Speaker questions?

[big_teee]

I want to build a bass cab with 1 15", and 2 10" speakers.
Problem is they all 3 are 8 ohms.
Is there a feasible way to connect 3 8 ohm speakers.
I guess if you ran them all in parallel you could run them on a 2 ohm tap, or maybe at 4 ohm tap?
Thanks in advance.
T

[g1]

Are they all rated for the same power handling, and do you want them each to receive the same amount of power from the amp?

[big_teee]

This is Hypothetical, but yes they would all be similar wattage.
I haven't purchased anything yet.

[g1]

Put them all in parallel for a 2.6 ohm load, running off the 2 ohm tap will not be a major mismatch.

[Enzo]

He says "tap", but is it a tube amp or solid state? SS amps have no taps per se, and as long as they are OK at 2 ohms, they are OK at higher than that. And yes, I surely would never concern myself over 2.6 ohms in a 2 ohm jack, even if it were a rube amp.


All in parallel, they all equally share power, so 1/3 of total per each. But you have other options. Run the two 10s in series and put that across the 15. That is 5.3 ohms, also a reasonable thing to work with. Now the woofer gets half the power and each 10 gets 1/4 of the power. Sounds imbalanced, but not really. That means all equal, the 10s each would be 3db down. That is only 3db, and that assumed the equal thing. Well look up the efficiency, what if the 10s are already 3db hotter than the 15? Then that would mean they evened right out. Then again maybe the punch of the 10s makes them seem louder when compared to the 15, so a little 3db loss might be cool. Or directional aspects of the 10s versus the 15.


Gonna run all of them full range? or gonna use some sort of crossover elements? PV made a couple cabs that come to mind, the 1516 and the 1820.

The 1516 was a 15" woofer and a pair of 8" mids, and the 1820 was a pair of 10" scorpions on top of an 18" woofer. Those cabs used crossovers. That affects your project. And meet me in the middle, you could run the 15 full range and crossover just the 10s.


You have a lot of options.

[big_teee]

This is just a lot of thinking out loud here.
The amp ain't built either, but it will be a tube amp, either 2 6L6s or 2 6550s.
I can easily, and cheaply get a fender type 60 watt OT, in either 2,4,8, or 4,8,16 ohms.
I thought the 2,4,8 would be better for bass.
I have 4,8,16 OTs on my guitar amps.
So how hard is it to come up with crossovers, don't know anything about them?
And, would it be worth it just for a shop warehouse rig.
If I make the speaker setup big enough to small gig with, then it would probably sell easier, if someone wants it more than me!
T

[g1]

Well, now that you've thrown gigging potential into the mix, consider separate cabs for the 10's and the 15. For real small gigs you can just use one of the cabs, larger gigs use both. Easier to lug around also.

[big_teee]

Well, now that you've thrown gigging potential into the mix, consider separate cabs for the 10's and the 15. For real small gigs you can just use one of the cabs, larger gigs use both. Easier to lug around also.

I think Mojo sells just that.
a single 15 cab, and a pair of 10s in a cab.
Make them where they look good stacked up?
I do like the sound of the 15 bottom end.
Then stick the small head on top.
I think it would better if I could come up with 4 ohm 10".
Then run the two 10s in series paralleled with the 15, and get 4 ohms.
T

[big_teee]

I think Mojo sells just that.
a single 15 cab, and a pair of 10s in a cab.
Make them where they look good stacked up?
I do like the sound of the 15 bottom end.
Then stick the small head on top.
I think it would better if I could come up with 4 ohm 10".
Then run the two 10s in series paralleled with the 15, and get 4 ohms.
T

I looked, and they don't sell their 1x15, and 2x10 bass cabs anymore.
T

[km6xz]

For more efficient use of the drivers, build a high pass filter for the 10s, put them in a separate cabinet so they are not seeing the sub-sonic portion of the signal they can't reproduce well and which only consumes power, stresses the drivers and created unpleasant distortion. This in particular if you are doing any percussive techniques where the attack is an important part of the sound. Having the upper lows and mids handled by the 10s which can be done in a small cabinet, the mid tone harmonics will be better defined, much more efficient and can get louder for any power rating they had. If you had two channels, or just a current booster to drive those separately, the whole rig would produce higher clean spl at any given power than the 3 drivers in one band plan you asked about.
Bi-and Tri- amplification greatly improves bass guitar sound and acoustic power out for a given power aggregate over a single cabinet absorbing more power that is full range. PA systems that are full range never are as efficient or loud as band divided system, so it can actually be smaller with less power requirements for a specific power level.
Also, depending on your playing style, adding a small piezoelectric hf driver can be a nice touch, for real snap, and tight sounding bottom. The impression of tightness is due to upper harmonics, not any character of how the fundamental is reproduced. 40hz is 40hz and there is nothing "tight" or "loose" or "brown" about it. How you handle the harmonics and whether the ear is fooled into assuming the harmonics are related to the slow developing fundamental is how the brain judges how articulate and expressive it is. A 4x10 cab with a tiny 10 watt horn "sounds" louder than one without the horn even though during a note peak, it is seeing only 1/10 watt or a little more. But the brain integrates the two ranges as having the same fundamental and in nature any normally heard sound that has a 1/10th watt acoustic power level, say, at 9khz infers a very strong fundamental. The brain adds significance to the highs that you might not actually here but goes into the calculations the brain makes to characterize the sound impression. If they are NOT harmonically related, id does just the opposite and becomes noticeable as if a different origin of the sound. The cluttered noisy sound is the result when the brain makes us aware of it, as if it is a different sound from a different source. An aligned harmonic distribution results in our perception of a clean distinct musical note even if the harmonic content is the same as another note that the brain does not judge the harmonics to be of the same fundamental and imparts the impression of a busy less distinct note. All important elements in timbre or musical color. With guitar and bass, you have less tonal flexibility in color if the speaker shifts everything to the busy and messy side of the ledger. With paying attention to the speaker system, the full range of tonal flexibility is available to a player.

The band divided or band limited setup also means you would get 10 drivers that would not need to be a high power(which reduces efficiency , thereby requires more power for a specified spl) or as extreme of excursion.....which translates to "cheaper" an lighter. By optimizing two stackable cabinets you increase gigging flexibility, some small venues might only need the 15, or the 10s if you include direct input jacks that bypasses the HPF. For the big money gigs, take both since transport and handling money is usually allocated.
By trying to use drivers that cover full range you accept a lot of compromises that are not needed for band limited drivers so more and cheaper options are available. Some high efficiency guitar oriented drivers for the upper low and mids in the 30 watt range, would run circles around the low efficiency 15 that is optimized for deep bass, at 200 watts.