Ampeg PF-50t - loud cab

[Pick53766]

I apologise for a possibly stupid question. As I guitarist, I seldom face the problem of not being loud enough. Given the nature of the instrument, quite the opposite is the truth and I happily run my 35W into just about any box and it works.

Now I need to get that sweet Ampeg PF50 working. With bass, obviously.

I am not saying it is not loud or sufficient, it is loud aplenty and very, very nice. But you guys here often talk about "effective speakers" and how the right cab loaded with right speakers can get punchy and perceivably loud.

So, in a scenario where you would want the PF50 to get a little help from its cabinet friend... what cabinet would it be?

(Yes, I can hook the PF50 into the 800W Genzler and call it a day. Or just use the Genzler.)

 

[gtirard]

Yes, the cab's efficiency has more influence on the total volume than the power of the amp.

Sensivity is the measure of a cab efficiency, it represents the ability of the cab to transform 1W of electrical power (received from the amp) into decibels, measured at a 1 meter distance.

I say the sensitivity of the cab is more important for the total loudness than the power of the head, because when you double the power of the head you get only +3 decibels, whereas when you increase the number of decibels of the cab's sensitivity, each added decibel is added to the final loudness (SPL, Sound Pressure Level).

In, the example bellow, a 50W head + a super efficent cab (103 decibels for 1W at 1 meter) is louder than a 100W head + a less efficient cab (95 decibels for 1W at 1 meter) - at least in theory.

I say "in theory" because some brands are more "optimistic" when they measure the sensitivity of their cabs, other are more honnest or caution, so we cannot really compare the sensitivity ratings of 2 cabs from different brands and assume the figures translate in real life experience. So for the same cab, an "optimisitc" brand could pretend it has a sensitivity of 102 dB, whereas a more cautious company would rate it 98 dB. That's because they all brands don't use the same methodology to make their measurements.

In general the more speaker area the more sensitivity, all things being equal.

I have a 50W tube amp and 2 very efficient cabs, a Barefaced 1x12 and a GR Bass 2x10.
I never use the 2 cabs together, but my 50W amp + one or the other cab is enough for my needs, I play in an Indie Rock band, but our drummer plays quite softly. I think it wouldn't be enough if our drummer was hitting hard.

I think most people think you would need a 2x12 or 6x10 cab for a loud rock band.

 

[Jefenator]

The Bag End S-15D has a higher sensitivity spec than most and I have found it to be great for gigging out with my 50W tube head.

 

[Wasnex]

With a tube amp, the available power is the same as long as the amp sees the expected load. The PF50T makes ~50W at either 4 ohms or 8 ohms.

With only 50W you want the highest possible sensitivity rating. The decibel change produced by raising the power from 1W to 50W is [Log(50) x 10] = ~17dB.

So you can simply add 17dB to the 1W/1m sensitivity rating of any speaker to estimate how loud it can play.

Assuming you have an 8 ohm cab with a 97dB 1W/1m sensitivity rating, the calculated SPL is:

17 + 97 = 114dB​

When you double the number of cabs (assuming they match), the sensitivity goes up approximately 3dB. So if you add a matching cab:

17 + 97 + 3 = 117dB​

 

[Bisounourse]

I think most people think you would need a 2x12 or 6x10 cab for a loud rock band.

You miss-spelled 4X12, 8x10 and 2x15

But to echo previous posts: a sensitive cab (or 2) should do it, depending on your needs.
For brands: Fearless/Fearful/Greenboy, Barefaced, Audio Kinesis,... are some that come to mind.

 

[gtirard]

You miss-spelled 4X12, 8x10 and 2x15

But to echo previous posts: a sensitive cab (or 2) should do it, depending on your needs.
For brands: Fearless/Fearful/Greenboy, Barefaced, Audio Kinesis,... are some that come to mind.

I would add Mesa and GR Bass.
- Mesa is IMO the perfect example of a super honnest/cautious brand, so their the sensitivity rating may not appear very impressive by themself, but the cabs are loud (according to the crowd).
- On the opposite, GR Bass seems to be "optimistic" regarding their specs. So their sensitivity ratings look too good to be true. But still, their cabs are very loud.

