Driving SRT's (Type of amp, power level, and what they can truly handle?)

villian

Been thinking a lot lately about the SRT's capabilities and wanted to know what everyone else thinks about this.

Polk claims that they can handle in excess of 1,000 watts RMS on each upper half (Or "Satellite") of each tower (Which I don't doubt), but I also know from experience that they're easily driven with as few as 80 watts RMS. What's everyone's take on this? What are my fellow SRT owners using to drive their towers? Is anyone Bi-amping?

The lowers (2x 10" Subs) are driven by a 600 Watt Class A/B plate amp..correct? And the satellite towers put a 4 ohm load on whichever amp is used to drive them..correct?

My SRT towers are currently each being driven by a dedicated Crown XLS 1500 amp. They're bridged giving a claimed 1,550 watts @ 4ohms in output. I have reached 119db @30hz measured at 3m away from the speakers, just for the record. I'm sure my peak output was in excess of 140db somewhere in the 500hz to 5khz range..but I have some power conditioning issues to fix before I ever try maxing out the SRT's again.

chefkungfu

Hey villian, I've had mine no higher than 101db!
From last time I remember, I may have had them slightly higher... but the bass pressure may have caused a misfire in my brain! I'm currently running adcom gfa amps, but I'm going to upgrade after my TT purchase! They are not Bi-amped, just connected from the receiver to the amp, to the control boxes, and on to the SRT's.
I used my digital spl meter resting on a tripod from the listening position to achieve that reading. The TT purchase will happen with-in the next two to three weeks (pioneer plx1000). Then I'm on the hunt for some Carver Sunfire amps! For sure, if not, then parasound amps. The big if, should I still have funds, I would love to look around for McIntosh amp(s). But I doubt it!

I haven't pushed them as hard as you have, I probably won't take them that high. Too scared I'll break something in the house! I also believe that the subs are powered by 300W apiece! I'm probably wrong... most of the time I'm wrong!! I'll have to check the manual.

140db sounds really high... how are your ears? I would really be impressed if they can go that high! But I'm not sure they can! Perhaps I'm wrong! Again...
Other proud SRT owners and previous owners will chime in.
Frank

chefkungfu

Also, If you want to unload your SRT's.... you know what to do!
Frank

F1nut

They are capable of 125dB maximum, which would require about 4200 wpc.

chefkungfu

^^^ F1nut hit it right on the head!!!

villian

Mine are in a 1500 cubic foot room

F1nut

So, roughly a 14x14 room? Way too small for an SRT system. Regardless, you're not getting anywhere close to 140dB given the speakers and power.

ZLTFUL

Decibels (dB) Degree Sound Source

225 Deafening 12" Cannon @ 12' in front and below

195 Deafening Saturn rocket

180 Deafening Aircraft at take-off

160 Deafening Ram jet

150 Deafening Turbo jet

140 Deafening Artillery fire

130 Deafening Threshold of pain, decibels at or above 130 cause immediate ear damage. Hydraulic press, pneumatic rock drill

120 Deafening Riveter, chipper, thunder, diesel engine room, fireworks display

110 Deafening Punch press, close to a train, ball mill

100 Very Loud Passing truck, home lawn mower, car horn @ 5 meters, wood saw, boiler factory

90 Very Loud Decibels at or above 90 regularly cause ear damage. Noisy factory, truck without muffler

80 Loud Noisy office, electric shaver, alarm clock, police whistle

70 Loud Average radio, normal street noise

60 Moderate Conversational speech

50 Moderate Normal office noise, quiet stream

45 Moderate To awaken a sleeping person

40 Faint Average residence, normal private office

30 Faint Recording studio, quiet conversation

20 Very Faint Whisper, empty theater, ticking of watch

10 Very Faint Threshold of good hearing

0 Threshold of excellent youthful hearing


OSHA Regulations state that anything over 90db for 8 hours requires hearing protection. The time of exposure drops drastically as dbs increase. For example, at just 97db, the exposure time drops to 3 hours and at 102db, it drops to 1.5hrs.

Even movie theaters are regulated to an average level of 85db. They are allowed very short bursts of sound up to 115db but the entire film has to average that 85db or below.

Even trailers are being subjected to legislation (see the TASA standard) to bring them in line with this average requirement.

If you are hitting a consistent and steady 140db, not only are you, excuse me for being blunt, stupid, but you are most likely close to or already legally deaf.

