Statement project begins

[bostonmurf]

just ordered the crossover parts for the R44's and I'm reading up on the walls needing 3/4 sonic barrier and Acoustic Damping Sheet. is the acoustic sheet totally necessary? I've seen a couple of build that don't use it. also would regular 3/4 eggcrate foam be ok instead of the sonic barrier? just thinking cost wise it would help to just use the egg crate instead.

[bostonmurf]

just a little more done, starting to take shape though

[kevinm]

I can't wait to hear what you think of these. these might be great height speakers!

[bostonmurf]

building the crossovers and hit a problem. one of the resistors (3.5 ohm) was glued in the wrong place and when i tried to remove it some of the coating came off as you can see in the pic. i can see a little of the coil now. is this still usable if i glue it back in place? it damage is on the base of the resistor. also if i have to re order some places only stock 3.3 resistors. would that be an issue if i used that instead? thanks for any help in advance

[wkhanna]

I appears the coils of the resistor are exposed.
Do not use it.

[bostonmurf]

thanks Bill, Jim said the same thing. new ones on order. should be here tomorrow.

[Philzeemon]

Nice looking build...When securing your drivers to the baffles, did you use woodscrews or machine screws with hurricaine or t-nuts? I am also wondering what size and style screws you used..

[bostonmurf]

Thanks Philzeemon, its been a lot of fun!
so as for the screws i used wood screws from Parts Express.
I used #6 x 3/4 for the Tweeters and Midrange and #8 x 3/4 for the Woofers. Don't use a drill to drive the screws in, do it slowly with a screw driver after you've made the pilot holes, this way your less likely to slip and damage the speakers. i did think about using hurricane/t-nuts but was put off after hearing some problems. if your careful you can screw and unscrew the drivers many times just using the wood screws. just take your time and don't over tighten.

[kevinm]

Thanks Philzeemon, its been a lot of fun!
so as for the screws i used wood screws from Parts Express.
I used #6 x 3/4 for the Tweeters and Midrange and #8 x 3/4 for the Woofers. Don't use a drill to drive the screws in, do it slowly with a screw driver after you've made the pilot holes, this way your less likely to slip and damage the speakers. i did think about using hurricane/t-nuts but was put off after hearing some problems. if your careful you can screw and unscrew the drivers many times just using the wood screws. just take your time and don't over tighten.

This has been my method too for the last couple of years. No problems yet and I've removed drivers plenty of times before!

[bostonmurf]

Crossover built, took a little planning to get it on a 3in piece BUT it is removable from the cabinet quiet easily. Ready for the drivers to be installed now.

[bostonmurf]

Finally put together one of the R44s and here's my thoughts.

Build - super easy to make, crossovers are a tight fit but really not that bad to put together and can be removed if needed.
Sound (please bear in mind i only completed one speaker with parts from my center channel to test if i was going to buy the drivers) - as a stand alone speaker there just ok. sound is rich as to be expected but it desperately needs bass. I expected that after reading a few reviews but I did think it would have a little more bass than it did.
However, just as id written it off i tested it with some classical music that doesn't really use much bass and it sounded incredible! totally filled the room and it was crystal clear. so... hooked up a sub and tried again with some regular music. a different story, the sub brings these to life.

Overall Thoughts - if i was going to build two speakers just to listen to music with I wouldn't build these, there not a cheap build and are going to cost you just over 500 to complete PLUS your going to have to get a sub to go along with them. Id probably go statement monitor instead. I built them for surround speakers and as i understand surrounds don't rely on heavy bass, the subs take care of that for you. the center channel does most of the work and the surround sides/rears are more filler sound. with that in mind I probably would recommend them IF you already built Statement towers and center. the mid sound is going to match nice to your other speakers and as a plus, aesthetically they look great together. Im torn at the moment - should i complete the build or go Statement monitor? I do like the bonus of being able to place them close to the wall which you cant with the Statement monitors. I do think ill complete them, if i change my mind ill have some of the parts to build the monitors if i go that route in the future.

So to finish If your looking for a surround speaker that's really easy to build and will match your statements and these will do just fine. Place them close to your wall and your good to go. hope that helps

EDIT: - Just chatted with Jim, you CAN go close wall with the statement monitors when using them for surround speakers!!! sorry i had no idea, this changes everything for me. I'm going to start the monitor build in the new year. also my error on the surrounds not needing the bass - the monitors are going to make a huge difference in my final build.
thanks Jim.

