Your suggestions for 6.5" two-way L/C/R speakers in $500/pair range? - Page 4

Sounds good jakewash, that's my plan.

I have a shelf above my TV that has about 14.5" vertical clearance, so most 6.5" two-way speakers will fit.

I moved both speakers out away from the rear wall a bit and that made a big (positive) difference in the sound stage of the Axioms.

The difference in tone is still the same though -- it is especially obvious when setting levels using pink noise. The Axioms definitely emphasize the low mids. The Rockets are brighter and thinner sounding.

I still prefer the Rockets, but this round was closer. In some instances, especially at lower volume, the Axioms sounded better -- or, if not 'better', different -- in a good way.

It depends a lot on the music you're listening to, but at the end of the day the Rockets sound more natural, less colored.

As I said above, the Axioms are fine speakers, and I can see why some people would like them, but particularly at high volumes they tend to sound muddy.

Well, there may be a couple problems here:

1) My hearing may be different than many people's. Still, when I EQ music, most people like the sound.

2) Semantics. When I say 'warm' I mean the lower mids seem to be emphasized.

3) My room and/or speaker placement may be playing a roll.

I'm using a Sony CD player, Yamaha receiver (as a preamp), Sony switchbox, and two Mackie two channel pro amps.

As I said above I changed the placement and that seemed to help the Axioms.

I also switched amps but that made no difference.

Thursday night, I moved the speakers out into the room again and this time I set them side by side instead of placing the Axioms on top of the Rockets.

This seemed to help the Axioms even more. The sound stage was often almost identical when switching between the two. If anything, the Axioms had a stronger center image.

However, the Axioms still had the low mid emphasis I referred to in my previous posts. It isn't obnoxious -- in fact, some people might prefer the sound of the Axioms over the Rockets -- but it does seem like a coloration. It becomes more noticeable at higher volume levels.

The Rockets have more detail and inteligibility.

Tonight (Friday night) I loaned the Rockets to a coworker who is a member of the AVS forums, a fellow tech, and a serious audio and videophile. I am anxiously waiting for his impressions of them.

In the meantime, I have just been playing around with two Axioms (L/R) and a Rocket in the center -- trying different signal processing settings on the Yamaha receiver. Ordinarily, what Yamaha calls "disco" seems to sound best (it doesn't use the center speaker). In this case, using Dolby Pro Logic seemed to have a better sound (at least in some ways) due to the use of the Rocket in the center position.

This is a coworker's review of the Rocket RS250MkII vs. his Boston Acoustics micro 100x speakers:

Rocket RS250 MkII opinions


Speaker calibration: The Rockets need 5 or 6 dB higher calibration level than my Boston Acoustics Micro 100x speakers.


The acoustic guitar in They Never Really Wake Up by Viva Voce seems a little laid back.


Some vocals seem a bit distant. On the other hand, the female vocal in Revolution by Mother Earth was very up-front.
Am I hearing a bit of a smile EQ? Midrange laid back?


A bit sibilant.


Revealing in some ways. I heard a triangle that had not sounded that good before.


Sometimes the soundstage seems wider than the Micro 100x.


Some of the harsh or gritty sound I attributed to the aluminum dome tweeters in the Micro 100x persists, so I suppose it could be my hearing or the particular recordings. THX Re-EQ helps.


As expected, the Rocket's low end reaches the 80 Hz crossover with my subwoofer better than my Micro 100x speakers, but sounds a bloated at some frequencies near the crossover. This is a room acoustics issue, in part. The right speaker is near a corner and has a sizable peak at about 65 Hz.


Very good speakers, but probably not the best choice for my receiver with a fixed 80 Hz crossover. I still want to try some speakers with acoustic suspension and 12dB/octave roll-off designed to work with an 80 Hz crossover.

I have a new appreciation for my Boston Acoustics Micro 100x speakers after comparing them with the Rockets. Not that the the Rockets are inferior, but I think that my speakers are very good and work well in their positions in my living room.

