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Keep order for DSW PRO 660 or order XV15 or VTF-15H? - Page 2

post #31 of 44
Thread Starter 
Quote:
Originally Posted by Kini62 View Post

"Passive bi-amping

Passive bi-amping (also known as "fools bi-amping" for good reason) requires loudspeakers with the dual binding posts used for bi-wiring, again with the shorting bar removed. The difference (and profit advantage for the retailer) is that it requires two stereo power amplifiers, instead of one, and an additional pair of speaker cables. (Can you guess who is getting fooled by passive bi-amping?)

In passive bi-amping, the output from the pre-amplifier is fed to a pair of identical stereo power amps. All four amplifier channels are fed the same, full range, signal from the pre-amp. This is important, so take note of it. The output of the power amps is fed to the stereo loudspeakers, the left and right outputs of one power amp to the left and right loudspeakers' high frequency binding posts and the left and right outputs of the other power amp to the left and right loudspeakers' low frequency binding posts. We now have the same, full range signal everywhere. The high frequency part of each loudspeaker's passive internal crossover is doing what it always does with a full range signal, as is the low frequency part of each loudspeaker's crossover.

From the listener's perspective, if all goes well, the sound quality should remain exactly the same. However, the placebo effect insures that most folks who passively bi-amp their music systems report a sonic improvement."

A pretty good explanation from a quick internet search- smile.gif

I still don't get why it is offering nothing. Each of my mains have 6 speakers in them. And my Denon AVR can only output 110 watts per channel. So all 6 speakers have to share 110 watts. VS if I biamp them, 3 speakers can share 110 watts. I can say for sure that there was a dramatic change in the audio by doubling the wattage. I didn't buy a new amp (yet) to do the biamping. I already had the two unused channels to do the biamping with.

As for adding another sub, I just don't have the room for another sub, if it is needed. My room is only 13 feet x 13 feet. But I can't wait to get the new XV15. My current sub can not even be heard with the RTAi9's. They completely over power the sub.

BTW while I'm posting... Once I get my new XV15 (will be here next Tuesday), should I have my AVR send LFE or LFE and main to the sub? I have always just sent the LFE to it in the past.

Thanks.

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post #32 of 44
Quote:
Originally Posted by ColdBrew View Post

I still don't get why it is offering nothing. Each of my mains have 6 speakers in them. And my Denon AVR can only output 110 watts per channel. So all 6 speakers have to share 110 watts. VS if I biamp them, 3 speakers can share 110 watts. I can say for sure that there was a dramatic change in the audio by doubling the wattage. I didn't buy a new amp (yet) to do the biamping. I already had the two unused channels to do the biamping with.

As for adding another sub, I just don't have the room for another sub, if it is needed. My room is only 13 feet x 13 feet. But I can't wait to get the new XV15. My current sub can not even be heard with the RTAi9's. They completely over power the sub.

BTW while I'm posting... Once I get my new XV15 (will be here next Tuesday), should I have my AVR send LFE or LFE and main to the sub? I have always just sent the LFE to it in the past.

Thanks.

Coldbrew, your avr is rated 2ch driven. So when you biamp you are dividing the power output to the towers into 4 outputs instead of 2. There is no actual power gain or if there is its not much...its definately not doubling power. The avr only has one amplifier and one powersupply and all channels pull there power from one source. A external amplifier works differently as each cannel has its own supply and are rated all channels driven. That being said those A9's need alot more power than what a avr can supply to shine. I would let the sub do all the heavy lifting and cross the mains at 60-80hz. You can run lfe to the mains but your avr is going to run out of steam fast trying to drive those A9's full range plus the rest of the speakers. I can only get to -5db of reference with my A7's full range and diving the rest of the speakers. In 2ch stereo I can get to reference, but if I cross all speakers at 80hz the avr will drive all speakers past reference fairly easily. It will actually go louder than my ears will tolerate.
post #33 of 44
Quote:
BTW while I'm posting... Once I get my new XV15 (will be here next Tuesday), should I have my AVR send LFE or LFE and main to the sub? I have always just sent the LFE to it in the past.

Set your sub to LFE.......................... LFE+Main is used when you set your mains to full range. With XV15 in business you don't wana set your mains to Large. When you set a sub to LFE+Main; the avr sends full range signal to your mains + it copies the signal below the crossover point to the sub also. What you get, resultantly, is bloated bass. Your mains cannot handle the bass down to where the sub is at its best.

For checking purposes, just play the Pulse lab scene or FOTP plane crash scene at reference volume. Your mains will struggle badly.


As regards the passive bi-amping; it's more to do with the SQ not loudness. A lot of people attribute loudness to SQ, which is wrong. Even if you bi-amp your mains, both the LF and HF drivers receive the same full range signal. The actual hair splitting takes place in the passive crossover inside the speaker cab. Passive bi-amping is mere wastage of two extra amp channels.

