Polk, Martin logan, Definitive, Which floorstanding speakers best for this receiver?

[jlaavenger]

MartinLogan Motion 12 Floorstanding Speakers, Definitive Technology BP-8060ST (Ea) Bipolar Tower with Built-In Powered Subwoofers or Polk Audio Monitor 70 3-Way Floorstanding Speakers? Which floorstanding speakers are best for this receiver?

Onkyo TX-NR709 7.2-Channel Network A/V Receiver

Most watching Blu Rays and HD Satellite TV, some music. I like the sound of Martin Logans, I like the price of the Polk but the Def Tech's might still be the best it's just that purchasing might be limited to one speaker every six months.

[Blu-Dog]

Originally Posted by jlaavenger

MartinLogan Motion 12 Floorstanding Speakers, Definitive Technology BP-8060ST (Ea) Bipolar Tower with Built-In Powered Subwoofers or Polk Audio Monitor 70 3-Way Floorstanding Speakers? Which floorstanding speakers are best for this receiver?

Onkyo TX-NR709 7.2-Channel Network A/V Receiver

Most watching Blu Rays and HD Satellite TV, some music. I like the sound of Martin Logans, I like the price of the Polk but the Def Tech's might still be the best it's just that purchasing might be limited to one speaker every six months.

You're really looking at speakers that call for 4 ohm amplifier compatibility - you might be able to do the DefTechs, but I'd be wary of the other two. They all sound good. If you kept the volume down, you might get away with it, but I wouldn't risk it.

I lean towards DefTech anyway, take what I say with a grain of salt. The Martin Logans sound great...

[jsr]

I'm looking at the Martin Logan Motion 10 or 12s also. I have Polk Monitor 70s now.
I'm concerned my Onkyo won't be able to drive them safely, even if Martin Logan says compatible with 8-ohm rated receivers on their website.

[drewzus]

Originally Posted by Blu-Dog

You're really looking at speakers that call for 4 ohm amplifier compatibility - you might be able to do the DefTechs, but I'd be wary of the other two.

The Monitor 70s are 8 ohms though.

[Blu-Dog]

Originally Posted by drewzus

The Monitor 70s are 8 ohms though.

The Monitor 12's claim a sensitivity of 92db - at 2.83 watts input. They're power-hungry, at least for home theater. Music, you could get away with a 100 watt receiver, maybe.

The ohm rating of 8 ohms is a saving grace, but they drink the juice, like all Martin Logan units. I truly love their sound, but they must be fed.

You're right, after I got up off my duff and looked up the specs, but I'd only run those in a 5.1 setup if I had a separate amp. As a 2.0 setup they'd be OK, probably.

[drewzus]

Originally Posted by Blu-Dog

The Monitor 12's claim a sensitivity of 92db - at 2.83 watts input. They're power-hungry, at least for home theater. Music, you could get away with a 100 watt receiver, maybe.

The ohm rating of 8 ohms is a saving grace, but they drink the juice, like all Martin Logan units. I truly love their sound, but they must be fed.

You're right, after I got up off my duff and looked up the specs, but I'd only run those in a 5.1 setup if I had a separate amp. As a 2.0 setup they'd be OK, probably.

Sorry, I should have clarified. I was talking about the Polk Monitors being at 8 ohms.

[Big Daddy]

Originally Posted by Blu-Dog

The Monitor 12's claim a sensitivity of 92db - at 2.83 watts input.

I believe you meant 2.83 volts and not 2.83 watts. Moreover, a sensitivity of 92dB isn't bad at all. There are many speakers that have a sensitivity in the mid 80s.

Just so that nobody is confused, here is a brief explanation of sensitivity. There will be a short quiz tomorrow.

Sensitivity is calculated by measuring the sound pressure level at one meter, with 1 watt of input power, at 1KHz (1,000Hz) or pink noise. This may be important because it requires twice the power to increase the volume of a speaker by 3dB. Horn loaded enclosures such as Klipsch are used to manufacture very sensitive loudspeakers. A funnel is placed in front of the speaker, acting as an acoustic amplifier, thus improving the efficiency and the directivity of the speaker. However, sensitive speakers do not necessarily produce better sound.

Many companies use voltage to measure sensitivity. Here again, 2.83 volts are inputted and measured at 1 meter.

Note that from Ohm's Law, P = V^2 / R. Therefore, 2.83 volts into an 8 ohm load is equal to 1 watt, P = (2.83)^2 / 8 = 1 Watt.

A speaker's efficiency in transforming power into sound is to a certain extend determined by the impedance of a speaker, 2.83 volts becomes 1.5 watts at 6 ohms and 2 watts at 4 ohms, a 3dB increase.

