Question: New amp or what for more volume???

TONYGVISINET

:eek:
Hello folks, I am a veteran polk enthusiast for over14 years and now enjoy a pair of SDA 2b's with a PSB Powered Subwoofer.

My question is:

Most times I cannot achieve the clean loudness I want without my NAD 3400 100w Integrated amp clipping at volume level 5, so I am looking for the best solution!

What would be the best scenario: buy a bigger amp or buy some bigger polks?

I have inquired about a amp/pre-amp configuration and have come up with a new NAD C160 / C270 combination that would provide 120w. I don't think it will be enough. (This would be $900.)

Bi-amping seems to be the new fad now, but I am unsure of the wiring to my Subwoofer will work with that scenario. (Using a line level interconnect from the "pre-out" into the Sub, which sends back the signal to "main in" without the lower frequency.

Thanks is advance for any expert help you can
Tony G
Glloucester, Va
provide!!!:p

RuSsMaN

More clean power. If you are clipping your amp, thats the solution, imo.

Step up to 200-250 w/continuous. Carver, Nad, Adcom would be good places to start looking. 100 to 120, I doubt you would even notice.

Cheers,
Russ

TroyD

To get a really noticeable difference in power, double it.

BDT

rlw

Consider this: let's say your Polks are 89dB efficient [1w of input power produces 89dB of sound at 1m in front of the speaker, ignoring reflections from the room].

To get 92dB, you'll need 2 watts.

95dB -> 4 W
98dB -> 8 W
101dB -> 16 W

you get the idea: watts double for every 3dB increase in volume - doubling the volume is about 10dB.

Remember, this doesn't take into distance further from the speaker - you might need 5 Watts to get that 89dB if you sit 4 Meters from the speakers. The power curve then looks like:

92dB -> 10W
95dB ->20W
98dB -> 40W
101dB ->80W

Also figure that non-mass-market-pop CD's can have peaks 15-20dB above "average" levels. That means you need some pretty hefty reserves - unless, of course, you listen to commercially produced crap which has 2dB peaks.

This is why I think 600W a channel is not excessive for 89dB efficient speakers.

Now, interestingly, in theory, adding another pair of speakers will increase the sensitivity by about 6dB - so your 89dB efficient speakers become 95dB efficient, and that's a huge gain.

However, the price you pay is phasing problems, hookup issues, space issues, etc. And it typically isn't a good tradeoff.

I'm also really curious about your setup: it's the bass frequencies which gobble the power - 80Hz and lower. If you're truly filtering that out at line level, I'm pretty amazed that you are clipping a 100W amp that easily. How loud do you listen?

Just some thoughts. Hope it helps.

TONYGVISINET

To RLW:
Thanks fro such a thorough answer- that really put it in perspective.
I must say that your question is easy to answer- I must listen to the music TOO LOUD! No, really- I am a classic rock fan, and I do like it VERY LOUD (but clear).
I think the opinion that I have had given about getting bigger speakers in not that good. Those SDA 2b's will be able to handle to loudness better of I give them what they want- more clean watts. Now I am bummed out about having to let go my Nad 3400 in lieu of a very expensive Amp/pre-amp.
BTW- I cannot find which NAD 200 watt amp model to look at.. any suggestions?
Also- who would recommend Rotel over NAD??? They have a nice 200 watter for about $1k.
Thanks again very much for all the help!
Tony G

wlrandall

Heh heh heh...find an old Bedini to drive those SDAs. The best I ever heard a pair of SRSs was through a Bedini. The clincher? The store I used to listen to them at let them go for $500. If I'd only known...

Wally

tryrrthg

If your NAD integrated amp has pre outs then just use that as a preamp until you can get a new one. Spend the money on a new amp. You could also look at used amps such as Bryston, they carry a 20 year transferable warranty. So you would be covered for a long time!

TONYGVISINET

To wlrandall:
Found a bendini on ebay for $450... what are the specs on that?

RuSsMaN

My first SDA demo, was 2b's on a 25 watt Bedini Class A.

Music to my ears.

wlrandall

Tony, it depends on the model.

TONYGVISINET

Now, how is that? I just digested all the computations from rlw's post, and you tell me it can be done for 1/4th the watts instead of double.

jmasterj

Hi TONYGVISINET,

I had a pair of SDA-2's driven by a Carver M1.5t rated at 350watts a channel peaked at 600 watts a channel with dynamic headroom to 700 watts one channel for musically significant time periods. AKA short burst. I saw one on Audiogon.com not too long ago it will do the trick I guarantee.