Ported vs. Unported speakers

[playdough]

3 hours ago, davewantsmoore said:

but either could be designed to have insignificant distortion.

Thanks Dave

Numbers aside there is still the "actual  power required" factor.

Would have thought that the driver travelling less distance, using less power,  less convolution, provided design is sound, would measure less distortion ? Physics of linear distortion ? I know I'm not wrong, due to mechanical and electrical Theory.

 

Not necessarily regarding the last ported design I built, just I had the jpeg. photo measurement handy. Build dozens of enclosures of all types, some good some bad and some monumental. 

 

cheers

playdough

 

Oi, a photo for fun

Lack of linear distortion and the first watt is where it's at, that is what experience has made irrevocably clear .

Edited October 28, 2023 by playdough

[davewantsmoore]

4 hours ago, playdough said:

Numbers aside there is still the "actual  power required" factor.

Power is only a problem is you don't have enough... or the driver has hit it's limit.

 

4 hours ago, playdough said:

Would have thought that the driver travelling less distance

It's a lot less than half.

 

You could make it the same, by making the sealed box woofer larger, or the overall SPL target less (by 3 or 4dB or whatever).

 

It all just depends.

 

4 hours ago, playdough said:

using less power

As long as it isn't using problematic amounts of power... then it's no problem.

 

Where ported really comes into it, is if you have a budget for excursion, or power, or (maximising) SPL at some frequency , or all of them.... then a port might get you over the line.

 

4 hours ago, playdough said:

less convolution

If you mean EQ ... then this is not an advantage.... unless you do not have that capability, in which case a ported woofer can extend lower (flatter) than sealed.

 

4 hours ago, playdough said:

provided design is sound, would measure less distortion ?

In theory... for the same frequency response, a ported box would has less distortion due to less driver excursion and amplifier power.

But.

Is the port linear.  If not, then this distortion can be a problem
Can you design a sealed system where the excursion and amplifier power are both not causing distortion.  If so, then ported is "pointless".

 

4 hours ago, playdough said:

Physics of linear distortion ?

?

 

If the two boxes are calibrated to the same frequency response, and are not operated close to any other non-linearities... then they have identical linear distortion.

 

By above comments on "distortion" are on non-linear distortion.

 

4 hours ago, playdough said:

I know I'm not wrong, due to mechanical and electrical Theory.

<shrug>

I can't really tell, what you're saying isn't clear enough.

 

4 hours ago, playdough said:

Not necessarily regarding the last ported design I built

It was hard to tell from the limited data, but I suspect something was quite wrong.

 

4 hours ago, playdough said:

Lack of linear distortion

If a ported box and a sealed box are calibrated to the same frequency response..... heh.... I'm repeating myself.

 

4 hours ago, playdough said:

the first watt

If you do not have enough efficiency (power or excursion are too high) then things get bad quick.

 

Otherwise, I don't think "high efficiency" is a very good yardstick for anything much.

[davewantsmoore]

4 hours ago, playdough said:

photo for fun

Is the port not yet fitted?

[playdough]

1 minute ago, davewantsmoore said:

Is the port not yet fitted

Yea, if you are talking box above. That was as long as WinISD suggested for the volume/shape, outcome graph seems to support the Math. 

Took my time with that design as I sort of knew I was on a winner with the SIM

Have often thought of making an adaptor to make it 60 or so mm longer, for fun and measurements.

 

Doesn't chuff and a heck of a volume of air can move through it..Most accurate bass system I've ever heard and I've installed/set up/auditioned and work a Backline quite a lot, so it's a ridiculously honest statement.

You know very well exactly were they reside and you are welcome.

 

There is nothing wrong with the design and application, if that's what you elude to. Can operate it with 10w happily, proved that it made  (1 of a pair) 103 dB @20Hz would have to look ?.

 

I worked out the hole in the waterfall graph was room suck out, simple as that.

 

This L shaped room is getting better all the time, just effectively shortened the "L" in one direction by a meter and I've noted over the last few weeks of building, the room sound a little better. Will measure it again soon.

 

Enclosures before that were 4 x 35litre separate sealed boxes for 1000w 12" Alpine Subs. They liked EQ and 1000w each.

Next enclosure will be a Twin 15" JBL Clone, some 130 litres.

Got anything on the go Dave ? 

 

 

26 minutes ago, davewantsmoore said:

I don't think "high efficiency" is a very good yardstick for anything much

 

Everyone is entitled to their opinion. Mine is slightly misaligns with this statement and that's quite ok.

 Thanks for the information, you have helped cement some logic into the grey matter.

