Why did my speaker distort?

[Steve S]

Last Saturday, I took my UL 310 and EA 112 speakers along with my WT 550 to a gig. During some of the loud passages, when I hit the strings hard on my Mustang Bass, the 112 would sound like it was breaking up. It didn't do it when I played my Lull MV4. The UL 310 sounded fine.

The 310 is slightly higher than 5 ohms and the 12 is 4 ohms. Would the difference in ohmage with the 550 cause this or is it the bass?

[Mr. Foxen]

Probably more bottom hitting it than it can cope with. The distortion is the speaker passing its clean excursion limit. Do you have any bass boost going on anywhere? That will do it.

It is not to do with the impedance, the 3x10 is probably capable of shifting more air, so can cope with the bass.

[Bass_Pounder]

Originally Posted by Steve S

Last Saturday, I took my UL 310 and EA 112 speakers along with my WT 550 to a gig. During some of the loud passages, when I hit the strings hard on my Mustang Bass, the 112 would sound like it was breaking up. It didn't do it when I played my Lull MV4. The UL 310 sounded fine.

The 310 is slightly higher than 5 ohms and the 12 is 4 ohms. Would the difference in ohmage with the 550 cause this or is it the bass?

A: Your Mustang obviously has a hotter output signal than your Lull

B: Your 2 cabs are close in impedance. meaning they are getting about equal power sent to them.

Your 310 has 3 speakers to share it's half of the load, whereas your 112 is a single speaker taking the power.

Putting it simply, your hotter bass caused your output to overload the single 12 cab.

[Steve S]

Originally Posted by Mr. Foxen

Probably more bottom hitting it than it can cope with. The distortion is the speaker passing its clean excursion limit. Do you have any bass boost going on anywhere? That will do it.

I had a small boost on the bass knob. Maybe it's not a good idea to use two different speakers with an amp that cannot control the volume for each speaker?

[Sartori]

Originally Posted by Steve S

I had a small boost on the bass knob. Maybe it's not a good idea to use two different speakers with an amp that cannot control the volume for each speaker?

Indeed.

You also might not want to boost your lows so much when playing through the 12.

[WingKL]

Your Lull MV4 probably isn't putting out as much fundamental or low bass frequency as your Mustang.

[Petebass]

Think of each speaker cone as a shock absorber. Both cabs are seeing a similar input, but the UL310 is sharing the load between 3 shock absorbers to the EA's one shock absorber.

In other words, the 3x10 likely has three times the available suspension travel in the speaker's movement mechanism (X-max). When the speaker runs out of suspension travel, it bottoms out and distortion is the result.

[B-string]

Also the 12 is getting more power than the 410. 4ohm single 12 will get more feed to it than the 5(?) ohm cab.

[Petebass]

Originally Posted by B-string

Also the 12 is getting more power than the 410. 4ohm single 12 will get more feed to it than the 5(?) ohm cab.

Yes but it's only marginal.

Lets say the 3x10 recieves 300w and the 1x12 350w. That's 100w per driver for the 310, but 350w per driver for the 1x12.

[B-string]

Originally Posted by Petebass

Yes but it's only marginal.

Lets say the 3x10 recieves 300w and the 1x12 350w. That's 100w per driver for the 310, but 350w per driver for the 1x12.

What "but"? You are reinforcing my point (and I suspect the 310 is a 6 ohm cab). More power to less drivers is why it happened.

[IvanMike]

well yeah the 112 is getting a tad more than the 310, 350 watts sounds about right ish - what's the 112 rated for? It has nothing to do with an impedance mismatch, just that the 112 got more juice than it wanted. I bet you can recreate this with just the amp and the 112.

[B-string]

Originally Posted by IvanMike

well yeah the 112 is getting a tad more than the 310, 350 watts sounds about right ish - what's the 112 rated for? It has nothing to do with an impedance mismatch, just that the 112 got more juice than it wanted. I bet you can recreate this with just the amp and the 112.

And the total output is limited by the "weakest" link: The power handling of the 12". If both cabs were the same impedance, the multiple driver cab could receive more power before you hit the limits of the single 12".

