Bridging Front mains or a Amp?

[maccat39]

I was wondering should I bridge my front main speakers or get a amp?, I want more power when listening to 2ch audio. The AVR manual says I can almost double my front main output, by bridgeing I'm running a 8.2 sys now sounds good, but just want more power without taxing the avr in 2ch stereo. 140wpc 2 channels driven if bridged 270wpc. All an any advice needed.

THANKS!


Display: LG 60" PX950
AVR: Onkyo TX-NR3008
SPK: Def Tech 8060ST Ft. mains
Def Tech BP7006 Fw Lfe 2
Def Tech Mysthos3 Center
DeF Tech 800Promonitors Sr, Sb
Directv: HR21-200
Oppo BD-103 Bluray
PS3
SW: Klipsch Synergy 12" / Polk PSW 10"
Ethernet Sever 2Tb

 

[j_garcia]

This one gets covered at least a few times a week. You are not "bridging" a receiver, it is called biamping, which most receivers these days can do to a net benefit of very little. If you try to bridge a receiver, you will fry it.

If you find your receiver does not deliver enough power and it has preamp outputs, I'd recommend at least a 2ch amp. http://shop.emotiva.com/collections/amplifiers/products/xpa2

What exactly is the issue? You turn it up and get distortion or it simply does not get any louder? Your receiver is THX Ultra 2 Plus certified, so I'd be kind of surprised if it doesn't have plenty of power, but it still won't have as much as a decent amp IMO. The speakers are also 92dB sensitive, which shouldn't be too hard to drive.

 

[maccat39]

Also what are the pro's and cons of both options. Bridging or adding a separate amp

 

[markw]

Re-read what J said. You can NOT bridge the amps in that receiver.

Correction: the manual says you can but since you're still drawing off the same power supply, the advantages will be acedemic more than real. All bridging does is increase the stress on the amp by cutting the speaker load in half.

You do realize those speakers have built in powered subwoofers, don't you? What's not driven by the subwoofer amp is basically a pair of 4 1/2" midrange speakers and a tweeter. You don't think 140 watts in stereo is enough for them? What do you think increasing the power will do to help them?

If you need more power, which is doubtful, simply get an external amp that's made to deliver the real power you think you need.

 

[j_garcia]

Interesting, I didn't check the manual to see that it could bridge. That's the first receiver I've heard of able to do that, that I can think of. Again, still the same power supply.

 

[maccat39]

This one gets covered at least a few times a week. You are not "bridging" a receiver, it is called biamping, which most receivers these days can do to a net benefit of very little. If you try to bridge a receiver, you will fry it.

If you find your receiver does not deliver enough power and it has preamp outputs, I'd recommend at least a 2ch amp. XPA-2 | 300W x 2 | Emotiva Audio | High-end audio components for audiophiles and videophiles, spanning 2-channel music systems, as well as 5.1 and 7.1 home theaters. Products include multichannel amplifiers, stereo amplifiers, and monoblock amplifier

What exactly is the issue? You turn it up and get distortion or it simply does not get any louder? Your receiver is THX Ultra 2 Plus certified, so I'd be kind of surprised if it doesn't have plenty of power, but it still won't have as much as a decent amp IMO. The speakers are also 92dB sensitive, which shouldn't be too hard to drive.

Thanks, Yeah I like it loud! 2ch music, I was just wondering cuz I was planning on getting a Emotiva Xp2 or Outlaw Mono block 2200 also considering the Crown XLS1500. I didn't think Bi amping /Bridging the manual said. was the way to go. When play at reference levels it seems too kind of strain, sounding fatigue-ing.( -81db +16db ) when I'm really in a good jamming mode I usually play at -10 to 0 reference that's when I notice the stress on the AVR Dt. 8060st are begging for wpc

 

[j_garcia]

Yep. You are a candidate for an amp then. Either of those choices will be a pretty solid step up from the Onkyo. My old AVR was 120W THX Select, but my mains are all 4 Ohm. My XPA-3 has powered them effortlessly in two different and very large rooms.

 

[maccat39]

The DT can handle 300wpc. I'm sure 140wpc 2ch driven. when I'm jamming hard its kind of putting a strain on the avr, an not really unleashing the true potential of 8060's.

 

[j_garcia]

The wattage rating on the speaker itself is almost irrelevant. That's a max rating before things fry, not how much power they need. I ran my Pioneer BS22-LRs on the XPA-3 at very elevated levels without issue. They are rated at 80W max and the XPA-3 is 200W. Just because that's the wattage the amp is capable of does not mean that's how much power the speakers are using, however when you crank it and run out during big peaks, you typically know pretty quick.

 

[markw]

No matter how much power you feed them, those little drivers can only move so much air before distortion starts kicking in. They may not fry, but there's no guarantee they will sound good while trying to absorb that power.

 

[j_garcia]

This is true. Though they are 92dB sensitive, it is entirely possible that the speakers are hitting their limits regardless of the amplification, but I sort of don't think that's it. With dual mids, I'd expect them to be able to fill a good size room even with the current power.

