vanderrg Posted July 25, 2005 Share Posted July 25, 2005 I had a very brief exchange with Speakerdoctor previously about Biamping my RF-7's using my 3805 as described here: http://www.audioholics.com/productreviews/avhardware/Denon-AVR3805_review04.php To broaden the question and open it up to all who would care to contribute: 1. I know that separates are supposed to be the very best, but bi-amping with this Denon should give me 240 wpc total to each RF-7. Shouldn't that be plenty of power to deal with the impedance drops the RF-7's can experience? 2. I have a decent subwoofer: an SVS 20-39 PC+ crossed over at 80hz with all speakers set to small. Do you think bi-amping in this way would produce any discernable benefit or is the Denon's normal 120wpc plenty given the fact that the RF-7's are already not having to produce the full spectrum of sound? 3. I know that good separates are supposed to provide huge amounts of clean power that can increase the RF-7's bass response and warm up the sound which is what I'm hoping would happen if I do this bi-amp thing. At the end of the day if the group here thinks there's even a decent chance that this would work I could always just do it and see how it sounds...but I don't want to waste my time if everyone here is confident that it wouldn't accomplish anything... Thanks in advance- Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted July 25, 2005 Share Posted July 25, 2005 I honestly do not think that you would gain much by doing it. Doesn't the Denon 3805 have only one pair of main speaker outputs? I assume that you are only using the receiver for two channel operation then if you are going to use another pair of speaker outputs (i.e. Rear, Rear Surround) to accomplish this. I guess it would be worth a try though. I think you would get much better results by adding a more stout high current amplifier running off the Denon 3805's main outs. What is prompting you to do this? Not happy with it currently? Not enough ooomph out of the Denon? Quote Link to comment Share on other sites More sharing options...
Fish Posted July 25, 2005 Share Posted July 25, 2005 I biwired,biamped and a few more things on my Denons/3802/03/05.It didn't hurt but it really didn't help till I got an outboard amp.Then I tried seperate pre/pros through my seperates amp,BIG difference.Long story short,the 3805 and the other 38xx are great avrs,but not even close to mid fi seperates in sound quality,imo. Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted July 25, 2005 Share Posted July 25, 2005 ---------------- On 7/25/2005 10:28:09 AM Frzninvt wrote: ... Doesn't the Denon 3805 have only one pair of main speaker outputs? I assume that you are only using the receiver for two channel operation then if you are going to use another pair of speaker outputs (i.e. Rear, Rear Surround) to accomplish this. I guess it would be worth a try though. ---------------- The Denon 3805 is a 7 channel receiver. I didn't click on the link he provided, but I remember If you are running a 5.1 set up, you can redirect your other 2 channels using the rear (or "Multi-zone 2") configured to your mains for a bi-amp situation. If you do it vanderrg, let us know how it turns out. Quote Link to comment Share on other sites More sharing options...
vanderrg Posted July 25, 2005 Author Share Posted July 25, 2005 Good question- My desire to try it stems from the fact that when I turn off the sub there just doesn't seem to be the kind of bass that I would expect from the RF-7's. Now of course I can remedy that by turning the sub back on but then I wonder if I'm missing out on higher bass frequencies that the RF-7 should still be producing. My understanding is that the reason that separates generally warm up the sound is somehow related to their presentation of lots of clean high-current power to the Rf-7's (i.e. 200wpc or more). I don't really understand why this would increase the bass response but everyone seems to say that it does. Now I have heard that the Denons are good receiver for delivering close to their rated RMS power (and doing it cleanly) and was hoping that bi-amping the Denon and thus sending lots and lots of power to the RF-7's might accomplish (or come close to) the same effect that a separate 200wpc amp might do... BV Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted July 25, 2005 Share Posted July 25, 2005 If you want more bass out of your RF-7s, get a separate amp of 200 watts or more. Such an amp needs to drive low impedance loads. An amp that can drive 2 ohm loads would be a plus, since the minimum impedance of the RF-7s is 2.8 ohms. Most flagship receivers do not have the power to drive RF-7s, biamped or not. The Denon 3805 does not have the power. It is a typical Japanese receiver with 1 pair of output devices per channel. Look for a separate amp with 5 pairs of devices per channel and you will hear all the bass you ever wanted from the 7s. Bill Quote Link to comment Share on other sites More sharing options...
T2K Posted July 25, 2005 Share Posted July 25, 2005 If you want to 'warm' them up I have to assume that they sound somewhat 'bright' to your ears. Try setting the speakers large for more low end, or the crossover lower, whichever your case may be. Keith Quote Link to comment Share on other sites More sharing options...
vanderrg Posted July 25, 2005 Author Share Posted July 25, 2005 Okay- I probably won't try it then. Looks like at some point it will have to be separates for me. It's funny- if I had known that I had to buy a $1000+ separate amp to hear great bass from these RF-7's, I probably would have just bought RF-5's or 35's instead...since they don't suffer from the dreaded impedance drop so much I probably would be hearing good bass right now with my Denon, correct? Also MrMcGoo- does the fact that I'm using a separate sub impact your advice at all? Will I still get noticeable improvement if I step up to a separate amp even though I've got the SVS doing the low bass? Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted July 25, 2005 Share Posted July 25, 2005 Setting them to "Small" is choking everything below 80Hz out of them and routing it to the sub. Start with setting them to "Large" so they get a full range signal before taking any other measures, you may be surprised. I just can't see taking a speaker like the RF-7 and setting it to small! What a waste of speaker! Quote Link to comment Share on other sites More sharing options...