When you are dealing with sensitivity, do not confuse the cabinet size with driver size. The size of the cabinet will affect the sensitivity. Generally, bookshelf speakers are more inefficient than larger floor standing speakers. What this really means is that smaller bookshelf speakers need more power to play as loud as their bigger brothers.

Larger driver cone size helps the low frequency extension of the driver, but not necessarily its sensitivity. Some very small full-range drivers such as the Fostex 4" drivers have sensitivity over 100dBs. This is also true about some super tweeters. Although they are very small, their sensitivity is around 106dBs.

Something else that you should be aware off is that manufacturers do not use the same standards when they measure sensitivity. Speaker sensitivity is usually specified in dBs with 1 watt input measured with a microphone placed one meter from the speaker and on the speaker axis between the tweeter and midrange. Some manufacturers use a single frequency, often 1,000Hz, to measure sensitivity. If the speaker has a peak or dip at that frequency, the results will be a little misleading. Measurements at National Research Council of Canada (NRC) are normally done with a range of frequencies between 300Hz and 3,000Hz.

Also, for an 8-ohm speaker, 1 watt input is equivant to 2.83 volts. Do you measure a 4 ohm speaker at 1 watt (1.42 volts) or at 2.83 volts (2 watts)? If you use 2.83 volts on a 4-ohm speaker, the result will be 3dBs higher. Some marketers may prefer that.

[callas01]

All three of these speakers claim they are either compatable with or nominal ohm rating of 8 ohms. I don't see the 709 having a serious issue powering the speakers. Granted adding a power amp is probably not a bad idea, but the onkyos from the 700 series and up are 4 ohm stable. I don't know the impedance swings of any of these speakers, but Im sure the 709 could handle them, however if he is trying to power them to extremely high volumes or fill a really big room, then he should probably buy an amp.

My speakers are 4 ohm rated, technically a 5.5 ohm speaker, they have an 86 db sensitivity, so they don't look like easy speaker to power, but my Integra powers them just fine without issue or lack of power.


OP, personally speaking, I would get the Def Techs.

[lojack1976]

I've demoed the Motion 10 and 12 as well as the Def Tech 8060ST and they are not as difficult to power as one might think. I've turned up the volume quite a bit on the receivers I demoed them with. Most of these receivers had similar power to the TX-NR709 and some of them had a little less. The more powerful receivers could open them up more, but the lesser receivers I used never sounded strained.

I don't think the 4ohm dips with these speakers happen very often, so the 709 will be fine like Callas said. I also agree that the 8060ST is the better sounding speaker. The Motion 12 is pretty good, but the 8060ST has a fuller sound to me. It just sounds right to my ears. I think both are better than the Monitor 70 myself, but I'm not a Polk fan so I'm a little biased there.

[prerich]

Originally Posted by lojack1976

I've demoed the Motion 10 and 12 as well as the Def Tech 8060ST and they are not as difficult to power as one might think. I've turned up the volume quite a bit on the receivers I demoed them with. Most of these receivers had similar power to the TX-NR709 and some of them had a little less. The more powerful receivers could open them up more, but the lesser receivers I used never sounded strained.

I don't think the 4ohm dips with these speakers happen very often, so the 709 will be fine like Callas said. I also agree that the 8060ST is the better sounding speaker. The Motion 12 is pretty good, but the 8060ST has a fuller sound to me. It just sounds right to my ears. I think both are better than the Monitor 70 myself, but I'm not a Polk fan so I'm a little biased there.

Ditto, however I am unbiased because I enjoy and have owned Polk speakers.
OP, listen and demo for yourself and pic the ones you like- that being said ... I would go Definitive Technology myself---just my 2 cents

[drewzus]

Originally Posted by prerich

Ditto, however I am unbiased because I enjoy and have owned Polk speakers.
OP, listen and demo for yourself and pic the ones you like- that being said ... I would go Definitive Technology myself---just my 2 cents

Agreed. I would say that you're basically getting what you pay for. The Definitive Technology speakers cost almost twice as much as the MartinLogan speakers and 6 times as much as the Polk speakers.

[lojack1976]

Originally Posted by drewzus

Agreed. I would say that you're basically getting what you pay for. The Definitive Technology speakers cost almost twice as much as the MartinLogan speakers and 6 times as much as the Polk speakers.

Yeah, you are getting more speaker with the 8060ST at $2000/pair. If one was looking for Martin Logans in this range then audioadvisor.com has Purity's for $2000/pair and the new ElectroMotions are $2000/pair as well. These are what I would be comparing with the 8060ST. I've heard all three and I'm quite partial to electrostats, so I would lean toward the ElectroMotions. I was quite blown away when I demoed them, and they're much easier to drive than the Purity which I love as well. I do like the 8060ST a lot though.

