looks...that needs to come after power handling/tone
- This isn't a matter of "tone", it's a matter of blowing or tearing up your speakers


EDIT: Ok, so as not to be completely negative...the only way I could see this working is if you ran your bass into a GUITAR tube amp/head, then keep some guitar speakers in the cabinet, and run the GUITAR tube amp into that cabinet. You'll get far less low end, since the head may be applying a HPF of sorts and the speakers won't really go down that low anyways.

Now if you're running a stereo rig, with a bass head hooked up to a bass cabinet and then a guitar amp head to the aforementioned cabinet (loaded with guitar speakers) then you're running a rig like Dug Pinnick did for years. However, you can get similar/better results from a modern-designed cabinet with a focus on full-range response. You could also look for a cab with an adjustable tweeter and get plenty of high end (or maybe too much).

My honest opinion is I'd either do that with the guitar cab or sell it. You're trying to use a hammer as a screwdriver here...sure, it'll hammer the screw into the wall like a nail, but the threading on the screw is now pointless and it's actually worse than just using a nail to begin with.

 

[blr2]

In order to work as a bass cab, the enclosure should be calculated for the speakers that are to be mounted in it. In a random enclosure, even best speakers may sound boomy, thin or honky... 4 Pulse 12s will be $350-400, so an expensive experiment that will, most probably, end in frustration. .

 

[raketenmann]

You're going to get plenty of explanation as to why, but I'll keep it short and sweet....

- Don't do that
- Buy a bass cab that's already designed to work with bass amps
- NEVER buy a cab for (or start based on) looks...that needs to come after power handling/tone
- This isn't a matter of "tone", it's a matter of blowing or tearing up your speakers


EDIT: Ok, so as not to be completely negative...the only way I could see this working is if you ran your bass into a GUITAR tube amp/head, then keep some guitar speakers in the cabinet, and run the GUITAR tube amp into that cabinet. You'll get far less low end, since the head may be applying a HPF of sorts and the speakers won't really go down that low anyways.

Now if you're running a stereo rig, with a bass head hooked up to a bass cabinet and then a guitar amp head to the aforementioned cabinet (loaded with guitar speakers) then you're running a rig like Dug Pinnick did for years. However, you can get similar/better results from a modern-designed cabinet with a focus on full-range response. You could also look for a cab with an adjustable tweeter and get plenty of high end (or maybe too much).

My honest opinion is I'd either do that with the guitar cab or sell it. You're trying to use a hammer as a screwdriver here...sure, it'll hammer the screw into the wall like a nail, but the threading on the screw is now pointless and it's actually worse than just using a nail to begin with.

Exactly this is what I expected. But my question would be: Is there anyone who can give me the maths?

 

[raketenmann]

In order to work as a bass cab, the enclosure should be calculated for the speakers that are to be mounted in it. In a random enclosure, even best speakers may sound boomy, thin or honky... 4 Pulse 12s will be $350-400, so an expensive experiment that will, most probably, end in frustration. .

Yes, I know. So are you able to do the maths?

 

[wjcstp]

Exactly this is what I expected. But my question would be: Is there anyone who can give me the maths?

I don't have the math, but the method is to look up the specs for those speakers and find the cab volume recommended for a 4x configuration (manufacturers often supply this), then compare it to the cab you have.

OTOH, for 1/2 the price of just those speakers you could likely find a bass cab with 410s or 412s.

 

[blr2]

Yes, I know. So are you able to do the maths?

There is software that can do this for you, but chances this particular enclosure to suit these speakers are extremely slim. Not worth $400. For that money, you can get a nice preowned bass cab, or even something new.

 

[agedhorse]

Is the existing cabinet completely closed, or is it partially open back?

 

[raketenmann]

Is the existing cabinet completely closed, or is it partially open back?

completely closed

 

[raketenmann]

There are these specs I don't know what to do with it...

Sd
530.9cm2 / 82.29in2
Fs
45Hz
Mms
47.6g / 1.68oz
Qms
2.74
Qes
0.49
Qts
0.42
Re
5.8Ω
Vas
104.6l / 3.7ft3
BI
12.71Tm
Cms
0.26mm/N
Rms
4.92kg/s
Le (at 1kHz)
1.0mH
Xmax
4mm / 0.15in

 

[dbsfgyd1]

Deal Community

I know that probably a lot of you will argue that my plans are no good, but still I am trying to figure out if it could work or not

I am a guitar player that plays sometimes bass. I like old school sounds, nothing super deep modern. I like Ampeg or Orange Bass tones. So I have this old Carlsbro Cab fom the late 60ies that was built for guitar, a Tall 4x12 cab, which is oversized and way bigger than a regular Marshall 4x12. I would like to convert it to a bass cab - the speakers need to be replaced and I have no use for another guitar cab, but I love that cab for its style, therefore I would like to keep it and probably use it sometimes for bass tone. I know, it is likely not to be eathshaking and for most of modern bass players not satisfying - but as we all know Lemmy also played a 4x12 cab and had a tone that at least some bass players find adorable.
So I would liket to but in 4 Celestions Pulse 12, making the cab an 8 Ohm 800 watt cab.

I am just wondering if this will be a somewhat working pairing for my needs? I know some speakers are not made to be used in closed cabs, but I think the Pulse 12 can do that.

The inside dimensions of the cab would be 280mm deep, 725mm wide and 915mm high.

What are your thoughts? I am very curious!

There is already good advice posted. Cabs and speakers are designed to function as one unit. They both have specific characteristics so they can work as one. Add a variable to the equation , what you will end up with is just speakers in a box and most likely something that will not provide a suitable sound, and or if not properly matched may result in the premature failure of your drivers.

