Cabs - technical question

[bassdood]

I have been evaluating some recent cab experiences I have had, and would like to hear what other folks may have to add to the picture.

Take two cabs, each 8 ohms, each made by the same company. One is a 210, 400 watts, with a sensitivity rating of 103. The other is a 212, 600 watts, sensitivity of 98.

Say you do an A / B test, using a single head, a single bass, and one venue. Hook up one cab, adjust the volume, etc, check how loud it plays with your band playing. Leave the volume and other settings alone, switch to the other cab, and see loud it is.

Which one is louder? The 212, due to more surface area? Or the 210, due to the more efficient higher sensitivity? Or will it be decided by other factors? Or totally unpredictable?

I think the 210. What do you think? Anybody actually done something like this?

Thanks

[will33]

The 210 would be a good deal louder due to it's 5db higher sensitivity. That said, no 210 does 103db. Sensitivity at what frequency also matters, the quieter cab may also be louder in the lows, the louder cab having all it's volume in the mids.

Basically the "specs" you see in ads are virtually meaningless.

[billfitzmaurice]

Originally Posted by bassdood

Or will it be decided by other factors?

That, as you also must see both an SPL chart and know driver displacement.

Or totally unpredictable?

It's 100% predictable with SPL charts and driver displacement specs. But no one publishes them. Barefaced comes close, providing displacement and honest -3dB specs. But since no one else provides them you can't compare them to anyone else.

[bassdood]

Originally Posted by will33

The 210 would be a good deal louder due to it's 5db higher sensitivity. That said, no 210 does 103db. Sensitivity at what frequency also matters, the quieter cab may also be louder in the lows, the louder cab having all it's volume in the mids.

Basically the "specs" you see in ads are virtually meaningless.

Well, according to the specs in the owners' manual, this 210 is rated at 103db. It is from a company that has a reputation for having, at least compared to others, pretty good (conservative) specs.

And in my A/B test scenario, these two cabs are from the same company, so even if the specs are exagerated, one might think they could be somewhat similarly exagerated, so that the 5db difference might be ballpark close.

And since they are both from the same co., then very possibly they would be measuring sensitivity at about the same freq on rhe two cabs.

[bassdood]

So here's the thing.

I actually did an A/B test similar to the above, except that mine was done with two different models of a company's 210 (both rated at 400 watts): an older premium model (103db), and a new Neo model (98db). I was blown away at the loss in volume coming out of the Neo.

So I started thinking about upgrading to the Neo 212 (600 watts). But then I started wondering if that would really make up for the 5db (or whatever it may accurately be) difference in sensitivity (since the 212 is also rated at 98 ).

I'm thinking maybe it won't. What do you think?

[JHAz]

What a sensitiivity should be, in effect, is this: Put the speaker in an anechoic chamber or outside so it doesn't get reinforcement from sound bouncing off nearby walls.

Play a test tone at 1 watt into the speaker.

Have a mic/spl meter placed one meter away from the speaker.

Record the SPL you get.

Done.

So theoretically, 2 cabs with the same sensitivity ratings SHOULD be the same loudness at the same volume setting.

But there are different ways to go about defining sensitivity for speakers. To start with, musical instrument speakers are not perfectly flat in their frequency response. That means that one watt at 100 Hz might yield 98 dB while one watt at 1 KHz might yield 103 dB. Manufacturers don't typically state the conditions of their testing (one watt, at one meter 20-20Khz or at 1 KHz or whatever), so you don't really know what the number means. If the 103 dB at one watt happens to fall at the point where the cab has a 6 dB peak in its frequency response, it's a little misleading with respect to the full sonic spectrum.

So it's hard to compare. but FWIW, I'd expect one manufacturer's ratings, within the same product line (ie all the GK Neos, or all the GK MBs) to be similarly-to-identically specified. So if your 212 cab is 98 dB, it's not going to be louder unless you turn up the volume.

Which is the next question : how much headroom do you have in your amp? how much of it can your speaker take while still getting louder in proportion to the increasing signal? How loud you can get is a function of power, speaker sensitivity, and the speaker's limits (typically the limit of excursion sets the loudest it can get, but as I understand it you may hearing the speakers distort by the time you get there. So lots of factors work together . . .

