Altec Lansing PT6021

[Rob Williams]

Altec Lansing fields us a new concept in powered audio – a simpler route to home theater sound. Their new PT6021 system holds special promise for Home Theater PC applications. But can it meet the performance challenges of true home theater use?

You can read the full review here and discuss it here.

Welcome Rory to the staff peeps! This is his first review, and as you can probably tell, he knows his stuff. You can expect some more content from him soon. If he wants anything else known about himself, he can post it here :techgage:

 

[Tech-Daddy]

Wow!

Nice job!

 

[Greg King]

Rory, well done review. Indiana in the house!

 

[madmat]

That's odd, when did Plantronics enter the picture? Last I heard, Sparkomatic bought Altec and formed Altec Lansing Technologies...I've been out of the loop. I've also got to ask, with multiple drivers you run into the problems of wave cancellation which is why high-end home speakers tend to avoid multiple tweeters (it's not as big of a problem with lower frequencies such as the midrange and midbass). I'm just wondering if you noticed any sort of dropouts in the upper registers that could be found by moving your head? I've often wondered about that with speakers that use multiple tiny drivers...it could be that the upper registers are rolled off in certain drivers too so that is avoided.

Anyways, nice read, I hope to see more from you but how about a bit of dissection for the audio geeks among us?

 

[Rory Buszka]

The InConcert driver arrays aren't true line arrays. If they were, all of the drivers in each satellite would reproduce the same frequency band. Instead, there's some frequency shading going on (with the outermost drivers only operating up to 1500 Hz and the second innermost set of drivers operating up to 6000 Hz). This means that only the two center drivers are reproducing treble. However, since the wavelengths involved are still very small at those frequencies, the two stacked treble sources do create self-interference at extreme vertical angles, creating pattern control in the vertical plane. Indeed, the spacing of the other two sets of drivers is intended to create the same vertical coverage pattern with decreasing frequency, creating a line source of increasing length as frequency decreases, maintaining the same narrow vertical coverage pattern from the treble range through the midrange. However, they do have wide coverage in the horizontal plane, owing to the narrow horizontal dimension of the line source. Still, you wouldn't place these speakers on their sides.

About me:
I'm currently a senior at Purdue University, and I've had a fascination with loudspeakers and audio since I was a child. I've designed and built my own loudspeaker projects for about the last eight years, and I've learned a lot in that time, which I'm glad to be able to apply to my review-writing. I also recently held a job at a company in Philadelphia which manufactured large-scale professional audio loudspeakers, such as you'd find in auditoriums and theaters.

 

[Rory Buszka]

The Altec Lansing PT6021 system is particularly intriguing, because of its apparent orientation toward home theater use. With the popularity of the home theater or "media center" PC, I think this review provides a valuable chance to comment on the HTPC phenomenon and the role that PC speaker manufacturers could find themselves playing. I foresee a day when the home theater PC replaces the stereo or multichannel receiver as the "head" of the modern home theater system. In order for this revolution to take place, high-quality amplified speaker systems must be developed to supply the home theater enthusiast's demand for high-fidelity sound. In the world of home theater, powered speakers are a long way off from being the standard, though many current receivers already have preamp-level outputs (my H/K AVR335 included). The home theater market has been dragging its feet when it comes to powered speakers, but the rise of the HTPC provides what is, in my opinion, the perfect venue for the powered speaker revolution to take place, since most computers already depend on powered speakers. The HTPC-as-head-unit would integrate input signal switching, volume control, and CD/DVD playback into one unified audiophile-quality component.

