Speaker for ROCK

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Hi,

Here are the 2 solutions with Eminence drivers I will probably choose from (more solutions are welcome);

1. Delta 15LFA + Beta 8A + APT150

2. Delta 15LFA + PSD2002 +flare (compression driver, XO at 1.5kHz, 18db)

Both 1,2 cost each about 230 CDN (without the XO)+ shipping per speaker.

I have never heard a compression horn driver, do they sound OK in the mid + high...

PI speaker uses the same driver and XO (almost, they use 12LFA) for the 3PI.

Any thought on 1 vs 2.

Thanks,
Eric
 
Hi,

I found this quote on a PA forum;

''If you want chest thump, you need to make sure that you emphasize the frequencies that cause that effect. Typically, the human chest resonates around 75 Hz to around 90 Hz. So. put that in your crossover and clean out everything "above" and let the mains carry those frequencies.
Thus my suggestion for a "generic" crossover frequency is around 90Hz to perhaps 95 Hz.
Personally, I am using slightly lower crossover specifically due to the operating capabilities of my subwoofers and my mains. My point is that you need to "start" with the 90-95 Hz setting and then do your own adjustments as fits your own equipment until you find the results (chest thump) that you are looking for.

Chest thump is a combination of subwoofer output which includes power and crossover frequency.''


Based on this, should I build the enclosure max flat or should I tune it slightly higher with a 1-1.5 db bump in the 60-100Hz region. Will this make the box boomy..

Thanks,
Eric
 
Ex-Moderator R.I.P.
Joined 2005
First

A 2way is really more simple
But with this it would mean a very big woofer crossed very high, and a small CD/horn crossed low
Its way too complicated to do this way
I would forget that one completely

In the other design it is the Beta-8A itself that could make this possible at all
Its really the most important driver
Chest factor or not
You said it yourself, with a no good midrange the rest becomes pointless

To say that the chest factor thing happens around 70hz is really to oversimplify it
And just to make the box too small to get some "gain" in that region is really not that simple
Besides, its not really free "gain", but unwanted ripple, that could result in boring one note bass
And how much
How much gain do you have from your room
If it was that simple there would be no such thing as equalisers

Fore the Delta15LFA I would choose an optimum closed box at around 180liter
If it shows to be inadequate below 100hz it will be easy to convert it into bassreflex, and 180liter would be optimum fore that one too

And that very low 90hz xo point is really only possible with an active setup
And with a completely different design too
 
e_fortier said:
Hi Cal,

Thanks for the link. The 12 in woofer has a Qts of 0.75 so better fit for OB this is probably why the review say that the woofer has no bass.

Exactly, this is what I want to do with the Sammi's. OB on the coax and a box for the helper woofer.

At an efficiency of 95db i would be better off with my FE206E and these are free since I already have them ;)[/B]


I agree with Tinitus that the Fostex might take a beating even with a high pass. Those are more of a critical listening driver.

I have surfed quite a bit today and it's amazing that there is barely NO info about DIY with pro drivers. Maybe I haven't search enough...[/B]


I hear ya. Some of the manufacturers will give you box sizes for the woofers but not always complete systems.

EDIT: Some interesting stuff at the Pi site too, thanks Norris.
 
MJL21193 said:
Tri amped. 3 LM3886 chipamps on active filter boards. These boards have level controls, to adjust the power output. The power output to the woofer is ~70watts, the mid is turned down to 50% (that driver is VERY efficient) and the tweeter is at about 70%.
:

Beautiful. Is it typical for a Chipamp to make 70watts into an 8ohm load? I always thought of them as much lower output. What do you have invested $ wise in each 3 amp board?
 
Hi Norris,

I had mentionned PI speaker in my post no.41 but thanks for the recommendation.

Would yo know which PI speaker would suit my needs, I was looking at 3 PI that uses the Eminence Delta 12LFA + compression driver PSD2002, which is almost as my plan no.2 on post 41.

Have you heard any PI speaker.

Thanks,
Eric
 
Hi Tinitus,

A 2way is really more simple
But with this it would mean a very big woofer crossed very high, and a small CD/horn crossed low
Its way too complicated to do this way
I would forget that one completely


This is what PI speaker is doing but with a 12 in woofer. The tweeter is a compression horn driver, I had in mind that these cold be XO low enough to be used with 12 in or 15 in woofer. The fs of PSD2002 is 500Hz therefore 1.5KHz would be OK (correct me if I'm wrong)

I will try to find review (not bias) of the 3PI speaker.

Thanks,
Eric
 
Ex-Moderator R.I.P.
Joined 2005
e_fortier said:
Hi Tinitus,

A 2way is really more simple
But with this it would mean a very big woofer crossed very high, and a small CD/horn crossed low
Its way too complicated to do this way
I would forget that one completely


This is what PI speaker is doing but with a 12 in woofer.

Thanks,
Eric


:headbash: I thought that might happen :D

Only a slight misunderstanding

Note I said " too complicated to do THIS WAY " ;)

Wayne is a pro and measures his speakers, which makes a whole lot of difference
CD/horn needs special xo, but he knows how to

I did think about Pi speakers, but didnt seem possible at first
Though I have also heard before that his plans are free through his forum, but wasnt sure
But sure, if its possible you could order drivers locally

Not sure which horn is used, and you may have to buy it from him, dont know
CD B&C250 is said to be a very good cost benefit

But I would contact Wayne, nice man, Im sure he will help you

Considering your budget maybe look at either Three Pi or Eight Pi, but Im sure Wayne will know
Eight Pi will no doubt take some wood building skills

No doubt, one of those will be the right choise fore you, if possible
 
Hi,

After my last post and before your reply I actually wrote an e-mail to Wayne, he is known to be very good and helpful.