The Rockets may be the best of that speaker type for the money. For my room I think the Micro 100x low end roll-off may be an advantage since the speakers are close to walls.


Check the review on page 69 of the February/March 2000 issue of Sound & Vision (not available online).

Tom Nousaine's test results for my Boston Acoustic Micro 100x speakers:


Frequency Response (at 2 meters)
front left/right 85 Hz to 17.9 kHz +/-3.2 dB


Bass Limits (lowest frequency and highest SPL with limit of 10% distortion at 2 meters in a large room)
satellite 50 Hz at 75 dB SPL

I have decided to return the Axioms.

When I checked before ordering, their estimated return S&H cost (per M3 v2 speaker) was $5.69 from NYC. I checked on the UPS site today and the cost was almost $40 (total) for ground shipping! When I spoke with an Axiom rep ('JC') he offered to email me some return labels for about $7 each ($21 total) -- and DHL will come here to my house to pick up the speakers.

IMO, that's how ID speaker mfrs should operate.

The true test of a company is how they treat customers _after_ the sale -- especially when the customer wants to return merchandise. JC was very polite and professional.

I would not hesitate to order speakers from them in the future.

Once again, the M3 v2s are good speakers -- especially considering that three (3) of them were under $500 delivered, including S&H (the same price as two of the Rockets). They have a pleasing sound, and I imagine that some people would prefer them to the Rocket RS250MkIIs. Overall though, to my ears in my room, I prefer the sound of the Rockets. The highs are more crisp and clear, and the vocals -- while somewhat thin sometimes -- have more presence. Some drums sound better on the M3 v2s -- they can give them a 'fatter' fuller sound. Unfortunately, if a recording is at all bass heavy, that fat sound can turn muddy. Same with vocals --particularly male vocals. They can sound better on the Axioms, but sometime they can sound thick or chesty.

I did some testing with my wife, who is a musician (a singer) and there were times when (without knowing which speaker was playing) she preferred the Axioms (and I could see why). Other times though, she clearly preferred the Rockets.

Anyway, enough of that. I just wanted to give Axiom and JC some credit for their customer service and explain that just because I'm returning the M3 v2s does not mean that I think they're bad speakers. In another room, I or someone else might prefer them.

Sorry I haven't posted in a few days.

I haven't abandoned the search, but it can be frustrating trying to find some of the higher end speakers. The mfrs' sites are often hard to navigate and/or don't give much info. To find a local dealer, some refer you to a distributor who you must call -- rather than the more typical 'dealer locater' function most sites have. The distributor will often mistakenly give you the names of companies that do installations only (no retail sales or listening room). Often there are no authorized Online dealers at all.

Take Sonance for example. I called the distributor for the Mid-Atlantic area and they referred me to a company that only does installations. This same company was also incorrectly listed as a dealer for another brand of speakers I was interested in.

The Sonance dist. also suggested Myer-Emco (I bought the B&W 685s at the smaller Myer-Emco near my house). I called the store near where I work and was told the speakers would be a special order and that he (the salesman) would call me back. That was several days ago...never heard back.

I thought I might try out some Polk RTi A3s. They are available at Tweeter. Apparently they have them in stock, but only the smaller RTi A1s were set up in the listening room. I asked if it would be possible to listen to the A3s and the salesman said he'd have to ask his boss. He said he would call back but never did.

NHT speakers are available at only one local store -- Pro Video -- and IIRC they didn't have the model I was interested in set up to listen to, and it may have been a special order also.

Monster (whose products I would not ordinarily consider) has some THX certified speakers that seem to be _very_ similar to some Crystal Acoustics speakers (same factory?). Although they claim that Circuit City carries them, neither I nor the Monster rep could find any local CC store that had them. Called CC and they said they'd never heard of them...

If I didn't know better I'd swear these companies don't want my money.

