Ported vs. Unported speakers

[playdough]

23 minutes ago, davewantsmoore said:

size/depth of the ports

137mm high x

366mm wide x 

118mm deep

chamfered inside the enclosure. 

tuned for 27Hz ? can't remember. Tuning  was lower than the Fs of the driver which concerned me during the build, came out ok though.

 

 

[davewantsmoore]

26 minutes ago, playdough said:

that would cover transonic to 200Hz

 

Right.   It's all starting to make more sense now (the data you sent me, etc.... where there's a 30dB of very low frequencies missing)

 

 

The port dimensions is about correct at a rough guess..... I just assumed it was wrong, because I assumed the driver/box was good for "infrasonic", like you said.... and in that case it would need to be much bigger.

 

With the cabinet you have (which is roughly close enough to "ideal" at a quick sim), the SPL is about 20dB down at 20Hz, and 40dB down at 10Hz...... which is why (derrrr @ me) the measurements you sent me had roughly this amount of bass missing too.

 

My brain just went charging off down the path of "well it should make bass to really low frequencies because it's a huge woofer" ...... and ended up with "well the port must be wrong", or you "just need to EQ the bass back"..... but it was wrong for me to think that.

[davewantsmoore]

11 minutes ago, playdough said:

tuned for 27Hz ? can't remember.

Yep, 27-29 ish with those vent dimensions.

 

[playdough]

5 hours ago, davewantsmoore said:

this amount of bass missing too

A little DSP, room load,  can do wonders.

Will get back into speaker builds, have a kitchen to build first.

THanks for the prompts over time to get this mystery sorted, a lot of fond memories coming back. 

Cheers

On with the Ported vrs Sealed discussion.

 

All good except for the 50Hz room suckout, still working on that, it's not audible narrow Q 

Edit, would I run them sealed, no, they are not designed for it and there is something magical about ported bass, done right. 

Will get this one right,  just need time, still building the room, no time for tweaking, yet.

Edited October 29, 2023 by playdough

[POV]

4 hours ago, MattyW said:

Fantastic bass from these and none of the phase issues associated with a crossover. Exceptionally transparent with excellent performance right across the frequency range. Course at 103db efficient it’s really only well suited to low wattage amplification and each speaker is the size of a refrigerator so not suited to many people but perfect for me. Does right in with my low gain, low wattage class A amplification approach to great sonics.

 

 

Generalisations never work out well…. Though I’ve been guilty of it plenty of times also.

 

That’s a 75” Sony TV for reference. Speakers have front ports tuned to 30Hz. Front ports mean it doesn’t interact with the front wall like rear ported speakers which is important for speaker cabinets of this size.

 

Utilises Lii Song Platinum-10 drivers (click here), Mundorf Angelique CAW solid core copper/silver/gold allow wire and low mass gold plated copper EIZZ EZ301 binding posts and some very thick birch plywood construction with jarrah veneer all round. Performance is limited by the electronics up front only.
 

Hear hear.

 

That's really quite a unique system you have built there.  Would love to hear it some time.  

[POV]

2 hours ago, Keith_W said:

 

What speaker do you have in mind? 

 

Well...I have quite a few options.  My preferred ported speakers are VAF i93 crossed over at 60hz  (24 dB slope) to dual (soon to be quad) SVS SB-16 Ultras.  But I also have a pair of KEF R5 Metas, and even a pair of R3 Metas all which EQ up beautifully in my room.  

 

More broadly, I'm just curious why an industry professional would say something so foolish, and would like to discuss it with him.  Tell him the red wine is on me

 

Edit:  as an additional thought, I wonder if he has considered that many modern systems deploying ported speakers are also utilising subwoofers crossed over above the port tuning frequency?

 

Edit 2:  If he's one of thos philistines that doesn't appreciate the majesty of South Australian red wine then he's **** out of luck and will have to BYO.

