Must a sealed subwoofer have DSP?

[Zeppelin]

Whose in generally up to 500 Hz on both speakers and sub's.

Don't understand this.

Let's revert this to the bigining.
What frequency response are you receiving as it is in the first place (measured with calibrated measurement microphone like UMIK-1)?
How is your hearing state (audiologist hearing test)?
What do you hope to achieve in conjunction to above?
For what amount of money on disposal if it's achievable at all in consideration of above?

Still doesn't have the sub. The speakers will arrive on friday, and the amp the next week.
If it's necesary I can do the measurements with a mic, which I don't have, but I think I could get one.
I have not been tested on a hearing test, but how this apply in the very low freq adjustment?

As I said, what I want the setup for is music, many kinds of. On a small room, so normally with not very high volume needs. I am conscient the 20hz can not be in my horizon, but I am keeping an eye into 2 o 3 second hand subwoofers which achieve sub 30hz frequenies, and maybe room gain is going to help for the rest.

The expandable money is not huge, so please stop speaking about SVS subwoofers hahaha

 

[Chrispy]

Don't understand this.

That's why I posted the article on the schroeder frequency, which is what it refers to.

 

[Zeppelin]

As long as you don't block the port badly, you have about the same considerations as sealed.

That's what I thought, but it's also for this a sealed is better for me (for small rooms), because I don't have many positioning options.

You can get along without PEQ with any sub, depending on how picky you are about your bass.

If it goes somewhere below 30hz, even if it's just a little, I would be satisfied. The specs on the 2 subwoofers Iam looking at states that. One saying 28hz, and the other 25hz. Probably they will not perform this well and they only down 4-5hz higher that stated, but maybe with room acoustics those numbers would be enough.

 

[ZolaIII]

This graph helps to clarify.

Until now, it seems DSP it is not mandatory, but kind of improve bass signal. Also seems DSP is "only" an automatic PEQ.

Do you know a cheap PEQ that can be connected to my setup? The SNR of my Aiyima 08 Pro is 110db, for if it guides you to a non low SNR device.

Cheapest (but not simplest) way to get a fully diverse and great regarding learning digital signal processing is relatively old and cheap desktop PC with multichannel DAC in case of use of sub's.
PEQ's or doing it in digital domain are neither new nor mandatory but it's most flexible. There were analog PEQ's (vocal usually) even 50 years ago. Some things can be done and without PEQ's with regular fixed frequency EQ's. Or with automatic room corrections on amps and AVR's that have them. There are and sub's with cuple embedded PEQ's.
I use relatively cheap (half to third of the price of SVS 12" one's new) Warfadale 10" closed enclosure sub's that I am satisfied with and they have embedded high pass filter @ 80 Hz and Linkwitz transform filter. Two of them have 30 Hz - 3 dB response and 0 dB in room.

 

[Zeppelin]

That's why I posted the article on the schroeder frequency, which is what it refers to.

Ok, will read it carefully in a couple of hours.

Thanks for it

 

[Chrispy]

Ok, will read it carefully in a couple of hours.

Thanks for it

Part 2 may be a bit friendlier....

 

[Zeppelin]

I use relatively cheap (half to third of the price of SVS 12" one's new) Warfadale 10" closed enclosure sub's that I am satisfied with and they have embedded high pass filter @ 80 Hz and Linkwitz transform filter. Two of them have 30 Hz - 3 dB response and 0 dB in room.

But in specs states is only 40 - 120Hz ±3dB. Goes down to 30hz due the room gain?

 

[FeddyLost]

What do you think?

It depends. DSP - it's the cheap and dirty way of controlling subwoofer settings and even integrating some "room correction" into it.
In fact, you should understand simple rule: everything that emits sound inside your room, and room itself are making single system in low frequencies. Even big closet with clothes or leather sofa may significantly affect subjective bass qualities.
So, DSP correction is the easiest way if one is producing "universal" subwoofer that must tailor well into a lot of different systems.
Martin Logan and ELAC make subwoofers with integrated "room correction", for example. Sometimes this is only reason not to throw out subwoofer (when you have only one very unlucky place for it).