Not to mention, F1 is right in the regard that to get from 120db to an honest 140db would require a 100 times increase in power.

nguyendot

In a home 140db is.... ridiculous. In a car that would require a very well designed box, and a thousand watts or more. A car is what, 50 cu ft for a medium SUV? In a home with 1500 cu ft, which is 30x the volume it would require something in the neighborhood of tens of thousands of watts.

boston1450

Louder the better
Keeps the critters away

skrol

NASCAR race is around 96dB for spectators, around 130dB in the pits.

villian

ZLTFUL wrote: »

Decibels (dB) Degree Sound Source

225 Deafening 12" Cannon @ 12' in front and below

195 Deafening Saturn rocket

180 Deafening Aircraft at take-off

160 Deafening Ram jet

150 Deafening Turbo jet

140 Deafening Artillery fire

If you are hitting a consistent and steady 140db, not only are you, excuse me for being blunt, stupid, but you are most likely close to or already legally deaf.

Don't worry, I wear double ear protection whenever trying to max out a system. Did you really think I was dumb enough not to? Oh, and you didn't need to post the DB sound scale reference. I am not a child. I had an F/A 18 pass 60ft over my head at take off today, so I think I'm more than qualified at judging what does, and does not constitute sound pressure levels in the 130db+ range. Besides, my post mentioned that I metered 119db at 30hz, yes...with an actual DB meter, and I am only claiming to hit a higher SPL at a higher frequency. In the range of 500hz to 5khz.

F1nut wrote: »

So, roughly a 14x14 room? Way too small for an SRT system. Regardless, you're not getting anywhere close to 140dB given the speakers and power.

Looks like my measurements were off. Just pulled up the CAD designs of my home. My Home Theater measures 16'8" long, 10'8" wide, and 8' high. So that actually puts me at 1,280 cubic feet of volume. What makes you think that I'm "Nowhere near 140db"? I'm running nearly 11,000 watts RMS total in the theater, with a room that's 1/3 the space of what Polk states the maximum output from the SRT's was designed for. Does nobody hear actually consider the rooms effect on things? That's a big oversight for such audio minded folks. Ha. My room is giving ridiculous amounts of gain across the entire spectrum. I am actually running the SRT subs at -18db of gain compared to the rest of the setup. Yes, I have the course knob at -10db and the fine tuning knob at -8db. In the previous room they were set to 0db and +4 respectively. Nothing has changed in the setup, just the room.

villian

Either way I'm just wondering what everyone else is pushing their SRTs with, because I'm contemplating moving up from the XLS 1500's to the XLS 2500's.

F1nut

villian wrote: »

What makes you think that I'm "Nowhere near 140db"? I'm running nearly 11,000 watts RMS total in the theater, with a room that's 1/3 the space of what Polk states the maximum output from the SRT's was designed for.

This for one thing.....

My SRT towers are currently each being driven by a dedicated Crown XLS 1500 amp. They're bridged giving a claimed 1,550 watts @ 4ohms in output.

What else can I say other than, welcome to my BOZO list.

villian

F1nut wrote: »

villian wrote: »

What makes you think that I'm "Nowhere near 140db"? I'm running nearly 11,000 watts RMS total in the theater, with a room that's 1/3 the space of what Polk states the maximum output from the SRT's was designed for.

This for one thing.....

My SRT towers are currently each being driven by a dedicated Crown XLS 1500 amp. They're bridged giving a claimed 1,550 watts @ 4ohms in output.

What else can I say other than, welcome to my BOZO list.

Don't knock it till you try it. Just saying..it's not the 80's anymore..

ZLTFUL

As you are so fond of saying, "What makes you think he hasn't? He isn't a child."

I have seen countless "professionals" (and I use the quoted word VERY loosely) in car audio showing off their SPL systems with no hearing protection whatsoever. Rockford Fosgate, back in the Power1000 days, had a demo van that was running 12 18s and a rack of 12 Power1000s and they would close folks into this thing and crank it. I wanted to check it out and asked them for hearing protection to which they said they didn't have any. Sorry, I'll pass.

So forgive me for not giving you the benefit of the doubt. Most folks who brag about their SPL levels could give 2 squirts less about their hearing and only care about showing off their e-peen.