Many retailers also make it very expensive for the customer to return speakers if they aren't satisfied with how they sound. I touched on this above. Crystal Acoustics is the worst I've come across. Many others, while they may not have a "restocking fee" still require the customer to pay S&H both ways. This may not be a problem if you live near the mfr's warehouse and/or the speakers are every small and light, but shipping charges can get very expensive very quickly if the speakers are being shipped across the country, which is often the case for those of us on the East Coast (many speaker mfrs seem to be located on the West Coast).

Luckily -- there are a few local and Online dealers that have decent policies:

Crutchfield is by far the best in this regard -- free shipping _both_ ways, and a 30 day free trial period.

Vann's is pretty good -- free shipping to the customer and a 15 day free return period, but (for example) est. return shipping for two (2) KEF iQ3s to MT is $51.

J&R is about the same -- free shipping to the customer and a 30 day free return period

One Call (while they seem to be a good company) is pretty bad -- 15% restocking fee but 30 days return period and free shipping to customer. I contacted them about the KEF iQ3s. The person I spoke with there offered to reduce the restocking fee to 10%, but that would still be $50, on top of the cost of return shipping.

Local stores seem to be a better bet -- _if_ they have what you're looking for. BB, CC, and higher-end stores like Myer-Emco, Tweeter, and Graffiti all have pretty decent return policies.

Tonight I bought a pair of Polk RTi A3s from Tweeter. I will be comparing them to the Rocket RS250MkIIs.

To be continued...

They both have the same basic shape and design, although the Polks are about half the weight of the Rockets and are designed to be hung on a wall. They have a mounting bracket attached to the rear of the cabinet toward the top, and two 'feet' toward the bottom so that it will hang vertically and not angle downward when hung by the bracket.

Interestingly, the Polks are front ported but also have another port under the mounting bracket on the rear. On the underside of the bracket is what looks like a diffuser of sorts (shaped like a Hershey's Kiss, for lack of a better image) -- so that any air coming out of the port doesn't slam into a flat surface, but is spread out over 360 degrees.

The Polk cabinets have a bit of resonance when given the 'knuckle test', the Rockets seem more solid, like rapping on a block of wood(which stands to reason since they are made from 1" MDF). The Polks are also made from MDF, but I don't know how thick it is.

The Polks have an attractive real wood veneer finish like the Rockets, but do not have the nice piano black top and bottom plates.

When it comes to sound, they are almost indistinguishable, depending on material. The Rockets have slightly more sibilance in some cases. Drum sounds seem to be identical. Vocals may be a bit warmer with the Polks, but even that seems to depend on what I'm listening to.

To my ear, they are _very_ close. Many of the slight differences in imaging seem to reverse themselves from song to song. I doubt I would be able to consistently identify them in a blind A/B/X test.

Unless I am able to detect significant differences in further testing, I am inclined to keep the Rockets. If I return the Rockets I'll have to pay shipping to CO for one of them. Also, while the Polks cost less ($400/pair) they are too tall for the center shelf. I'm not sure about their center speakers, the CSi A4 and CSi A6, but I imagine I would want the A6, which is $400 (the A4 is $250) so that would bring the total to $800 -- and I'd have potential problems with off-axis response.

Does anyone have any opinions about the Polk RTi and/or CSi speakers -- or know of any reviews?

Testing continues...

Last night I pulled the speakers out into the room further.

I have them set on wooden stands so their tweeters are at about ear height. They are positioned so that both Rockets are on the left and both Polks on the right so the pairs are the same distance apart.

Unfortunately I cannot move away from the speakers any further (and still A/B them) because I am using a Sony switch box that is connected to the receiver and the two Mackie amps and I am at the limit of the reach of the patch cords. What this meant was that my listening position was somewhat closer than the ideal equilateral triangle.

Interestingly, there was an extreme difference in sound with this setup. The Rockets had an incredible center image -- the strongest I've ever heard. It was as if there was just one center speaker being fed a mono signal. That's the good news -- the not so good is that there was almost no soundstage. This turned out to be due in large part to my listening position. When I got up and moved back away from the speakers the center image remained and the soundstage widened. The Polks had a less focused center image, but had a wider soundstage at the closer listening position.