[BBLV]

Beautiful build. Can't wait to see your final placement. Looks to be similar to what I plan to EVENTUALLY do.

[kevinm]

So you're plqnning on switching to the Statement Monitors?

Thats what I was thinking too, but they huge. Hmmm

[bostonmurf]

Beautiful build. Can't wait to see your final placement. Looks to be similar to what I plan to EVENTUALLY do.

thanks BBLV, its been an amazing experience. you learn so much AND you end up with something thats going to last a lifetime.

So you're plqnning on switching to the Statement Monitors?

Thats what I was thinking too, but they huge. Hmmm

Hi Kevin, yes i really hoped the R44s would be perfect but i ended up trying to talk myself into wanting to keep them rather than really wanting them. im not saying they wouldnt work with the right setup, the mids are incredible and they most probably would work really well for someone with awesome monster subs in there set up - yes i mean you

i just think im this far into the project and id hate myself for not going the whole way and from what ive read on your posts your the same as me. it'll be a while before i start the monitor build but in the end im sure its the best way for me to go. Im not sure what to do with the cabinets yet. i may finish them and use them as rears with the monitors as sides (or vice versa). i think ill look out to see if i can get some of the drivers on the cheap.

[Jim Holtz]

So you're plqnning on switching to the Statement Monitors?

Thats what I was thinking too, but they huge. Hmmm

Come on Kevin! They aren't that big. :E

[bostonmurf]

what wall mounts are you using Jim, there really nice and very discrete.

[bostonmurf]

what wall mounts are you using Jim? there really nice and very discrete.

oops sorry, double post!

[Jim Holtz]

what wall mounts are you using Jim, there really nice and very discrete.

I bought them from PE several years ago. They were rated up to 55 lbs. if I remember correctly. I don't think PE carries them anymore but I'm not certain. They are very sturdy and nicely made if you can find them.

Jim

[kevinm]

Come on Kevin! They aren't that big. :E

[ATTACH=CONFIG]23725[/ATTACH][ATTACH=CONFIG]23726[/ATTACH]

Haha, those things are massive to wall mount. I would kill to use them, but I am sure not I can aesthetically. My TV area is apart of my dining room/kitchen. One side has a wall that I could work with, but the other side is open space to the stairs/door. And behind is the dining/kitchen. I've tried using stands, but they are awkward in the room. Hmmmm

[Philzeemon]

Hey bostonmurf...

Make certain you attach those brackets to a wall stud...I wouldn't trust half that weight to anchors or even togglers in wallboard..I cant imagine those statement monitors tumbling to the ground from 7 ft up...(This would NOT be a joyful noise)...Phil

[bostonmurf]

Sorry I've been away for a while Gents, big changes. were finally moving house in 3 weeks to a bigger place with huge basement area. new HT room will be approx 14ft W x 24ft L x 12ft High.
I'm seriously considering an ATMOS amp/Power amp but would love it if anyone could give me advice on power amps and if i need one. I've never used one so any help would be great. going to drape the walls in thick blankets for the time being until i can afford the build probably next year. going with my Statements for fronts and center, 4 Statement monitors side and rear (still to build) and possibly pre-built ceiling speakers unless someone has a suggestion to match the Statements. I'm going to be picking your brains Kevin when i get to the Sub woofer build, I'm going to steal your Subwoofer mod so i have some real power in there for the movies!
Also Jim, i know for a fact your pretty used to moving these speakers around. any tips for moving day? they are the heaviest items we have to move
here's a pic of the basement as it stands

[Jim Holtz]

It looks like a new adventure!

I don't know if you have a Harbor Freight or Northern Tools near you but they have 5'x7' moving blankets for around $5 each. I wrap the Statements in the blankets using heavy duty packing tape to hold everything in place. They also have inexpensive 2 wheel carts that I can't live without. I have one in the garage and one in the basement. I've also found the 1" pipe insulation is a perfect addition to the 2 wheel cart that protects the finish of the speakers as you're rolling them around.

That's my solution for moving large speakers. BTW, I had 6'4" tall line arrays before the Statements. The Statements look tiny next to them.

Good luck with the new home!

Jim

[bostonmurf]

Thanks Jim, yes we have a harbor freight near by. It's very affordable and very handy! I've got some blankets but will definitely get the 2 wheel cart. Thanks for the help, I'll let you know how it goes

[kevinm]

Ohhh, you lucky dog. You even have 12ft ceilings to work with! And it's unfinished, so no remorse on tearing apart finished walls. Congratulations, man!

