Bass Reflex Port Tuning: Which Woofer Is Better, The Dayton Designer Or The Dayton Classic?

Really taking my time with this RCA STS-1230 project, a 12” 3 Way Ported Vintage Speaker from RadioShack, that I'm doing a DIY customization to make them sound better.
In this video, I'm modifying the ports to accommodate the Woofers, using recommendations from Parts Express and Speaker Box Lite , I'll be tuning the original enclosures to an FB of about 35 Hz give or take.
Watch as I put the Dayton Classic Woofer up against the Dayton Designer Series Woofer. Identical cabinets, identical ports, crossovers bypassed and the midrange and tweeter are disconnected, so it's nothing but bass in a box.

[@zefrog7482]

Lol, those cabinets are so thin, amazed they can hold the Dayton without disintegrating.😂 Fair play though for saving them.

[@wattspeakers]

Thanks for watching and the reply! Yes the majority of vintage mass market speakers are built with 1/2" particle board / low grade MDF (barely can be classified as MDF). They're actually quite strong, especially when braced and gusseted. They're not as dense or heavy, so I give them some structural rigidity too, but to mitigate resonance they're lined with sound deadener.

[@ninehundreddollarluxuryyac5958]

Todd, you have made me aware that woofers do a halfway decent job of reproducing most of the music if the crossover is bypassed. What if you do the same with the tweeter? Does the long wavelength bass cause the tweeter to bottom out and become nonfunctional? What really happens if you just wire all drivers in the cabinet in parallel with no crossover? Why does a sharp cutoff crossover sound better to people who can hear the difference?

[@wattspeakers]

Excellent observation and questions! Back when I used to walk to school, 8 miles in the snow up hill both ways, tons of loudspeakers were made with minimal crossover components. With the exception of the higher quality designs from those companies making speakers for more discerning listeners, 2 way loudspeakers would often have nothing to filter the Woofer and either a single capacitor on the tweeter or a 2nd order, (capacitor and inductor), on the tweeter. Similar for 3 Way designs, with nothing on the Woofer, but with simple first order, (just capacitors), or 2nd order, (capacitor with inductor), on the tweeter and the midrange. While it may have been to keep costs down when manufacturing a million speakers for people who couldn't hear the difference. The truth is, for most, especially at low to moderate volume, it worked out just fine and still can today. This is especially true with decent transducers that have a fairly wide frequency response and can handle plenty of power... Like the Dayton Designer I'm working with. If you ask me, I think that I could make an okay sounding 2 way and not even filter that woofer. As long as I protected the tweeter from lower frequencies, (which will eventually harm the more delicate driver), it would sound fantastic to most... Maybe even to me. So, to your point, it's possible to run 2 or 3 transducers, e.g. woofer, mid-range, tweeter, without anything in the way, but there's inherently going to be issues with that design philosophy. The most important reason, is that a crossover network presents a pseudo minimum load to the receiver or amp. By filtering them, it side steps ohms law. 3 x 8 ohm drivers connected without a crossover results in an ultra low impedance... Not a deal breaker, and "back in the day" those beastly receivers and amps from the likes of Harmon Kardon, Marantz, Pioneer, etc. could handle those loads. With today's cheapo consumer receivers you'd likely smoke the receiver. Once you get to a certain price point today, better amps and receivers can indeed still handle fairly low resistance, some as low as 2 ohms, but for the majority of receivers it would destroy them. The second and less obvious reason to use the crossover, is to filter out the bulk of frequencies that would otherwise harm a tweeter or mid-range, because they have physical limitations in terms of low frequencies they'll play, (creating an audible buzz until they fail), or high frequencies that'll make them ring, screech and distort. The higher frequencies won't harm the drivers but it will make them sound funky. The remaining reasons have to do with how clean the system will sound and how loud it will play. Application specific transducers like subwoofers, woofers, midranges and tweeters have a "sweet spot". That sweet spot is where the frequency response is the flattest with a consistently linear impedance. By crossing them over, (transitioning from lower to higher frequencies), it allows each driver to play music or source material most effectively. The advertised useable frequency response is an indicator of that. For example, the Dayton Designer I'm using has a useable frequency response of 25 Hz to 2500 Hz. It'll still try to play lower and higher frequencies, albeit less effectively. By rolling off the majority of frequencies by way of box tuning and the crossover, it behaves better and plays music better. Since passive crossovers like most use, are only filtering and rolling off those frequencies at a certain rate, 12 Db per octave for the crossovers I usually work with, which are considered "2nd" order, because a first order is 6 Db per octave, a 3rd order is 18 Db per octave and so on... But it's not magic and the frequencies are still playing, just at less SPL sound pressure level, making them less audible. In other words, filtered frequencies still bleed into the drivers that don't play them back well. As the output a.k.a. volume increases, those become more audible. In the case of the Dayton Designer, I will use a 12 Db per octave filter that's roughly 600 Hz to 800 Hz. By doing that, frequencies near the limit of its useable upper range of 2500 Hz will be in the neighborhood of 20 Db lower in output than the rest of what it's playing... Thereby preventing any nastiness caused by cone break-up, (higher frequencies literally vibrating/shaking the paper cone material to the point that it loses structural integrity). The handoff of those higher frequencies beyond 2500 Hz are better suited to the mid-range and it supplements that region the woofer doesn't work well at. Rinse and repeat for the tweeter. Conversely, the "Fb" of the box is important to the lower frequency limits of that woofer. Currently they're tuned to roughly 40 Hz which allows a rapid decrease, (vented enclosures have a 4th order roll off, or a decrease of 24 Db per octave in lower frequencies from making the woofer distort and generally misbehave in the deep bass region. That way, at 20 Hz the Woofer isn't trying to playback at the same volume as the rest of the bass, thereby eliminating distortion. If you get the chance check out my goofy cardboard speaker video, kzbin.info/www/bejne/Y5iZeX-AjZikfK8 because there's a point where I'm playing the Dayton Designer Series crazy loud with drums and there's literally no audible distortion. That's because the box tuning and low frequency roll off is pretty good for that Woofer. All the drivers, regardless of the crossover design, will attempt to playback all frequencies, but by using a combination of high pass and low pass points, it limits how much of those frequencies are audible. Initial calculators and math are the science that will get you in the ball park, but blending them is the art and the hardest part of the whole build. For a speaker design intended for an audiophile, it may very well be the most focused and time consuming area of design. In a nutshell, crossovers make the Loudspeaker system as a whole operate better, producing better sound and less stress on the receiver or amp.

[@sajibsln]

What about the box dimensions used here ?

[@wattspeakers]

Thanks for the question. Advertised outside dimensions are 25-5/8" x 14-3/16" x 12-1/4” which works out to about 2 cubic foot internal volume.

[@sajibsln]

@@wattspeakers thanks

[@TriAmpHiFi]

Those subwoofers need to be crossed no higher than 250, which is a problem for those midranges. 🔈🔉🔊

[@wattspeakers]

Thanks for the comment. Neither the Dayton Designer or Dayton Classic is designed to be a subwoofer. They're home audio woofers with a usable frequency range of 25 Hz to 2500 Hz.

[@TriAmpHiFi]

@@wattspeakers Any driver claiming near flat spl's at 25 is a sub.

[@TriAmpHiFi]

@@wattspeakers poof

[@josephlalock8378]

@@TriAmpHiFi 😂