As I wrote above, at first I thought they sounded almost identical. This time, I began to notice some differences in timber that I hadn't heard initially. In general, I wouldn't say one speaker is necessarily better in this regard -- it's more a matter of taste. The Rockets are also more forward sounding -- the Polks seem to have all of the detail of the Rockets, they're just more laid back.

In most other ways they remained very similar sounding.

I still prefer the Rockets and will probably be returning the Polks.

As with the Axioms, this doesn't mean the Polks are 'bad' speakers. I imagine some (many? most?) people would prefer them, but I like the solid center image of the Rockets and the more forward sound, which some might call 'presence'. They just sound a bit more 'live' -- like the players are right there in front of me.

Of course, maybe I'm being fooled by the fact that the high end on the Rockets is boosted a bit (from the freq response graphs I've seen).

Who knows?!

My impression of the Monitor Audio BR2s is very similar to what I thought of the Polks, and to a lesser extent, the Axioms and B&Ws -- unnatural warmth (esp. male vocals), frequent lack of solid
center image. There was an over emphasis of some bass frequencies, which excited a room mode
in at least one particular song. Male vocals don't have the edge or
presence that they do with the Rockets.

Of course, what I am calling a coloration or distortion is sometimes a
pleasing sound -- like the difference between a tube amp and a solid state
one.

Also, since I am now somewhat used to the Rockets, I suppose I could be
predisposed to preferring their sound. I don't think that's the case, but
it's possible.

One thing I'm concerned about is that the speakers I've rejected seem to
have similar qualities -- it's possible that they are accurate and it's the
Rockets that are off. I suppose the bottom line is that (so far) I prefer
the clarity of the Rockets, but it bugs me that it may be them (and not the
others) that are designed to appeal to 'unsophisticated ears'. It has
occurred to me that speaker mfrs might cynically design speakers that have
harmonics/colorations/boosted or cut frequencies in order to sound good to
the greatest percentage of people (similar to a video display permanently
set to 'torch mode'). To the extent that is true though, I would think they would
try for the sound I'm hearing from the other speakers.

As with the others (especially the Polks) the Rockets and the BR2s have a
lot in common -- even my wife (who is a professional singer) said at one point, "They sound very similar".
They do -- on a lot of material. Drums and keyboards often are almost
indistinguishable. The high end (cymbals) are also very close with the
Rockets getting the nod in some cases.

The main differences are in vocals and the strength of the center image.

I may compare the Polks and the BR2s just for the hell of it. My guess is
that they will be very close.

As with the Polks, I would say these are good speakers for the money and if
I didn't have the Rockets to compare them to I might be happy with them.
They seem well built (although not quite as solid as the Rockets) and can
keep up with them when playing loud (~100 db @ 2m). In fact, in some cases
the bottom end (i.e. kick drum) has a bit more punch than the Rockets. This
seems a bit strange, since all the channels on my receiver are set to 'small'. Even if one
has a bit lower extension than the other it shouldn't be noticeable.

Anyway, it looks like they are going back. I'll probably return them
tomorrow.

BTW, for anyone in the mid-Maryland area, Hunt Audio in Hagerstown is where I got the BR2s. The guys there are very nice and low pressure. They have two listening rooms and a nice 'home theater' setup. Lots of high-end gear, including some sweet McIntosh amps. They seem to be a good alternative to the snooty 'audiophile' stores. They did have some 'questionable' stuff though -- like $10/foot speaker wire that looks like nothing more than two twisted pairs of #16 solid (not stranded) wire -- but at least I didn't see any Monster Cable!

During my testing with the BR2s, I noticed the OL (over load) LEDs flashing on the amp driving the Rockets. The amp driving the BR2s was fine.

The FR-2500 is capable of 575 watts into 8 ohms, 750 watts into 4 ohms, and 1,400 watts into a 2 ohm load. I was surprised to say the least to see it come close to clipping when the Rockets were pumping out ~100 db @ 2 meters.