Further, there is more than just calculating ti interior dimensions of the cab. Proper spacing between drivers and porting (if any) are additional considerations, so it's not just about some simple arithmetic and replacing drivers.

I'm not trying to tell you what to do, it's your checkbook and cab you want to repurpose. Me, I'm with the first responder to your post. This is not a cost effective option with too much potential for failure. JMO.

 

[raketenmann]

There is software that can do this for you, but chances this particular enclosure to suit these speakers are extremely slim. Not worth $400. For that money, you can get a nice preowned bass cab, or even something new.

Yes - I don't know to use these softwares. Therefore I am asking for help of the experienced ones.

I knowI could get a cheap bass cabinet for that price. I also know that it is probably not worth it money wise. But right at the moment I aminterested in a clear statement with the maths done that it is no way gonna work and speakers will blow up.

 

[agedhorse]

completely closed

Then it may be possible.

Is it worth doing is another question. Also, the results may not be what you want or expect. That's why buying a finished cabinet that you can try out BEFORE spending a bunch of money is generally a better idea.

 

[raketenmann]

There is already good advice posted. Cabs and speakers are designed to function as one unit. They both have specific characteristics so they can work as one. Add a variable to the equation , what you will end up with is just speakers in a box and most likely something that will not provide a suitable sound, and or if not properly matched may result in the premature failure of your drivers.

Further, there is more than just calculating ti interior dimensions of the cab. Proper spacing between drivers and porting (if any) are additional considerations, so it's not just about some simple arithmetic and replacing drivers.

I'm not trying to tell you what to do, it's your checkbook and cab you want to repurpose. Me, I'm with the first responder to your post. This is not a cost effective option with too much potential for failure. JMO.

Yes, I know it is not cost effective - that was never the idea. The idea is to keep a nice cab that looks cool and get some use out of it. If this is not possible, then I will not do so. But at the moment I am looking for a clear statement, not "chances are high it won't work" - if it is possible to match a speaker to a specific cab, it should be possible to match my cab to a certain speaker - doesn't it. I would like to learn something about this process.

OK, so I see the volume alone is not all that matters... I could measure the distance from the speakers, no problem....

 

[blr2]

Yes - I don't know to use these softwares. Therefore I am asking for help of the experienced ones.

I knowI could get a cheap bass cabinet for that price. I also know that it is probably not worth it money wise. But right at the moment I aminterested in a clear statement with the maths done that it is no way gonna work and speakers will blow up.

I doubt that someone will be willing to perform these calculations, just because you want to make some experiment, but just in case, you will have to supply:

1. Accurate measurements of the internal size of the cab.
2. Thiele/Small parameters of the speakers that you decided to play with.
3. Intended design (i.e. closed or ported).

 

[raketenmann]

Then it may be possible.

Is it worth doing is another question. Also, the results may not be what you want or expect. That's why buying a finished cabinet that you can try out BEFORE spending a bunch of money is generally a better idea.

Yes - I see. But that is actually not what I am up to at the moment. Sometimes I like the idea of soing something crazy


If the cabinet sounds completely garbage, I can send the speakers back. I have a 30 day money back warranty at Thomann, this is not the case. But I need to know if the speakers can handle being pushed in that enclosure... So would need someone who can do the maths....

 

[KevInDaBassment]

Exactly this is what I expected. But my question would be: Is there anyone who can give me the maths?

"The maths" to what?

Each bass cabinet and speaker is different, so the more efficient way to do it is look up the Thiele-Small parameters for the speaker you want to use and design the cab around it. That information would also be more readily available for the speakers.

You don't need to know the biochemistry of burning fossil fuels to know putting Diesel into a car that only does Regular Unleaded is a bad idea. You're asking how to redesign a car engine to use Diesel instead....

Can it be done? Possibly, depends on the engine.
Is it worth the time and effort? Will it give you decent results? Very likely not...

 

[raketenmann]

I doubt that someone will be willing to perform these calculations, just because you want to make some experiment, but just in case, you will have to supply:

1. Accurate measurements of the internal size of the cab.
2. Thiele/Small parameters of the speakers that you decided to play with.
3. Intended design (i.e. closed or ported).

OK - since I don't know how time consuming the process of the caluculation is... Yes, if it is to much work, I see... but if not:

1. 80mm deep, 725mm wide and 915mm high (accurate inside measurement
2. I don't know what parameters these are, the celestion page shows me some parameters:

PULSE12 - Celestion

These 200W 12 inch bass guitar speakers by Celestion deliver an ideal combination of responsiveness and rock solid low end.

celestion.com

3. closed cab

 

[raketenmann]

Each bass cabinet and speaker is different, so the more efficient way to do it is look up the Thiele-Small parameters for the speaker you want to use and design the cab around it. That information would also be more readily available for the speakers.

As I posted in the latest post, I don't know what parameters these are, but Celestion provides some information for that speaker:

PULSE12 - Celestion

These 200W 12 inch bass guitar speakers by Celestion deliver an ideal combination of responsiveness and rock solid low end.

celestion.com

You don't need to know the biochemistry of burning fossil fuels to know putting Diesel into a car that only does Regular Unleaded is a bad idea. You're asking how to redesign a car engine to use Diesel instead....

Well, not exactly - or not as I would put it. You've ever seen a VW Beetle rolling by with an E-Motor? Makes absolutely no sense. But it has style!



EDIT: As I mentioned before: If it is possible to design a cab around a speaker it should be doable to reverse engineer it? I just don't know how to do that, but is it really that complicated for the people that know how to do that?