TTT wrote:
"Stephen McLuckie" wrote in message
et...
TT wrote:
Hi

I'm building a 1x12" speaker cabinet to use with my guitar amp head. I
have all the thiele/small parameters for my speaker, and have used a
program called BandBox Pro to design the speaker cabinet. I have also
used a program called WinIsd to check and both programs give me similiar
results.
What's the speaker model and what are the basic parameters?

It's Eminence Cannabis Rex

fs: 96Hz
6.56
Le: 0.44mH
Qms: 9.28
Qes: 0.69
Qts: 0.64
Vas: 50.0 litres
Vd: 45cc
Cms: 0.11mm/N
BL: 11.8 T-M
Mms: 24 grams
EBP: 139
Xmax: 0.8mm
Sd: 558.6cm2

8ohm, 50W, sensitivity 102.

TTT



With an Xmax of only 0.8mm, you really do need to keep the bass out of
this speaker. I haven't come across it before - being from the UK,
Celestion has always been the first choice.

d

Stephen McLuckie wrote:

Use a speaker designed for guitar

Typically one with a paper suspension at the edge rather than linen for more overtones.

Graham

Trevor Wilson wrote:


**Nonsense. The lowest useful frequency from a bass guitar is higher than
80Hz. Almost no fundamental is audible. It's all second harmonic.

Because it's an amplified instrument, the amount of fundamental present depends purely on how much you dial in. That, of course, depends on a lot of things, but an amplified bass is still quite capable of generating large amounts of 41Hz.

Commercial bass guitar amp manufacturers tune their cabs to between 40 and 50Hz. Some even mention this on their websites. If you can show me a company that tunes to above 80Hz, I'll give you a banana.

TTT wrote:
"Stephen McLuckie" wrote in message
What's the speaker model and what are the basic parameters?

It's Eminence Cannabis Rex

That particular driver has quite a good reputation.

Apart from the fact that virtually nobody builds reflex cabs for electric guitar, a Qts of .64 does not really lend itself to a reflex design. It's too high. Putting this driver in a 150 litre box will give you a flat response down to 60Hz, which you really don't need - or want.

I put the parameters through Eminence's own box design software and it suggests anything between 15 and 50 litres for a sealed cab. 25 litres looked quite good with a Qtc of .82. It's certainly quite forgiving in terms of box size.

Eminence says it is suitable for both sealed and open back cabinets. Here's a guitar amp that uses one: http://www.carramps.com/hammerheadmk2.html#specs.
The site contains a sound sample (which is quite impressive) and the dimensions of their 1 x 12 cabinet using that driver. You could do a lot worse than simply copying that particular box.

"Stephen McLuckie"
Trevor Wilson wrote:


**Nonsense. The lowest useful frequency from a bass guitar is higher than
80Hz. Almost no fundamental is audible. It's all second harmonic.

Because it's an amplified instrument, the amount of fundamental present
depends purely on how much you dial in.


** Plus, of course, how and where along its length the player excites the
string.


That, of course, depends on a lot of things, but an amplified bass is
still
quite capable of generating large amounts of 41 Hz.


** Pure sine wave are perfectly possible with many electric basses.


Commercial bass guitar amp manufacturers tune their cabs to between 40 and
50Hz. Some even mention this on their websites. If you can show
me a company that tunes to above 80Hz, I'll give you a banana.


** TW would appreciate that - being the trumped up Google monkey he is.

Bet he has never examined or tested an electric bass guitar in his life.

Nor any bass amp of any kind.




..... Phil

"Stephen McLuckie" wrote in message
et...
Trevor Wilson wrote:


**Nonsense. The lowest useful frequency from a bass guitar is higher than
80Hz. Almost no fundamental is audible. It's all second harmonic.

Because it's an amplified instrument, the amount of fundamental present
depends purely on how much you dial in. That, of course, depends on a lot
of things, but an amplified bass is still quite capable of generating
large amounts of 41Hz.

**I've measured a few and none (that I've measured) deliver appreciable
amounts of fundamental. By appreciable, I mean more than 10dB below the
second harmonic.


