New 18" speakers.

Dedicated to those large boxes at one end of the room
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pre65
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#1 New 18" speakers.

Post by pre65 »

I've now got my new 18" Beyma speakers, and they are in an unusual box.

The speakers are mounted sideways, and the front output is blocked off, and the rear output exits through two slots facing front-back.

Can anyone attempt to describe the logic for this ?

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#2 Re: New 18" speakers.

Post by ed »

looks very much like a band pass cabinet.

I dabbled quite a bit in the 1980s with stage cabs similar to this particularly like the Eminence cabs.

from one of the old Eminence refs I have:

"A relatively new type of design that has become popular for sub-bass applications up to 150hz. The driver output is isolated and the vented output has a narrow band pass characteristic normally restricted to 3 octaves. Better than bass reflex in terms of efficiency"

good for 30-150hz..often seen in isobaric config.
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#3 Re: New 18" speakers.

Post by pre65 »

Thanks for that Ed. :D

I'll be unloading them from the car after lunch and seeing what I can do with them.
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#4 Re: New 18" speakers.

Post by IslandPink »

They look heavy ...
Have a listen to them as-is , if you can, would interesting to know if this loading has any advantages.
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#5 Re: New 18" speakers.

Post by pre65 »

Not too heavy Mark.

Now I've got them indoors, I see I have erred in my description of them. :?

The rear of the driver has a rear facing slot, and the front of the driver has a forwards facing slot.The rear facing slot is approx 3x the volume of the front facing one.
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#6 Re: New 18" speakers.

Post by pre65 »

I've connected them up to the main system.

A) They both work.

B) Bass does not seem "strong".

Three options.

1) Use one pair of the baffles that came in the deal to mount the 10" Beymas and see what happens.

2) Take the boxes apart and try the 18" Beymas in place of the 18" Fanes on my original baffles.

3) Modify the Beyma boxes to a conventional front/rear radiation.

I favour option 2, where's my electric screwdriver. :wink:
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#7 Re: New 18" speakers.

Post by pre65 »

Option 2 is done on one of the original baffles.

Seems a bit better, so now to do the other one and see what happens in stereo.
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#8 Re: New 18" speakers.

Post by JohnG »

Hi Phil,
You had a run across the country to pick these bad boys up.
If I did a overnighter on the Huddersfield Day, I was going to detour to have a look at these on the journey home Sunday.
I hope they are a worthwhile aquisition.

John
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#9 Re: New 18" speakers.

Post by pre65 »

JohnG wrote: Sun Feb 24, 2019 4:05 pm Hi Phil,
You had a run across the country to pick these bad boys up.
If I did a overnighter on the Huddersfield Day, I was going to detour to have a look at these on the journey home Sunday.
I hope they are a worthwhile aquisition.

John
With "bargains" one has to act quickly. :wink:

Now got both baffles running, and I'm pleased with the result.

Even with my earwax problem, I find the bass lines a tad more prominent, which is what I was after. I've not changed the crossover at all, but there is scope for adjustments if necessary.
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#10 Re: New 18" speakers.

Post by IslandPink »

Did you post the details of the Beyma units anywhere, Phil ?
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#11 Re: New 18" speakers.

Post by pre65 »

IslandPink wrote: Sun Feb 24, 2019 6:36 pm Did you post the details of the Beyma units anywhere, Phil ?
Try this

https://www.beyma.com/speakers/Fichas_T ... 005176.pdf
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#12 Re: New 18" speakers.

Post by IslandPink »

Thanks.
Nice unit, good specs for an OB driver. the Qm could be a little higher, but generally very suitable.
I assume it's been run-in a bit now ? - would take some usage to sound good.
No chance of running out of excursion on that - unless you are aiming to knock down an interior wall :confused3:
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#13 Re: New 18" speakers.

Post by pre65 »

Thanks Mark.

I don't think they have had a lot of use before I got them, so they will need a bit of loosening up.

Mind you, with my "plinkity plop" type of music (Copyright Colin Topps) it might take 15 years to get there. :lol:
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#14 Re: New 18" speakers.

Post by Cressy Snr »

pre65 wrote: Sun Feb 24, 2019 11:13 pm Thanks Mark.

Mind you, with my "plinkity plop" type of music (Copyright Colin Topps) it might take 15 years to get there. :lol:
Get some Bert Kaempfert at full chat, up those woofers and they'll loosen up nicely.
A bit of "Fever" by Peggy Lee wouldn't go amiss either. :D

"Plinkity Plop?" you mean "Keith Don't Go" isn't? :D
Last edited by Cressy Snr on Mon Feb 25, 2019 9:45 am, edited 1 time in total.
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#15 Re: New 18" speakers.

Post by steve s »

My back is quite impressed by the weight.. or lack of it.. they are 1/2 what my fanes weigh...
Hope they work out... they are not what I would choose on the specs, but at the right price they look a good buy
The're probably more suited to the traditional open baffle concept as mark said so should work well.

If using those boxes i would line the insides with black car carpet and cut them off quite low.
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