[Petebass]

Originally Posted by B-string

And the total output is limited by the "weakest" link: The power handling of the 12". If both cabs were the same impedance, the multiple driver cab could receive more power before you hit the limits of the single 12".

You're arriving at the right answer, but you're getting there the wrong way

The wattage difference between a 5.33ohm cab and a 4 ohm cab isn't as big as you think it is. A 5.33 ohm single 12 is impossible to obtain, and a 4 ohm 3x10 is possible but highly unlikely... you'd need 3 x 12 ohm drivers which you'd only get as an OEM order. Or you'd have to chop a NV610 in half

The more realistic solution is to replace the 1x12 with something with the same or similar impedance but with more than one driver.... to share the workload so to speak.

[B-string]

Originally Posted by Petebass

You're arriving at the right answer, but you're getting there the wrong way

The wattage difference between a 5.33ohm cab and a 4 ohm cab isn't as big as you think it is. A 5.33 ohm single 12 is impossible to obtain, and a 4 ohm 3x10 is possible but highly unlikely... you'd need 3 x 12 ohm drivers which you'd only get as an OEM order. Or you'd have to chop a NV610 in half

The more realistic solution is to replace the 1x12 with something with the same or similar impedance but with more than one driver.... to share the workload so to speak.

I didn't say it was possible, if the 12" was an 8 ohm driver then the 310 would take the most power. The down side is the 12" would be much harder to hear over the 310, but higher power output would be possible before the single 12" reaches it's limits. It is not an optimal combo with a single output amp.
As far as the difference, by pure numbers the 4 ohm cab will present a 25% high load than the 5.33 ohm. Of course we don't know the actual impedance curve of either cab to make any accurate estimation?

[Petebass]

Originally Posted by B-string

As far as the difference, by pure numbers the 4 ohm cab will present a 25% high load than the 5.33 ohm.

If audio was a liner measurement, this would be correct. But audio is logarithmic. If you look at most amps, the power difference between a 4 ohm load and an 8 ohm load isn't double as most people would expect. It's closer to 60% or 70%. A typical 500w amp at 4 ohms puts out closer to 350 or 300w at 8 ohms, not 250w as linear math would suggest. The difference between 4 ohms and 5.33 ohms would therefore be closer to 10% than 25%.

Actually our suggestion of an 8 ohm 12" isn't a bad one! That would break the rig down to 4 drivers of 8 ohms each all sharing the power equally. Yes the 12" would be a little bit softer than it is now, but it'll still put out a similar SPL to each of the individual 10's and will therefore contribute to the overall sound, depending on driver efficiencies of course. And as you correctly point out, impedance curves also need to be considered. You'd definitely have to audition such a set up before committing to it.

[Steve S]

Wow! I learned a whole bunch more than I thought I would about speakers. Thank you all for your comments. I'll have to be more careful how much bass I run through them if I hook both of them up.

I'm sort of disappointed that the Japanese Mustang had a hotter pickup than the Lull.

[johnk_10]

Originally Posted by Steve S

I'm sort of disappointed that the Japanese Mustang had a hotter pickup than the Lull.

i wouldn't be disappointed at all, since IMO, hotter doesn't = better.

[Steve S]

Originally Posted by johnk_10

i wouldn't be disappointed at all, since IMO, hotter doesn't = better.

I always thought that better pickups were louder so was surprised that the Fralins are not as loud as the Japanese pickups. Thanks for clarifying this.

[wideyes]

Originally Posted by Steve S

I always thought that better pickups were louder so was surprised that the Fralins are not as loud as the Japanese pickups. Thanks for clarifying this.

Try volume matching them and see what you think then. If you just unplug one and plug in the other, the Mustang will probably sound better to you just because of the volume jump. Often it will make you think, "Oh, that bass sounds more present and juicy" when really it's just the psychology of volume messing with you. Figure out amp volume settings that give you equal output and then let's see what you think about that Lull tone

EDIT: also, have you looked into pickup height adjustment on each bass? It makes all the difference in the world!