Commercial bass guitar amp manufacturers tune their cabs to between 40 and
50Hz. Some even mention this on their websites. If you can show me a
company that tunes to above 80Hz, I'll give you a banana.

**Tuning above 80Hz would not be smart. Tuning APPRECIABLY below 80Hz is
simply wasteful. There is no point in tuning to 50Hz. IF (and I have
certainly not measured every guitar) a guitar exists that delivers
appreciable fundamental, then and only then, would there be a point to tune
at or around 40Hz.


--
Trevor Wilson
www.rageaudio.com.au

"Eiron"

WinISD will allow you to tweak the box and port size, and show the
frequency response graph.
So there's no problem.


** There IS one trap though - you must have an amplifier with low output
impedance( ie good damping factor) or the response graph model used by
simulators like WinISD are gonna be hopelessly wrong.

Most SS bass guitar and guitar amps have low output impedance - but some
are deliberately made to have a high one. Which is which is not east to
tell as makers very rarely spec it.

With valve guitar amps, the vast majority have high output impedance (
anywhere from 5 to 100 ohms) though again exceptions exist there too.



...... Phil

"Stephen McLuckie" wrote in message
et...
Trevor Wilson wrote:


**If you use a bass guitar, then don't bother tuning much below 80Hz. For
lead/rhythm guitars, there is no need for any signal remotely that low.
Use a smaller box and tune higher.

I have been following this list for a while - mainly, but not always, as a
lurker - and I must say, I am in awe of the knowledge and expertise of the
people who post here. It's interesting, however, that there are a few
areas in which complete ignorance reigns.

Because the lowest frequency of a bass guitar cab (4-string) is around
40Hz, you should tune a bass guitar cab to around 45Hz. For normal
electric guitar, don't use a reflex cab, use a sealed cab or an
open-backed cab, depending on the parameters of the speaker.

5-string bass guitars are not uncommon - particularly
on recording sessions. The lowest string is normally
tuned to B natural, at approx 30Hz.

Iain

"Stephen McLuckie" wrote in message
...
TTT wrote:
"Stephen McLuckie" wrote in message
What's the speaker model and what are the basic parameters?

It's Eminence Cannabis Rex

That particular driver has quite a good reputation.

Apart from the fact that virtually nobody builds reflex cabs for electric
guitar, a Qts of .64 does not really lend itself to a reflex design. It's
too high. Putting this driver in a 150 litre box will give you a flat
response down to 60Hz, which you really don't need - or want.

I put the parameters through Eminence's own box design software and it
suggests anything between 15 and 50 litres for a sealed cab. 25 litres
looked quite good with a Qtc of .82. It's certainly quite forgiving in
terms of box size.

Eminence says it is suitable for both sealed and open back cabinets.
Here's a guitar amp that uses one:
http://www.carramps.com/hammerheadmk2.html#specs.
The site contains a sound sample (which is quite impressive) and the
dimensions of their 1 x 12 cabinet using that driver. You could do a lot
worse than simply copying that particular box.

So if I put a driver like this in a 150 litre box, what problems do I
encounter? Why are guitar speakers put into small boxes? To control the
amount of bass they produce?
How will my 150 litre box sound? It's already nearly finished, what kind of
results are you predicting I will get? If it is too bassy I will remove the
bass reflex holes and then I will have a 150 litre sealed cab. How do you
think it will work that way?

From my experience, normal guitar cabs sound like they lack in bass
response. They are tight, and clear, I want something with a bit more bass.
What should I go for?

Many thanks for the good discussion and helpful answers in this group

TTT

"Trevor Wilson" wrote
in message

**Nonsense. The lowest useful frequency from a bass
guitar is higher than 80Hz. Almost no fundamental is
audible. It's all second harmonic.

Written by someone who has obviously never actually analyzed the signal that
comes out of a pickup from a bass guitar.

The fundamentals can be there if you don't lose them along the way.

I do suspect that few bass guitar amps are actually competent reproducers of
the region 32 Hz, which is approximately the fundamental of the lowest note
playable on a 5-string bass guitar.