Do you have a HUGE room? Have you run the calibration on the Onkyo and then checked out how it set things?

 

[maccat39]

Yeap, I hear you. The Emotiva XPA3 sounds real good about now! Just knowing I have good clean power when I need it is my peace of mind. Especially when the wife leaves

 

[maccat39]

good point, so driving the 8060 at say 160 or higher (clean power an separate amp) will strain the 8060's ?

 

[fmw]

One of the things people fail to undertand about bridging amplifiers is that the result causes the amplfiers to see 1/2 the impedance of the load. In other words, if your speakers are nominal 8 ohms, the biamped units will see 4 ohm. If they are 4 ohms, the biamped units will see 2 ohms etc. That's why Garcia told you that the process would fry the receiver. Lower impedances draw more current and there is a limit to the amount of current an amplifier final stage can handle. Your speakers must be inefficient. Mine have an efficiency rating of 86 db (about average) and you wouldn't be able to stay in the same room with my 140 watts per channel feeding full output to the speakers without ear plugs. I don't think the speakers would stay in the room either. Good luck with whatever you decide to do.

 

[maccat39]

This is true. Though they are 92dB sensitive, it is entirely possible that the speakers are hitting their limits regardless of the amplification, but I sort of don't think that's it. With dual mids, I'd expect them to be able to fill a good size room even with the current power.

Do you have a HUGE room? Have you run the calibration on the Onkyo and then checked out how it set things?

Ran Audyssey on the Onkyo, {mains are set at full band sounds good} My room size is 20x24 with a vaulted celling about 22ft. I sit about 16ft center position from mains

 

[maccat39]

One of the things people fail to undertand about bridging amplifiers is that the result causes the amplfiers to see 1/2 the impedance of the load. In other words, if your speakers are nominal 8 ohms, the biamped units will see 4 ohm. If they are 4 ohms, the biamped units will see 2 ohms etc. That's why Garcia told you that the process would fry the receiver. Lower impedances draw more current and there is a limit to the amount of current an amplifier final stage can handle. Your speakers must be inefficient. Mine have an efficiency rating of 86 db (about average) and you wouldn't be able to stay in the same room with my 140 watts per channel feeding full output to the speakers without ear plugs. I don't think the speakers would stay in the room either. Good luck with whatever you decide to do.

Thanks FMW, I know my speaker are efficient their 92db. I took every body good advice and i'm not going to bridge these speakers, deciding on what amp to go with now.

 

[fmw]

The DT can handle 300wpc. I'm sure 140wpc 2ch driven. when I'm jamming hard its kind of putting a strain on the avr, an not really unleashing the true potential of 8060's.

How do you know that? Have you measured the output power from the amps? Maybe what you need is bigger speakers, not a bigger amp. This will come as a surprise but folks who use powered subs rarely use more than 10 watts per channel reproducing the mids and highs. Assuming you are in a room in a home and not in an auditorium, you already have way, way more power than you can ever use. If you want a big amp then buy one. But don't expect it to resolve your problem.

 

[maccat39]

The Onkyo NR3008 owners manual gives you the option of Bi-amp or BTL (Bridge). my speaker aren't capable of Bi-Amp, the other option would be btl by using the surround back speaker amps. and changing the settings in the speaker setting menu. If I need more power I'll decide on a amp. Thanks for all the great advice.

 

[slipperybidness]

How do you know that? Have you measured the output power from the amps? Maybe what you need is bigger speakers, not a bigger amp. This will come as a surprise but folks who use powered subs rarely use more than 10 watts per channel reproducing the mids and highs. Assuming you are in a room in a home and not in an auditorium, you already have way, way more power than you can ever use. If you want a big amp then buy one. But don't expect it to resolve your problem.

I'm guessing that there really isn't a problem at all with the Onkyo/DT combo. Relatively beefy amp and relatively efficient speakers. I doubt you are gonna notice a big improvement, if any improvement.

However, investing in good amps isn't a bad idea whether or not a problem really exists.

 

[TLS Guy]

good point, so driving the 8060 at say 160 or higher (clean power an separate amp) will strain the 8060's ?

Probably.

I don't know how low those speakers crossover, but since the woofers are side firing I would bet that those mids are going down below 200 Hz. The power divide is 400 Hz, so even at 92 db sens they will be handling a lot of power.

I suspect your main problem is thermal compression and probably distortion. Making small 4.5" drivers or any driver for that matter that can play loud and clean is an expensive proposition. At the price of those speakers there is going to be very little money in those drivers.

I have played and listed to the DEF tech line at Best Buy. In my view they are dogs ad real dogs at that.

I would get a more powerful amp, but I doubt it will make a difference. However, you are then ready to power your next set of speakers. If you like clean and loud be prepared to triple or quadruple your speaker budget. Before you do that be mindful that playing music loud will destroy your hearing. Please note that is not might, it will. There are no replacements for the hair cells of your inner ear. Please bear that in mind.