Are dipoles better (40 – 1500Hz)? What’s the most important?

[rick57]

What do you think:

How many DIYers who've built a dipole have "gone back" to boxes (sealed/ vented/ TL)?

Also, What’s the most important part of the spectrum?
Whilst most of the music is in the mids, systems vary most in the quality of their bass, by a significant amount.

Agree/ disagree – examples . . .

[Nuuk]

I can't imagine returning to boxed speakers after dipoles although I am curious to try some horns one day.

Now I have my TL woofers working well with my open baffles, I am very satisfied with the sound that now goes down to 22 Hz (-3db)

I would suggest using the Ciare 250 'full-range' on its own at first. You can then decide if you want to add a tweeter (us a single cap for xover) and some woofers if you want to go real low.

I was going to use open baffle woofers (and may still do so) but the TL works well for me and I already had the drivers so it was a cheapo option. The only negative is the size of the box although placed behind the baffle, they are not visible from the listening position!

[Rudolf]

Are dipoles better (40 – 1500Hz)? What’s the most important?

As always: it depends

My dipole configuration consists of 3" fullrange drivers on OBs (12" wide) supported by 10" woofers in H-frames. X-over is active 18 dB at ~ 250 Hz.
Recently I put the fullrangers back in sealed boxes to re-gain that last bit of pinpoint imaging that got lost in the transition to the OBs. In return I had to give up some of the openness and depth of space that made me turn to dipoles in the first place. "Boxiness" hasn´t been an issue with the sealed boxes.

With the H-frames installed I have NEVER looked back to conventional (sub-)woofers. The advantages of the H-frame (no boominess, less roommodes excited) are too obvious to me to do without them. I might add a real (sealed) subwoofer below 50 Hz to get the pressure that I miss with the H-frames in some HT-movies.

My conclusion: In the complete range of distinct roommodes dipoles are indispensable to me. Up from there its a question of taste, preferences and in-room-situation whether dipole or monopole is preferable.

[rick57]

Rudolf

Fair assessment. As you’ve at least tried the same drivers in one part of the spectrum, what do you think of my ‘theory’ that whilst most of the music is in the midrange, systems vary more in the quality of their bass, and by a significant amount.

The follow on I believe is that if you're going to try dipole, consider dipole bass first.

And how did you avoid the boxiness with the sealed boxes?

Rudolf (or anyone)??

[johninCR]

Nuuk,

Beautiful work on those OB's. I do have a question though. It looks like you essentially have your main driver mounted in the center of a semi-circle baffle (unless there's something on the back that I can't see). Have you measured your speakers? I'm just wondering how big are the peaks and valleys in response with that driver positioning and baffle shape.

[Rudolf]

Originally posted by rick57
what do you think of my ‘theory’ that whilst most of the music is in the midrange, systems vary more in the quality of their bass, and by a significant amount.

My personal experience is totally in line with that. Before I changed to dipole bass, I was quite unaware how much quality bass could have. And how much bad boomy bass could veil a decent midrange. This experience made me also think again about the distribution of money along the bandwidth. My rule of thumb now is: Spend at least twice the money on woofers that you spend on mids and tweeters.

The follow on I believe is that if you're going to try dipole, consider dipole bass first.

At least the advantages of dipoles seem to be most prominent in bass IMHO. There is one caveat: Placement of dipole in room is quite different from placement of monopole bass. So if you just exchange one box for the other, you might be disappointed.

And how did you avoid the boxiness with the sealed boxes?

As I would say it: Boxiness is a function of low frequencies, high cone excursion (pressurizing) and vented systems. By releaving my small fullrangers from these "evils" (via high X-over), the usual provisions like rigid walls, golden ratio and quality stuffing were sufficient to let the boxes disappear.

[Nuuk]

It looks like you essentially have your main driver mounted in the center of a semi-circle baffle (unless there's something on the back that I can't see). Have you measured your speakers? I'm just wondering how big are the peaks and valleys in response with that driver positioning and baffle shape.

It's not easy to see in a photo but the glass panels are different widths, thus placing the main driver off-centre. I did some experimenting with a plain chipboard baffle prior to building the 'real thing'.

I have measured this system and it is remarkably flat from 22 Hz to 12K. That's with a basic RS digital sound level meter but my ears tell me there is nothing nasty there.

I agree with Rudolf. Dipole is most appropriate for bass but keep in mind that my main driver goes all the way down to 70 Hz.

I am currently writing up a 3-way active system on Decibel Dungeon. The original design used polystyrene enclosures for the midrange and tweeters. I bet that would work well with dipole bass! I believe polystyrene enclosures to be a good compromise between open baffles and closed boxes!

[rick57]

Nuuk

We look forwrd to further enlightening revelations, on your 3-way active system.

My sense is that about 50-500 Hz is where dipoles have a real advantage. I've heard the Orion and the mids were very very good, but not perhaps "in another league".

[Nuuk]

We look forwrd to further enlightening revelations, on your 3-way active system.

It's not my system. It was concieved by Christof Heinzerling, and details were published in Electronics World a couple of years ago.

I managed to contact Christof and he has given me permission to publish details on Decibel Dungeon.

[rick57]

Is Christof's system part dipole/ how far off is your posting at Decibel Dungeon?