Tinitus - any progress?
A bass guitar speaker question of my own - what's the general opinion of aluminium coned drivers?
I'm currently using (for bass guitar, practice only) a 10" combo amp of around 30w. The driver that's in is a paper coned midbass that, while sounding okay for the lower bits, doesn't have much top end.
A local supplier is selling these for under £20, so I was wondering if anyone thought it might be worth a try.
Cheers,
Chris
A bass guitar speaker question of my own - what's the general opinion of aluminium coned drivers?
I'm currently using (for bass guitar, practice only) a 10" combo amp of around 30w. The driver that's in is a paper coned midbass that, while sounding okay for the lower bits, doesn't have much top end.
A local supplier is selling these for under £20, so I was wondering if anyone thought it might be worth a try.
Cheers,
Chris
hey, have been busy with other projects
but ready to make a bit more sawdust
the alu cone woofer you link to
Xmax a bit low
but might work if not too loud
sensitivity and powerhandling on the low side too
but same again, if not too loud...
Qts is very high
use for open back only
a low cut filter ought help on several of those reservations
this 12" from same supplier looks stupidly good for the money asked
MCM Audio Select 12'' Die Cast Woofer with Paper Cone and Cloth Surround - 150W RMS 8ohm | 55-2962 (552962) | MCM Audio Select
I'll be ordering the driver at a local shop. They have the range of aluminium coned speakers, some Visaton stuff, and a few other midbasses (almost all poly cone) from MCM.
The combo amp I'm using is open backed, maybe 30-40w outputput, but, as it was originally a guitar amp, there is some low frequency filtering that cuts speaker excursion nicely.
I'm torn between rebuilding it so it's deeper, and add a (removable) back, or just buy a practice amp that has all the features I might need (compressor/limiter, overdrive?).
I think I'd prefer a short Xmax driver (the one I'm using has ~3mm), so long as Xmech was reasonably big, so I'd get some mechanical compression if I was to push it.
Chris
The combo amp I'm using is open backed, maybe 30-40w outputput, but, as it was originally a guitar amp, there is some low frequency filtering that cuts speaker excursion nicely.
I'm torn between rebuilding it so it's deeper, and add a (removable) back, or just buy a practice amp that has all the features I might need (compressor/limiter, overdrive?).
I think I'd prefer a short Xmax driver (the one I'm using has ~3mm), so long as Xmech was reasonably big, so I'd get some mechanical compression if I was to push it.
Chris
Cheers Pete, the combo it'll be put in (until I rebuild it, deeper and sealed) will be open back, but it's still only a bedroom practice amp, so it's likely to be okay for now. When I come to compete with the drummer, I'll probably mic the amp up anyway, so there's no need for huge SPLs from it.
I'm still working on altering the pre-amp frequency response (there's lots of bass cut, even with bass up to 10), so those cones will fly
I'm still working on altering the pre-amp frequency response (there's lots of bass cut, even with bass up to 10), so those cones will fly
Here is a website that should be checked out by anyone wanting to build their own bass cab. The fEarful project is fairly recent and is the subject of many threads over on the talkbass forum. There are lots of contributions from builders with pics and tips and reviews etc. I myself am planning on building two of the 15/6 tube cabs this summer when the weather improves.
fEARful enclosures for bass/drums/keys
Here's the designers web site. He has in essence contributed the designs to the bass playing DIY community.
Apologies to all if someone else has already pointed this out.
Graeme
fEARful enclosures for bass/drums/keys
Here's the designers web site. He has in essence contributed the designs to the bass playing DIY community.
Apologies to all if someone else has already pointed this out.
Graeme
Oh, I want to scream. Earlier this evening, I was looking at what I believe is the commonly used default equation for a closed box, and now I can't find it.
Roughly it was:
(Qb / Qts)squared = (Vb / Vas) + 1
Now, I might have reversed some parameters, I had a speaker handy that had a Qts of .7, and since a "flat" box has a Qb of .707 the left side came out to 1. And, since we add 1 to the expression on the right side, obviously this equation can't handle speakers with a Qts of over .7
But this equation is for "acoustic suspension" speakers, where the box adds compliance to the speaker, and a speaker with a Qts over .7 is quite happy working in free air (ie, an open backed combo). But bass players don't appreciate the cancellation you get with an open back, so....
In my experience with high Qts speakers, as long as the box is at least twice the size of Vas you won't get boomy, one note bass. Three times Qts is better.
(hopefully, someone will post the real equation for posterity)
If Qbox is above 0.707 then the speaker has a hump in the LF frequency response.
The closer that Qbox gets to 0.9 the worse the hump gets.
Going further and past Qbox=1 and the speaker is likely to sound terrible.