If your mains did not have crossover built inside them, only then actively bi-amping the mains by controlling the crossover externally would have yielded sonic discernible benefits.
post #34 of 44
If he had a external amp driving those A9's they would not struggle on those scenes...the tuning and hpf in the crossover would roll those lower frequencies off and they simply would not play those infrasonics. The reason to not use the mains full range is because the avr does not have enough power to driver them at reference. Running both the sub and mains full range does not bloat the sound if you turn the sub down and balance the bass out. The A7 and A9 speakers are quite capable down to about 28hz, then they roll off fast. However I agree that there is no need to tax the avr when you have a capable sub. Set the cross at 60-80hz and let the sub do the heavy lifiting.
post #35 of 44
Thread Starter 
Once I get the new sub I'll try switching the mains back to the small setting.

As for the bi-amping. Basically what you are saying is that I will get better sound quality only using 5 channels of the 7 channels that my AVR can provide? VS using all 7 channels. Since I'm only doing 5.1 and not 7.1.

BTW I have a Denon 2807 AVR.
http://www.crutchfield.com/S-Lk1lH2rq6L1/p_033AV2807B/Denon-AVR-2807.html

Thanks.
post #36 of 44
Quote:
As for the bi-amping. Basically what you are saying is that I will get better sound quality only using 5 channels of the 7 channels that my AVR can provide? VS using all 7 channels. Since I'm only doing 5.1 and not 7.1.

Nopes. What I meant was that you would waste to extra channels on passively bi-amping the mains. They won't shine on SQ. Alternatively, you can use those extra channels to power either front heights or surround back speakers. Your avr will do just fine.
post #37 of 44
Quote:
The A7 and A9 speakers are quite capable down to about 28hz, then they roll off fast.

Pulse lab scene is centred around 16Hz. Even if you somehow disable the passive xo inside A7/A9, I doubt they can match the performance of any good sub that digs that low.
post #38 of 44
Thread Starter 
I got my sub in today. Wow it makes me feel like I'm at the local IMAX!

I've also been reading the manual to my AVR and now I understand what is really going on when I set my speakers to large and small. The lowest I can set the crossover is to 80 Hz. So that will have to do. I now have all my speakers set to small so the sub will handle everything 80 Hz and lower. I haven't had a chance to find the right setting for gain and phase but I plan to work on that tomorrow.

I spent most of the day installing a wall mount for the new TV that should be here next week. The sub arriving was a nice surprise. It wasn't suppose to be here until Tuesday. But the FedEx guy got it off the ground truck and brought it to me today.
Edited by ColdBrew - 8/31/13 at 10:15pm
post #39 of 44
Wow that is great that you got it early, sounds like you got your settings right, just rub you auto cal to set the distance and trim of your speakers.
post #40 of 44
Quote:
I got my sub in today. Wow it makes me feel like I'm at the local IMAX!

I've also been reading the manual to my AVR and now I understand what is really going on when I set my speakers to large and small. The lowest I can set the crossover is to 80 Hz. So that will have to do. I now have all my speakers set to small so the sub will handle everything 80 Hz and lower. I haven't had a chance to find the right setting for gain and phase but I plan to work on that tomorrow.

I spent most of the day installing a wall mount for the new TV that should be here next week. The sub arriving was a nice surprise. It wasn't suppose to be here until Tuesday. But the FedEx guy got it off the ground truck and brought it to me today.

Measurements........
post #41 of 44
Quote:
Originally Posted by braveheart123 View Post

Pulse lab scene is centred around 16Hz. Even if you somehow disable the passive xo inside A7/A9, I doubt they can match the performance of any good sub that digs that low.


Could you please read my post again? I never said they could play that low...I said they would not struggle because they would not be trying to play 19hz...so being set to large or small wont matter as far as the speaker is concerned. Set large the AVR will run out of steam trying to drive the speakers reference...then I agreed its better to leave them set small and ler the sub do the work.
post #42 of 44
Thread Starter 
Quote:
Originally Posted by braveheart123 View Post

Measurements........

measurements?

BTW I was wrong I can set the crossover much lower than 80 hz. I did the autoconfig and I think the receiver set the mains at 60 hz. I can't remember. I'm going to spend some time with them today and see how they sound. Also it set the mains and centers to large, but I changed them back to small.
post #43 of 44
Quote:
BTW I was wrong I can set the crossover much lower than 80 hz. I did the autoconfig and I think the receiver set the mains at 60 hz. I can't remember. I'm going to spend some time with them today and see how they sound. Also it set the mains and centers to large, but I changed them back to small.

80Hz aint a yardstick but you must have a high current avr or a power amp to feed the mains if you want to lower the xo. Let the new bad boy do what it does best 80hz and below.
post #44 of 44
Thread Starter 
I hadn't used the system in several days because I had moved the TV connected to it, preparing for my new TV. It arrived yesterday but now it seems my AVR is giving out. It will stop responding to any changes such as volume and input. I have to power it off with the hard power button to get it to reset. Usually it locks up again with in a few seconds. It appears to start doing it after it warms up. The audio may still continue to play unless the audio type changes (DTS, DD, Stereo). I'm not sure if it is the new speaker setup (it was working fine on Monday) or the new TV. I did connect the TV to the AVR using the Audio Return Channel input (my AVR doesn't support it), but I don't think that would matter.

I really don't want to have to spend the money for a new one right now. If I do, I hope I can find one that will work well enough (for the money) to get me by until I can buy a nice preamp/amp (looking at Emotiva) setup.
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