Subwoofer bass myths, see here!

Mike

@mijostyn , I agree with you about the heat issue.  Except for the very first generation of my subwoofer system, dating back to 2006, I haven't been putting amps inside of subwoofers.  My observation (based largely on conversations with customers) is that high-power compact equalized sealed-box subs tend to have fairly high failure rates for their amplifiers and their woofers, and I think it goes back to the "oven environment" you described.

One of the reasons I use vented enclosures (tuned such that their response is the approximate inverse of typical room gain from boundary reinforcement) has to do with thermal power handling.  A comparable sealed-box sub will theoretically need roughly three or four times as much power in the region of the port tuning frequency in order to have the same frequency response.  Also, a port allows an exchange of air with the outside world, so you don't get that "oven environment" that you do with a high power sealed box sub.  In other words, imo there are arguably worthwhile thermal benefits from making a vented box approximate the frequency response of a very low-Q sealed box down to the port tuning frequency.

In my opinion.

Duke

Use a kill-a-watt meter or something and determine how many watts you are using when pushing the sub. You may be able to get away with a lot less power (than you think you need).

The problem with the Dayton Audio SA1000 amp, is, if it has a problem after the warranty expires you cant get parts for it.

They still make the amp though 🙁

Mine stopped working and it now sits in a spare room. That`s a shame

@mijostyn wrote:

I do not like Crown amps. I have had them twice and both times they were unsatisfactory.

I’ve previously used Crown’s Macro Tech class A/B series for subs duties for a short while, and found them to be very good amps (not only in the subs region, certainly with the 3600 model on down), but their built-in fans were noisy like angle grinders, and by now the Macro Tech’s also have quite a few years under their belt. The class H-based Crown K2 is another very good and popular subs amp, and moreover it’s passively cooled (but one needs to disable the auto standby function). I used the K2 over my subs for some years, as well as upper bass/lower mids duties, and it excels in the bottom octave in particular with good weight and control while lacking a bit of mid bass prowess.

A beast of a subs amp is the class TD-based Lab.gruppen FP6400, which I used for years with my subs as well as midbass section. Crazy powerful amp, though not as musically natural in the lower octaves compared to my current MC² Audio class A/B amps; finding a suitable subs amp isn’t only about having enough power (which is the easy part), but also and not least about what complements the audio range above the subs region. I find using essentially similar amps top to bottom to be very important for overall coherency and tonal imprinting - something few seem to be aware of and actually implement in their subs setup and considerations. Using a dedicated quality DSP (that acts as a digital XO for the mains as well) with a vast and intricate range of settings only adds to the advantages.

@audiokinesis wrote:

One of the reasons I use vented enclosures (tuned such that their response is the approximate inverse of typical room gain from boundary reinforcement) has to do with thermal power handling. A comparable sealed-box sub will theoretically need roughly three or four times as much power in the region of the port tuning frequency in order to have the same frequency response. Also, a port allows an exchange of air with the outside world, so you don’t get that "oven environment" that you do with a high power sealed box sub. In other words, imo there are arguably worthwhile thermal benefits from making a vented box approximate the frequency response of a very low-Q sealed box down to the port tuning frequency.

+1

Like ported boxes, tapped horns (contrary to sealed designs) also have excursion minima at the tune, but by comparison seem to be less marred by group delay effects. Being also they’re very efficient, certainly with a tune not much lower than 20-25Hz - in addition to having the driver’s backside exposed in free air at the mouth - makes them very resilient to thermal overheating.

@ditusa wrote:

Subwoofer bass myths, see here!

Mike

+1