[jsr]

I have an onkyo ht-rc360, basically a 609 equivalent. Its not rated for 4ohms in the manual and not as high a model as the 709. Do you guys feel it would be capable of driving the Motion 12s without damage at moderate to high volumes?

As for polks, I love my Monitor 70s for my purposes...movie watching and very low cost. They are lacking in midrange clarity for music though, but that's not my primary purpose for them.

[lojack1976]

The 609 is not rated for 4ohm performance, but it is THX Select2 and in order to get that certification it has to be 4ohm stable across the front channels. Also, note that it has the same power supply as the 709 which is rated for 4ohm performance by Onkyo.

Keep in mind that neither of these receivers are ideal with most 4ohm speakers, but the Motions are not as demanding as a lot of other 4ohm speakers. They have a high sensitivity and being that Martin Logan states them as being 8ohm compatible they probably have a 6ohm nominal impedance with the occasional dip down to 4ohms.

I know myself that they are easier to drive than my own speakers. I even demoed them with a Denon AVR-1911 which I would not use with 4ohm speakers in general, but they ran fine and without strain at higher volumes. The 609 is more robust so I doubt you will run into problems with it. On the other hand having the 709 would be better because if you did feel that they weren't getting enough power then you could add an amp. I've learned a lesson....always buy a receiver with pre-outs. It can save you headaches down the road.

[callas01]

Jack, speaking with Onkyo/Integra, they don't have the same power supply or amplifier in the 609 and 709. The PS is similar, and the amps are completely different, so that the 700 line can power 4 ohm loads continuously. The only units that have the same PS and AMP is the 809/1009, but the difference in those two units is the 7 ch v 9 ch.

[lojack1976]

Originally Posted by callas01

Jack, speaking with Onkyo/Integra, they don't have the same power supply or amplifier in the 609 and 709. The PS is similar, and the amps are completely different, so that the 700 line can power 4 ohm loads continuously. The only units that have the same PS and AMP is the 809/1009, but the difference in those two units is the 7 ch v 9 ch.

Yeah, I didn't think the amps were the same. I did figure that the power supply was the same being that they are rated the same but I guess that it's not. In that case I'm not sure how the 609 would hold up with the Motions compared to the 709. Its a THX Select2 receiver so it should still offer passable 4ohm performance on the front channels, and like I said I listened to the Motions on a Denon AVR-1911 and it was capable...certainly not the best performance in the room, but acceptable. I would think that the 609 would do better since it has a stronger power supply.

[jsr]

I got to audition the Motion 12s, 2 different ML Sources, and Jamo 426s. Of these, I liked the motions the most. However they weren't what I expected. The highs were more forward than I like. Otherwise the mids were nice, midbass was what I epxted for the drivers it had, and it was much smaller than I had expected. It has a unique look too and I liked the slim cab. But the forward highs and what sounds like incompatibility with my receiver all but killed my desire for them.

[jlaavenger]

I'm seriously considering the motion 12s. What would you recommend adding to it in the future? ie, sub, surrounds, center. And will the 709 drive them? Don't get me wrong I have an old low power JBL sub I'm using now with the two TV speakers.

The only other receiver consideration I have is the New Arrival Pioneer VSX-1121-K 7.1-Channel A/V Receiver but it does not offer as much power.

[callas01]

Originally Posted by lojack1976

Yeah, I didn't think the amps were the same. I did figure that the power supply was the same being that they are rated the same but I guess that it's not. In that case I'm not sure how the 609 would hold up with the Motions compared to the 709. Its a THX Select2 receiver so it should still offer passable 4ohm performance on the front channels, and like I said I listened to the Motions on a Denon AVR-1911 and it was capable...certainly not the best performance in the room, but acceptable. I would think that the 609 would do better since it has a stronger power supply.

when I was shopping around I was seriously concerned that they were the same too... which is why I called and talked with them, I didnt want to be buying a $1k integra and be getting an upscale 600 with an extra 1 yr warranty. what I learned was that the 708 and 40.2 were more similar then any other point in which onkyo/integra built their two lines, they were both built off the Integra 40.1 premise, but there were still some small differences like DACs and other slightly upgraded hand picked parts on the integra, so that they lines stayed consistent with the price and warranty. This was done to help control costs in this economy, but also why the lines sound more similar then ever before.

[callas01]

Originally Posted by jlaavenger

I'm seriously considering the motion 12s. What would you recommend adding to it in the future? ie, sub, surrounds, center. And will the 709 drive them? Don't get me wrong I have an old low power JBL sub I'm using now with the two TV speakers.

The only other receiver consideration I have is the New Arrival Pioneer VSX-1121-K 7.1-Channel A/V Receiver but it does not offer as much power.

the 709 will do fine.