Uhm, acoustical radiation impedance is directly proportional to (large) cone surface and large cone surface also helps to improve an "even flat" wavefront.
In this regard, science wise there is no way to outperform a big baffle 810 design with a 215
Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Why are Ampeg SVTs so popular?
- Thread starter Whitenoise17
- Start date
-
- Tags
- ampeg svt
In this regard, science wise there is no way to outperform a big baffle 810 design with a 215
I couldn't tell you one way or the other which is more efficient or which will play louder before it incurs damage, but surely the sensitivity, power handling, and Xmax of each designs' drivers factor into the equation, rather than simply cone surface area.
In acoustical science we have got this thing called "radiation impedance" which tells something about efficience but also tells something about the ability to throw an "more even" wavefront into the room, which I think is noticeable as increased 3D performance. Hope I could translate this right into your "slang" respectivley "3D" meaning in your language!
You can't simply ignore efficiency, displacement, and power handling.
Displacement is a way overrated number cause SPL is the derivation of air particle velocity. Velocity has nothing to do with displacement.
Power handling can be anything. Any 10" driver that can handle 1000 watts rms does not mean the driver was really louder at full power than a generic 300 watt rms 15" speaker at full power.
Efficiency actually is the thing that is proportinal to radiation impedance, dependent on frequency range (application) of course.
A 212 ported MI cab can't cope with a Martin W-bin at the lows. While a Martin sub bin sucks at mids. Acoustical radiation impedance vers application differs to much just to be compared. We don't want to compare apples to oranges.
edit, btw some folks may wonder by themself about this "strange" excursion peaking that ported cabs show in the range between cab tuning and (about) 150Hz. The Helmoltz resonator helps to improve radiation impedance at cabinet tuning frequnecy and actually that's the reason why we can observe this strange driver excursion curve with ported cabs.
Last edited:
Sensitivity for the 810E is listed as 100dB with 800W RMS power handling
Sensitivity for a single 3015LFs is listed as 98.4dB, so a pair should come out at 101.4dB with 900W RMS power handling. Perhaps the pair of 3015LFs will loose a few dB of sensitivity to fEARful's the passive crossover.
Note: I am assuming sensitivity for both designs is based upon 1W/1M at 4 ohms.
The data above suggests a pair of 3015LFs could play slightly louder, but I wouldn't expect a huge difference in max volume at 100Hz.
IMHO one matter that needs to be cleared up is how low and loud each design can play. Unfortunately I don't have supporting cone displacement data for either design. I suspect both designs would be mechanically limited to less than their thermal power rating.
I don’t know much about any of this science stuff, but I can’t imagine needing any more volume than my Heritage 810 puts out. Goes plenty low and plenty high for me too - but I guess I’m admittedly an old school fundamental player. Best sounding cab I’ve ever used.
No kidding.
Does anyone really give a care about science?
It either sounds good or it don't.
Efficiency?
Really?
Efficiency is for Toyotas.
Speakers are for rock-n-roll!
The SVT is certainly an iconic amp. It's not my favorite choice, even though I had one back around '71 with TWO 810 cabs. It was a PITA to move them back then when my back wasn't 66 years old. But I love the look on Marshall wielding guitarist's faces when I flipped it off of standby. It was loud! And an amazing improvement over what passed for "bass amps" up to that point. These days I'd rather be playing through my Bergantino amp and cabinets.
I would like to see some bass player on the Tube NOT playing a P bass thru an SVT, if only for a little change of pace. Let's see some of that other great equipment out there.
I would like to see some bass player on the Tube NOT playing a P bass thru an SVT, if only for a little change of pace. Let's see some of that other great equipment out there.
Smooth_bass88
vaxx!
- Oct 31, 2006
- 12,122
- 16,794
- Disclosures
- have been on nationally released albums, charting on the Billboard 200
Why are Camrys so popular? Why are Harleys so popular? Why are iPhones so popular? Why are Nikes so popular? Why are Ray Bans so popular?
I have no doubt that an 8x10 will match something like a fearful in one small window of frequencies.