If the driver has Qts ~0.7 then it needs a Linkwitz transform to reduce the Qbox figure or it needs no box, open baffle, infinite baffle, or some such.
The closer that Qbox gets to 0.9 the worse the hump gets.
Going further and past Qbox=1 and the speaker is likely to sound terrible.
If the driver has Qts ~0.7 then it needs a Linkwitz transform to reduce the Qbox figure or it needs no box, open baffle, infinite baffle, or some such.
More HF?
Chris,
Seems like your original issue was with a lack of HF from the stock speaker in a standard combo guitar amp. Consider that most guitar amp speakers have considerably better HF extension than bass guitar speakers. What you are asking for really will require the installation of a small midrange or a tweeter, if you want to work with the stock speaker. You could just mount a tweeter coaxially, across the front of the 10-inch. Another 10-inch (especially a bass guitar driver) is not likely to provide the HF you are looking for.
An alternative would be to build a 1x12 or 2x10 cab with a midrange or 'low' tweeter. That leaves the combo guitar amp unmodified, and provides much better overall sound quality in a 2.5-3cf box, sealed or ported depending on the driver chosen. Less expensive and smaller would be a 2x8 (8 ohms each) or 4x6 (4 ohms each) in a 1.5-2cf box, sealed or ported. Probably no HF driver required. Nice tone for a practice amp.
If you just want quick, inexpensive and works (better than the existing setup), the stock 10-inch could be replaced with a long Xmax 8 (sealed or ported out the back) and a small tweeter (if needed). The spl's would be limited to moderate practice levels, but the tone could be pretty good.
Unless you can tolerate the HF noise (hiss) from the amp, you are best off choosing a tweeter with only moderate HF extension.
More alternatives...
Regards,
Bob
Chris,
Seems like your original issue was with a lack of HF from the stock speaker in a standard combo guitar amp. Consider that most guitar amp speakers have considerably better HF extension than bass guitar speakers. What you are asking for really will require the installation of a small midrange or a tweeter, if you want to work with the stock speaker. You could just mount a tweeter coaxially, across the front of the 10-inch. Another 10-inch (especially a bass guitar driver) is not likely to provide the HF you are looking for.
An alternative would be to build a 1x12 or 2x10 cab with a midrange or 'low' tweeter. That leaves the combo guitar amp unmodified, and provides much better overall sound quality in a 2.5-3cf box, sealed or ported depending on the driver chosen. Less expensive and smaller would be a 2x8 (8 ohms each) or 4x6 (4 ohms each) in a 1.5-2cf box, sealed or ported. Probably no HF driver required. Nice tone for a practice amp.
If you just want quick, inexpensive and works (better than the existing setup), the stock 10-inch could be replaced with a long Xmax 8 (sealed or ported out the back) and a small tweeter (if needed). The spl's would be limited to moderate practice levels, but the tone could be pretty good.
Unless you can tolerate the HF noise (hiss) from the amp, you are best off choosing a tweeter with only moderate HF extension.
More alternatives...
Regards,
Bob
Bob, thanks.
The driver I'm using is a pro midbass (Eminence 10" driver), but I changed it to a fabric dustcap for guitar use (the paper dustcap had too much HF for guitar use, I wanted something smoother sounding).
To be honest, I'm reasonably happy with how it sounds. There's other things I should probably try before a different amp: new strings (I bought the bass 2nd hand, the strings on are old so probably sound dull), then experiment a little with the tone controls on the combo amp. It's got a lot of bass cut in the pre-amp, so even turning the bass control all the way up doesn't bring things flat again.
Of course, it's an open-backed cabinet, and changing that for something better would certainly help the low end.
I did try adding some piezo tweeters I have lying around, but they're ~93dB @2.83v, and the driver I'm using is 98dB. I'll try the cheap changes first, then try spending a little money if I'm still not 100%.
Chris
The driver I'm using is a pro midbass (Eminence 10" driver), but I changed it to a fabric dustcap for guitar use (the paper dustcap had too much HF for guitar use, I wanted something smoother sounding).
To be honest, I'm reasonably happy with how it sounds. There's other things I should probably try before a different amp: new strings (I bought the bass 2nd hand, the strings on are old so probably sound dull), then experiment a little with the tone controls on the combo amp. It's got a lot of bass cut in the pre-amp, so even turning the bass control all the way up doesn't bring things flat again.
Of course, it's an open-backed cabinet, and changing that for something better would certainly help the low end.
I did try adding some piezo tweeters I have lying around, but they're ~93dB @2.83v, and the driver I'm using is 98dB. I'll try the cheap changes first, then try spending a little money if I'm still not 100%.
Chris
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