Anyway, good luck with that. LOL

nguyendot

10'8" wide with an SRT system? Assuming you allowed the correct spacing from adjacent walls for the mains of the SRT (3ft give or take?), that would put them like 4'8" apart?

Also, 140db at 500hz to 5khz would mean the mains are doing that SPL. They're 89db 1w/1m. With 3100 (1550x2) watts, 2-4 ft from the walls you'd get a max of 129.9db at 1 meter. 11,200 watts to the same setup (mains only, no subs) you're still only looking at 135.4db at 1 meter. 140db requires about ~32000 watts in an ideal setting at 1 meter. Unfortunately, the mains can't take even remotely that amount.

ZLTFUL

@nguyendot Don't you go throwing logic, common sense, math and science into this discussion! He isn't a child after all!

nguyendot

Sorry, got over zealous

villian

nguyendot wrote: »

10'8" wide with an SRT system? Assuming you allowed the correct spacing from adjacent walls for the mains of the SRT (3ft give or take?), that would put them like 4'8" apart?

Also, 140db at 500hz to 5khz would mean the mains are doing that SPL. They're 89db 1w/1m. With 3100 (1550x2) watts, 2-4 ft from the walls you'd get a max of 129.9db at 1 meter. 11,200 watts to the same setup (mains only, no subs) you're still only looking at 135.4db at 1 meter. 140db requires about ~32000 watts in an ideal setting at 1 meter. Unfortunately, the mains can't take even remotely that amount.

So since you've accounted for all the variables, how much room gain am I getting and how is that effecting things? Also, aren't the SRTs efficiency 92db?

nguyendot

89db 1w/1m.

https://us.v-cdn.net/5021930/uploads/attachments/5/4/8/0/9/37075.pdf

Your room gain is meaningless, you aren't getting 10.1 db of gain from your room especially at 1 meter.

villian

What do you think is the peak SPL of the SRT system, by itself then? 120db @30hz is by no means its peak. That's simply an impressive number for comparisons sake against various other systems.

nguyendot

No idea, but it's easy to say it's not anywhere near 140 especially with the power levels you're running. 20db is over 6 times doubling in power and volume.

SRT_13

Enjoyed reading this post and the only question i have is, since Polk always using the max numbers in everything they publish, how come they only calculated 120 dB SPL above 30Hz using only 1 pairs of subs and not all 3 pairs (6 subs total, SEISMIC System). Any input nguyendot? Just curious that's all.

tonyb

Depends on the room, you have to remember in room response will almost always be different given that speaker specs are decided in special chambers. Any of you live in a special chamber ?

nooshinjohn

villian wrote: »

I had an F/A 18 pass 60ft over my head at take off today, so I think I'm more than qualified at judging what does, and does not constitute sound pressure levels in the 130db+ range.

BS..... there is no WAY in hell that a Hornet driver flew his jet that low over a civilian population, even if it was a demonstration flight at an air show. Naval Aviator wings are too hard to earn, and being that stupid with his aircraft would ruin a career.

villian

nooshinjohn wrote: »

villian wrote: »

I had an F/A 18 pass 60ft over my head at take off today, so I think I'm more than qualified at judging what does, and does not constitute sound pressure levels in the 130db+ range.

BS..... there is no WAY in hell that a Hornet driver flew his jet that low over a civilian population, even if it was a demonstration flight at an air show. Naval Aviator wings are too hard to earn, and being that stupid with his aircraft would ruin a career.

Who said anything about a civilian population?

Gatecrasher

Why are you so obsessed with the decibel level? Seems pretty dumb. You do know that once you damage your hearing that's it don't you?

There is no getting it back once it's gone.

villian

Gatecrasher wrote: »

Why are you so obsessed with the decibel level? Seems pretty dumb. You do know that once you damage your hearing that's it don't you?

There is no getting it back once it's gone.

1. Because nobody else is in the home audio world. Especially in conjunction with quality sound.
2. Yes, I understand and have understood that since a young age. I take proper precautions to protect my hearing when possible, and do yearly exams so that I can know if anything changes. I have no desire to be deaf, so I'll work my best to prevent that. Just because I can reach an ungodly decibel level doesn't mean that I listen at that level. I just like knowing that the capability, and headroom is there. In the same way that Americans love their trucks and V8s. The rest of the world doesn't understand, but there's nothing wrong with our societies choice. It's just a preference.