A full range speaker?

william53b OP166 posts08-05-2021 11:35amVery nice.
I like Seas drivers as well, but also Eton Symphony’s, and Scan Speak Revelators.

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Troel Gravesen uses both Eton and scan's, both excellent speakers,,
Here is my brief biase and heavy prejudiced review of the build on the DL 6.5 which just arrived, Tech is out of shop, so a  listen will have to wait til tomorrow .


I did say BIASEd and PRE-judiced.
https://www.youtube.com/watch?v=YAFNVCXk93Y

Concentric vs
Single driver
Whizzer AND
Phase Plugs

Whizzer cones have an effect, a lot lower than 7Khz. If you compare the response of the speaker with and without the whizzer cone, not just the frequencies where the whizzer is the sole source of sound.

An 8" driver with 160mm cone and 80mm horn shaped whizzer with and without whizzer, was tested. They found the whizzer cone starts to have a large effect on the off axis response as low as 2.5Khz.

Specifically the presence of the whizzer cone reduced the on axis response from 2.5Khz to about 6Khz by nearly 3dB, but increased the (30 degree) off axis response by several dB. The dispersion between 2.5Khz and 6Khz was greatly improved at the expense of -1db loss of on axis response.

On axis response without the whizzer actually had a +3dB shelf from 2.5Khz to 6Khz, which suggests the main cone of the driver was designed with an increased output in this range (a slight convexed taper)  so the response was balanced once the whizzer was placed.

Above 7Khz the response of the single main cone by itself disappears. At 7Khz the output is almost entirely the whizzer cone.

So technically the whizzer is only acting as a second separate cone above 7Khz, but between 2.5Khz and 7Khz it is still acting as a source of sound as well as a directivity modifier for the main cone.

The improvement in dispersion is so great that at 4Khz without whizzer cone the 30 degree off axis response was -9dB with on axis response (severe beaming). With the whizzer cone in place the 30 degree off axis response at 4Khz was only -1.8dB from the on axis response...

Now think concentric driver with a whizzer for better off axis and phase plug for back wave distortion reduction.

My question is can you still keep the acoustic center of the two drivers and use the correct phase plug to stop the back wave (BASS), from the rear/side walls first reflection.

Hypothetically the HF driver would have to be set inside the phase plug or Open Baffle the HF driver backwards.. (I’ve seen that).. and it works if the rest of the driver system is in a box, bipoled the opposite direction.
(I haven’t seen that)

What I’ve seen and herd though was BOTH sides of the driver were in an open baffle. So it was dipole for the bass and bipole for the HF driver (it had it’s own chamber) and it was facing the front wall..
A nightmare to get the timing right.

The acoustic center only stay aligned, IF the driver and structure are placed in a chamber, I don’t think you could get it to work correctly in a listening room. Maybe.. within 1/2" to get it right..

3 years I worked with the old GRs at a buddies.. 90s. (Super Wedge or something).

He gave up.. I didn’t have much of a choice.

Regards

Now think concentric driver with a whizzer for better off axis and phase plug for back wave distortion reduction.

My question is can you still keep the acoustic center of the two drivers and use the correct phase plug to stop the back wave (BASS), from the rear/side walls first reflection.

Hypothetically the HF driver would have to be set inside the phase plug or Open Baffle the HF driver backwards.. (I’ve seen that).. and it works if the rest of the driver system is in a box, bipoled the opposite direction.
(I haven’t seen that)


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Wayyy over my head, 
btw what is 
~~~HF~~~

I really have no idea what you are descriving.
Anyway. My DavidLouis 6.5 whizzer wide band just arrived , Up N running. 
Very nice gain over the DL4 incher wide band.
Added some bass, , mids are claener, highs not rolled off. = A WINNER.
$450 includes ship
 The Crescendo/Seas wasa HUGEEEE disappointment, Seas claims 92db, My tech hook it to his sens gadget,, maybe 85db, when i hooked it up to a  Mundorf 2.2 Supreme cap,,I COULD HARDLY HEAR IT ,, I;d say its more like 83db,,which means I have to ship it off to madisound for testing,, No way seas would lie.. We will find  out if something is wrong,,Bought it as new off ebay auction,

Anyway,,I'd say this DL 6.5 is the very best wide band in production
versus\
Fesatrex, 
AER
Voxativ.
Yep, thats my 2 cent opinion, The DL  at $450, needing NO HORN cabinet, just a  12 inch x 12 inch x 12 inch sanded ply from Home Depot, cut in 4 1 inch port hole at each corner = and you have a  $20 cabinet.
I just feel the big 3 labs will not hold up against the DL 6.5.
No have not heard the big 3 , all models,, only the Vox AC1A, 
The DL completely totally annihilates and destroys the Voxatiiv AC1A 's @ $2k.
Davidlouis Gold Standard in Wide band.
I'd take this DL6.5 over any Wislon and Vandersteen 

Enjoy

Some tech geek in china, knows how to build a  wide band. 

https://www.youtube.com/watch?v=-h8TRoILZEg

Concentric is two drivers in one chassis with the center being the High Frequency (HF) driver independent of the outer Lower Frequency (LF) driver. Tannoy speaker drivers.

Read what it says over a few times and it will make sense.. We want it, in your head, not over your head. :-)

Regards

Read what it says over a few times and it will make sense.. We want it, in your head, not over your head. :-)

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Yes I looked over the Tannoy's. Interesting,, Seas also has a  ~~Co-axil__.
Interesting if you read the descript, Seas says they designed this ~~concentric~~  with the highest regards for super high fidelity.
Again, interesting. 
But note, Seas says  bass is 150hz, more as a  midrange-tweet.

https://www.madisoundspeakerstore.com/coaxial/seas-excel-c18en002/a-e0060-6.5-coaxial-each/
I am sure the Seas along with a  Seas W22 Graphene would be a  nice speaker, caveat $$$$$$$$./
So I went with the 
DavidLouis wide band @ 91 ~~TRUE!!!~ sens and bass does in fact hit the 60hz, if not 50hz before roll off. 
Mids/vocals are accurate and nothing harsh nor  showing signs of stress at moderate db levels on gain.
Highs are there, rolling off, maybe like 13k/14kish. 
= highs are sweet and satisfactory.
So for $450 its right in my budget, vs the layout for the Tannoys  which I may have some issues with either in the bass/, mids or highs.
I have no issues whatsoever in the DL 6.5
This lil DL 6.5 is the speaker to beat out ina  shootout  IMHO/2 cents worth.

Here's another demo of the DL6.5 in action,.
Its everything i hoped for in a  speaker. My experiements , though costly, have paid off.

 The DavidLouis has no other YT  uploads except on my channel. I will be making a  long series of vids over the next weeks showing just what this speaker is capable.



https://www.youtube.com/watch?v=-h8TRoILZEg&t=2s