[hum4god]

hi All

i am looking for a higher sensitivity bass driver that works well in an OB .
i mean in the mid 90ies db or better if possible.
size could be 12" 15" or 18"
needs to x over at around 100hz or 150 hz. low extension into the 30ies or better would be nice.

brands that come to mind are Beyma and Eminence also the driver offered by bd design (bd 15) which is used in their quasar and also the box that goes with their horn.

i still don't know what design of OB bass to try .
i think i would like to just try a few prototype  baffles with different size and wings and see what the response will be .

i looked into the Dipole / Ripole design and like the idea but it seems that it would need quiet a bit of space behind to work properly .

that being said , my space is restricted . there is about 3 feet behind the baffle and about 2 feet of width ( a little less ).
i have some acoustical panels 2x4 mineral wool that are placed on the front wall right now , which should help a little.

any and all ideas to a OB Baffle Bass construction with higher sensitivity is very welcome.

thanks
malcolm

[NealH]

This might work for you. 

http://www.hawthorneaudio.com/drivers.htm

[hum4god]

the augie is 88.7 dB 1w/1m !!!
kind of lowish .

[scorpion]

Malcolm,

lizardBrain pointed to these in a thread on 'B200 + 2 15" woofers', they might suit you and are amazingly cheap:
http://www.musicsupplycenter.com/ProductDetails.asp?ProductCode=100%2D186 .

/Erling

[JoshK]

Malcolm,

lizardBrain pointed to these in a thread on 'B200 + 2 15" woofers', they might suit you and are amazingly cheap:
http://www.musicsupplycenter.com/ProductDetails.asp?ProductCode=100%2D186 .

/Erling

They recently had a 21" executioner for around $100-150 iirc, that some were using OB.  I saw a couple of people who were using them that reported very good results (who have experience with OB woofers).  They have the recone kit still but not the woofer.  Maybe them are just temporarily out.

[JohninCR]

I broke down and ordered 6 of those myself.  Their Knight 15 for $65/ea looks like
a very good candidate as well.  The higher price is still a deal for a cast frame/high
eff/mid-hi Q/low Fs driver. 

Something to keep in mind is that the efficiency in the 30-40hz range isn't going
to be anywhere near the quoted overall efficiency for virtually any driver.  That's
why I finally broke down and went to biamping and EQ.  Once you do that, matching
efficiency isn't an issue.  As long as I can generate a sufficient max SPL at the low
end, then baffle size is otherwise irrelevant as well.

I believe you have to start with your goals for bass augmentation.  Just looking to
add some satisfying OB bass fill for a fullranger much different than flat response to 30hz. 

[hum4god]

I believe you have to start with your goals for bass augmentation.  Just looking to
add some satisfying OB bass fill for a fullranger much different than flat response to 30hz. 

hi john
i agree. just needed to start somewhere .
how do you eq the bass ?
are you using a behringer ?
how to measure in room freq. response?
some plate amps come with parametric eq for one or two frequencies which lets you manipulate the response a bit .
would you recommend to do more?
or do you mean to go for something like the TACT approach?
thanks
malcolm

[JohninCR]

I've been using my computer as a source for years, but recently found a computer
based XO/EQ solution that I'm really happy with.  So far I've only done tuning by
ear and crude use of my SPL meter, but very soon I'll start really measuring everything.
I really need measurements to try complex XO's, since with measurements you can
see graphically exactly what you're doing.  It used to be that only the real PC jockeys
could use the computer based approaches, but this one is quite user friendly.  Once
I'm able to really use the system, I'm sure I'll be recommending it, because it's far superior
to the Behringer boxes.... no multiple digital/analog conversions, total flexibility with
real computing power behind the filters and everything is handled in the digital domain,
so I'm finding it totally transparent.

I spent $80 on the software, $250 on a pro-type multi-out sound card, and $75 on a
measurement mic, stand, and cable.  I'll never have to spend a penny on XO components.
I can output to up to 5 stereo channels.  Each stereo pair starts with an exact copy of
the digital signal.  I can filter each with variable Q filters and parametric EQ, including time
delay and phase correction.  Then all I have between a clean digital signal and my drivers
are the DACs, amps, and cables.  I can make changes real time with just a mouse click.
Add to that the extreme convenience of serving up music from a PC, and I believe it's a
real taste of the future.