The efficiency of the Rockets is fairly typical at 88 db, the impedance is 6 ohms (nominal), and with the levels carefully matched (within about +/- 0.5 db) both amps were had their level controls at about the same position -- it's not like the amp driving the Rockets was cranked.

Very strange.

All I can say is that a typical (really any) receiver isn't going to be able drive the Rockets to reference level.

One thing I remember that an AV123 rep told me was, "the RS250MkII is factory tested with 800 and 1,000 watt amps "cranking heavy metal".

At the time I thought that was just sales talk, but apparently it's true.

I wonder what's going on, because a speaker with 88 db efficiency should be able to put out 100 db @ 2m with much less power than the the FR-2500 is capable of.

The efficiency of the BR2 is 90 db, but still, I'm thinking that either the Rockets are less efficient than the mfr claims, or those Mackie amps are somewhat lacking.

Any thoughts?

Well, they aren't as close as I thought they'd be.

After listening to just a few songs, it seems the Polks are the clear winners.

Now I'm going to compare the Polks with the Rockets one last time.

Very thoughtful post Meparch, thank you.

I like your piano analogy. I agree with much of what you said but I question whether it's good to have an amp that will go up in smoke before it blows the speakers. Long before it goes into meltdown, an amp will start to clip. The Mackie FR-2500 amps have a defeatable clip limiting circuit as well as red 'overload' (OL) LEDs on the front panel next to the level controls, but most consumer gear does not. I've always read that the main cause of blown speakers isn't too much power -- it's not enough power, which causes clipping when people try to get more out of the amp than it's capable of.

Who is "eD"?

Regarding speakers, I wish we could just look at lab test results and buy accordingly. Believe me, I would be very happy if it were so simple. Unfortunately, while many characteristics of speakers can be measured, it seems that we must still listen to them to determine which ones we prefer. I'm not sure why that is -- you'd think that it would be possible to devise a series of tests that would be able to convey the sonic characteristics of any speakers. Then, once a person determined which characteristics they prefer, they could simply buy according to the test results.

One problem is that even if there were one or more "perfect" speakers out there, our rooms and our hearing are often very different. So it's not enough to say a speaker is "perfect". Perfect to whose ears? In what sort of room?

Even the type of music a person listens to makes a difference. For example, older recordings that have a lot of noise and tape hiss might sound better on a speaker that has less than flat response (a roll off at the high end).

Suppose there were a speaker that had excellent specs -- that was universally considered to be the best in the world, won tons of awards, etc. A person gets it home and compares it to their existing speakers, or some others they are trying out and find that they like the sound of some other (lower rated) speakers better. Then what? Do they ignore the fact the other 'less than perfect' speakers sound better and keep the ones that are supposed to be more accurate?

Starting with a basic design (6.5" two-way) I've been reading reviews and looking at specs to narrow things down. While lab tests alone can't predict which speaker(s) will sound best they do seem to be able to determine which ones will likely sound mediocre. IOW, if they test good we may still not like them, but if they test bad we almost certainly won't. That's my theory anyway. In any case, after doing the research I then try to find the speakers locally, which (as I posted above) can be very frustrating.

At this point, I'm about out of serious options. I'm running the Polk RTi A3 vs. Rocket RS250MkII test again. They're very close but I think I'm still going to give the nod to the Rockets. My wife (who has a trained ear) said, "You can't go wrong with either of them", and I agree. I would suggest that anyone in the market for speakers audition the Polks. At $400/pair I'd say they're a relative bargain, and they're more readily available than many of the others I've been listening to. In fact, you can get them from Crutchfield for $400 with free shipping _both_ ways and a 30 day free trial. The Rockets are $500 a pair and AV123 did have a free shipping both ways deal going on as well (don't know if they still do). So a person could audition both of these speakers for absolutely no cost.

I would love to hear any suggestions for other 6.5" two-way speakers I could audition. THX certification is a plus. Keep in mind, they must be available in the Baltimore/Washington area, or be available Online with either a) free shipping both ways or, b) reasonable return shipping costs (no more than say $25).

Thanks again for your reply.