For the amp, are you referring to the amp for your L&R or subs?

Definitely wire for ATMOS. I heard it and was immediately impressed - of course I LOVE immersive audio, though.

[bostonmurf]

thanks Kevin! yes I was sold as soon as we went down into the basement.
for the amp I'm thinking about the L and R speakers, possibly the Center too. To be truthful I've never used Power amps so I'm not sure how id need to set them up. would i need a dedicated one for the L and R, one for the Center and let the Main Receiver power the surrounds?

[Jim Holtz]

thanks Kevin! yes I was sold as soon as we went down into the basement.
for the amp I'm thinking about the L and R speakers, possibly the Center too. To be truthful I've never used Power amps so I'm not sure how id need to set them up. would i need a dedicated one for the L and R, one for the Center and let the Main Receiver power the surrounds?

I'll toss my $0.02 worth in. I've been using separates for over 20 years once I figured out that a good amp will last decades not just a few years as receivers do. Plus, the rated power is real power with all channels driven. The Statements like lots of good clean power.

I've had great luck with Emotiva. I have a LPA-1 that I used for several years that's now in my Finalist system. The Statements are powered by an XPA-5 now which is my main system. If you shop around a bit, you can find a used one for a good price that will also carry a transferable 5 year factory warranty. Emotiva is phasing out the UMC-200 pre/pro which is also something I can recommend. It's very flexible and sounds great.

Jim

[bostonmurf]

Thanks Jim, ill look into it.

[kevinm]

I like Jims rec. I use Emotiva, too, and am really happy with them. I currently use the UMC-200 - amazingly powerful for the price. Very transparent sound and parametric EQ really adds opportunity for refinement.

I had my Statements running off the XPA-5s little brother, the UPA-5 and they sounded great. I did end up upgrading to the XPA-1 monoblock sand that was a treat. Fairly audible improvement in added depth, clarity and punch. Definitely recommend if it makes sense financially for you.

I've some compare some of the Pro Amps and say as long as it has decent distortion characteristics and ample headroom, it'll sound just as good - I haven't tested this theory though. Would like to try it someday just for fun. For now, my XPAs work great

[bostonmurf]

Thanks Kevin, ill start looking into them when i get in the new place. really looking forward to upgrading to a new system!

[bostonmurf]

so after a bit of research i think I'm going to get a Atmos enabled receiver and an Emotive power amp. now my question is are there any benefits to having multiple power amps apposed to something like a XPA-5 or XPA-7. my thought is to go with the XPA-7 for the front, center, side and back and let the receiver power the height channels. do you think this is over kill? should i go XPA-3 for front and center and power the rest with the receiver, i know thats also dependent on the receiver i decide to get. plus the price difference between the XPA-5 and XPA-3 is 200 bucks apposed to 600 from he XPA-5 to the XPA-7.
this isn't something I'm going to be getting yet. I'm waiting fore the Atmos prices to drop a little and would like to pick a receiver up for under 1000.
thanks again for your help gents!

[Jim Holtz]

so after a bit of research i think I'm going to get a Atmos enabled receiver and an Emotive power amp. now my question is are there any benefits to having multiple power amps apposed to something like a XPA-5 or XPA-7. my thought is to go with the XPA-7 for the front, center, side and back and let the receiver power the height channels. do you think this is over kill? should i go XPA-3 for front and center and power the rest with the receiver, i know thats also dependent on the receiver i decide to get. plus the price difference between the XPA-5 and XPA-3 is 200 bucks apposed to 600 from he XPA-5 to the XPA-7.
this isn't something I'm going to be getting yet. I'm waiting fore the Atmos prices to drop a little and would like to pick a receiver up for under 1000.
thanks again for your help gents!

My opinion is, the three most important channels in the system will be the mains (music & effects) and the center. I like amps with big toroidal power supplies. The XPA-5 has a 1.2 Kv power supply. The designer, Lonnie at Emotiva, told me that the power is pooled so that its all available to two channels for music or all five for home theater as needed. The XPA-3 has an 800 Kv power supply if I remember correctly. These specs are all for the Generation 1 design. Current designs are Generation 2's which I can't comment on. I'd start watch Emotiva's for sale forum and see what pops up. I bought an XPA-5 that was like new, 2 1/2 years warranty left for 60% of new price last December.

