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DCM Time Window 7 - AMP & PREAMP

I’ve Found out that I’m the owner of 1 of only 200 pairs of DCM TW7 speakers ever made.
I am running 2 Carver A500x amps in mono block mode into these speakers. The speakers are rated at 700W max into 4 ohm. The Carvers in Mono Mode are 800W.

My question is …does anyone else have these speakers and what kind of amp are you using, and what are your thoughts on the DCM Time Window 7?
And to the Tube AMP experts I ask, how many watts would be appropriate for these speakers? They are efficient at 92DB, but they're still power hungry.

I am thinking of introducing a Tube PreAmp into my system and take the Denon out…any suggestions for something under 1k?

My system:
Denon AVR 3300, Emotiva XDA-1, Rotel 991 AE, (2x) Carver A 500x, DCM Time Window 7.

Thanks
128x128dfgkali
hifihvn
943 posts
 
Wiki link.[http://en.wikipedia.org/wiki/Decibel]
dfgkali's avatar
dfgkali OP
23 posts
 
Ooo..This is neat stuff.. Thanks :)
tonywinsc
583 posts
 
Ok, 3dB is double the Sound Intensity. It is still correct that it takes about a 3dB change in Intensity then, to perceive a change in sound level. 6-10dB which is double the loudness is a very big change. Think about normal conversation- it is 40-60 dB. Long term exposure to 85dB SPL will cause hearing damage. 100dB is standing next to a jack hammer. If someone must shout in order to be heard over your music, then it is very loud and likely approaching 75-80dB at the position where they are standing. Also consider that the sound Intensity then, drops 3dB every time the distance away from the speakers is doubled. So if sensitivity, for example, measures 92dB at one meter, then it drops to 89dB at 2 meters. And lastly, if each speaker is generating 92dB, I think the combined SPL is 95dB.
dfgkali's avatar
dfgkali OP
23 posts
 
Okey all this is very good stuff...learning more than I had bargained for. So mg next question is : what is this DB rating that speakers come With. What am I being told that a speaker with 92 DB is better than a speaker with 87db?
hifihvn
943 posts
 
What am I being told that a speaker with 92 DB is better than a speaker with 87db?

Not necessarily better, jut easier to drive to a volume level.

For example, a 87 db (at 1 watt, 1 meter) speaker can reach the volume you want with a 200 watt amp.

If you have a 90 db ( at 1 watt, 1 meter) speaker, it should reach that same volume level you want, needing only 100 (half) watts.

If you have a 93 db ( at 1 watt, 1 meter) speaker, it should
only need 50 watts to reach that same volume level again.

So, if these speakers were 100% identical in every way, including sound, looks, size, etc, I guess you could say the one with the higher rating can be better, since it needs less power, if everything else is equal. The all else being equal, usually doesn't happen. This just helps you find a speaker that can play louder for a given amount of power.

This Wikipedia link may help more. [http://en.wikipedia.org/wiki/Loudspeaker#Efficiency_vs._sensitivity]
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