 

[playdough]

34 minutes ago, davewantsmoore said:

I suspect something was quite wrong.

Don't.  

[davewantsmoore]

3 hours ago, playdough said:

Yea, if you are talking box above. That was as long as WinISD suggested for the volume/shape, outcome graph seems to support the Math. 

So???..... Yes, the port is "yet to be fitted"

... or do you mean that picture is of the actual port?

 

3 hours ago, playdough said:

There is nothing wrong with the design and application, if that's what you elude to.

I worked out the hole in the waterfall graph was room suck out, simple as that.

I was going by the outside measurement you posted of it.

It would be too hard to tell anything based on an in-room measurement.

[GregWormald]

My first set of speakers were unported (AR2ax) and since then all but one pair have been unported. I never considered whether or not the speakers were ported but how they sounded to me given the cost.

[playdough]

1 minute ago, davewantsmoore said:

So???..... Yes, the port is "yet to be fitted"

Hi Dave sorry, yes when tested the calculated port length was installed, very carefully  the build was nerve wracking, there was a lot of time in design/coin (a month full time +) in all those sheets of ply and drivers, grills  travel dollies and rain covers. 

All I'm trying to suggest not so clearly obviously, sorry, is that,

 

There will be 2 Teams, one will be the high efficiency brigade with giant vented/horn type speakers, purely analogue, valves, TT's a lot of very cool stuff, they have their reasons

 

The other team, the Tech everything DSP multiamp . Impulse time correcting Crew with in a lot of cases more friendly WAF speakers, sealed bass, much more power. Hi Tech wonders

 

 

Nothing wrong with either, love them all.

.

 

 

 

[davewantsmoore]

11 hours ago, playdough said:

a photo for fun

What woofers are they?  (I had assumed they were Celestion... but maybe not)

Edited October 28, 2023 by davewantsmoore

[POV]

On 27/10/2023 at 10:07 PM, LogicprObe said:

 

I have speakers with ports and speakers without them.

 

I prefer them without.

Do you mean the same speaker from the same designer with a ported and a sealed enclosure design or are you comparing different speakers?

[POV]

On 27/10/2023 at 8:01 AM, Keith_W said:

Alan Langford (from DEQX, at the SNA show): "no speakers should have ports! Ports create more issues than they solve. You get different problems with unported speakers, but they are less position dependent and you can solve those issues with subwoofers or with DSP". Another attendee: "but 80% of speakers have ports". Alan: "that's why 80% of speakers are awful". 

 

I agree with him. I don't like ported speakers myself, for the same reasons. 

 

Discuss. 

I get where Alan is coming from, but if he indeed said that 80% of speakers are awful that’s a pretty stupid comment (will give him benefit of doubt that maybe it was a throwaway comment)

 

I can name a bunch of ported speakers that are measurably and subjectively excellent in room and produce a fantastic musical experience.  I’d be happy to demonstrate to Alan what a first rate ported speaker system enhanced with DIRAC Live sounds like (and it sounds superior to me to anything I have heard running DEQX be it ported, sealed, or isobaric)

 

 

Edited October 29, 2023 by POV

[Ittaku]

It's never a question of technology, but implementation.

[playdough]

12 hours ago, davewantsmoore said:

What woofers are they?  (I had assumed they were Celestion... but maybe not)

I didn't know, so pulled one out. Big thing with a fair chunk of neodymium on the back, 100mm+coil, now get it back in it's hole.. The last few years  I've lost part of my speaker build  library of work so, hopefully find the Small Parameters of the driver and backward engineer it.

[VanArn]

      An easy to find specification sheet    p-audio.co.uk/pdf/SD21_1800N.pdf   . The SD21 suits a B4 alignment with an approx.  240 litre enclosure after allowing for all solid parts.

Edited October 29, 2023 by VanArn

[stereo coffee]

42 minutes ago, Ittaku said:

It's never a question of technology, but implementation.

But at the same time incomplete or misguided by not being sufficiently observant technology exists as well , depending on what and how much is chosen to be missed, and rolled out , when had closer inspection of thoughtful choice,  been given time to develop.

 

if one wishes,, and freedom exists,  one can be subjective about objective choices, and be seen as charmingly  discerning , which IMO always leads to a better product.

 

[playdough]

19 minutes ago, VanArn said:

      An easy to find specification sheet    p-audio.co.uk/pdf/SD21_1800N.pdf   . The SD21 suits a B4 alignment with an approx.  240 litre enclosure after allowing for all solid parts.