[AJinFLA]

very soon I'll start really measuring everything

Glad to see you've come around on this issue. It is essential for speaker building.

no multiple digital/analog conversions, total flexibility with
real computing power behind the filters and everything is handled in the digital domain,
so I'm finding it totally transparent.

Sounds like a perfect description of the DCX2496 when using the provided digital input. Are you suggesting the DCX is less than transparent when implemented competently?

recently found a computer based XO/EQ.... it's far superior to the Behringer boxes

How?

A very good buy here for a crossover (it is far more than that) is a Behringer DCX2496, an amazing unit for the price.

Tom Danley

I'm very much in agreement with Tom. Is your comparison based on real world experience with these units?

cheers,

AJ

[JohninCR]

very soon I'll start really measuring everything

Glad to see you've come around on this issue. It is essential for speaker building.

no multiple digital/analog conversions, total flexibility with
real computing power behind the filters and everything is handled in the digital domain,
so I'm finding it totally transparent.

Sounds like a perfect description of the DCX2496 when using the provided digital input. Are you suggesting the DCX is less than transparent when implemented competently?

recently found a computer based XO/EQ.... it's far superior to the Behringer boxes

How?

A very good buy here for a crossover (it is far more than that) is a Behringer DCX2496, an amazing unit for the price.

Tom Danley

I'm very much in agreement with Tom. Is your comparison based on real world experience with these units?

cheers,

AJ

Measurements are needed for what I want to do, part of which is to prove some of the "measurement geeks" wrong about
a few things, but "essential to speaker building" is too broad for me not to take exception.  Even MJK hasn't measured his OB's.
He just used math to help him in the design.

Sure the 2496 is great for the price, but totally transparent it is not.  Otherwise there wouldn't be entire forums dedicated to
modding it.  I borrowed one from a friend for a week, and I was planning on getting one myself and spending a few hundred $ more
on mods until I found my current solution.  I guess I just wasn't competent enough to use it properly.

[goo]

I've been using my computer as a source for years, but recently found a computer
based XO/EQ solution that I'm really happy with.  So far I've only done tuning by
ear and crude use of my SPL meter, but very soon I'll start really measuring everything.
I really need measurements to try complex XO's, since with measurements you can
see graphically exactly what you're doing.  It used to be that only the real PC jockeys
could use the computer based approaches, but this one is quite user friendly.  Once
I'm able to really use the system, I'm sure I'll be recommending it, because it's far superior
to the Behringer boxes.... no multiple digital/analog conversions, total flexibility with
real computing power behind the filters and everything is handled in the digital domain,
so I'm finding it totally transparent.

I spent $80 on the software, $250 on a pro-type multi-out sound card, and $75 on a
measurement mic, stand, and cable.  I'll never have to spend a penny on XO components.
I can output to up to 5 stereo channels.  Each stereo pair starts with an exact copy of
the digital signal.  I can filter each with variable Q filters and parametric EQ, including time
delay and phase correction.  Then all I have between a clean digital signal and my drivers
are the DACs, amps, and cables.  I can make changes real time with just a mouse click.
Add to that the extreme convenience of serving up music from a PC, and I believe it's a
real taste of the future.

Hi John. Ive been fighting with modding the Behringer boxes or looking into what your describing
Can I ask what software, and which soundcard?
goo
oh yeah Hi Bob,Nigel,Fergs,..
 

[goo]

oops how did we get off topic
After reviewing Martin's data comparing the Alpha to the auggies I went for the Eminence Alpha 15A
sorry about no link, my company's filter has a problem with Partsexpress.com

now to cut some wood

[ohenry]

...my company's filter has a problem with Partsexpress.com

now to cut some wood

Mine too, it must be the partSEXpress thing.