In my room there is only three spots where it could go, so I hope one of them would be a good one

Download REW, try out with Room Sim and maybe you'll not need a subwoofer.

 

[ZolaIII]

But in specs states is only 40 - 120Hz ±3dB. Goes down to 30hz due the room gain?

It's WH-D10 model.
This are measurements (blue):

But I use two of them which in my not big listening room whose enough for - 3 @ 20 Hz but I cut them under 23 Hz anyway.
They are nothing to write home about really with usual problems for most of such (auto off not working really good and far from precise low pass potentiometer controls) but I am satisfied with them. Both them on discount 270€ a piece of course.

 

[Zeppelin]

You might like this article on schroeder frequency effects https://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-1 to help explain bass in typical rooms

Thoughts on Schroeder freq:

-Does the cases of having a high Schroeder freq are usually those of we know are not good for "acoustics" in general? Let's say perfect square rooms without courtains nor objects breaking/absorving the waves?

-In the case I have a high Schroeder freq can I lower it buy placing bass traps planels?

-Thinking about solutions, if they are needed, I could buy a good speakers which doesn't travel down so much in frequencies. This could help, if it's the case, but still the subwoofer would need to be place in a good spot

In the beggining Ithought Schroeder freq seems to be something like room gain, but then I understood it doesn't

Thanks for this info

 

[Zeppelin]

Download REW, try out with Room Sim and maybe you'll not need a subwoofer.

When you say "maybe you'll not need a subwoofer" do you mean I couldn't have a good spot for it? Or maybe because room gain the low herz are generated naturally by a speaker which reach something like 40hz?

EDIT: To all users, I have no inconvenient to do some sonorising on the room

 

[Timcognito]

Several small subs come with dsp apps example;

SB-1000 Pro

Sealed cabinet home audio subwoofer punches well above its class with stunning impact and musicality.

www.svsound.com

 

[Zeppelin]

It would be wonderful if we could just dig in a little more in to the problematics we were talking about. If some of the questions I asked in my last two messages could be clarified it would help me a lot.

@FeddyLost @ZolaIII @Chrispy Hope this message summons you!

 

[ZolaIII]

It would really be helpful to see what you are getting as frequency response and impuls response (in room measurement with measurement microphone) and what speakers you use and what's their in chamber measured response.
Regarding schroeder frequencies 100 to 200 Hz range and generally up to 800 Hz it's not a easy thing to cope with. Not with available traps and they are expensive. Making your own resonance absorber isn't easiest thing either and it would need to be 30 cm or 12" deap in order to be efficient and that's a lot of room and efficiency place them. Main part is getting a good ratio of early-to-late arriving sound energy (C50 to ISO 3382-1) on reference frequencies of 125 and 250 Hz. That's why it's better to go with closed enclosure subwoofer's and speakers in the first place but most folks don't get it to start with.
A scientific paper with direct proposal to make them and on budget not costing more than rock wool panels with measurements that is illustrated, not hard to follow and understandable:

Development of a Panel Membrane Resonant Absorber

The bass ratio describes the relationship between the reverberation energy in the low frequency region and that of the middle frequency. An appropriate bass ratio can create a warm sound; however, too much bass can influence speech clarity (C50) and work efficiency and can even cause listeners...

www.mdpi.com

For those who can sacrifice that much place in the room.
But now we are talking about more than a cheap or even not so cheap subwoofer('s).

 

[Chrispy]

It would be wonderful if we could just dig in a little more in to the problematics we were talking about. If some of the questions I asked in my last two messages could be clarified it would help me a lot.

@FeddyLost @ZolaIII @Chrispy Hope this message summons you!

A square room is a problem to begin with, but multiple subs may help resolve. Room treatments for low bass can be big and ugly, your decision.

 

[Zeppelin]

It would really be helpful to see what you are getting as frequency response and impuls response (in room measurement with measurement microphone) and what speakers you use and what's their in chamber measured response.

Today arrived the amp: Aiyima 08 Pro, and on monday/tuesday will arrive the speakers: 2x Polkaudio r15.

I can measure what you think it is usefull to discover if a subwoofer would be good here. In my head it is better to wait until the speakers that goes into that room arrives to start with testing the frequency response in each corner. The at the moment speakers don't go down as much as the new comers. What do you suggest me to do?