If you can get your max needed volume with your amp at 1/3 power with speaker A but can still get your volume with the amp at 2/3 power 3dB less sensitive with speaker B, how important is sensitivity, really?

[will33]

Originally Posted by bassdood

Well, according to the specs in the owners' manual, this 210 is rated at 103db. It is from a company that has a reputation for having, at least compared to others, pretty good (conservative) specs.

And in my A/B test scenario, these two cabs are from the same company, so even if the specs are exagerated, one might think they could be somewhat similarly exagerated, so that the 5db difference might be ballpark close.

And since they are both from the same co., then very possibly they would be measuring sensitivity at about the same freq on rhe two cabs.

That means each individual driver would have to do 100db at 1 watt at one meter. It may do that at some peak in response somewhere but not across the whole bandwidth and especially not in the lows. A one number rating like that doesn't tell you much. A response graph is needed to really know what's going on.

[greenboy]

Once you've been around bass guitar loudspeaker puttering for awhile, 103 dB is wavy gravy. As in, mind altering substances would have to be at play to actually believe that nonsense. This is not coming from a company that has any respect for honest referenced specs.

[will33]

Originally Posted by bassdood

So here's the thing.

I actually did an A/B test similar to the above, except that mine was done with two different models of a company's 210 (both rated at 400 watts): an older premium model (103db), and a new Neo model (98db). I was blown away at the loss in volume coming out of the Neo.

So I started thinking about upgrading to the Neo 212 (600 watts). But then I started wondering if that would really make up for the 5db (or whatever it may accurately be) difference in sensitivity (since the 212 is also rated at 98 ).

I'm thinking maybe it won't. What do you think?

5db makes a big difference. 3db is considered a small but noticable change, 10db sounds half as loud, you're in between there. To get the 5db back using power you'd have to increase your amp power by roughly x4 or 5 or so. If the speakers could handle it which they likely can't.

[rockstarbassist]

use both cabs n00b

[bassdood]

Wow, thanks for the responses, guys.

I am trying to make some decisions, and doing so on whatever data (and experience) I have, even if it is imperfect / incomplete.

I had never much paid attention to the sensitivity stat before. But when I experienced the older 210 totally blowing away the Neo 210 from the same company, I started paying attention. So I'm thinking it is telling us at least something.

The numbers may well not be that accurate, and we may need a lot more such (good) numbers to evaluate it confidently. But the end result was unmistakable to me, in terms of it being very, hugely, significant. And since the Neo 212 (same co.) has the same reported sensitivity as their Neo 210, I'm wondering if it will be that much louder.

I was maxing out the Neo 210 with the vol at about noon on the dial, and the cab was starting to fart. I could get the same vol with the older 210 with the vol about 10:00, with no farting or feeling like I was maxing it out.

Now the Neo 212 I am considering does have a higher wattage rating, so that might mean I could keep pushing it past the point I had to stop with the Neo 210. If that is the case, then the 212 might effectively increase the usable headroom to the point that the lesser sensitivity doesn't matter so much.

Whatcha think?

[will33]

That wattage number/power rating is a thermal measurement that tells you how much heat the voice coils can take before they burn up. The farting threshold is determined by excursion, the xmax spec which isn't published. That's how far the cone can travel back and forth before it can't make any more bass. Since you never really know this, with commercial cabs, unless they use a premium driver like the kappalite series or similair which most don't, it's safe to assume it'll start to distort at roughly half it's power rating....some of them 1/3.

[dhomer]

The question you should ask yourself.. will this rig deliver the tone I want at the desired sound pressure level?? Sensitivity alone won't answer that one.. A clue to help find answers.. you get what you pay for..

[bassdood]

Originally Posted by dhomer

The question you should ask yourself.. will this rig deliver the tone I want at the desired sound pressure level?? Sensitivity alone won't answer that one.. A clue to help find answers.. you get what you pay for..

Thanks. The tone is good on both of them. It's a quality brand. I already had the volume I needed with the older 210, but it is fairly heavy, and I am interested in lightening the load. I just had not anticipated that going to Neo's would involve a trade-off of volume loss.

I've acquired one Neo cab (210), and I'm hesitant to assume that I can fix this by getting a Neo 212. If I could try one in a live band setting I would be able to tell.