All the surround channels will be much less demanding of power availability and sound quality since they are primarily effects channels.

Jim

[bostonmurf]

Thats great info. ill definitely take a look at the Emotive for sale forum and see if i can pick something up.
Thanks Jim
Darren

[wkhanna]

There is no denying the popularity & affordability of the Emotive brand.

The performance is also quite good.

Their business strategy takes advantage of direct sales thereby eliminating middle-man mark-up, low cost foreign labor & bulk purchase discount on mid-level components with a design focused to hit a V attractive price point.

If, however, you are interested in high-quality music reproduction in conjunction with movie viewing, there is no substitute for what a well-designed & built amp brings to the table.

For those who put music equal to or higher on the list, I would suggest considering the long term economics of looking into something like the Odyssey Khartago Stereo or Stratos HT-3.

No, you will not find deep discount deals, or weighted published power output specs.

What you will end up with is an American made hand-built product (by no less than owner Klaus or more likely his wife).
The design, quality of domestic sourced components (when available & including the sheet metal fabricator, plating/anodizing house; foreign made products are used only when no domestic equivalent is available) & most importantly, the the sound are at a level of performance that exceeds other hi-end offerings at two, three or more times the cost.

I realize this is likely at least twice what most of us would budget for an amp.
But having been through five main amps in the past 21 years, I can speak from experiance.
The value of these amps is in their ability to meet all expectation for years to come regardless of the level of upgrade to all other components in your system.

I have heard most of the amps offered by Odyssey.
Many of them in my own system.
I have friends who have them & are in love with them.
These are guys who have heard all kinds of amps from vintage tube, to SOTA $30k SS units.

I recently met Klaus & his lovely wife, sharing some libation at the bar during last year's Capital AudioFest.
His seminar held during the event was enlightening to say the least, as he offered his perspective of the audio industry as is exists today with its need to beat down any upstart companies willing to disrupt the status quo by offering real value & performance without the hype, charlatanesque marketing tactics & outsourced materials & manufacturing.

Yes, I am a fan-boy of sorts.
But I have also been in this hobby long enough to have learned a thing or two.
If one is willing to take a long-term view of true value, sometimes you end up saving $ by spending a little more now.

One last tidbit of trivia....

Klaus tracks used sales of his equipment.
Over 90% of the few Odyssey amps offered on-line (which hold impressive resale value, btw) do so only because they have upgraded to another Odyssey unit.

JMHO YMMV

Edit: Just to clarify, there is no intent on my part to 'bash' Emotive equipment or its owners.
There is undeniable value in their offerings.
My comments are of all brands in general.

My opinion is offered only as possible alternative based only on the equipment I have heard which includes the Emotive brand.

[bostonmurf]

Hi Bill, ill check them out. its good to have a few options to look in to before making my final purchase.
thanks for you help, much appreciated.
Darren

[wkhanna]

Hey Darren.

Glad to hear of your good fortunes with the new krib & your system.
I offer my opinion on amps based on my experiences of integrating a system that plays movies in 4.2, but is primarily intended for two channel music.

Emotive is a good product with real value.
But in the event someone is curious about the next level which your Statements are capable of utilizing, there are some high-value options available.

Be well.

[bostonmurf]

just thought it may be worth mentioning, Parts Express are selling the Tang Band W4-1337SD at 15% off and with this code CJTENQ1 you save another 10 bucks on shipments over 100. just picked up 4 for 206 including delivery. thinking ahead so I'm ready to start my statement monitors.

[eduardokbb]

Hey, gentlemen! What would be your recommended amplifier wattage to amplify a Statement without clipping? And what's the lowest impedance it'll reach? If the needed power is just the sum of the recommended RMS power of the drives, than it's something around 370W RMS at 8ohms, that nominal, per speaker. I guess the Statements impedance can reach 4ohms at certain frequencies. If that's right, than the optimal amplifier would be something like 400W RMS at 8ohms, that is capable of 4ohms loads. Of course, those 400W would push the Statements to their limits, that's not something someone would usually do. Can someone confirm if that's right? And if that is, giving you're all on the DIY route, I'd recommend you to take a look at the DIY amps I'm building, from the land down under. Holton Precision Audio, founded by Anthony Holton. His NXV500 series amplifiers are always compared with Pass Labs, Krell and Bryston. http://holtonprecisionaudio.com/
Thanks for your attention and sorry for bad english!

