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Old 6th September 2008, 11:36 PM   #21
diyAudio Member
 
Join Date: Sep 2008
Location: Massachusetts
Wow ... you guys ****** rock!

Thanks for all the input from everyone here , its much appreciated.

There's been a couple of different ideas being thrown around and I'd just like to get some more opinions to assist in the narrowing down of what i'm going to get.

I'm 99% sure i'm going to go with the x1 plans for the lows , it seems to be the most practical and widely suggested.

However there is the issue of the drivers -

In the other thread i've got going on over @ speakerplans:
http://www.speakerplans.com/forum/fo...=190487#190487

It was said that with the X1 design to avoid most drivers because the cabinet has a reputation of eating drivers - Opinions ??

I have heard a couple times that:
since i'm in the states it would tough to obtain the 1850 so I should instead go with the p-audio SD18. aubergine also suggested the SD18.

But - Iand said that:
I shouldn't go with the SD18 but go with a VOID V18-1000 ... Reasons/Opinions??

Next FlipC suggested that:
the size of the Driver isn't what matters and that I shouldn't just jump at putting an 18 in there because "the driver and cabinet must work together" because the size of the driver doesn't matter in producing more bass ... and suggested the Eminence Lab12 Generation II 12" sub with a listed response of 25hz-125hz ... Reasons/Opinions compared to 18's ??

Also - Jbell mentioned:
Building a similar PA system based around the MCM 55-1740 10" driver which has a response down to 60hz. Would these be your main low speakers or your mids?? Also if you were to use 4 of them like you say would the 4 of them together produce lows below 60??
What other drivers will you be using for your system , namely highs and mids , assuming those 10's are your lows?

Jbell also said:
"Just be careful on what you look at, and make sure the math all adds up... After all, it's all math." ... What are equations I absolutely NEED to be aware of not to **** this up and burn my money??

:::

About the crossover -

The DCX2496 has been recommended multiple times for reasons such as price and no analog parts to break off.

The DriveRackPX was suggested by electroaudio and if it truly is superior to the DCX and I wont be stressing about it shitting the bed on me than i'll spring the extra 130 bucks to get it. I wouldn't want to be nervous about the DCX breaking down , especially at a gig. And he also suggested the LEM DX24 but that appears to be available only in the european countries ... and the Rane however that appears to not have nearly the amount of functions the dbx and DCX have ...

So i'm still in a toss up between the dbx DriveRackPX and the Behringer DCX2496 - with the favor being slightly towards the DCX because of it being suggested so many times.

Also for the mids/highs the only thing thats really been suggested is the x15 cabinet design so i'm assuming this is a safe move??

And for amps I haven't really even explored anything yet so i'm not sure what direction i'll end up with that ...

as always , thanks for the help friends
~ meta
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Old 7th September 2008, 12:19 AM   #22
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Join Date: Mar 2004
Location: stockholm
Quote:
Originally posted by metaverse

The DriveRackPX was suggested by electroaudio and if it truly is superior to the DCX and I wont be stressing about it shitting the bed on me than i'll spring the extra 130 bucks to get it. I wouldn't want to be nervous about the DCX breaking down , especially at a gig. And he also suggested the LEM DX24 but that appears to be available only in the european countries ... and the Rane however that appears to not have nearly the amount of functions the dbx and DCX have ...

So i'm still in a toss up between the dbx DriveRackPX and the Behringer DCX2496 - with the favor being slightly towards the DCX because of it being suggested so many times.
If you actually need a digital processor or if the rane or something similar is adequate depends entirely on what speakers and amps you get.

My personal approach would be the rane with good speakers that doesnt need any correction and amps with built in limiters that is slightly too small to burn the speakers.
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Old 7th September 2008, 12:32 AM   #23
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Join Date: Sep 2008
Location: Massachusetts
any suggestions on speakers to go with that rane?

or amps with built in limiters to go with said speakers?
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Old 7th September 2008, 12:44 AM   #24
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Join Date: Mar 2004
Location: stockholm
Sorry no.
I mostly work with much larger budgets and factorymade stuff so i dont have any experience with diy approaches that would be useable for your situation.
And i also suspect that our view of music is very different from eachother, so i think it is best if i stay out of that part.

However, EAW 850SB is very popular around here for your kind of music, maybe its internal rising response is a clue?
But i think that is best answered by someone that loves the same thing as you do.
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Old 7th September 2008, 12:58 AM   #25
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Join Date: Sep 2008
Location: Massachusetts
I just now looked at the price of a SD18 and didn't quite expect them to be over 400.00 ...

When compared to the Eminence 12" thats 150 or so my next question is ...

What are the pros/cons for going with that 12" in the X1 box and what are the pros/cons going with the SD18 in the x1 box?

Would there be a dramatic difference?

i'm guessing the 12 would give more punch and the 18 more of a wave - bowl of bass soup feeling ?? Or does this hinge more upon the box itself?

electro - thanks for your help and honesty
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Old 7th September 2008, 02:43 AM   #26
jbell is offline jbell  United States
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Join Date: Apr 2003
Location: .
To answer a couple different questions:

yes, a T36 makes bass indoors where wall loading/corner loading is possible. Outdoors, it just doesn't cut it. That and the fact that 40hz is -13db vs 100hz, prevented me from using it. Yes, I gave them a fair shake, and built 4 36" wide, but it wasn't what I needed. My 3015lf TH worked very well, 102.5db@1W/1M@40hz where the T36 was only 95....

The mcm55-1740 is flat to 44hz in my TH that I just built/tested tonight, average 100db 1W/1M with a slight bump at 50hz. So bang for the buck, a $50 sub with driver and plywood... seems like a good deal with 4 subs / 4 tops.