vanderrg Posted July 25, 2005 Author Share Posted July 25, 2005 I've turned off the sub and set them to large... I would have expected much more bass than I got, and that is largely the impetus for starting the thread. I know the speakers work because if I put in a movie with tons of bass (i.e. The Incredibles) and crank it up (while disabling the sub so as to send the LFE to the mains) the speakers prove they can make nice rumbly low bass. But it's NOTHING like when I set the speakers to small and turn the sub back on. When I listen to music CDs the effect is even more pronounced..While set to large, zero of my CDs play with the kind of nice deep bass that I know those speakers are capable of. My room is carpeted and curtained. I struggle with the "large vs small" issue and have read lots of discussions about it here on the forum. So far I've left them on "small" for 2 reasons: 1. I've read many assurances here that even if the RF-7's are only playing down to 80hz they are still making lots of high-bass and you aren't "wasting" them- in fact several posters here have said that the speaker should sound better if anything since it isn't having to reproduce all of the lowest bass. For movies, there is also the matter of the main channels in a DD mix carrying info down below the RF-7's ability to reproduce...with mains set to large I would miss that sound entirely (not sure that I would miss it...but knowing that I wouldn't be getting it would bother me). 2. For the moment at least, there is no comparison in sound enjoyment between "large" and "small", particularly when listening to music. Large= not very much bass, small= as much bass as I tell the sub to put out! Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted July 25, 2005 Share Posted July 25, 2005 I have the RB-75's connected to my Denon 3805 in a 5.1 configuration. I have the Denon 4802 R connected to my setup listed below. I agree with Frzninvt about setting them to Large. In fact I have all of my speakers set to "Large." I also run my set up with the LFE selected to "both mains + sub." To my ear it gives better imaging. Are you setting the crossover in the Denon or on the SVS? Quote Link to comment Share on other sites More sharing options...
vanderrg Posted July 25, 2005 Author Share Posted July 25, 2005 When you listen to 2-channel CD music (i.e. no LFE channel...so basically your sub is silent if the RF-7's are set to large), do you find that the RF-7's put out nice deep bass without adjustment? To answer your question I have the sub's crossover disabled and just use the Denon's crossover setting. Quote Link to comment Share on other sites More sharing options...
Jay L Posted July 25, 2005 Share Posted July 25, 2005 cross them over at like 40 or 50hz. also how far from the wall is your rf-7's? they can be bass shy if they are too close. Quote Link to comment Share on other sites More sharing options...
vanderrg Posted July 25, 2005 Author Share Posted July 25, 2005 That's interesting...they are about 10 inches from the wall...how far out is optimal? Could this be a signficiant contributor? Quote Link to comment Share on other sites More sharing options...
Jay L Posted July 25, 2005 Share Posted July 25, 2005 try pulling them out about 18", see if you like it. also if your not already slightly toe them in which can give some more space from the wall. not to mention better imaging. Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted July 25, 2005 Share Posted July 25, 2005 ---------------- On 7/25/2005 1:50:05 PM vanderrg wrote: When you listen to 2-channel CD music (i.e. no LFE channel...so basically your sub is silent if the RF-7's are set to large), do you find that the RF-7's put out nice deep bass without adjustment? To answer your question I have the sub's crossover disabled and just use the Denon's crossover setting. ---------------- Hmmm. I am the wrong person to answer that question. I don't listen to Redbook CD's anymore. I have a Denon 3910 DVD/SACD player and I just played "Wanted Dead or alive," on the Bon Jovi SACD, "This Left feels Right," and the DVD-A, "The Best of REM," and the song "E-bow the letter." Both of them in stereo sound good--IMHO, I think these 2 recordings would sound better in stereo with something like the Cornwalls or above in the Heritage line (although I don't know that for sure). That being said the footprint of the RF-7's appear to be half as big as the Cornwalls and was developed to be used in at least a 5 channel configuration with a subwooofer. It may be an apples to oranges comparison. Hopefully within the next two weeks I am going to be able to listen to a 5 channel Cornwall set up and I would be more qualified to answer this question. The material I just listened to on the RF-7 sounded good in stereo--But with multi-channel music and my size room I prefer the latter. I wanted to add my 2 cents because of my previous post, but realize it may not be relevant in your situation. BTW: I also set my crossover at 60 Hz for music (80 Hz for movies). Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted July 25, 2005 Share Posted July 25, 2005 If you do bi-amp the 3805, please post your results. Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted July 25, 2005 Share Posted July 25, 2005 Bob, If you use a subwoofer and have your RF-7s set as "small", then the RF-7s need less power from your receiver. Bass frequencies require more power to reproduce than treble. When I went from a 140 watt B&K to a 225 watt Sunfire, there was a dramatic increase in bass. The Sunfire has the ability to drive low impedance loads, so the increase in bass was dramatic. Bill Quote Link to comment Share on other sites More sharing options...
sivadselim Posted July 26, 2005 Share Posted July 26, 2005 ---------------- On 7/25/2005 2:49:28 PM tkdamerica wrote: I don't listen to Redbook CD's anymore. ---------------- ok it's vinyl or hirez only, eh? Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted July 26, 2005 Share Posted July 26, 2005 Vanderrg What are some of your CDs your listening to which are not providing you with bass? It may sound like a stupid question, but it has to be there in the recording to begin with. Quote Link to comment Share on other sites More sharing options...
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