Peace,
Eduardo Barth.

[deewan]

Hey, gentlemen! What would be your recommended amplifier wattage to amplify a Statement without clipping? And what's the lowest impedance it'll reach? If the needed power is just the sum of the recommended RMS power of the drives, than it's something around 370W RMS at 8ohms, that nominal, per speaker. I guess the Statements impedance can reach 4ohms at certain frequencies. If that's right, than the optimal amplifier would be something like 400W RMS at 8ohms, that is capable of 4ohms loads. Of course, those 400W would push the Statements to their limits, that's not something someone would usually do. Can someone confirm if that's right? And if that is, giving you're all on the DIY route, I'd recommend you to take a look at the DIY amps I'm building, from the land down under. Holton Precision Audio, founded by Anthony Holton. His NXV500 series amplifiers are always compared with Pass Labs, Krell and Bryston. http://holtonprecisionaudio.com/
Thanks for your attention and sorry for bad english!

Peace,
Eduardo Barth.

Are you asking this questions because you want to build the Statements and you are curious about the amps you are currently building, or is this a post to help market the Holton amps?

If you really are curious, the Statements are fairly easy to drive considering their size. I first drove my Statements with a Denon AVR rated at 110wpc, which we all know is over-rated. Even with simple AVR power the Statements sounded great. However now I have 600 watts into 8-ohm and 1,000 watts per channel into 4-ohms.

If this is a shameless plug about DIY amps, next time please post someplace more appropriate.

[eduardokbb]

Are you asking this questions because you want to build the Statements and you are curious about the amps you are currently building, or is this a post to help market the Holton amps?

If you really are curious, the Statements are fairly easy to drive considering their size. I first drove my Statements with a Denon AVR rated at 110wpc, which we all know is over-rated. Even with simple AVR power the Statements sounded great. However now I have 600 watts into 8-ohm and 1,000 watts per channel into 4-ohms.

If this is a shameless plug about DIY amps, next time please post someplace more appropriate.

I'm building one of his amplifiers and my next build will probably be the Statements II, that's the only reason I asked. I'm not marketing anything, and I don't have any reasons for that. If you look at my profile you'll see that I live in Brazil, theres no possible way I have anything to deal with Holton's amplifiers that are from Australia. I was just giving an idea - or suggestion, take that as you want - of something that could be interesting for someone who DIY it's own speakers.

The amp I'm building will output 500w/channel into 8-ohms and 800w/channel into 4-ohms, being capable of driving 2-ohms loads. Assuming that the power needed for the Statements is the sum of all it's drivers recommended power -perhaps it's way more complex than that, but if I knew I wouldn't come here to ask-, it would be something like 370w into 8-ohms (nominal). Despite the 2:1 power ratio not being something that is always correct, it's a good point to start. That said, the recommended power to not clip the amplifier would be something around 700w into 8-ohms. It could be a problem in my future system if what I guessed is right.

Now that you said you could drive your Statements with an AVR, I shall assume I won't have any kind of problems, but, still, I would like to know how much juice an amplifier needs to not clip when driving the Statements regardless of the volume. Finally, I'm really sorry if you took that as a marketing and it offended you so hard, but when another guy recommended Emotiva's amplifiers no one complained about that or told him to post that in a more appropriate place. Despite partially answering my question, as you can see, that was my very first post here and your reply was the worst kind of 'welcome' to date I was given in any foruns I can remember.

[Kevin P]

Welcome aboard, Eduardo.

I apologize if we came across a bit harsh about your first post. We take spam seriously here, and the first post of any new member bears extra scrutiny, especially if there are links within that link to a less familiar manufacturer's website. The forum rules also state that posting links for marketing purposes is forbidden, but it's ok to post a link when providing information as part of the discussion in the thread. Your post could be interpreted either way.

IMHO, I think your post is ok, though perhaps editing out the part that sounds like marketing the amp would make it fit better in our culture here.

Anyway, back on topic, it's always considered better to have too much clean power than not enough. Amp clipping causes a lot more harm to speakers than driving them with too much clean power. Most of the power is in peaks anyway, average power while listening at normal volumes isn't nearly as much.

[5th element]

Now that you said you could drive your Statements with an AVR, I shall assume I won't have any kind of problems, but, still, I would like to know how much juice an amplifier needs to not clip when driving the Statements regardless of the volume.

