Pass SLOB Build Discussion

[2 picoDumbs]

Now call Voxativ and ask them if they will let you demo some of their full range drivers. I want to know how good they are.

Belgium:
Pierre Wauthier
Rue des Artisans 14
5537 Maredret-Anhée
Belgique
Téléphone: +32 (0) 82 699 361
Email: pierre(at)voxativ.com


Voxativ GmbH
Ringbahnstraße 16 -20
12099 Berlin (Tempelhof)
Germany
Phone: +49 (0)30 - 2100 5662
Email: contact@voxativ.com

 

[naca5]

Already done,
In a previous life I had a pair of Vox speaker....really nice fullrange but extremely directive and over priced IMHO. They were the big BLH ones.

Also the pair used in this project is overpriced but I inherited them in a trade deal, better use them and they sound very decent too, alnico blabla...and really nice since they are crossed (diffraction thing I guess).

 

[2 picoDumbs]

Cool

 

[dady]

Recently I got a Beyma 18LX60V2 with a Qts of 0.48, is cheap and monster.

Also, with a good relation ship between price and quality, Lowther still is the best option.

 

[naca5]

also tried the PHY HP....really thin.
All in all the Mark Audio are rather good (I built a FHXL for family set-up)..

 

[naca5]

Recently I got a Beyma 18LX60V2 with a Qts of 0.48, is cheap and monster.

I still have a complete Beyma loudspeaker somewhere, amazing speaker for money I agree.

Those Faital used here are cheaper than Beyma and still good.

 

[2 picoDumbs]

I purchased some cast aluminium eliptical tractix horns from Faital. Absolute quality product at a very reasonable price, much better than the crappy plastic horns I have tried.
FaitalPRO | HF Horns | STH100

 

[naca5]

Slot:

jh
Front:

Both

 

[Kjeldsen]

This actually shows no benefit from the slot. I have tried slot loading myself, and also came to the conclusion that the slot is of no real value

 

[Kjeldsen]

Thanks for the measurements. I guess the real benefit is the smaller footprint. You can fit two 15" woofer without making a 150 cm tower.

 

[2 picoDumbs]

Looks like you are performing the sweep with the signal going through B5.
Can you do it again without the crossover.

 

[naca5]

will do Pico,
Where must I set the mic?
For those graphs above the mis with in the front 15" axis.

 

[2 picoDumbs]

Place the mic between the two drivers, eg around 1 foot off the floor.

Also take a measurement at ear level at your seated listening position.

 

[Retsel]

This actually shows no benefit from the slot. I have tried slot loading myself, and also came to the conclusion that the slot is of no real value

While the slot may not affect the frequency response, it may effect the impulse response. If so, it is because the slot couples the air better to the driver than the driver on a flat baffle.

A different version of slot loading a woofer is summarized in a thread about a speaker called the Kazba, which is a Karlson style open baffle speaker. The people who tried it reported a better impulse response by the driver compared to an open baffle speaker on a flat baffle, and I think that it was backed up by measurements.

Retsel

 

[2 picoDumbs]

I have tried slot loading myself, and also came to the conclusion that the slot is of no real value

Yeah me too but the geometry was completely different, so I'm still reserving judgement.
Even if the slot did nothing I would have expected having the driver more effectively playing down on the floor would have produced more efficient floor gain. Based on the measurements even that seems to be a myth or at least overstated.

 

[naca5]

Listening position with Xover FR+Both 15"

Listening position no Xover both 15"

 

[naca5]

NO XOVER SESSION
Both 15"

Slot 15"

Front 15"

 

[naca5]

Last one for today
All drivers connected
I played with the position of loudspeaker
Mic is 1' from floor
Seems to remove the pike

 

[Kjeldsen]

While the slot may not affect the frequency response, it may effect the impulse response. If so, it is because the slot couples the air better to the driver than the driver on a flat baffle.

A different version of slot loading a woofer is summarized in a thread about a speaker called the Kazba, which is a Karlson style open baffle speaker. The people who tried it reported a better impulse response by the driver compared to an open baffle speaker on a flat baffle, and I think that it was backed up by measurements.

Retsel

I did not save my measurements

But, my Impulse respones was worse with the slot. I have also read somewhere that the a plane open baffle do have the nivest impulse response.

Someone also mention that a benefit from the slot is increased velocity, but to my ears the plane and wide open baffle seems more natural. But, I do not have the space for a wide open baffle, so will try damped U baffle.

 

[perceval]

Great read, you all. I enjoyed this thread very much.

Unfortunately, I don't have the space for dual 15", even though the room is big, space is limited.

I settled on sealed bass drivers (only 8" at the moment) with a small OB on top.

What can I say, besides that I've become enamoured with OB sound!

I've built sealed, ported and arrays (which were the best I had heard for a while), but the OB trumps them all, regarding my taste and my ears anyway.

My FR looks quite nice, but my impulse response is a bit all over the place... so, that will be next on the agenda, as soon as I build them proper enclosures and baffles.

Exciting times!