Small bass gig

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szaboti
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Re: Small bass gig

#16 Post by szaboti » Wed Oct 28, 2015 1:37 pm

I've stared my own project! :chainsaw:

I need some advice so please help!

I can't find an Eminence BGH25 near here.
What are the most important parameters for the substitution?

What is the total load (ohm) of the two 8 ohm speaker + crossover setup?
(Or how can it calculate?)

Do you propose a "low pass" filter a woofer only cab?

Thanks in advance!

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DJPhatman
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Re: Small bass gig

#17 Post by DJPhatman » Thu Oct 29, 2015 2:26 pm

szaboti wrote:I've stared my own project!
Excellent! This is where you start....
szaboti wrote:I can't find an Eminence BGH25 near here.
1- I don't believe that driver is a recommended driver. Why are you seeking that driver?
2- We don't know where you live. At the top right=hand corner of every page on this site is a link to "User Control Panel". Follow the link and fill in your city and country. Maybe someone near you can help.
3- Read this thread if you are in Europe. It is a LONG thread to go through, but worth the read!

Above all else, have fun! Read the plans many times, until you can build the cabinet in your imagination. If you have any questions about the plans, ask on this forum. Especially if you don't understand what is written in the plans.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

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Bill Fitzmaurice
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Re: Small bass gig

#18 Post by Bill Fitzmaurice » Thu Oct 29, 2015 2:56 pm

szaboti wrote: I can't find an Eminence BGH25 near here.
Where's here? Not that it matters, I can't get them where I live either. But I can order them on-line.
What is the total load (ohm) of the two 8 ohm speaker + crossover setup?
4 ohms.
Do you propose a "low pass" filter a woofer only cab?
If so it would be in the plans.

szaboti
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Location: Budapest

Re: Small bass gig

#19 Post by szaboti » Thu Oct 29, 2015 4:28 pm

If so it would be in the plans.
Because it is not in the plans, it is still a good idea. Is it? 8)
load
I wanted to ask is not how much the total load of two 8 ohms cabinet...
I want to know how works a crossover network with two speaker (woofer and horn).
What does the Crossover Do?
1) The crossover allows you to place two 8 ohm speakers in parallel, one for the highs and one for the lows, and still present an 8 ohm, not a 4 ohm load to the amplifier (which is what the amp would see without the network)

Source: http://www.audioholics.com/loudspeaker-design/crossover

But I'm still confuse about, which shematics is god for me ....
8 ohm tweeter + "8 ohm" high pass shematics + 8 ohm woofer + "8 ohm" low pass shematics = 8 ohm toal load?!

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DJPhatman
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Re: Small bass gig

#20 Post by DJPhatman » Thu Oct 29, 2015 4:39 pm

Bill Fitzmaurice wrote:
szaboti wrote:What is the total load (ohm) of the two 8 ohm speaker + crossover setup?
4 ohms.
If you are asking about the total between the woofer and the tweeter with a passive crossover in-between them, 8 Ohms if the woofer is 8 Ohms.
To get to a 4 Ohm total cabinet set, you would need to parallel wire 2 8 Ohm cabinets together, or parallel wire 2 8 Ohm woofers together in a double woofer cabinet.
szaboti wrote:Because it is not in the plans, it is still a good idea. Is it?
If it is not in the plans, you don't need it. Waste of time and money.
szaboti wrote:I want to know how works a crossover network with two speaker (woofer and horn).
See my answer above...
szaboti wrote:1) The crossover allows you to place two 8 ohm speakers in parallel, one for the highs and one for the lows, and still present an 8 ohm, not a 4 ohm load to the amplifier (which is what the amp would see without the network)
This is correct but incomplete. A crossover filters the correct frequencies to the right driver, and prevents the wrong frequencies from going to the wrong driver. Sending 500Hz to a tweeter that only works down to 1200Hz would be bad for the tweeter driver, most likely over-excursion of the diaphragm.
szaboti wrote:But I'm still confuse about, which shematics is god for me ....
8 ohm tweeter + "8 ohm" high pass shematics + 8 ohm woofer + "8 ohm" low pass shematics = 8 ohm toal load?!
This is completely dependent on the drivers that you use. If you use the drivers that are recommended in the plans, using the crossover/filters from the plans will give you the in-cab response that is shown in the plans. If you don't use the driver that are recommended in the plans, then you will not get the plans response results.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

szaboti
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Re: Small bass gig

#21 Post by szaboti » Thu Oct 29, 2015 5:24 pm

Bill Fitzmaurice wrote:This is completely dependent on the drivers that you use. If you use the drivers that are recommended in the plans, using the crossover/filters from the plans will give you the in-cab response that is shown in the plans. If you don't use the driver that are recommended in the plans, then you will not get the plans response results.
There are recommended drivers and the plan contains 4, 8 an 16 ohm shematics, but does not contains exapmples how to combine them for the appropriate result.
But maybe I'm wrong...

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DJPhatman
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Re: Small bass gig

#22 Post by DJPhatman » Thu Oct 29, 2015 5:34 pm

szaboti wrote:There are recommended drivers and the plan contains 4, 8 an 16 ohm shematics, but does not contains exapmples how to combine them for the appropriate result.
But maybe I'm wrong...
Those examples are for the individual driver impedance, or the combined impedance of the drivers reproducing the same frequencies, such as dual 8 Ohm woofer wired in parallel (4 Ohms impedance) or wired in series (16 Ohms) or using 16 Ohm tweeters. This is why it depends on the drivers you use.

I will state this again. For the time, effort and expense to build cabs, you are much better off building a pair of single Deltalite II 2512 loaded Jack 12, regular or light version, without tweeters. They are only slightly harder to build than the Simplexx 12.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

szaboti
Posts: 10
Joined: Thu Aug 20, 2015 6:18 am
Location: Budapest

Re: Small bass gig

#23 Post by szaboti » Fri Oct 30, 2015 11:16 am

DJPhatman wrote:I will state this again. For the time, effort and expense to build cabs, you are much better off building a pair of single Deltalite II 2512 loaded Jack 12, regular or light version, without tweeters. They are only slightly harder to build than the Simplexx 12.
I've started a Simplexx now... so this is not a valid option right now. :fingers:
Next one maybe...

BUT let me clarify my question again.
If I wanna use a BGH25-8 (Bill recommends it for bass gig use) - and there is no other impedance of this type -, and I have an Eminence DeltaLight NEO (right now), and I vant to be combine them in a crossover network (in one cabinet):
- what shematics have I to use ? (8 ohm, and 2,5kHz low and high pass...?)
- it leads to a 4 ohm total (cabinet) load?

Thaks!

Bruce Weldy
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Re: Small bass gig

#24 Post by Bruce Weldy » Fri Oct 30, 2015 11:20 am

szaboti wrote: - it leads to a 4 ohm total (cabinet) load?

Thaks!
No, it's an 8 ohm load. That's because the two drivers are not producing the same frequencies. So, the load over the entire frequency spectrum is 8 ohms.

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szaboti
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Re: Small bass gig

#25 Post by szaboti » Sun Nov 29, 2015 2:24 pm

ALMOST DONE!
Image

Lot of thakn's :hyper:

Dale Hammer
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Re: Small bass gig

#26 Post by Dale Hammer » Mon Nov 30, 2015 5:40 pm

Looking good! Nice bass.

Dale Hammer

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Tom Smit
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Re: Small bass gig

#27 Post by Tom Smit » Mon Nov 30, 2015 11:04 pm

Looking forward to the review!
TomS

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