Edited October 29, 2023 by POV

[andyr]

44 minutes ago, POV said:

Well...I have quite a few options.  My preferred ported speakers are VAF i93 crossed over at 60hz  (24 dB slope) to dual (soon to be quad) SVS SB-16 Ultras.

 

Given you have these SVS subs ... maybe you need to try dipole spkrs - to understand why ports really aren't a good idea?    Likewise, sealed boxes have their problems.

 

44 minutes ago, POV said:

More broadly, I'm just curious why an industry professional would say something so foolish,

 

Why - I've heard foolish things said by other "industry professionals" here!    Alan's comment is not an outlier, IMO.

 

44 minutes ago, POV said:

Edit:  as an additional thought, I wonder if he has considered that many modern systems deploying ported speakers are also utilising subwoofers crossed over above the port tuning frequency?

 

Your wording is not precise enough, Drew!

 

Do you mean:

 

1.  the subs roll-off at a frequ which is above the port tuning frequency ... and the mains are rolled off at that same frequency?

 

Shirley, this takes the port out of the equation - the mains are acting as sealed boxes?

 

2.  or the mains are not rolled off at all?  Why on earth would you want to do that - when it means there is a band of (low) frequencies which are being shared by the ported mains and the subs.  Why not simply save your amplifier power by rolling off the mains, to match the subs?

 

[POV]

6 minutes ago, andyr said:

Given you have these SVS subs ... maybe you need to try dipole spkrs - to understand why ports really aren't a good idea?    Likewise, sealed boxes have their problems.

 

I've heard a few very nice di-pole systems Andy, but my experience to date is that they tend to fall apart with heavier and busier music and since I tend to mostly listen to prog, metal, industrial, and electronica not sure they are for me.  Happy to be schooled by someone though if my observations are not right as I have very limited experience with di-poles.

 

9 minutes ago, andyr said:

Why - I've heard foolish things said by other "industry professionals" here!    Alan's comment is not an outlier, IMO.

 

Possibly so, but then they too should be questioned.  Sorry but I think it's totally ludicrous to describe 80% of the speaker market as 'awful'.

 

10 minutes ago, andyr said:

Your wording is not precise enough, Drew!

 

Do you mean:

 

1.  the subs roll-off at a frequ which is above the port tuning frequency ... and the mains are rolled off at that same frequency?

 

Shirley, this takes the port out of the equation - the mains are acting as sealed boxes?

 

2.  or the mains are not rolled off at all?  Why on earth would you want to do that - when it means there is a band of (low) frequencies which are being shared by the ported mains and the subs.  Why not simply save your amplifier power by rolling off the mains, to match the subs?

 

 

Sorry, I meant that the mains are crossed over to the subs at a frequency above the tuning frequency of the ports.  It's not entirely correct though to say that this makes the speaker act as a sealed enclosure, it depends on the design and poor designs (which is what I think that Alan was probably referring to) leak mid and high frequency energy which obviously wouldn't (couldn't) happen with a selaed enclosure.

[andyr]

10 minutes ago, POV said:

I've heard a few very nice di-pole systems Andy, but my experience to date is that they tend to fall apart with heavier and busier music and since I tend to mostly listen to prog, metal, industrial, and electronica not sure they are for me.

 

I would certainly agree with you that Maggies & electrostatics are not good at those types of noise (just kidding - I listen to electronic music, too!   ) ... but I would have thought cone-driver dipoles would be able to present it well?

 

If you plan to visit Melbourne ... bring a couple of those LPs over (or bring the files on a USB stick) and have a listen on my cone-based dipole system.  

 

10 minutes ago, POV said:

Sorry, I meant that the mains are crossed over to the subs at a frequency above the tuning frequency of the ports.

 

Do you mean by this that there is a HP filter on the mains ... at the frequency of the subs' LP roll-off?

 

2 hours ago, POV said:

It's not entirely correct though to say that this makes the speaker act as a sealed enclosure, it depends on the design and poor designs (which is what I think that Alan was probably referring to) leak mid and high frequency energy

 

That's true, Drew.  But if there is a minimum 24dB HP & LP slope (better 48db!) between the mains and the subs ... I don't see how the mains can "leak mid and high frequency energy"???

