Can I bi-amp with the Denon AVR-8500H receiver using a external amp?

[Hayes]

I have a Denon AVR-8500H receiver and I have two external amps (2 Rotel 1095 model amps) connected to the receiver using the pre-outs. I have been told by different sources that I cannot and I can bi-amp using this receiver. Why wouldn't my receiver be "bi-amp-able?" I was considering bi-amping by running a y-adaptor out of each main preout on my receiver, then taking the 2 male RCAs leading out of the pre-out and connecting each RCA to a separate channel on my Rotel 1095 amp; hence, using 4 of the channels on my Rotel amp instead of just 2 channels. Please someone tell me why this can or cannot be accomplished. And, what is the difference between a bi-amp-able receiver and a non-bi-amp-able receiver other than stating the obvious (one can and the other can't)... What is different inside the unit that determines whether it is bi-amp capable and how would I know this as a user? THANK YOU!

 

[everettT]

What speakers do you have? Passive biamping is typically as waste unless the speaker designer implemented a crossover for such.

 

[Hayes]

Polk RTIA9 mains

 

[everettT]

Polk RTIA9 mains

Not worth it at all. If your using the external amps, that's more than enough. Those speakers can be power hungry but you have that covered regardless.

 

[Hayes]

Good to hear, thanks Everett! For curiosity sake, is bi-amping (although as you said not necessary) possible with my Denon AVR8500H as some have told me it is not possible, or is it very possible to bi-amp using the preouts on the receiver and running them through an RCA Y-adaptor to my external amp? Even though it is not going to change performance, would it hurt anything to do so?

 

[everettT]

Good to hear, thanks Everett! For curiosity sake, is bi-amping (although as you said not necessary) possible with my Denon AVR8500H as some have told me it is not possible, or is it very possible to bi-amp using the preouts on the receiver and running them through an RCA Y-adaptor to my external amp? Even though it is not going to change performance, would it hurt anything to do so?

No it wont hurt anything, just extra wire with no audible benefit. Biamping off the same power supply gains no additional power, and with a passive crossover still maintains the exact same power divide.

 

[Hayes]

Thank you Everett, I know so little about these things. So, if I follow your response, then to properly bi-amp a speaker one should use 2 different power amplifiers? I was thinking that using 2 different channels on the same amp would be appropriate, but I hear you saying using the same amp (power supply) is not going to change anything; using two different amps to bi-amp would definitely add additional power. Is this correct?

 

[lovinthehd]

Try this article https://www.audioholics.com/frequent-questions/the-difference-between-biamping-vs-biwiring

The 8500 does have a bi-amp feature, but like everettT says, if you have ample power I think you're set. If you want to try it looks like page 74 of the pdf download manual is where to start (I assume that you can use the pre-outs same as the speaker terminals for such).

 

[AcuDefTechGuy]

Short version: Don’t bi-amp.

I think the salient question to ask is, “Does the benefit outweigh the risk?”.

Benefits?
1. Possible sound improvement
2. Feeling good knowing your speakers are bi-amped and you put your amps to use

Risks?
1. Expense
2. Time
3. Potentially damaging your speakers (thermal and mechanical damage)
4. No audible improvement
5. Fear that you could potentially damage your speakers if something goes very wrong
6. Loss of sleep due to fear that your speakers could be damaged if something goes very wrong.

But don’t let me scare you. Any AVR with preouts + external amps can bi-amp speakers made for bi-amp.

 

[Hayes]

I appreciate the feedback and the advice Lovinthehd and AcuDefTechGuy posted. I get what you all have said and maybe this is why one Denon rep said the AVR-8500 cannot be bi-amped using the preouts and an external amplifier. Inspired by the feedback on this thread, I called Denon today for the second time and a different Denon rep said that bi-amping can be done using the AVR-8500 and an external amp as I described. Unless I hear someone say definitively that bi-amping will cause damage to my receiver, amp, or speakers, I will try bi-amping and see if the benefits out weight the cons/risks as stated above. I am betting you all are right and that there is no noticeable difference. I have ordered the RCA cables so I cannot test this set up until cables arrive... maybe by Monday or Tuesday of next week, so that gives us more time to speculate or for others to weigh in on this discussion. If you observe a mushroom cloud explosion coming from Southern California on Monday, then you might be witnessing a thermo-nuclear catastrophe caused by my attempt to bi-amp! I appreciate yalls' comments, thanks for your help!

 

[Hayes]

I'd still like to hear Everett clarify if he meant that to bi-amp my Rtia9 speakers, I would need to use two different amps... I have never heard of this before. I thought all I needed to bi-amp a single speaker were two channels from the same amplifier to power the one speaker; and thus, I would need 4 of the 5 channels on one of my Rotel amps to bi-amp both of my front main speakers. But, if I heard Everett correctly, I should use one channel on Rotel Amp A and one channel on Rotel Amp B (I mentioned earlier in the thread I have 2 Rotel 1095 amps) to bi-amp each of my front main speakers in order to gain additional power. Is this true? Sounds strange to me; perhaps I misunderstood Everett's comment.

 

[PENG]

Of course you can biamp with the x8500h. It has 13 channels so at long as you have 2 spare channels you do it but there will be virtually no benefits. For more theoretical benefits, use the preouts and 4 amp channels from a 5 channel amp or 2 identical (much preferred) two channel amps.

The RTiA9s are designed for passive biamp. There are pros and cons for passive and active biamp. Passive biamp is easy to do with your speakers and there should be no risk if you do it right. Chances are great that the theoretical benefits will not result in audible improvements, though expectation bias/Placebo effects can help.