Two things need to happen in order for this technology transition to take place. First of all, manufacturers like Altec Lansing who have already been producing powered speaker systems must develop new powered speaker products capable of delivering sound with extremely high fidelity and low distortion, patterned after the current crop of passive high-fidelity speakers or studio monitors in both style and functionality. This means high-quality drivers and substantial, elegant cabinets as well as powerful amplifier circuitry and intelligent processing. In order for the consumer to accept the new type of product, it must perform as well as or better than the competing product that uses the old technology. Luckily, powered loudspeakers do have something significant that they can offer in this area. Powered loudspeaker systems can integrate signal processing to impart ruler-flat frequency response and perfect phase alignment, among other things (like synthesized deep bass response). While some manufacturers have tried, the same active processing just can’t be accomplished elegantly with a separate receiver/amplifier. One problem facing powered loudspeakers is the question of how to distribute power to each of the loudspeakers, since each loudspeaker would have its own amplifier. One answer is to produce complete loudspeaker systems, with the amplifiers for each channel housed in the subwoofer, as already done by nearly every powered loudspeaker system with “.1” in its classification. The other option is to use a multi-conductor cable which integrates power and signal wires. Given the benefits of powered loudspeaker technology, the engineering challenges are chump change.

The second thing that must happen is that home theater PC manufacturers must ensure that their products are capable of handling all the tasks that a receiver originally would. This will require the sound card manufacturers to get in on the action and offer hardware infrared volume and source selection control, as well as input from several external sources in addition to the PC itself. The sound card should provide visual output to a small external display, such as a two-line VFD. This second point, however, is not as critical as the first one – the market is now ripe for high-quality powered loudspeaker systems to take over the tasks typically performed by a big, hot receiver unit. Once these products are in place, the home theater PC can claim center stage in the modern home theater.

 

[Greg King]

It's painful to read through those posts. Simply because I do now know anything about audio. I know thats bad but I really don't know anything butthe basics.

 

[madmat]

Personally, to me, the ultimate high end HTPC speaker system would be completely wireless with the frequency operating in a band that's extremely high (9.6ghz anyone) that would allow for operation with extremely good treble response and no problems with interference from other wireless devices such as phones, bluetooth devices and what have you. Also several channels with a master channel selector on the controller would be nice as that would allow all the channels to be changed at once. I don't like the whole phase and EQ on a per speaker basis though, the ultimate goal of a high fidelity speaker system is to be a straight wire with gain, nothing more, nothing less. If your speakers are so fracked that they need phase alignment and equalization to achieve that goal then it's time to scrap the design and start from ground zero with a clean sheet. The only things done to the speakers is crossing over the frequencies that they can't (or shouldn't) be reproducing. I don't even like 2nd order and 3rd order crossovers (not to mention 4th order) as they add phase issues to the speakers. I've built speakers that were crossed with 1st order networks (yep, just a cap and choke) that were some of the most pristine sounding speakers I've ever heard. I just put several hundred hours of thought into what were the proper points of rolloff at 6db per octave and did even more experimentation with the frequencies I used in applied usage.

I wish I had the facilities to build drivers as I'd like to make some single focal point drivers with the tweeters mounted inside the voice coil of the mid and experiment with inverted domes and such. I came up with a design for a 3.5" mid with a 2.5" voicecoil and close to 1.5" of throw a few years ago for sub/sat systems, I think that something along those lines with the ability to play cleanly bellow 80hz would be the answer for HTPC speakers especially with the axially mounted tweeters as there'd be one small enclosure with a single focal point of sound.

 

[Greg King]

Uhhh, yeah. I just wanted to beat Matt to 1000 posts. Not going to happen now. However, in this discussion, I am way out of my element.

"Donny, your out of element Donny!"

 

[Rory Buszka]

By phase alignment, I don't mean like the user-adjustable knob on today's powered subwoofers. I'm referring to the phase alignment between drivers in a full-range speaker, which is typically accomplished to some extent or not at all by today's passive crossover networks -- creating phase shift that slightly delays the tweeter's output so that wavefronts from the tweeter's acoustic center and the woofer's acoustic center reach your ears at exactly the same time. Usually, crossover designers try to place the crossover point at a frequency where the phase shift caused within the drivers themselves is about the same. Some speakers you'll see have their front baffle angled backward. This isn't done to direct the sound upward -- it's done to bring the acoustic centers of the tweeter and woofer in line. However, the high-order crossover slopes that would be possible with active circuitry would almost render phase-alignment a nonissue since frequency bands in which the tweeters and woofers overlap would be extremely small.

