fredbatch

When a hole in one isn't necessarily a good thing?

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Elsewhere, I've raised this issue before, but I'm still not really convinced I have a good answer.

Loudspeakers come in all shapes and sizes and in an ideal world, for the regular box type design, there is a commonly listed ideal combining:

1. Low bass extension
2. High efficiency
3. Small enclosure

But, reality intervenes and we can only choose any two out of the above three criteria at the expense of the remaining one shifting in the opposite direction.

Bass loading techniques come in several guises, but apart from the more unusual types (horn, transmission, isobaric, aperiodic...) the vast majority fall into two categories, namely reflex ported or sealed box.

For a long time it has seemed that reflex tuning rules the roost. Yet, despite their ability to better optimise the above three criteria, from a purist point of view there is a good argument that the closed box approach provides a better solution, or at least offers a valid alternative which is on a par. Closed box designs have a slower bass roll-off rate with a potentially better transient performance which avoids the resonance tail, eliminates port "chuffing" and provides a larger margin for error. It seems to be a case of quantity versus quality, in the crudest sense.

So, whilst I was waiting for the paint to dry, I explored a list of 100 contemporary designs. I'm sure it wasn't a perfect sample and I purposely ignored anything that wasn't reflex or closed box. Anyway, I was still surprised that 92% of the ones on this list opted for reflex ports of some description. 

It seems to me to be bewilderingly skewed?

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Super Dealer

Spec wars.

Keith

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Super Wammer

I have always preferred sealed enclosures, but the downside has always been lack of efficiency. But with the coming of age of class d amplification, and their copious amount of watts available, at real life prices, my active sealed enclosures have never sounded so good.

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23 minutes ago, greybeard said:

I have always preferred sealed enclosures, but the downside has always been lack of efficiency. But with the coming of age of class d amplification, and their copious amount of watts available, at real life prices, my active sealed enclosures have never sounded so good.

I would suggest that the important part is the 'active' bit.

The control that active drive brings to the bass driver is, for me crucial.

My own active speakers are very simple, two small chassis 5 inch drivers, 4 inch cones, each driven by 50 watt amplifiers. The drivers are in the same enclosure which has two rear facing ports, no idea what Adam have done but the integration of driver, enclosure and tuning is spot on.

For what is a pretty small speaker the bass is good down to 50hz, more importantly it is totally under control. On a lot of material, adding a sub is marginal at best. 

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Super Wammer
18 minutes ago, MGTOW said:

The control that active drive brings to the bass driver is, for me crucial.

Yes, when I changed to active speakers, it was the biggest improvement in SQ, that I have ever had, in this mad/wonderful, hobby of ours. I have not heard a pair of your speakers, but I have always enjoyed the Adam speakers I have.

Building my own speakers, I have always found sealed cabinets easier, and more forgiving to design, and put together, and the bass, although not necessarily the deepest, always sounds right to my ears.

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Yes, as Lindsayt says, it is disappointing.

I’m with Greybeard in personally preferring active closed box designs, but given the preponderance of high- powered amplifiers, especially the newer breed of compact class D types, I still don’t quite get why vented boxes are so much more popular as a concept when starting from a blank sheet.

Of course, there will always be varying degrees of success regarding different implementations, but that does not explain the skew I refer to. Maybe it is indeed down to a marketing/spec war.  I’m certainly not decrying vented boxes per se.

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Super Wammer
Posted (edited)

Ports certainly dominate today, just as sealed boxes did when I first got serious about Hi-Fi in the 1970s.  Whole ranges by KEF, AR, Wharfedale etc., were infinite baffle or acoustic suspension types.  Then ABRs came along - remember them?  Ports with an undriven cone in the way!  The KEF 104ab sticks in my mind, though I never liked them.

The trend for slim and tall boxes has surely been the biggest factor here?  Despite the lack of big diameter cones, two or three smaller woofers can still woof quite well if properly designed.  Plus they seem to take less effort to stop and start quickly, so can be more satisfying in a typical living room.  But I agree overall that sealed box roll off naturally seems to fit better with room reinforcement.  Another factor aside from looks was the availability of CD and now streaming as digital sources, whereas reflex designs and warped LPs didn’t sit well together.  

I was delighted with the crisp, articulate bass from my (sealed box) ATCs when I first heard them at home three years ago. And, yes, my ideal is the active version. I just need the money!

Edited by Nopiano

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12 hours ago, lindsayt said:

It's disappointing how many hi-fidelity speakers there are with low fidelity bass because they have small drivers in slimline ported boxes.

This has always been a gripe of mine. They try and find the smallest driver possible and whack it in a cabinet which looks like a horizontal floorstander. Then they say it's ideal for small rooms... err, no. Take the Kef R3 or any modern brand and they need substantial room to stop any flabbiness in the LFs. If they so ideal for small rooms why do they supply bungs? They might be slim in width but the depth is ridiculous.

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4 hours ago, Nopiano said:

Ports certainly dominate today, just as sealed boxes did when I first got serious about Hi-Fi in the 1970s.  Whole ranges by KEF, AR, Wharfedale etc., were infinite baffle or acoustic suspension types.  Then ABRs came along - remember them?  Ports with an undriven cone in the way!  The KEF 104ab sticks in my mind, though I never liked them.

The trend for slim and tall boxes has surely been the biggest factor here?  Despite the lack of big diameter cones, two or three smaller woofers can still woof quite well if properly designed.  Plus they seem to take less effort to stop and start quickly, so can be more satisfying in a typical living room.  But I agree overall that sealed box roll off naturally seems to fit better with room reinforcement.  Another factor aside from looks was the availability of CD and now streaming as digital sources, whereas reflex designs and warped LPs didn’t sit well together.  

I was delighted with the crisp, articulate bass from my (sealed box) ATCs when I first heard them at home three years ago. And, yes, my ideal is the active version. I just need the money!

Yes indeed, I remember the ABR “flapping baffles” and I agree with you with regard to the Kef 104’s which sounded slow and dynamically squashed to me when I was expecting something of a revelation, so the occasion sticks in my mind.

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Super Wammer

At the end of the day we get too hung up on the theory (of which there is no clear winner when you bring the compromise of room size and speaker size into play).

I avoided reflex enclosures in the 70s - they all had forward facing ports and you could hear them chuffing at times.  I chose the Gale GS401s a sealed box design of not massive proportions that had what I thought was a decent bass response UNTIL  I compared them against a transmission line (PRO9TL) and whilst the transmission line had its faults the overall satisfaction of the deep bass more than made up for it (very few records induce the dreaded drone).

Against both of these though were the electrostatics - which are bass light by comparison, even the Acoustat 4x which for many years was my dream loudspeaker but the type of room and room placement due to all that rear energy was a bridge too far.

As for active - yes you can induce the response you want from a smaller cabinet - but over many years I have yet to hear an active system that touched my soul .. that breathed out to me the emotion and feel (god i sound like a bloody reviewer) .. I was visiting a manufacturer who was working on a three way active design -  as an experiment they slotted a passive crossover into another pair to compare the two - and the passive ones  and the active models were ditched ..  Having said that I thought back to when I chose my Gale GS401s over Yamaha NS1000Ms .. so it could just be a personal preference - and yet we see lots of arguments and discussions about what is best.

The answer at the end of the day is to audition and let your ears decide what is best and stop worrying about what someone else might say :)  

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