I agree with your thinking about speakers -- better to have accuracy and then try and correct for room acoustics and individual preferences with EQ.

The problem of course is knowing what is "accurate". The only way to _really_ know would be to ask the artist or producer to come to your house and listen, or somehow be able to switch between listening to a live performance and a reproduction of that same performance. Perhaps the closest we could get to that would be in a studio -- if one were able to walk between the studio and the control room and switch between a variety of monitors that are reproducing what has just been recorded. Ideally, you could walk back and forth between the control room and the studio and hear no difference.

Without a reference though, it's next to impossible. The best I can think of is to pick speakers that have a good reputation, listen to them, and pick the pair that sound the most like a live performance. Of course, that's just my recollection of the sound of a live concert, so the speakers I choose could be pretty far off. All of the speakers I've auditioned so far have decent specs but there are distinct differences bewteen them that a person wouldn't necessarily expect from reading the lab test results.

What do you mean by, "don't play the speakers so loud??!"

Seriously, I ordinarily listen at 85 to 95 db max -- 100+ db is _very_ loud, but the fact is that the THX 'O db' reference level is 105 db. Any decent speaker should be able to put out that level, particularly at just 1 or 2 meters, with much less power than the Mackie FR-2500 produces. I mean, 1,400 watts into 2 ohms?! That amp shouldn't even break a sweat driving any speaker to 100 db @ 2m. I would think that most typical two-way bookshelf speakers would explode before the OL LEDs on the FR-2500 begin to light. To answer your question, yes, the Rockets were loud enough for my normal listening well below the point at which the amp began to clip, but ideally the amp/speaker combo should be able to produce at least 105 db (peak) to comply with THX specs.

If it makes you feel better, the clipping happened with a signal from XM radio off of DirecTV -- I haven't noticed it when playing CDs (briefly) at that level. I'm not sure why that is, unless the _average_ power level is less with CDs because the signal isn't compressed like XM via DirecTV is.

That said, you're correct that as long as you're careful and listen for distortion, you will probably never blow a speaker with a lower powered amp. With a more powerful amp you still have to be careful -- clipping may not be as much of a concern, but physically damaging the driver may be. It could bottom out or the voice coil could go. I guess I would rather have too much power rather than too little though. Excess power means having plenty of headroom for transients, regardless of the overall average spl. That's why I bought the Mackies. My wife uses a Mackie powered mixer for her jobs. I brought it into the house one day and connected it to my old Pinnacle PN8+ speakers and then to the Maggies I use for surrounds. The improvement over my Yamaha receiver was incredible! Sure, they played louder, but they were also so much more dynamic and 'live' sounding. I had thought that the distortion I heard when turning up the Yamaha was due to the speakers but it turned out it was the amps in the Yamaha that were the weak link. I never would have thought that a more powerful amp would make that dramatic a difference but it really did.

Still, if you listen at lower levels (say <85 db) it probably won't make much difference that you are driving them with the Yamaha v663. The three Big Foots should sound really good!

Thanks jakewash! Nothing like a little factual information.

I've seen power requirement charts that show at a glance the _huge_ variation in power required depending upon spl and speaker efficiency. The range is incredible!

I'll try to find the link and post it.

From post #110 above:

"The problem of course is knowing what is "accurate". The only way to _really_ know would be to ask the artist or producer to come to your house and listen, or somehow be able to switch between listening to a live performance and a reproduction of that same performance. Perhaps the closest we could get to that would be in a studio -- if one were able to walk between the studio and the control room and switch between a variety of monitors that are reproducing what has just been recorded. Ideally, you could walk back and forth between the control room and the studio and hear no difference.

Without a reference though, it's next to impossible."

What I said above rather clumsily is put much better by Floyd Toole in this pdf:

http://www.harman.com/wp/pdf/maximizingloudspeaker.pdf

See the last couple paragraphs on page 8 below figure #5.

(The remainder of that section is also very interesting).

The following was an email from my coworker (who is also an AVS forum member). I thought it might be helpful:

[Sound & Vision, Behind the Numbers: Digital Surround Receivers,
January 2002 page 94].