There are two things to consider when looking at amplifiers power ratings. The first is the power into 8 ohms and then the maximum current capability, or its power output into lower ohm loads.

The 8 ohm load specification literally tells you how much voltage an amplifier can swing and this is important when addressing the voltage sensitivity of your loudspeakers. Regardless of how much power a pair of loudspeakers will require they always have a sensitivity figure provided in the specifications, for example 87dB referenced to 2.83vrms. Sensitivities are almost always referenced to a fixed voltage and nominally this is 2.83 volts root means square, or 8 volts peak to peak for an AC sinusoidal waveform. The reason why the sensitivity is referenced to a voltage is because loudspeakers are voltage driven devices. Amplifiers are constant voltage devices vs frequency, loudspeakers are measured and designed with constant voltage amplifiers and a constant voltage amplifier is assumed to be what you will drive them with, thus the sensitivity figure is given with respect to a fixed voltage.

This is much easier than trying to reference the loudspeakers sensitivity to a number of watts because watts automatically involve current and the current a loudspeaker will draw from the amplifier varies constantly with frequency and driven phase angle. In other words the current changes with frequency and thus so do the number of watts required to drive the loudspeakers, but the number of volts on the output of the amplifier remains the same regardless of what frequency you pick (that is if you don't touch the volume control!).

Now what does all that mean?

The sensitivity for the statements, as far as I can see, isn't given, but as it runs a pair of RS225s and after bafflestep compensation, they probably sit at around 89dB re 2.83vrms. Now lets say you want to reach 110dB peaks with these, you would need 110-89dB = 21dB of extra output. To convert this into voltage gain we use use 20*log(V2/V1) = dB gain, where V2 = our unknown voltage, V1 = 2.83 and the gain we require = 21. This ends up giving us an answer for V2 of approximately 32 volts rms. We can then convert this into an equivalent 8 ohm power rating by squaring the rms voltage and dividing it by 8. In other words (32*32)/8. This gives us an 8 ohm power rating of 128 watts.

This does not seem like all that much, but here is where the current comes into play. If you look at the impedance for the statements you will see that they hit an impedance maximum at around 15kHz, ignoring the fact that there's hardly any musical content up here, the impedance maximum is about 10.5 ohms with almost zero degrees on the phase angle. Given that our amplifier is going to be outputting 32 volts rms we can calculate the current requirement for the impedance maximum using ohms law V=IR. 32/10.5 = 3 amps. This isn't much at all and when converted into watts comes out at around 96.

Now lets look at the impedance minimum. This occurs at around 75Hz, again with a zero degree phase angle, but this time the impedance is pretty much 4 ohms. Given our 32 volt requirement we can now calculate that 32/4 = 8 amps or 256 watts. Quite a difference.

You can see here from just these calculations that the power requirement, to hit a given SPL, changes considerably with frequency. This is why loudspeakers are usually rated with respect to a driven voltage and not a power into a certain load.

If you want to have a little extra to spare, I would say a good quality amplifier, capable of delivering 150 watts into 8 ohms and around 250 watts into 4 ohms would be absolutely fine for pretty much all requirements from these loudspeakers. You do not need 2 ohm capabilities, regardless of how nice it may seem, the speakers are not that demanding to drive.

Besides, two loudspeakers, each delivering peaks of 110dB at one meter, in room, is extremely loud and dropping the amplifiers power capabilities down to 75 watts into 8 ohms and 125 into 4 ohms will only reduce the max to 107dB. This is why people say the statements will work fine on most quality receivers - they will - unless you want to really get the absolute most SPL out of them and also risk your hearing!

The only other thing you need to pay attention to is whether or not the loudspeakers can handle this amount of power and this is another area that is extremely difficult to pin down. Music is NOT steady state. In other words it is continuously variable and all genres are vastly different in nature, nothing is fixed. If music were like listening to a single frequency sine wave then we could easily come up with power figures for loudspeakers, but the truth is that we cannot. Most loudspeakers can usually withstand very high peak levels of power without risking damage from thermal overload. This is as much true for tweeters as it is for woofers, it is long terms exposure to high levels of power that is usually responsible for thermally destroying loudspeakers. As music delivers repeated peaks of high power to the drivers, the voice coils slowly heat up and over time the gradual increase in temperature means that at some point the music peaks could result in the glues and insulations breaking down, which causes your voice coils to fry. What power levels does this occur at? It depends entirely on what you are listening to.

