K&Q Sound Genesis Model 1

[admin]

Every year there are many exhibitors who do just plain crazy things. K&Q ranks high on this list for 2009. They were displaying a rather large floor standing loudspeaker which seemed to have no low end at all. When I walked around the back, it was obvious as to why. The speakers are mounted on a long tall narrow baffle, just large enough to mount the drivers.


Discuss "K&Q Sound Genesis Model 1" here. Read the article.

[MatthewB.]

Everytime I see Genesis in a speaker name I am reminded of a Home Depot parking lot and a white van and somebody telling me how their boss screwed up and they wound up with an extra set(s) of speakers and are willing to sell me these "high end" speakers at pennies to the dollar.

[Mrdplobrat]

No, no, no! You're obviously wrong, you need your ears checked! The speaker is great, as it uses cutting edge technology to sense room acoustics and use the whole room to create bass frequencies, which results in unbelievable lows! (add in more technobabble garbage) LOL

[bumpyride]

There are actually a lot of open panel dipole speakers out there that are very well engineered. Paul was correct to point out that the rearwave cancellation reduces low frequency output, but it amounts to a 6 dB/octave rolloff. This can be easily equalized in an active design and possibly in a passive design such as the K&Q here (not much for electronics myself) but not equalizing it is certainly a poor design and, if that's the case, would explain the lack of low end response heard. More on open baffle dipoles, and just about everything else relating to loudspeaker design can be found here:

http://www.linkwitzlab.com/models.htm#C

[JasonA]

There are actually a lot of open panel dipole speakers out there that are very well engineered. Paul was correct to point out that the rearwave cancellation reduces low frequency output, but it amounts to a 6 dB/octave rolloff. This can be easily equalized in an active design and possibly in a passive design such as the K&Q here (not much for electronics myself) but not equalizing it is certainly a poor design and, if that's the case, would explain the lack of low end response heard. More on open baffle dipoles, and just about everything else relating to loudspeaker design can be found here:

Ha! I was just about to post a link to the Linkwitz site, also. I have heard a lot of dipole, omni and other open-baffle designs (as well as hybrids), and I can attest that they can in fact sound excellent - in fact many I've heard sound better than a lot of typical "box" speakers.

[Paul_Apollonio]

If you are lucky, a direct radiator loudspeaker may give you 1-2 % efficiency. To say by using an open baffle we merely trade off a 12db (closed box) or 24db (Vented Box) rolloff for a 6 db (Open baffle) rolloff without mentioning the rolloff frequency had increased from 50 hz to 250 is either intellectually dishonest or worse, ignorant. Much of loudspeaker design involves compromise, and often the designer will intelligently choose to add mass or more motor force or use a sealed system versus a vented one for reasons of preference. The preference stated by this manufacturer was "It makes the midbass sound better". I am sure that this midbass was clearer as it had no low end to speak of it need compete with for the attention of his ears. There are NOT "many" (if any) good open baffle designs that go low enough to be able to claim "Full range" status, and there is far too much going on in the low end that adds to the musical experience to simply throw it away for the sake of being different so as to distinguish oneself in a crowded marketplace. Intelligent people can disagree. That said, to use 3 woofers on an open baffle is like striking three matches in a moving car while refusing to close the open windows, then wondering why you cannot light the flame. In a word, stupid.

[ratso]

emerald physics. even there old cs2's go 3 dB. down from 20 Hz to 20,000 Hz. and that's for their $3500 speaker. there are a ton of dipoles out there, and many of them have gotten great reviews over the years. many are meant to be paired with a subwoofer. the linkwitz site is run by an EE who has designed many groundbreaking products including speakers over the years, not some fly by night 'audiophile' guy. he invented the Linkwitz-Riley Crossover - perhaps you've heard of it. would love to hear a discussion between you and him when you call open baffle speaker designs "stupid". please check out his site.

[ratso]

or actually you may be only calling the K&Q speaker stupid. which may be exactly spot on, perhaps that speaker does indeed suck. it just seems kinda silly when the main peice seems to condemn all OB speakers (not to mention it seems tube amps?). i know this is HT and not 2 channel but come on. if a 2 channel site would openly scoff at "those old out of date plasma displays" it would be because they don't know what the hell they're talking about wouldn't it?

[bumpyride]

If you are lucky, a direct radiator loudspeaker may give you 1-2 % efficiency. To say by using an open baffle we merely trade off a 12db (closed box) or 24db (Vented Box) rolloff for a 6 db (Open baffle) rolloff without mentioning the rolloff frequency had increased from 50 hz to 250 is either intellectually dishonest or worse, ignorant. ...There are NOT "many" (if any) good open baffle designs that go low enough to be able to claim "Full range" status, and there is far too much going on in the low end that adds to the musical experience to simply throw it away for the sake of being different so as to distinguish oneself in a crowded marketplace. Intelligent people can disagree.

Those are all good points, but, as you mention, engineering is about tradeoffs. The 6 dB/octave roll off starts higher, and the 12 dB/octave first-order roll off of the speaker resonance is still there as well, but most unbaffled subwoofers have a low resonance in the 20's so that's not much of an issue.

At any rate, you're correct in saying that dipoles aren't often full-range. Linkwitz's Orion is down 6 dB at 20 Hz, but because of the dipole equalization it can only provide serious, clean output down to about 50 Hz. That said, though, there are advantages to dipole bass such as reduced coupling to room modes (http://www.aes.org/e-lib/browse.cfm?elib=7579), and, in the midrange, the back and front wave interact in such a way that the speaker doesn't become as directional at high frequencies as it would in a conventional box speaker giving it a more uniform polar response. Additionally, the null in a dipole's figure eight pattern can be pointed at the side wall reflection point to reduce the first reflection.

Anyway, the issues with bass output discussed above are true of all dipole sources whether they're open baffle or not, so if you're going to build a dipole front speaker than an open baffle is as good a way as any to do it. However, these designs should always be active because providing dipole equalization in a passive design would kill the efficiency of the speaker by lowering everything to the efficiency of the bass drivers - possibly the reason for using 3 of them here.

[justincz]

If you are lucky, a direct radiator loudspeaker may give you 1-2 % efficiency. To say by using an open baffle we merely trade off a 12db (closed box) or 24db (Vented Box) rolloff for a 6 db (Open baffle) rolloff without mentioning the rolloff frequency had increased from 50 hz to 250 is either intellectually dishonest or worse, ignorant. Much of loudspeaker design involves compromise, and often the designer will intelligently choose to add mass or more motor force or use a sealed system versus a vented one for reasons of preference. The preference stated by this manufacturer was "It makes the midbass sound better". I am sure that this midbass was clearer as it had no low end to speak of it need compete with for the attention of his ears. There are NOT "many" (if any) good open baffle designs that go low enough to be able to claim "Full range" status, and there is far too much going on in the low end that adds to the musical experience to simply throw it away for the sake of being different so as to distinguish oneself in a crowded marketplace. Intelligent people can disagree. That said, to use 3 woofers on an open baffle is like striking three matches in a moving car while refusing to close the open windows, then wondering why you cannot light the flame. In a word, stupid.

you oviously have no clue about OB speakers.

these speakers is a good design with the correct drivers for OB. probably eminence with the right qts and fs spesifications.
claiming that it is dumb to use 3 woofers in OB is the dumbest thing iv ever heared. its a piece of cake to get flat response from this kind of speaker with the right woofers. and multiple drivers = more dynamics.
the manufacturer is correct, bass sounds alot better in open baffle. but you wouldnt know how live music sounds until you tryed them for some time. box speakers sound colored and compressed in comparison.