We'll see what he has to propose.

On the 3PI and 4 PI the horn is the PSD2002 this is the reason I had proposed that model ;) why reinvent the wheel when the guy knows what is doing.

You are correct is plans are free, just add the PI logo for publicity and you are all set.

Go on PI web site and click on Products and then scroll down you will see the drivers used.

Regards,
Eric
 
Ex-Moderator R.I.P.
Joined 2005
e_fortier said:
Hi,

On the 3PI and 4 PI the horn is the PSD2002

Go on PI web site and click on Products and then scroll down you will see the drivers used.

Regards,
Eric


Yeah, I know and have looked, many times before this
And why I didnt suggest the Four pi as the Omega woofer didnt seem within your budget
Though it might be a good choise

The PSD2002 is an Eminence CD and not a waveguide/horn

Wayne has previously said that the B&C DE250 is a significant upgrade over the Eminence PSD2002
No doubt you should choose the B&C, but though relatively cheap it may cost half your budget, so maybe not possible
He also mentioned which waveguide, but I cant remember

Do you know the prices of the drivers in Australia
 
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Joined 2007
901Fixer said:

Is it typical for a Chipamp to make 70watts into an 8ohm load? I always thought of them as much lower output. What do you have invested $ wise in each 3 amp board?


I am running these at 42V rails (yes, the maximum). That gives me roughly 70 watts but these will very rarely see that much power.

The active amps were from another project. When I "evolved" my electronics skill and knowledge, these became obsolete. I reassigned them for these speakers.
 
I helped a friend build a pair of Pioneer B20 based Full Changs. Not quite the big PA driver you seem to have been thinking of, but they overpower his space in a most entertaining way. In my smaller room they didn't sound as good, but in his space they provide satisfying club-style output. Not the last word in HiFi, but not bad.

There's a thread around here about the 12LTA (that's the one with the whizzer, yes?) in a BIB. Truly a monstrous box. Silly big. There was discussion of effective tweeter and crossover in that thread as well. Ah, I could dig it up if you have trouble finding it yourself.
 
Hi Tinitus,

For the price in Australia, I'm not so sure ;) but here is a link to Q-Components in Ontario, Canada, just scroll down to get the price list for Eminence and B&C spkrs. Price are CDN so divide by 1.2 to get equivalent USD.

http://www.loudspeakers.ca/products.htm


Hi Adams,

If I place an order with Q-Components I'll make sure to order a few of these B20 and the small pioneer A11EG80..., I have been really curious about them (for a few years), with a supertweeter they are apparently a fun speaker.

They can also be used in the Half Chang that I'm planning to build eventually for my FE206E (more critical listening, vs the PA style spkr)

BIB wise, my downstair ceiling is not high enough for the FE206 BIB except maybe for the short version, but hey if you built a BIB might as well go for the full length ;), the B20 is probably just as big.

Regards,
Eric
 
2 way options

http://www.audiokarma.org/forums/showthread.php?t=150939

Long thread devoted to 2-way design with either a 12", 14", 15" woofer and compression horn driver. People prefered using different woofers.

For the cost, the Selenium D220Ti, thread-on version, 8 Ohms paired with a $9.00 horn from JBL has won many devotees.

There are different versions of the crossover designed, based upon which woofer you choose.

I think the price is in your ballpark. I'm not entirely sure if it is "chest thumping". There is no question many people are very satisfied with the sound. Nice collaborative project.


best wishes,

Brian

PS

I'm building them when I get enough dough....
 
MJL21193 said:
If you want a cheap, really good bass driver consider this one.
I found 4 of these at Goodwill and it took some time to find out who made them. I measured the T/S specs and they are very good for OB and ESPECIALLY good for acoustic suspension.

I built a pair of speakers for my workshop with 2 of these:

Picture196.jpg


Boxes are 25" high, 19" wide and 15" deep.
Give the kind of bass that hits you in the chest. Excellent power handling too in this small box.

I'm still intrigued by these and their crazy low price. How would they work in a vented enclosure or horn like say the "Shadow"? Since they can be crossed over much higher than a typical "sub" I'd like to mount them up near the mid, maybe even side firing, but also wanna maximize the LF by positioning a vent or horn mouth on the floor.
There is a Shadow plan for an SDX12 but I doubt it has much extension above 100hz.
 
Disabled Account
Joined 2007
901Fixer said:

I'm still intrigued by these and their crazy low price. How would they work in a vented enclosure or horn like say the "Shadow"?

Hi 901,
These woofers will not work well in a vented box - wrong T/S specs. Like I said, either acoustic suspension (smallish sealed box) or open baffle.

e_fortier said:
Hi MJL21193,

Would you mind sharing the T/S for the 15 in.

Thanks in advance,
Eric


Hi Eric,

Specs in the pic below entered in Unibox. These are fairly efficient (93db/1watt).
 

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