 

[Grizaudio]

IMHO…. You can’t beat a well implemented compression driver/waveguide + 12/15inch bass driver for electronic music, or for that matter any music. 

Edited October 29, 2023 by Grizaudio

[POV]

12 hours ago, andyr said:

I would certainly agree with you that Maggies & electrostatics are not good at those types of noise (just kidding - I listen to electronic music, too!   ) ... but I would have thought cone-driver dipoles would be able to present it well?

 

If you plan to visit Melbourne ... bring a couple of those LPs over (or bring the files on a USB stick) and have a listen on my cone-based dipole system.  

 

Thanks...would definitely be keen.

 

12 hours ago, andyr said:

Do you mean by this that there is a HP filter on the mains ... at the frequency of the subs' LP roll-off?

 

Yes that's what I mean.

 

12 hours ago, andyr said:

That's true, Drew.  But if there is a minimum 24dB HP & LP slope (better 48db!) between the mains and the subs ... I don't see how the mains can "leak mid and high frequency energy"???

 

Well it depends on the design of the speaker, but if it's an open box then radiated energy from mid range driver and tweeter can leak from the port.  This is well and truly above the high pass filter frequency so the crossover is not relevant.

[cheekyboy]

Hello folks, an interesting thread this and my thoughts on bass reflex enclosures are that they can sound superb, but need to be correctly designed and implemented, which is a more difficult task compared to a sealed enclosure.

 

I currently have three different systems playing largely into the same space and the loudspeakers are all different design types, being bass reflex, sealed and transmission line. I enjoy all three types of loudspeakers and each has their own strengths, but I do find myself listening more often to the sealed 2 ways, which have the bass augmented with two 10” sealed subs. I feel this slight preference for these loudspeakers is because of the tonal quality of the sealed 2 ways more than anything else, but it has nothing to do with any perceived preference for sealed enclosures over bass reflex or transmission line for that matter.

 

Cheers,

 

Keith

[Grizaudio]

I have always gravitated to large ported floorstanding designs for dynamics and what I perceive to be a more natural sound. 

But just for fun, I'll be DIY'ing an all sealed design. 

 

The design will be all active, with DSP delivered via CamillaDSP. I already have the top section drivers in hand, I'll be in search of the bass drivers shortly.

 

HF/Mid: 12inch Seos waveguide, B&C de250

Mid Bass: Faital 12pr300 sealed

Bass: Sealed Perhaps Dual lower 15inch (or dual 12's per side).

 

 

 

 

  

 

 

Edited October 30, 2023 by Grizaudio

[MattyW]

4 minutes ago, Grizaudio said:

I have always gravitated to large ported floorstanding designs for dynamics... I always found ported designs to be more my cup of tea... I just found them to sound more natural. 

But just for fun, I'll be DIY'ing an all sealed design. 

 

The design will be all active, with DSP delivered via CamillaDSP. I already have the top section drivers in hand, I'll be in search of the bass drivers shortly.

 

HF/Mid: 12inch Seos waveguide, B&C de250

Mid Bass: Faital 12pr300 sealed

Bass: Sealed Perhaps Dual lower 15inch (or dual 12's per side).

I hope I see the thread about this. Should be an interesting read.

 

For me though the best I've heard in no particular order are:

 

• open baffle
• front loaded horns
• back loaded horns
• large single driver ported

 

I've not been lucky enough to hear Mike Lenehans latest and greatest though everything I've read indicates they're rather special.

 

Though yeah.... A few different types there so I guess I just like any well engineered speaker. For my main system though I stick with high efficiency single driver designs though. Matches better with my components.

Edited October 30, 2023 by MattyW

[POV]

I do wonder if musical preferences contribute to preferred speaker cabinets, or if there is any correlation between the two.