[hum4god]

anybody tried Altec drivers for bass in OB ?
which model and with what results?

malcolm

[goo]

http://www.decware.com/cgi-bin/yabb/YaBB.cgi?board=diy;action=display;num=1162819072

maybe this will help   
goo

[AJinFLA]

Measurements are needed for what I want to do, part of which is to prove some of the "measurement geeks" wrong about a few things

You are going to "measure" to prove some of the "measurement geeks" wrong?
Interesting.
Would Linkwitz be one of the "measurement geeks" about to be proved wrong?

but "essential to speaker building" is too broad for me not to take exception.  Even MJK hasn't measured his OB's.
He just used math to help him in the design.

I fail to see any relevance with this statement. What does MJK not measuring show?
Linkwitz, Geddes and Toole measure. A lot. I see (and hear) relevance  in that.

Sure the 2496 is great for the price, but totally transparent it is not.  Otherwise there wouldn't be entire forums dedicated to modding it.

Amateurs tinkering with the products of engineers is proof of a lack of total transparency? I suppose Beraneks law dictates that this must be so.
Internet engineers living in their parents basement always tend to know much more than the ones paid by big corporations. CD players, amplifiers and digital crossovers will always continue to be made "more transparent" by this set, till the end of time I suppose.
BTW, could you link me to the statistically significant data gathered during scientifically rigorous testing by any of these modders to demonstrate their accomplishments? I don't recall ever seeing any. The only thing I seem to see is someones non audiophile wife who never pays attention to anything hearing jaw dropping differences when bearing witness to the above modders handiwork. Slightly below my threshold for scientific proof, but different strokes for different folks I imagine.

I borrowed one from a friend for a week, and I was planning on getting one myself and spending a few hundred $ more on mods until I found my current solution.  I guess I just wasn't competent enough to use it properly.

I'm not in a position to accurately determine this. I can only judge by my own experiences and those of others who have used the units with no loss of resolution from straight wire when inserting into a system. Perhaps it is we who are doing something wrong, or maybe lack the hearing acuity of those convinced by themselves that they have better hearing abilities? Who knows?
I wonder if the computer driven solutions (some of which I have heard myself) are as transparent as you think it may be? I don't recall seeing any proof that this is so either, but who knows.
Good luck with your computer solution. I'll chug along with the DCX 'till they make a newer version. Works just fine for my low res ears, using such a low transparency speaker system like mine, which utilizes drivers like the W22.

cheers,

AJ

[JohninCR]

AJ,

I don't recall mentioning Linkwitz, so please don't put words in my mouth.
I meant measurement geeks like yourself.

Again, I didn't say anything about Linkwitz, Geddes, or Toole.  What I
dispute is that measurements are the be all to end all.  Many fine speakers
are designed and built without scientific measurements ever being done.

If the 2496 was as perfect as you seem to think then it's lack of transparency
wouldn't be so commonly mentioned.  I ignored that info and tried it myself,
and I found it fairly obvious using the analog inputs and less so with digital input. 

My opinion is that what I'm using is far superior.  I have the capacity of unlimited
outs vs being limited to a 3-way with the 2496.  My filters use 64 bit processing
vs 24 bit with the 2496.  The 2496 has far less flexibility in it's XO and EQ's.  The
2496 can't address phase correction.  These factors plus the fact that I found
the Behringer to be less than totally transparent are how I justify my opinion.  That
doesn't mean that it's a great budget unit, packed with a lot of great features.  I
just went a different, and potentially even more economical yet powerful route.

If you insist on arguing for argument's sake, I'm not going to participate.  I went
down that road with you before, and you were proved wrong, so I'm not wasting
my time again.

As long as you're happy with your own system, that's all that really matters, and I
wasn't knocking your system in any way.  I'm sorry that you took my comments so
personally.

[goo]

John
I hate to be a pain, I need to ask again; what sound card, and what software did you go with? I fine my B200 sounds best when I bypass the Behringer boxes. I've tried everthing to make these work. I thank you for your time
goo

[ashok]

I hate to be a pain, I need to ask again; what sound card, and what software did you go with? I fine my B200 sounds best when I bypass the Behringer boxes. I've tried everthing to make these work.

Software might be one the products here: http://www.thuneau.com/products.htm. Do not know what the output card might be. See also this thread: http://www.audiocircle.com/index.php?topic=33470.0.

Ashok

[goo]

Thx so much ...sorry about the spelling, it's a combination of being late for work and California public skool