Then there's the other area of loudspeaker destruction, which is mechanical failure and in any well designed loudspeaker will only occur if you throw far too much extreme bass at them. Unlike thermal failure, which tends to happen after a while of listening, mechanical failure can be instantaneous. If you turn the volume up too high on low bass signals that the loudspeakers shouldn't really be reproducing then you overload the drivers and they move further than they are supposed to. This usually results in the voice coil former slamming into the back plate and causing a horrible cracking type sound. If you're lucky the loudspeaker will survive long enough for you to mute or turn the system down. If you're not the impact will smash the voice coil to bits.

In short, power ratings are almost meaningless under the right circumstances. They only truly come into play (and require truly measuring properly) if you are aiming at breaking records or designing high performance systems around severe compromises or limitations. But if you're building a large pair of floor standing loudspeakers, have an amplifier of decent power rating and value your hearing it is unlikely to ever be a problem.

[eduardokbb]

There are two things to consider when looking at amplifiers power ratings. The first is the power into 8 ohms and then the maximum current capability, or its power output into lower ohm loads.

The 8 ohm load specification literally tells you how much voltage an amplifier can swing and this is important when addressing the voltage sensitivity of your loudspeakers. Regardless of how much power a pair of loudspeakers will require they always have a sensitivity figure provided in the specifications, for example 87dB referenced to 2.83vrms. Sensitivities are almost always referenced to a fixed voltage and nominally this is 2.83 volts root means square, or 8 volts peak to peak for an AC sinusoidal waveform. The reason why the sensitivity is referenced to a voltage is because loudspeakers are voltage driven devices. Amplifiers are constant voltage devices vs frequency, loudspeakers are measured and designed with constant voltage amplifiers and a constant voltage amplifier is assumed to be what you will drive them with, thus the sensitivity figure is given with respect to a fixed voltage.

This is much easier than trying to reference the loudspeakers sensitivity to a number of watts because watts automatically involve current and the current a loudspeaker will draw from the amplifier varies constantly with frequency and driven phase angle. In other words the current changes with frequency and thus so do the number of watts required to drive the loudspeakers, but the number of volts on the output of the amplifier remains the same regardless of what frequency you pick (that is if you don't touch the volume control!).

Now what does all that mean?

The sensitivity for the statements, as far as I can see, isn't given, but as it runs a pair of RS225s and after bafflestep compensation, they probably sit at around 89dB re 2.83vrms. Now lets say you want to reach 110dB peaks with these, you would need 110-89dB = 21dB of extra output. To convert this into voltage gain we use use 20*log(V2/V1) = dB gain, where V2 = our unknown voltage, V1 = 2.83 and the gain we require = 21. This ends up giving us an answer for V2 of approximately 32 volts rms. We can then convert this into an equivalent 8 ohm power rating by squaring the rms voltage and dividing it by 8. In other words (32*32)/8. This gives us an 8 ohm power rating of 128 watts.

This does not seem like all that much, but here is where the current comes into play. If you look at the impedance for the statements you will see that they hit an impedance maximum at around 15kHz, ignoring the fact that there's hardly any musical content up here, the impedance maximum is about 10.5 ohms with almost zero degrees on the phase angle. Given that our amplifier is going to be outputting 32 volts rms we can calculate the current requirement for the impedance maximum using ohms law V=IR. 32/10.5 = 3 amps. This isn't much at all and when converted into watts comes out at around 96.

Now lets look at the impedance minimum. This occurs at around 75Hz, again with a zero degree phase angle, but this time the impedance is pretty much 4 ohms. Given our 32 volt requirement we can now calculate that 32/4 = 8 amps or 256 watts. Quite a difference.

You can see here from just these calculations that the power requirement, to hit a given SPL, changes considerably with frequency. This is why loudspeakers are usually rated with respect to a driven voltage and not a power into a certain load.

If you want to have a little extra to spare, I would say a good quality amplifier, capable of delivering 150 watts into 8 ohms and around 250 watts into 4 ohms would be absolutely fine for pretty much all requirements from these loudspeakers. You do not need 2 ohm capabilities, regardless of how nice it may seem, the speakers are not that demanding to drive.

Besides, two loudspeakers, each delivering peaks of 110dB at one meter, in room, is extremely loud and dropping the amplifiers power capabilities down to 75 watts into 8 ohms and 125 into 4 ohms will only reduce the max to 107dB. This is why people say the statements will work fine on most quality receivers - they will - unless you want to really get the absolute most SPL out of them and also risk your hearing!

