My tactics for improving vintage 3 way open baffles

Bumpy · « **Reply #40 on:** 10 Dec 2018, 12:40 pm »

This is an idea I hold in my mind for future reference. Anyone tried anything like this?

mcgsxr · « **Reply #41 on:** 10 Dec 2018, 12:49 pm »

I have heard the Mirage line of omni directional speakers that use a tweeter positioned over the woofer with a ball like that directly above the tweeter.

They did a great job of a diffuse soundstage in my room. Good friend of mine owns them.

matevana · « **Reply #42 on:** 10 Dec 2018, 02:58 pm »

The German loudspeaker company Duevel was one of the first to promote this idea with their Planets speaker:

They also have some pretty interesting ways to address omnidirectional dispersion. They use high efficiency pro sound compression drivers for the mids/highs in both up and down firing configurations.

Bumpy · « **Reply #43 on:** 18 Dec 2018, 09:16 am »

I was sitting listening to my open baffles last night reflecting that despite playing the music at a reasonable volume I cant see the mid range drivers cone moving at all.

I can feel the vibrations in the driver's cone, but visually you would not know it was on. Its a new driver and is reckoned to take up to 200 hours to run in properly in a box where I guess the cone and suspension will move about more. I know there are ways to run the drivers in more rapidly buy I am enjoying the ride.

Has anyone else noticed this phenomenon?

FullRangeMan · « **Reply #44 on:** 18 Dec 2018, 09:28 am »

Most vintage FR drivers have XMAX 1mm, the Audio Nirvanas being a old recipe drivers also have Xmax around 1mm, some has less, same as Alpair, but I already see Xmax around 3mm in FR usually in pro audio.

If it have a large Xmax it can be a woofer or midrange.

Bumpy · « **Reply #45 on:** 18 Dec 2018, 04:11 pm »

Quote from: FullRangeMan on 18 Dec 2018, 09:28 am

Most vintage FR drivers have XMAX 1mm, the Audio Nirvanas being a old recipe drivers also have Xmax around 1mm, some has less, same as Alpair, but I already see Xmax around 3mm in FR usually in pro audio.

If it have a large Xmax it can be a woofer or midrange.

These SEAS Exotic 8" have a 6mm linear p-p and I'm just impressed that they make such lovely music without moving

mcgsxr · « **Reply #46 on:** 18 Dec 2018, 05:05 pm »

The Visaton b200's I used for a decade on OB had a similar PP XMAX (~6-7mm) and the only time I really saw them move much was when they were asked to play below 100Hz.

Where do you Xover your SEAS drivers? Lovely pieces by the way.

Bumpy · « **Reply #47 on:** 18 Dec 2018, 07:02 pm »

Quote from: mcgsxr on 18 Dec 2018, 05:05 pm

The Visaton b200's I used for a decade on OB had a similar PP XMAX (~6-7mm) and the only time I really saw them move much was when they were asked to play below 100Hz.

Where do you Xover your SEAS drivers? Lovely pieces by the way.

Trying to run it as wide as possible so crossing over to the Altec 416 15" bass at 6-700 Hz and to the Saba Greencone dipole tweeter at 6-7 Khz.

JohnR · « **Reply #48 on:** 18 Dec 2018, 07:15 pm »

Well, driver excursion increases by 4 times every time you halve the frequency, or conversely decreases by 4 times for each doubling of frequency. So for example at 640 Hz you would have 1/64th as much excursion as you would at 80.

Bumpy · « **Reply #49 on:** 19 Dec 2018, 08:50 am »

Quote from: JohnR on 18 Dec 2018, 07:15 pm

Well, driver excursion increases by 4 times every time you halve the frequency, or conversely decreases by 4 times for each doubling of frequency. So for example at 640 Hz you would have 1/64th as much excursion as you would at 80.

Now there's something I didn't know.

