Will this destroy my receiver?

darkmonohue · « **on:** 23 Sep 2003, 02:50 am »

I have a Denon 5.1 receiver, but I use it in stereo. It seems to lack the punch to drive my NHT ST4s (I know, I never should have tried to pair such power hungry speakers with a wimpy receiver). But I had a thought. Could I trick my amp into biamping with the unused channels? My thought was that I could run a Y-splitter from my source to the inputs for front and rear on each side, then run wire to the speakers as if the outputs for the two separate channels on each side were two separate amps. I guess I'd need to set the speaker configuration for rear channels without center. Two questions. 1) Would this actually double the current available to power the speakers, and 2) would this cause things to blow up and catch fire? I know I should replace the reciever, but I have reasons for waiting. Thanks--as you might guess, I'm new to all this.

warnerwh · « **Reply #1 on:** 23 Sep 2003, 03:38 am »

Even if you did this with the Denon you would still most likely not have the power you're looking for. That's definitely a good reason for separates. Even if you double the power you're still only gaining 3db. 3 decibels is just a little bit louder. Or in other words: every time you double the power your volume will increase 3 db. So if 100 watts equal 90db, 200 will be 103. This is just an example to make it simple. 10db is subjectively twice as loud and takes 10 times the power coincidentally. The first watt is the most important and it could be that you like more volume than maybe the NHT's can handle, I don't know as I'm not familiar with them. It could be that you need to get a more sensitive speaker. For example one that puts out 93db with 1 watt. As you see from above a 90 db speaker will require double the power to make it to 93db. If you're room is dead and/or large this will also affect things. Patience sounds like the best idea right now if you don't want different speakers.

Tonto Yoder · « **Reply #2 on:** 23 Sep 2003, 04:04 am »

Interesting reading:
http://www.theabsolutesound.com/newsletter/3_17_2003/nht_st4.html

I suspect the speakers might have more "punch" if the woofers had their own amp: I would think the Denon could safely supply those "extra" watts in the configuration you've suggested. It shouldn't be too expensive to try (if you're not using $$$$ wire).

Carlman · « **Reply #3 on:** 23 Sep 2003, 03:51 pm »

It won't destroy it but, it will present a higher load to the amp... and the sound will most likely sound identical since the voltage will remain the same. Receivers and amps have X amount of power; dividing it over additional outputs of the amp will not increase it, just redistribute it and change the load characteristics.... and probably add a little distortion.

The best way to add power is to add an amp. If you have power-hungry speakers, consider an external amp. Maybe a used B&K ST-202 would be enough? They can be found very reasonably.

Good luck,
Carl

Tonto Yoder · « **Reply #4 on:** 23 Sep 2003, 11:17 pm »

Carlman,
I'm not sure if you're right about the situation: seems the Denon receiver is designed to drive the 5 channels of home theater so it's a different situation than connecting multiple speakers to a stereo receiver's A/B & C speaker outputs. The few multi-channel Denons I looked up on the web gave equal power ratings for all channels: not like some lesser receivers that offer decent watts in stereo, but diminished wattage when spread out over more channels. I'm not familiar with Denons in detail, so I could be wrong. As you say, the hi-fi solution would be to add an external amp.

darkmonohue · « **Reply #5 on:** 24 Sep 2003, 01:18 am »

Well, maybe I'll give it a try, so long as it won't do permanent damage. At some point I guess I'll have to go for a more powerful amp, or more sensitive speakers. Thanks.

Rob Babcock · « **Reply #6 on:** 24 Sep 2003, 03:05 am »

If the implication is that a receiver has X amount of watts to spread over the channels, that's not necessarily true. If that was the case, a 5 x 100 watt reciever would be capable of 500 W, with one channel driven. I'm not aware of any unit that will do that. True, the power supply will be the limiting factor as to whether the unit can make rated power with all channels driven simultaneously: most cannot.

Assuming your Denon has taps for an A & B speaker pair (you don't mention which model you have), and again assuming you can have both active at once, you should be able to have the A set drive the woofers & the B set drive the tweeters. NOTE: BE VERY SURE YOU REMOVE THE SHORTING STRIPS BETWEEN YOUR SPEAKERS INPUT TERMINALS! Else you'll have a mess.

The downside to this is that you won't likely be able to change the level of one output relative to the other. One way you could would be to use Y cables to split the L & R outputs of your CD player and run them into the 5.1/7.1 ch analog inputs of your Denon. Then hook up the speakers to the corresponding outputs, minding the above caveat about removing the shorting strip. The downside to this: only being able to use one input.

The best bet, if your particular Denon has preouts, it to simply get an outboard amp to run your speakers. The old AVR-1800 (and some of the series that replaced it) and above have preouts for the front 3 channels. You should be able to get a decent amp at a reasonable price.

warnerwh · « **Reply #7 on:** 24 Sep 2003, 05:23 am »

Not sure what you have for a budget but for 500 you could get a Rotel 990 with 200wpc or some similar amp or an old Adcom GFA 555 for 350. It didn't dawn on me until I read the post above is that these receivers are rated for one channel and any more driven typically drops the output quite a bit. Your gain is going to be very little and I'm suspecting disappointing. I'd save the money for the Y adapters and put it toward an outboard amp.

WerTicus · « **Reply #8 on:** 25 Sep 2003, 06:14 am »

could built a kit amp ~300w /channelx2 for about $250 in parts.

hmen · « **Reply #9 on:** 26 Sep 2003, 12:08 am »

If the denon has preouts you should get a good, used 2 channel amp on ebay or audiogon. The owner's manual for my receiver actually warns against biamping with the A and B outputs.

randytsuch · « **Reply #10 on:** 26 Sep 2003, 12:29 am »

Since the NHT's have two sets of binding posts, you can biamp them. As long as all the amps in your denon are the same power, you can try biamping, as you described. Just take out the jumper between the binding posts.

Randy

stevirey · « **Reply #11 on:** 27 Sep 2003, 08:22 am »

If you basicly like the sound of your Denon and NHT's and just want to,well somehow,get more out of it,SUBWOOF!I have a Parasound HCA 750A amp rated at 75 watts@8 OHMs 100 watts into my 4 OHM speakers.
D'Appolito style Dynaudio floorstanders.Now I felt much like you.Just didn't have that umph.So I sent mt ols Adcom GFA 555 to the shop,dusted of my Audio Control Richter Scale III and wala!When you free up your main amp from lower bass duties and add a few hundred watts of sub,well it's like night and day.The Richter Scale uses a mic and warbel tone to set it's 6 band eq.It also has a level control which you almost never need except for recordings that are very bass shy.And fewer that are bass heavy.The man who noted that it takes twice the power to gain 3db is what I have read also.I cant do the math on what 400 watts below 125HZ does,but it make a big,BIG difference.You can do this on the cheep.Build you your own sub speaks,there are a bunch of Adcom 555's on Ebay,and at the moment one Richter Scale!