[Satanica]

15 minutes ago, POV said:

I do wonder if musical preferences contribute to preferred speaker cabinets, or if there is any correlation between the two.

I think the biggest correlation would be the general frequency response differences.
That being more often than not ported speakers will provide more and deeper bass.

So, how could this ever be bad?
When the room causes detriment i.e, pretty much in every scenario.

With it (the room) adding too much overall bass on top of ported speakers, causing more dreaded slow-thumping sound than if they were sealed.

So, my current opinion is that ported speakers, especially larger more bass capable ones probably need more bass rectification in room i.e equalisation and possibly treatment where possible.

Edited October 30, 2023 by Satanica

[stereo coffee]

19 minutes ago, Satanica said:

So, my current opinion is that ported speakers, especially larger more bass capable ones probably need more bass rectification in room i.e equalisation and possibly treatment where possible.

Whereas a acoustic suspension type, can very likely use a smaller cabinet , and reproduce bass without such equalization or treatment.

[Satanica]

3 minutes ago, stereo coffee said:

Whereas a acoustic suspension type, can very likely use a smaller cabinet , and reproduce bass without such equalization or treatment.

 

No.

[muon*]

I don't have a preference, I like what sounds best to me in my system and that seems to be well designed ported.

 

There are thousands of speakers I have not heard.

[MattyW]

20 minutes ago, muon* said:

I don't have a preference, I like what sounds best to me in my system and that seems to be well designed ported.

 

There are thousands of speakers I have not heard.

 

Given how many have been made since speakers were invented.... The figure may even exceed a million 

 

I know, I'm being facetious.

[POV]

I was just thinking how many speakers I've heard in my life and considering how tiny a percentage that would be of all the speakers ever designed and built across history.  

[playdough]

Some more reading along the same vein, with an unbiased conclusion echoed here in the thread.

https://boomspeaker.com/bass-reflex-vs-acoustic-suspension/

[playdough]

13 minutes ago, POV said:

I was just thinking how many speakers I've heard in my life and considering how tiny a percentage that would be of all the speakers ever designed and built across history.  

I remember building a sealed speaker (a single 8") into a piece of sewer pipe (12"dia) thought it was a good idea being correct volume but was a total dud, just didn't "have the goods". Played with it for a day trying to fix it to no avail. Scrapped the pipe, made the right sized box and yea, fixed. Was surprised about that, never made a pipe enclosure again either. .

So yes there are bad speaker designs, definitely.

Careful purchase is mandatory.

EDIT, the fear of ending up building a dud is quite real with every job, not an easy thing to build...

Edited October 30, 2023 by playdough

[playdough]

19 hours ago, Grizaudio said:

You can’t beat a well implemented compression driver/waveguide + 12/15inch

Agree, indeed leaning in that direction as I get older. Waveguides laying about here mainly JBL Pro. Use of pairs of drivers for bass to me is preferable as there is a free 3dB in the acoustic coupling of the 2 drivers.,

Edited October 30, 2023 by playdough

[Grizaudio]

50 minutes ago, playdough said:

Agree, indeed leaning in that direction as I get older. Waveguides laying about here mainly JBL Pro.

 

Difficult to beat... 

I actually don't think the ported vs sealed discussion is really that big of a deal. 

IMHO, directivity, or uniform directivity is probably far more important in the overall scheme of things.  I.e. what's happening above Schroeder. 

 

2 hours ago, Satanica said:

With it (the room) adding too much overall bass on top of ported speakers, causing more dreaded slow-thumping sound than if they were sealed.

So, my current opinion is that ported speakers, especially larger more bass capable ones probably need more bass rectification in room i.e equalisation and possibly treatment where possible.

 

I disagree with this statement. Its an opinion and generalisation. 

I use very large ported bass drivers in a small room and the setup requires minimal Bass EQ to hit Harman/preferred targets. 

Every room is going to behave differently. 

 

In any event, using software or hardware to equalise the delta (sealed v's ported) is not a concern. 

Edited October 30, 2023 by Grizaudio