FullRangeMan · « **Reply #50 on:** 19 Dec 2018, 09:59 am »

Quote from: Bumpy on 18 Dec 2018, 04:11 pm

These SEAS Exotic 8" have a 6mm linear p-p and I'm just impressed that they make such lovely music without moving

Please note these Seas FR dont follow the vintage old school which use accordion, conex or Fabric cloth surrounds, they use rubber as AER so they offer a different sound quality.

matevana · « **Reply #51 on:** 19 Dec 2018, 12:33 pm »

Quote from: Bumpy on 18 Dec 2018, 09:16 am

Its a new driver and is reckoned to take up to 200 hours to run in properly in a box where I guess the cone and suspension will move about more.

I've found that drivers move around more in OB, followed by a ported enclosure, and lastly a sealed enclosure. Probably b/c there is no 'slug of air' (spring effect) that acoustically dampens the driver, something that a boxed enclosure might otherwise provide. The high-ish crossover would explain why you see no real movement, as John mentions.

Have you listened to the Seas w/o a crossover?

Bumpy · « **Reply #52 on:** 19 Dec 2018, 01:39 pm »

Quote from: matevana on 19 Dec 2018, 12:33 pm

Have you listened to the Seas w/o a crossover?

Nope, but that's something I plan to try now it is beginning to run in.

Firstly running the SEAS full range on its own.
Secondly adding just the Saba tweeter to judge the impact - remember I specified the SEAS has no whizzer.
Thirdly adding just the Altec 15"

I should learn a lot from those experiments

matevana · « **Reply #53 on:** 19 Dec 2018, 05:57 pm »

Cool! I'd like to hear your listening impressions.

Bumpy · « **Reply #54 on:** 20 Dec 2018, 09:30 am »

SEAS Exotic on its own

Great speaker and great sound with no nasties or raggedness but boy did I miss the frequency extremes. Ultimately after an evenings listening I decided I could not live without the other frequencies any longer, nothing underpinning the presentation, a lack of air, and reduced imaging.

But on the plus side I now have a good idea of the frequencies that a good 8" driver is capable of in this environment and why 3 ways make sense

Next because, its easy to do, I will play just the bass and tweeter together to get a measure of the 'hole in the middle'

Of note, is that the SEAS driver still did not move to any great extent. Not sure what that is telling me, perhaps its just the way it is, or perhaps its a long way from being run in when I guess the suspension will breath more easily.

matevana · « **Reply #55 on:** 20 Dec 2018, 12:01 pm »

Good to know. I forgot you are working with the X2, which is sort of the woofer version of the full range X1. It's always good to listen to drivers on their own, so you can better appreciate what you are working with.

Bumpy · « **Reply #56 on:** 20 Dec 2018, 12:39 pm »

Quote from: matevana on 20 Dec 2018, 12:01 pm

Good to know. I forgot you are working with the X2, which is sort of the woofer version of the full range X1. It's always good to listen to drivers on their own, so you can better appreciate what you are working with.

Yes having owned various Lowthers and listened to other whizzer drivers. I did not want to go down that route. If the HFs are not to your liking you have to dump the whole thing, also the whizzer has moving mass and must influence the midrange a bit.

Bumpy · « **Reply #57 on:** 21 Dec 2018, 10:33 am »

Could a moderator please merge this thread with my other thread entitled "My tactics for improving vintage 3 way open baffles"

Just like my office desk I have stuff everywhere

Thanks for the merge

Bumpy · « **Reply #58 on:** 24 Dec 2018, 01:17 pm »

Experiment to play music with the mid range driver disconnected. Crossovers at 650Hz and 6.5KHz

Never tried this before so I was not sure what I really expected to get from this, but I guess my real intention was to see how much 'room' was left in the centre frequencies to accommodate the mid range driver. Attached is a You Tube video of the resultant sound played at typical listening volume. Here are my conclusions and I would be interested to hear what you think.

1. The female voices seem to push a long way down from the tweeter. (Saba 4")
2. The male voices seem to push a long way up from the bass driver (Altec 416 15")
3. The bass driver seems articulate and musical but missing a bit of impact - perhaps an open box on the back might be an idea.

https://www.youtube.com/watch?v=LQzmF8I8TPo&feature=youtu.be

FullRangeMan · « **Reply #59 on:** 24 Dec 2018, 02:18 pm »

Great experiment, the resulting are impressing, I would like to put a 10 or 12 inches for midrange this this OB speaker to see the results.