To illustrate that difference between optimistic and cautious brands, I'm going to do a little experience in a few days/weeks. I've got a Barefaced 1x12 and a GR Bass 2x10.
- The Barefaced Super Compact is rated 97 dB / 1W / 1m
- GR Bass NF 210V is rated 103 dB / 1W / 1m
For the moment, they are not used in the same location, so I haven't been able to A/B test them. I think they are both super loud (compared to average cabs), but I'm not sure there is a 6 dB difference between them. It's going to be fun to compare them.

 

[LowG]

I second the Bag End comment. Get one or 2 of their 15” cabs and it’ll be great.

 

[coy garcia]

Mine is pretty insanely loud with good clear mids on a bbc112 tank (4ohms). It also sounds full and loud with my boogie 115/210 (4ohm). I have no problem keeping up in a 2 guitar hard rock band or a blues gig with a jazz drummer. Lately I have only been using my bbc 112 though for portability and it cuts and sounds great...I LOVE this amp!!! I would buy another if anything happened to it.

 

[Mark Karwan]

I would add Mesa and GR Bass.
- Mesa is IMO the perfect example of a super honnest/cautious brand, so their the sensitivity rating may not appear very impressive by themself, but the cabs are loud (according to the crowd).
- On the opposite, GR Bass seems to be "optimistic" regarding their specs. So their sensitivity ratings look too good to be true. But still, their cabs are very loud.

To illustrate that difference between optimistic and cautious brands, I'm going to do a little experience in a few days/weeks. I've got a Barefaced 1x12 and a GR Bass 2x10.
- The Barefaced Super Compact is rated 97 dB / 1W / 1m
- GR Bass NF 210V is rated 103 dB / 1W / 1m
For the moment, they are not used in the same location, so I haven't been able to A/B test them. I think they are both super loud (compared to average cabs), but I'm not sure there is a 6 dB difference between them. It's going to be fun to compare them.

I look forward to that comparison. I've been following a lot of your comments re: GR.

 

[RandomKaren]

The secret is more cabs, not just one more-efficient cab. My PF-50t sounds great with a single PF-112HLF (only 96dB sensitivity), but is lost in a large room or outside stage. With a second cab there is a huge difference. I haven't put it through an 8x10 but by all accounts it's ridiculously loud for the wattage.

By the way amps and cabs sound better if the badges match, as everyone knows.

 

[Stylee Mousse]

I ran a 200 watt GK then later a 100 watt v-4b for ages with 2 115 cabs. It was never not loud enough

 

[coy garcia]

I ran a 200 watt GK then later a 100 watt v-4b for ages with 2 115 cabs. It was never nor loud enough

Things sure have changed...It's pretty amazing how much louder lower wattage amps are now compared to back in the day. I'm not sure my '91 boogie 400+ tube head is that much louder than my pf50t...both get louder than I would ever need.

 

[jmlee]

UOTE="hill76, post: 28296014, member: 398175"]The secret is more cabs, not just one more-efficient cab. My PF-50t sounds great with a single PF-112HLF (only 96dB sensitivity), but is lost in a large room or outside stage. With a second cab there is a huge difference. I haven't put it through an 8x10 but by all accounts it's ridiculously loud for the wattage.

By the way amps and cabs sound better if the badges match, as everyone knows.

View attachment 5391246[/QUOTE]

I feel your feeling (admittedly at 200 watts, though...)

[Q

 

[mcrawfordmusic]

I sometimes use a PF50T through a PF115 and it is only just loud enough to sit in a band with FOH support. You'll have better luck through a 2x12, 2x15 or 4x10 in my opinion.

 

[Rip Van Dan]

Yes, the cab's efficiency has more influence on the total volume than the power of the amp.

Sensivity is the measure of a cab efficiency, it represents the ability of the cab to transform 1W of electrical power (received from the amp) into decibels, measured at a 1 meter distance.

I say the sensitivity of the cab is more important for the total loudness than the power of the head, because when you double the power of the head you get only +3 decibels, whereas when you increase the number of decibels of the cab's sensitivity, each added decibel is added to the final loudness (SPL, Sound Pressure Level).