Regarding schroeder frequencies 100 to 200 Hz range and generally up to 800 Hz it's not a easy thing to cope with. Not with available traps and they are expensive. Making your own resonance absorber isn't easiest thing either and it would need to be 30 cm or 12" deap in order to be efficient and that's a lot of room and efficiency place them. Main part is getting a good ratio of early-to-late arriving sound energy (C50 to ISO 3382-1) on reference frequencies of 125 and 250 Hz. That's why it's better to go with closed enclosure subwoofer's and speakers in the first place but most folks don't get it to start with

The subwoofer is sealed, but the speakers have a bass-reflex port in the front. I have chosen a sealed subwoofer because this, but didn't think the not-so-much low frequency of the speakers would be a problem.

Speaking about frequency tests you only talk about schroeder frequency. I had understand there are some other points besides of Schroeder frequency, like denial or summings of sound wave. Can you clarify a little this point please?

 

[Zeppelin]

A square room is a problem to begin with, but multiple subs may help resolve. Room treatments for low bass can be big and ugly, your decision.

My room is not a squared one. It's rectangular, with one of the larges wall covered by books (which is good), another wall has a window without courtains (which is bad, but light is needed), and the other large wall has a closet which ends 50cm before arriving to the ceiling, breaking the poligonal regularity of the room.

Reading Zolalll it seems sonorisating it's a harsh thing. Didn't expect the panels to be 30m thick. Maybe in a couple of corners (probably the most complicated zone). Let's see.

For the actual moment my mind is thinking about how to measure it without having a subwoofer and a 40hz speaker.

 

[Chrispy]

My room is not a squared one. It's rectangular, with one of the larges wall covered by books (which is good), another wall has a window without courtains (which is bad, but light is needed), and the other large wall has a closet which ends 50cm before arriving to the ceiling, breaking the poligonal regularity of the room.

Reading Zolalll it seems sonorisating it's a harsh thing. Didn't expect the panels to be 30m thick. Maybe in a couple of corners (probably the most complicated zone). Let's see.

For the actual moment my mind is thinking about how to measure it without having a subwoofer and a 40hz speaker.

"sonorisating"?

 

[ZolaIII]

I really hope you can send those speakers back and with the money from them and one intended for for subwoofer buy a decent speakers (T15/P15 are the same speakers).

Polk T15 Bookshelf Speaker Review

This is a review and detailed measurements of the Polk T15 "Home Theater and Music Bookshelf Speaker." I purchased it last month. The T15 is supposed to cost US $115 but I think I only paid US $70 for my pair. With the grill removed, the T15 looks decent: I was surprised by the quality...

www.audiosciencereview.com

Amplifier actually isn't bad at all objectively, actually it's great for the price.

AIYIMA A08 Pro Amplifier Review

This is a review and detailed measurements of AIYIMA A08 Pro stereo amplifier with Bluetooth support. It was sent to me by the company and costs US $139.99. It is so nice to see a VU meter on an amplifier! This one actually seems high quality with nice ballistic response (fast jump, a bit...

www.audiosciencereview.com

So that one you should keep.
What are your old speakers?
Every speaker with port closed is a closed enclosure speaker and you lose 20~30 Hz of bottom end response that way which is not a problem with subwoofer to fulfill it. Same doesn't apply to subwoofer's because a need for Linkwitz transform with closed enclosure subwoofer's.
Edit: actually how much money would you have if you send back both speakers and amplifier with what you intended for subwoofer?
Asking cause there are rather fine (actually great for the price) active monitors that aren't expensive. Kali LP 6 V2's are 400 $/€ for pair (200 each) and you would be more than fine with them (as a speakers) for least money I can think of to get there.

Kali Audio LP-6v2 (Second Wave) 2-Way Studio Monitor Review

Kali Audio LP-6v2 2-Way Studio Monitor Review

www.erinsaudiocorner.com

Hope that helps.

 

[Zeppelin]

"sonorisating"?

Probably I am making a direct translation from my language and it is not correct. What I tried to say is the process to add some bass traps and panels in order to improve the acoustics of a room