Yea, cheers, a day of re-discovery  have to re measure the enclosures now. I'm remembering 650 litres for a pair, have a pair of enclosures..

1800 wrms, ridiculously efficient all round good driver, bit of over kill. 1mm excursion is well enough in room.

 

SD21_1800N.pdf

Edited October 29, 2023 by playdough

[POV]

23 minutes ago, stereo coffee said:

But at the same time incomplete or misguided by not being sufficiently observant technology exists as well , depending on what and how much is chosen to be missed, and rolled out , when had closer inspection of thoughtful choice,  been given time to develop.

 

if one wishes,, and freedom exists,  one can be subjective about objective choices, and be seen as charmingly  discerning , which IMO always leads to a better product.

 

I have literally no idea what you are saying here.   

[Addicted to music]

41 minutes ago, playdough said:

Yea, cheers, a day of re-discovery  have to re measure the enclosures now. I'm remembering 650 litres for a pair, have a pair of enclosures..

1800 wrms, ridiculously efficient all round good driver, bit of over kill. 1mm excursion is well enough in room.

 

SD21_1800N.pdf 143.34 kB · 6 downloads

off topic,

 

what was the factor in attaining this driver?

 

Reason I asked is because the advantage of deploying square wires in the voice coil and the way the voice coil is structured and implemented gives it such power handling…..  absolutely brilliantly implemented…..

 

https://www.goto-denshi.com/product-square-wire-melit.html

 

 

[MattyW]

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.
 

On 28/10/2023 at 10:32 AM, playdough said:

Lack of linear distortion and the first watt is where it's at, that is what experience has made irrevocably clear .

Hear hear.

Edited October 29, 2023 by MattyW

[playdough]

5 hours ago, Addicted to music said:

what was the factor in attaining this driver ?

Hi

I was after a HiFi quality, highly efficient speaker that would cover subsonic to 200Hz, for several HF multiway horn speakers I like to play. A true utilitarian bass unit can be used w/o EQ, eliminates a lot of problems in that frequency range, tiny power amp friendly. It likes 24dB slope or greater filter. Got a bit out of hand (the job) however, the drivers looked smaller in the pictures.

Hi Tech, modern driver, plays specifically in Ported Enclosures. 

I like ugly speakers, fatter the better.  

 

Edited October 29, 2023 by playdough

[playdough]

1 hour ago, MattyW said:

low wattage class A amplification

Such a beautiful rig, wow. 

[davewantsmoore]

3 hours ago, playdough said:

pulled one out

Cool.

What's the approximate size/depth of the ports.  Looks something like 50cm wide, 15cm tall, 10cm deep..... but I might be a long way off

 

[MattyW]

22 minutes ago, playdough said:

Such a beautiful rig, wow. 

My wife doesn’t like things loud so the system is typically played at extremely low volume levels. Well under conversation levels actually. I’ve found crossovers are typically detrimental to low volume playback, and high efficiency drivers seem to let more through on average also. The system still sounds great at higher levels though I can only do that when my wife is out.

 

Low mass sockets and connections seem to help where possible also. I dare say hard wired would be even better though that’s just too inconvenient.

 

As for beauty….. I need a bigger room as I think it all looks a bit crowded currently. Seeing an architect next week for a new build. Hopefully I can take care of that. Dedicated power circuits and network cabling throughout should help further also.
 

I think overall the system would look nicer with a tube integrated and possible sound just a touch better too…. Except my wife and child use this system. Not uncommon for it to be left turned on for 8 hours with nothing playing and cathode poisoning of quality tubes…… Well, expensive to replace. I’ll keep tubes for systems they’re not using only.

 

That said the build will take time so I’m almost more excited about the new car I have coming in February. I’m not great waiting.

Edited October 29, 2023 by MattyW

[Keith_W]

4 hours ago, POV said:

I’d be happy to demonstrate to Alan what a first rate ported speaker system enhanced with DIRAC Live sounds like (and it sounds superior to me to anything I have heard running DEQX be it ported, sealed, or isobaric)

 

What speaker do you have in mind? 

[playdough]

15 minutes ago, MattyW said:

Well under conversation levels actually. I’ve found crossovers are typically detrimental to low volume playback, and high efficiency drivers seem to let more through on average also.

Interesting, I went DSP for those reasons, for the bass in particular. Quite a lot better at low level, brought out the good things about high efficiency bass. Low frequency extension in particular, really brought the goods.

 

Quite the plan ahead with the build, keep us posted and good luck with the new car ! 

Patients, all good things come to those that work 

Edited October 29, 2023 by playdough