Technical Question

[Evyn]

Question:

If my enclosure Port is tuned to 28 HZ. Does my amplifier have to reach the same tuning? What if the Amp only goes to 33 hz?

[djg]

Then you'll only reach 33hz.

[billfitzmaurice]

Why would your amp only go to 33Hz?

[fpitas]

My amp goes to 11.

[DeZZar]

Question:

If my enclosure Port is tuned to 28 HZ. Does my amplifier have to reach the same tuning? What if the Amp only goes to 33 hz?

It's completely irrelevant. But I've never heard of an amp that cuts out at 33hz.

[billfitzmaurice]

My amp goes to 11.

So does my guitar. That makes 22.

[djg]

He asked this in his subwoofer build thread. Maybe his plate amp has a subsonic filter.

Edit: My SPA250DSP subwoofer plate amp has a subsonic function adjustable from 40 to 25hz, if you can believe the GUI. I assume Y'all weren't thinking of subwoofer subsonic filters. I looked at OP's other thread and deduced my response.

[DeZZar]

? I'm not having a go mate - I'm simply saying that in the context of the question asked, the right tuning for the subwoofer has nothing to do with amp.

[djg]

Then we agree. Being a bit of a smartass I guess. I was just proud of myself for figuring out the context of the OP's question.

[AEIOU]

INFRAsonic is the correct term, but I guess way back 60 years ago when most consumer electronics were made in Japan, they didn't know the correct translation and ended up using subsonic, which is the opposite of supersonic.

[johnnyrichards]

I'm gonna be the pedantic one and call it infrasonic or high pass filters, not subsonic. Would a low pass be called supersonic or hypersonic? Hmmmm... Sounds like a killer marketing term 😁

One of the plate amps at Apex had a peaking high pass at 34hz. I believe most subwoofer plate amps will have some type of infrasonic or high pass be default. I think I remember reading the Dayton 240W had a 19hz infrasonic filter.

[fpitas]

I may be over-thinking this (yeah, I am), but as I recall, WINISD allows you to put a high-pass filter in as part of the analysis. I'd tune the port appropriately for the cascaded response.

[billfitzmaurice]

That's both over and under thinking it, as the room is as much a part of the equation as the speaker and the electronics. You can't assume that the result in WinISD or any other software that give a half-space anechoic result will be totally accurate unless the speaker is going out in your back yard well away from the house or any other buildings. Modeling software is very useful, but only up to a point.

[djg]

Back in the days of turntables, the "subsonic filter" was used to remove very low turntable rumble, sub 20 hz frequencies. The name has persisted.

[johnnyrichards]

It has persisted, I suspect it takes up less space on a bezel. Pedantics aside, I think we all understand what is meant.

My Technics quadraphonic receiver (if I recall correctly - been 30 years) actually called it a rumble filter.

[Evyn]

The box is tuned to 28-30 HZ. The flares added 3" but the ends open wider 4" than the shaft at 3", (at about an inch on both ends).

So the tuning might be slightly above the intended 28hz.

Is this Amp going to work until I buy a DD Amp?

[rpb]

The box is tuned to 28-30 HZ. The flares added 3" but the ends open wider 4" than the shaft at 3", (at about an inch on both ends).

So the tuning might be slightly above the intended 28hz.

Is this Amp going to work until I buy a DD Amp?

Should work great! ....I see your confusion now. That 32hz setting on the amp is to adjust how high in frequency the sub is allowed to play. So, if you set it around 60hz, then bass above 60hz is rolled off. I think 60hz is a good starting point for experimenting to see what sounds best. I personally would not like a setting above 80hz. If your main speakers are tiny, then a higher setting may be an advantage. Location of the speakers plays a roll as well.

[Evyn]

Should work great! ....I see your confusion now. That 32hz setting on the amp is to adjust how high in frequency the sub is allowed to play. So, if you set it around 60hz, then bass above 60hz is rolled off. I think 60hz is a good starting point for experimenting to see what sounds best. I personally would not like a setting above 80hz. If your main speakers are tiny, then a higher setting may be an advantage. Location of the speakers plays a roll as well.

So you're saying that the amp tuning doesn't have a direct connection with the enclosure port tuning?

Just to clarify.

If I tune the amp to 45 hz the 28hz port will hit?