*Searches for a gif of lemmings...
*Searches for a gif of lemmings...
IMHO, the specs suggest the 1515/66 and 810E may be fairly evenly matched. I do think specs are important, but in this case I think most people would choose one design over the other based upon the sound they want.
I believe there are very few people who would push either design beyond its limits...but there are a few
.
Last edited:
I think the most important specs are : the sound, the weight, the look, the wallet.IMHO, the specs suggest the 1515/66 and 810E may be fairly evenly matched. I do think specs are important, but in this case I think most people would choose one design over the other based upon the sound they want.
I believe there are very few people who would push either design beyond its limits...but there are a few
Only played a bona fide svt head into an Ampeg 810 once, as a backline at a festival, and it was a lot of fun. Wall of wonderful bass.
I later played my own 810 rig, a few years later. Aguilar S410x2, powered by a Peavey cs800x from a sansamp rbi. Gave me every bit of the same warm tinglies. I could probably tell the nuance better now, but with proper speakers and that much power.....how bad can it be!
More bass>less bass
I later played my own 810 rig, a few years later. Aguilar S410x2, powered by a Peavey cs800x from a sansamp rbi. Gave me every bit of the same warm tinglies. I could probably tell the nuance better now, but with proper speakers and that much power.....how bad can it be!
More bass>less bass
To me the post important is the sound and projection. If a Fearfull 1515/66 or a Barefaced Big twin can do the same as an 810 without even breaking a sweat, then I'm in!
Damn! I really need to try one of these cabs
I think my 70's 810 cab sensitivity plays close to this 100dB number of the 810E. My 212 cab provides a sensitivity of 99dB on paper and, in real practice there is little audible difference in perceived loudness of my 810 vers 212.
Interestingly at big loudness wars (randomly I had to fight versus these "stupid" Marshall stacks you know) the 810 stands way better in the mix than my 212. This was of course an very interesting experiene cause (on paper) the 212 (ported) cab provides more of low end than the sealed 810.
Here you are with a cab simulation of 215 3015LF vers a 810 B810 modelling.
System input power equals 800 Watt for each system
The following pic demonstrates the meaning of "displacement" respectively the amount of "moved air volume" versus SPL.
It can be seen that for 800 watt input power at about 500 Hz the cone displacement stays rather small (0.15mm) while the generated SPL at 500 Hz is still high. At the lowish side of the spectrum the cone displacement rises up to noticeable higher numbers but, while the sealed cab shows a steady increase of displacement the ported cab drivers are supported by the Helmholtz resonator which helps to improve radiation impedance of the cab system at the lows.
It can be clearly seen that there is no way to interpret lots of "moved air volume" directly into plenty of SPL. Both cabs move plenty of air volume in the range of 70..100Hz but, generated SPL does NOT show any proportionality with cone displacemnt.
Great workup!
My understanding is the significance of displacement is not efficiency, rather it relates to mechanical power handling. Efficiency and power handling together determine max SPL.
Per your graphs it looks like the 810E would be a few dB louder above about 120Hz, and a pair of 3015LFs would be louder below about 120Hz. Neither design exceeds Xmax when fed 800W, so displacement is not a factor unless more power is applied. It's does appear that 800W puts both designs pretty much at their displacement limit.
Losses from the 1515/66 crossover would also be a factor, so the fEARful should actually require more than 800 watts to achieve the performance in the graphs.
It seems clear you prefer to tone of the 810E
. Although I have never played a fEARful, I am sure I would prefer the 1515/66...I have owned an Ampeg 810 and it is not my cup of tea. vive la difference
.
I remember the first time I saw a double SVT set up, the player even took both speaker grilles off, it was the most fantastic looking and sounding bass amp I'd ever heard and still is actually to me, forgetting that it weighs two tons. I was regularly using two cabs until about 15 years ago, I still have both of them though. Nothing like it. I'm 65 and still lug a head and one cab to most gigs, the last time I brought two cabs to an outside gig one of the guitar players started crying and complaining it was too loud before I took it off standby