 

[lovinthehd]

Passive bi-amping isn't about gaining power, it's more about separating it in the type of bi-amping you want to try. Active bi-amping with an active crossover is the more effective way of bi-amping. Did you read the article I linked? It explains the different ways it is gone about. Have fun playing around with it. Most important thing is to remember to remove the jumpers between the terminals on the speakers first so we don't see that mushroom cloud .

ps Generally I'd not bother calling customer service for technical questions....I think you've already found out why. Denon customer service can be quite meh.

 

[Hayes]

Thanks Peg and LovintheHD for your replies. Peg, I am not using just the receiver to bi-amp... I have no open channels on my receiver, since I am running a 13.2 speaker system. As you both said, I need to learn about active and passive bi-amping. I will watch the video tonight... thank you!

 

[Hayes]

Forgive me, PENG, not Peg, sorry

 

[AcuDefTechGuy]

I think one case of “pseudo-passive” bi-amp might have more benefits for experienced Audioholics.

This case has been done by NHT (Classic Four tower) and RBH (SX/SV Towers).

The external amp needs to be an amp with a high-pass/subsonic filter and volume/gain control. Crown amp has 30Hz HPF, Yamaha has 20Hz HPF, Dayton has 18Hz HPF, RBH has 16-40Hz HPF).

 

[highfigh]

I have a Denon AVR-8500H receiver and I have two external amps (2 Rotel 1095 model amps) connected to the receiver using the pre-outs. I have been told by different sources that I cannot and I can bi-amp using this receiver. Why wouldn't my receiver be "bi-amp-able?" I was considering bi-amping by running a y-adaptor out of each main preout on my receiver, then taking the 2 male RCAs leading out of the pre-out and connecting each RCA to a separate channel on my Rotel 1095 amp; hence, using 4 of the channels on my Rotel amp instead of just 2 channels. Please someone tell me why this can or cannot be accomplished. And, what is the difference between a bi-amp-able receiver and a non-bi-amp-able receiver other than stating the obvious (one can and the other can't)... What is different inside the unit that determines whether it is bi-amp capable and how would I know this as a user? THANK YOU!

What kind of SPL are you trying to achieve and if you use the Rotel(s), why did you buy the 8500 when you really need a preamp/processor?

 

[highfigh]

Bi-amping isn't about gaining power, it's more about separating it in the type of bi-amping you want to try. Active bi-amping with an active crossover is the more effective way of bi-amping. Did you read the article I linked? It explains the different ways it is gone about. Have fun playing around with it. Most important thing is to remember to remove the jumpers between the terminals on the speakers first so we don't see that mushroom cloud .

ps Generally I'd not bother calling customer service for technical questions....I think you've already found out why. Denon customer service can be quite meh.

Bi-amping is absolutely about gaining power- it uses an active crossover because the insertion loss from a passive crossover reduces the output by a significant amount.

Bi-wiring is totally different in that it uses the speaker's crossover and it still yields the headroom from using the two channels on each speaker, although this is only apparent/useful if the amplifier is driven close to rated/maximum output. Whether is's generally useful is, as we know, up for (endless) debate. Or Facebook- that would be a good place to argue about it.

 

[PENG]

I think one case of “pseudo-passive” bi-amp might have more benefits for experienced Audioholics.

This case has been done by NHT (Classic Four tower) and RBH (SX/SV Towers).

The external amp needs to be an amp with a high-pass/subsonic filter and volume/gain control. Crown amp has 30Hz HPF, Yamaha has 20Hz HPF, Dayton has 18Hz HPF, RBH has 16-40Hz HPF).

Assuming the Crown amp is a power amp and you are keeping the internal crossovers of the speakers, I would say such scheme is not a good idea because you are cascading the filters of the amp and the speaker's internal crossovers. Good or bad results will be luck/hit and miss dependent.

 

[AcuDefTechGuy]

Assuming the Crown amp is a power amp and you are keeping the internal crossovers of the speakers, I would say such scheme is not a good idea because you are cascading the filters of the amp and the speaker's internal crossovers. Good or bad results will be luck/hit and miss dependent.

Well, It's not something I thought up all on my own.

1. S&V did a review on that NHT Classic Four using an external XO/amp to do just that. NHT advertised it. The speakers' internal XO are intact. So this is not considered fully active.

https://www.soundandvision.com/content/nht-classic-four-surround-sound-speaker-system

2. I spoke to Shane Rich RBH Chief Engineer about doing the same thing with the RBH SX-6500/8500 towers, and he agreed.

If it were a hit/miss/luck issue, I doubt NHT or RBH would be recommending that.

From S&V:

Bi-amping the Classic Four requires removing the speaker "jumpers" that connect the bass driver to the upper three-way system and routing the front left and right channel outputs into the X2 crossover. This is easily accomplished with a system of separates consisting of a preamp/processor and multichannel amplifier. It can also be done with an AV receiver that offers the flexibility of both preamp output and power amp input connections. You'd run the pre-pro (or receiver's) front L/R preamp outputs full range into the X2's high-pass filters to remove lower bass from the signal, then feed the X2's output to the front L/R amplifier channels (or the receiver's L/R amplifier inputs). If your AVR only offers line "outs" and not amp "ins," you might be able to use the receiver's internal crossover to filter out lower bass, but for the best match make sure your AVR's crossover slopes match the 12dB/octave slopes of the NHT system.

Either way, this results in the front L/R channels' amplifiers feeding a bass-limited signal to the Classic Four's upper speaker terminals, while the X2's outputs feed lower bass frequencies to the A1 amplifiers, which drive the Four's side-firing 10" woofers.