Addendum: I just noticed what you wrote about a coincident-source driver. Perhaps you're familiar with the work of Jim Thiel? He developed a 3" driver that integrates a 3" aluminum cone and a 1" aluminum dome on the same voice coil, with a compliant material between the voice coil edge and the cone itself creating a mechanical crossover between the two diaphragms. Below the mechanical crossover frequency, the two diaphragms move as one. But if Thiel decided to build computer speakers, I probably couldn't afford them. For us, it's probably better to look at high-quality wide range cone drivers, such as the Tang Band W3-593 and W3-871 (which are at Parts Express). I've used the W3-593, and found that it provided such excellent high frequency extension that a tweeter really wasn't needed.

 

[madmat]

Actually the driver I spoke of is a 2.5" dome with .75" high roll surround (forgot that it was actually 4" not 3.5") and I'd have a dome tweeter that floats on the apex of the dome, hard to explain but it would feature a neodymium magnet that is attached to the mid's dome structure. I could do a drawing of it by hand but I'm sure you get the idea. The tweeter dome would be the 1/2" center of the mid's dome with a rubber ring suspending it and the motor would be attached to the dome.

Yes I know this adds mass to the mid but I'm thinking a full aluminum dome and the plastic motor structure of the tweeter would add damping to the dome of the mid and could be made pretty light. Besides, the magnet structure would have more than enough HP to overcome the mass.

 

[Rory Buszka]

Addendum (more bonus content for the forum folks)

I had the opportunity to compare the PT6021 system to my Cambridge Soundworks MicroWorks II system, which I've owned since the summer of 2006. The CSW MicroWorks II offers a warmer overall sound, without the depressed midrange of the PT6021's InConcert satellite speakers, yet I don't feel that I'm missing much in the way of detail. The PT6021's sub has more of the really low stuff to offer than the Microworks sub (though both have 6.5" active drivers with ~40w of power) by virtue of the Altec sub's vented design, but both systems offer a very "honest", un-embellished bass output that would be preferred by music lovers such as myself. The MicroWorks system lacks both the fully-featured control pod with tone adjustments (though the volume control is detachable and contains a headphone jack) and the infrared remote capability. I think I prefer the beefy "cube" styling of the Cambridge Soundworks satellites (and the sound of the 3" wide-range drivers) to the tall, narrow shape of the PT6021 satellite speakers, though neither design is particularly unappealing, and I respect the fact that the PT6021 sats are designed to look good with flat screen displays. That said, the MicroWorks sound a little peaky through the midrange, and lack the treble extension of the PT6021 system, so they sound a bit 'flat'. I still think that my MicroWorks II system is probably one of the best values in the 2.1-channel category, though the Logitech Z-2300 would be preferred by those who want the beefiest (though somewhat 'boomy') bass they can get. I know a lot of you have a nose for value, and so those two systems (Z-2300 and MicroWorks II) are my recommendations for the best value in the 2.1 category, though they aren't nearly as feature-laden as the PT6021.

 

[Unregistered]

New Purchase

With regards the review of the Altec Lansing PT6021 speaker system. Keeping in mind I know diddly-squat about this stuff, and I am looking simply to give my Sony HDTV and DVD a better sound quslity, will this sytem do the job. The room is 11 x 14 with the TV built into the wall and there is ample room to place the subwoofer etc. The room is so designed that rear sat speakers would be difficult to place, so I like the idea of the 2.1 design. The review makes it sound excellent, but there is the PC factor you keep talking about which does not apply in my case. Should I be looking for something elese, or can this sytem do the job? Can anyone give a simple answer that I might understand?

 

[Merlin]

I've had the FX5051 for a while, Altec makes some nice speakers. Since I use them for gaming and MP3, I have never used with a TV.
Now in the living room I use the Kenwood 500 watt suround system for the computer and TV, going from the sound out to the AMP system. Pretty nice. But for gaming in living room I have a headset.

Merlin

 

[Rory Buszka]

Well, The Absolute Sound liked the FX6021 speakers best out of 6 mass-market PC speaker systems they tested, and acoustically the PT6021 are the same. You don't easily come by a better 'second opinion' than that, in my book - The Absolute Sound is one of the foremost audiophile magazines in the country.