In, the example bellow, a 50W head + a super efficent cab (103 decibels for 1W at 1 meter) is louder than a 100W head + a less efficient cab (95 decibels for 1W at 1 meter) - at least in theory.

View attachment 5390608

***SNIP***
I think most people think you would need a 2x12 or 6x10 cab for a loud rock band.

A 610 or larger cab is not really needed as long as, like you say, it's a fairly sensitive cab. I gigged for about 6 years with a bass stack that was the old classic choice of a 410 plus a 115. My GK115 was a very boomy cab (their least expensive GK115bpx) and by using the balance knob on my WT500/800, I could send more power to the acoustic B410 than the 115 and eliminate the mud without stealing all the bass EQ from the 410. I was pretty happy with that for about 5 years. Then I bought a DNS-410 cab from DNA that I'd been drooling over for those same 5-years. That single 410 cab is far louder and much better sounding than my previous 410+115 stack. The sound is stunningly clearer and fuller.

So I believe a good 410 that will handle 700 to 800 watts or more is all he'll probably need. I ended up buying a DNS-210 in 2019 when I became part of the DNA Endorsing Artist group, so I could take that into small venues without being forced to use some 112 combo. Nobody looks twice at a bass player with a 210...doesn't scare anyone even though it probably should. So I could stack that on top of my 410 and run a 610 stack with my 800-watt DNA-800 amp, but I just haven't found a place that I needed to do that. If I'd been smart, I'd have bought one 210 first and then bought a second when I needed to play outdoor gigs.

I also have an Eden 2x112 set-up that sounds really good. They can handle 300-watts each but, without being mic'd, that might not be enough for outdoor venues, whereas a decent 410 will be. Like you mentioned earlier in your post, more speaker area starts the entire march up from 1-watt to whatever the amp's maximum is. Double your power or double your speaker area - either one will give you 3db increase. Speaker cabs are usually less expensive than amps that have twice the power your current one does.

 

[Engle]

The secret is more cabs, not just one more-efficient cab. My PF-50t sounds great with a single PF-112HLF (only 96dB sensitivity), but is lost in a large room or outside stage. With a second cab there is a huge difference. I haven't put it through an 8x10 but by all accounts it's ridiculously loud for the wattage.

By the way amps and cabs sound better if the badges match, as everyone knows.

View attachment 5391246

I brought my PF50T to a rehearsal space and plugged into an 810. And immediately got told to turn down!

 

[flatwound62p]

This old BT-15 pushed to the max with a single PF115he couldn't keep up with my band.

I recently got hold of a second PF115he and was blown away by how much louder it got. Volume to spare and the top cab is closer to my ears instead of having all the sound blowing past my knees. I'm another vote for a pair of Ampeg cabs with the OP's PF50

 

[JeezyMcNuggles]

I apologise for a possibly stupid question. As I guitarist, I seldom face the problem of not being loud enough. Given the nature of the instrument, quite the opposite is the truth and I happily run my 35W into just about any box and it works.

Now I need to get that sweet Ampeg PF50 working. With bass, obviously.

I am not saying it is not loud or sufficient, it is loud aplenty and very, very nice. But you guys here often talk about "effective speakers" and how the right cab loaded with right speakers can get punchy and perceivably loud.

So, in a scenario where you would want the PF50 to get a little help from its cabinet friend... what cabinet would it be?

(Yes, I can hook the PF50 into the 800W Genzler and call it a day. Or just use the Genzler.)

810e

 

[pyrat56host]

So...not tube (but your ears would never know) but I run my Quilter Interbass (45w @ 4ohms) into 2 2x12 or one 4ohm 4x10 w/ a really loud two guitar rock band and it never breaks a sweat. It reminds me of our old Sunn model T at high volume. Lots of grunt...and the smile on the drummers face told me all I needed to know!

 

[gtirard]

So...not tube (but your ears would never know) but I run my Quilter Interbass (45w @ 4ohms) into 2 2x12 or one 4ohm 4x10 w/ a really loud two guitar rock band and it never breaks a sweat. It reminds me of our old Sunn model T at high volume. Lots of grunt...and the smile on the drummers face told me all I needed to know!View attachment 5391609

It looks like you also have a BB800 behind, is it you backup amp?