It's better to consider an amplifier's power in terms of dBW
(Decibels relative to one watt) instead of watts because watts are
linear while our hearing is logarithmic.

dBW = 10 x log (W)

You can simply add the amplifier's power in dBW to a speaker's
sensitivity rating to determine an approximate, theoretical maximum SPL.

For example, a 100 watt amplifier equals 20 dBW.

If your speakers have a sensitivity of 87 dB SPL at 1 meter, the
theoretical maximum SPL will be 107 SPL at 1 meter.

If a speaker manufacturer provides a maximum power specification in
watts, I suppose you should be able to calculate the maximum SPL from
that number.

Pay attention. This will be on the test.

I agree with you about all of the subjective terminology -- it drives me crazy too. I don't mind reading a subjective review, but I'd like to see test measurements along with it (S&V usually does this).

There should be a glossary for all of the adjectives used by reviewers -- 'air', 'rhythm', etc, etc.

Tell me more about the 'heat cycle' you referred to. My understanding is that a speaker's power requirements for a given output remain pretty constant -- an increase from 200 to 600 watts is extreme.

Below is a link to the power requirement chart I referred to:

"...the average power required for most systems, even playing loud classical music at concert levels, is very low. It is the momentary peaks that require a big amplifier. The difference between the average and peak levels on classical material ranges from 8 to 12 dB, and although a well-designed amplifier can reach its maximum output level and "clip" occasionally with only a mild effect on the sound quality, an amplifier with generous headroom -- the ability to put out greater than its rated power for short periods -- has a real advantage over another one with the same continuous power but less headroom."

The Hidden Variable - Output Current

Until now we've been talking as though amplifier power ratings can be taken at face value. But not all amplifiers will deliver their rated power into a real loudspeaker. The figure on the spec sheet is measured with a pair of 8-ohm test resistors connected to the amplifier in place of speakers. But most "8-ohm" speaker systems have an impedance which falls to 5 ohms or less at some frequencies, causing them to draw more current than the resistor would.

In addition, the loudspeaker will present a reactive load to the amp that can increase the current demand still further, to as much as several times that demanded by a simple resistor. Since it is the current -- not the voltage -- that actually moves the speaker cone, output current capability is the limiting factor in most amps. Check the spec sheet, or published test reports, for the behavior of the amplifier at 4 and 2 ohms; its output should increase substantially over the 8-ohm value. Then test the amp with your own speakers -- or those you intend to buy -- before you commit yourself.

Finally, remember that you shouldn't be afraid of buying a bigger amp if you can afford it, especially if you like the features that come along with the extra power. That power will be used primarily on very brief musical peaks, and even a modest speaker system can safely absorb several hundred watts for a few milliseconds with no damage. It may actually be riskier to use an underpowered amplifier or receiver than an overpowered one; some protection circuits, when tripped, can produce ultrasonic oscillation at full power for long enough to burn out a tweeter.



http://www.smr-home-theatre.org/Power/
http://www.smr-home-theatre.org/Power/Graph_F.html

It shows that the power required for "very loud rock" (116 db, which is insane IMO) can run from just 40 watts to over 2,500 watts, depending on speaker efficiency.

"Very loud classical -- peak" (112 db) runs from 13 to 795 watts!

I decided against them because:

a) They would be a special order (they're not on display) and would not be returnable (IIRC, I'd have to double check this). So I'd be buying them without hearing them at all -- not even in the store.
b) There is only one local dealer and I had a bad experience with them previously.
c) At about $330, they are significantly over my max of $250.
d) I would need a third and they are only sold in pairs, meaning I'd have to shell out $1,320.

They look really nice though -- I wish they were sold individually. If they were, and went on sale for say $275 at a friendly dealer I'd check them out.

Edit to add:

One thing I have to question though is Def Tech's claim of frequency response down to 24 Hz! That seems _highly_ unlikely for any 6.5" driver. They also claim 26 Hz for the smaller one with the 5.25" driver.