For tops I have a slot loaded / horn top that works really well with the same 55-1740 driver, so for me, it's the ticket to "pa on the cheap"

Since you say you're new to PA and PA math:
Here's the basics I keep in mind -- define your lowest freq you need (40hz, whatever) find that efficiency of whatever sub you choose, and use that as a benchmark efficiency. 100watts adds 20db, 1000 watts adds 30db so efficiency is KEY. Power compression (where you add power but don't get any additional volume) usually starts pretty early --meaning: don't plan on running 1000 watt rated subs with 1000 watts, they probably aren't putting out much more (if any) sound than if you were feeding them 200-400watts. Decide if you can wall or corner load your subs, if so, you get a free 6db or more. Wall or corner load will almost always provide more even bass than separated subs (with comb filtering and cancellations) Sound drops off at 6db per doubling of distance, so 10meters away is 20db quieter, than at 1 meter. Since it's 6db for every doubling of distance, you can have much more even bass if your listeners are all 10-20meters away, than if they were 1-5 meters away.. That's the best reason to wall or corner load (and the free bass it gives) Doubling power gets 3 db, doubling cabinets gets 3 db, doubling both gives 6db. (So if you have an 8 ohm sub, and add another 8ohm sub, dropping your amp load to 4ohm, you've doubled your power and doubled your cabinet count which added 6 total db) "reasonable" PA listening levels are usually in the 100-115 db range You get 40hz-15000hz in that spl range -- people will be happy.

There's much more math, but that'll get you started in the right direction.
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Old 7th September 2008, 10:38 AM   #27
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Join Date: Apr 2008
Quote:
Originally posted by metaverse
I just now looked at the price of a SD18 and didn't quite expect them to be over 400.00 ...

When compared to the Eminence 12" thats 150 or so my next question is ...

What are the pros/cons for going with that 12" in the X1 box and what are the pros/cons going with the SD18 in the x1 box?

Would there be a dramatic difference?

i'm guessing the 12 would give more punch and the 18 more of a wave - bowl of bass soup feeling ?? Or does this hinge more upon the box itself?

electro - thanks for your help and honesty
Driver diameter is irrelevant, the LAB12 in it's designed box would give more of a 'wave' as you say, and there are 18" kick bins (take a look at the turbosound bandpass horns, among other free designs). The X1 is a 6th order bandpass design as you know, designed for the SD18, but the cheapest driver that works in there is the C18-650EL also from P Audio.

You can't just bung any driver in it, the box determines the driver when you pick a plan. The X1 with any driver has no 'kick', it doesn't play in the 'kick' region (just upwards of it's operating range).

See you on SP
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Old 7th September 2008, 10:44 PM   #28
iand is offline iand  United Kingdom
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Join Date: Feb 2007
Location: London
Quote:
Originally posted by metaverse
Wow ... you guys ****** rock!

Thanks for all the input from everyone here , its much appreciated.

There's been a couple of different ideas being thrown around and I'd just like to get some more opinions to assist in the narrowing down of what i'm going to get.

I'm 99% sure i'm going to go with the x1 plans for the lows , it seems to be the most practical and widely suggested.

However there is the issue of the drivers -

In the other thread i've got going on over @ speakerplans:
http://www.speakerplans.com/forum/fo...=190487#190487

It was said that with the X1 design to avoid most drivers because the cabinet has a reputation of eating drivers - Opinions ??

I have heard a couple times that:
since i'm in the states it would tough to obtain the 1850 so I should instead go with the p-audio SD18. aubergine also suggested the SD18.

But - Iand said that:
I shouldn't go with the SD18 but go with a VOID V18-1000 ... Reasons/Opinions??

as always , thanks for the help friends
~ meta
It all depends how hard you're going to drive the X1 (I haven't built one, but I've been following all the discussions for some time). If you put more than 1kW into it the Void V18-1000 has a stronger cone, higher power handling, and bigger Xmax than the SD18, and people have found it less prone to expiring under these conditions.

If you can't get either driver where you are then you're looking for an 18" driver, preferably with a BL product and Xmax as high as possible, and there aren't many of these around and they're not cheap -- there are some suggestions here:

http://www.speakerplans.com/forum/fo...s.asp?TID=9161

If you don't use a suitable driver the performance won't be good.

Ian
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Old 8th September 2008, 05:50 AM   #29
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Join Date: Sep 2008
Location: Massachusetts
Its late so I haven't quite processed all the info you guys just handed to me - although I do have a more clarified vision of things.

At this point i'm just getting ready to tear because I feel like i've found the ultimate box for what I want to accomplish and the best drivers , VOID v18, I can't get in the states ...

discouraging to say the least ...

time for bed , i'll be back at it tomorrow.

thanks guys
~ meta
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Old 8th September 2008, 12:20 PM   #30
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Join Date: Jan 2005
Location: Rotterdam, NL
For what you describe (the bar) a X1 loaded with a SD-18, powered with say a solid 700 W amplifier and 2 x 12"/1" quality tops (1.4" if you can afford it) sound fully up to the challenge.

An other choice for the basscab would be a good 2x15" reflex.

A single 18" reflex might do the business but the efficiency boost from the 6th order BP (the X1) surely does the trick, just to be on the safe side.

In any case a good high pass on the bass cabs is recommended (30 Hz or higher). For the tops I would recommend an amplifier capable of 2 x Wrms rating of the 12" driver, partially to be used as headroom, x-over above Fs and/or tuning of tops.

Regards Johan
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