The only other thing you need to pay attention to is whether or not the loudspeakers can handle this amount of power and this is another area that is extremely difficult to pin down. Music is NOT steady state. In other words it is continuously variable and all genres are vastly different in nature, nothing is fixed. If music were like listening to a single frequency sine wave then we could easily come up with power figures for loudspeakers, but the truth is that we cannot. Most loudspeakers can usually withstand very high peak levels of power without risking damage from thermal overload. This is as much true for tweeters as it is for woofers, it is long terms exposure to high levels of power that is usually responsible for thermally destroying loudspeakers. As music delivers repeated peaks of high power to the drivers, the voice coils slowly heat up and over time the gradual increase in temperature means that at some point the music peaks could result in the glues and insulations breaking down, which causes your voice coils to fry. What power levels does this occur at? It depends entirely on what you are listening to.

Then there's the other area of loudspeaker destruction, which is mechanical failure and in any well designed loudspeaker will only occur if you throw far too much extreme bass at them. Unlike thermal failure, which tends to happen after a while of listening, mechanical failure can be instantaneous. If you turn the volume up too high on low bass signals that the loudspeakers shouldn't really be reproducing then you overload the drivers and they move further than they are supposed to. This usually results in the voice coil former slamming into the back plate and causing a horrible cracking type sound. If you're lucky the loudspeaker will survive long enough for you to mute or turn the system down. If you're not the impact will smash the voice coil to bits.

In short, power ratings are almost meaningless under the right circumstances. They only truly come into play (and require truly measuring properly) if you are aiming at breaking records or designing high performance systems around severe compromises or limitations. But if you're building a large pair of floor standing loudspeakers, have an amplifier of decent power rating and value your hearing it is unlikely to ever be a problem.

Thanks for that reply. I never thought there would be so huge differences in terms of power needed to amplify different frequencies! Well, given that, I think I'll be able to push the Statements at 113db without much effort. Not that I'm planning to do that, of course not, but now I know that I can build the Statements, pair them with my amplifiers and unless my goal is to get deaf, I won't have to concern with clipping. I'm really sorry for bad english and, again, I apologize if my first post sounded like marketing, but it was really only a suggestion that I thought could be useful. I live in Brazil, things here cost much more than they should, that said, the only way to have a nice stereo is to DIY or being a rich man. Since I'm not a rich man, I'm in the DIY way of all my entire stereo.

Peace,
Eduardo Barth.

[Philzeemon]

first crossovers. not the best to look at but they sound great!

Boston...Hope all is well for you...
Have questions on your choice of resistors and their respective power values..
Looking at your Photos-(Post82)-
On the mid-board, they appear to be an aluminum clad wirewound, 25watt ?
On the tweets board, are those mills ceramic...12watt? .
How high a power rating is necessary?..
I've been looking into alternatives and was considering the NTE 50 watt wirewound aluminum clad resistors..
I certainly don't want a meltdown, much less a fire..
I've even drawn up a layout with twin 50's of double value to maintain resistance but up the power handling.
At what point would I be on the threshold of overkill?
Info and your thoughts would be appreciated..
Thanks Phil H

[bostonmurf]

Hi Phil, sorry for the late reply. unfortunately i can't help much as far as the specifics for the crossovers go. I originally ordered the pre built crossovers for the towers from meniscus and when building the center bought the components also from meniscus but this time built them myself. i tried to follow the pre-builds as much as possible as they were very similar so any part choice came from that. best person for crossover info is probably Curt or Jim. I'm a really new to speaker builds so id be afraid to give to bad info. However I've not had a problem with the center or towers even when played loud, although loud is different form person to person.
sorry i can't be of more help

[bostonmurf]

Zigmahornets

Hi everyone, its been a while since my last post. So I've been playing around with finishes and have been practicing to get ready for stripping down the statements for paint. As I had 4 spare w4-1337SD drivers that I tried to sell but couldn't i decided to find something simple to make with them. anyway found a nice little post about zigmanhornets and decided what the hell, ill build them and drop these drivers in and see how it goes. well it worked out great sounded much better than id imagined they would when paired with a small subwoofer. great to make for a gift for someone. used 80-20 wood glue/water mix to seal them, then kilz oil based primer/sealer and finally rustoleum interior satin finish oil based paint.