3 Way Active with 98db midrange

[DougL]

I am interested in creating a speaker that will support my interest in low power amps. I currently have a 6 channel class D amp and a DCX2496, and thought I could try a speaker with a compression tweeter.

Since I can go 3 way, and have 4 Dayton RS270 I can use for the prototype,
I need to select a mid-range and tweeter. I am trying to keep tweeter, mid and waveguide under $500 a pair.

I was looking at these mid-ranges:
B&C 6MD38
B&C 8PE21
B&C 10HPL64

What are my trade-offs?
The 6 inch will allow / demand a higher crossover with the tweeter.
However, I want to cross over the RS270 at no more than 400 Hz because of the nasty resonance higher up.

For a waveguide I was thinking of the DDS ENG 1-90.

For a Compression driver, a BMS 4528ND shows up on the BMS site.
Its a possibility, along with the B&C DEC 10 or DEC 250.

Any thoughts would be appreciated.

Thanks in advance.

Doug

[navin]

Will a midbass with say a 93db spec (like the 18sound 6ND430 also recommended by John Krutke) also work? The 6MD38 has limited bass ability and will have to crossed over at say 300-500Hz while the 18sound machine can be XOed lower (say 200hz) which means you can have all of the critical midrange being provided by one driver.

How much power will have on tap? In the 5W range or more?

[DougL]

For the prototype, I have the Teac A700 @ 30W per channel.

One way of looking at it, If I wanted a 93 db driver, I could go to a 10" Mid-base and probably get to the 80 to 100 Hz range. Basically a Nathan 10 Ripoff. However, I do see the appeal of a driver that can cover the entire mid-range.

Thank you for your comments.

I see I did not provide links to the drivers and waveguides.
Waveguide
http://www.ddshorns.com/ENG%201-90%20pro.pdf
Assistance_Audio

B&C 6MD38 6-1/2" Midrange | 6md38 pa midrange high efficiency midrange b&c cone midrange | Parts-Express.com
B&C 8PE21 8" Midrange | 8pe21 8" pa midrange cone midrange b&c midrange pa woofer | Parts-Express.com
B&C 10HPL64 10" Neodymium Woofer | Neo lightweight midbass bass mid DOTW 091509 DOTW_091509 | Parts-Express.com
Compression Drivers
B&C DE10-8 1" Mylar Horn Driver 8 Ohm 2-Bolt | compression driver tweeter horn driver high frequency 1" exit 1" throat HF PA driver tweeter driver DOTW 091509 DOTW_091509 | Parts-Express.com
Overview
Overview

[voltcontrol]

So much choice..
From Beyma 12GA50 to the 18Sound 6nd430. (I'm currently looking at these for projects as 'mid'drivers with a larger than usual range )
I do believe (haven't checked) that the 18Sound 6nd410 and 6nd420 do offer the sensitivity you're looking for.

All B&C and 18sound offerings are 'go' as far as I'm concerned. Very workable, high quality drivers.
Ciare also has a few unique looking options, but I don't know any real life experiences with their midranges.

Afaik BMS is the 'go to' brand for comp drivers, the DE10 is also a nice option though.

Ps; have a look at the waveguide in this picture...and click it... And order two for me too, USA clients only... Grr..

[CharlieLaub]

I have this same midrange - the B&C 8PE21. IMHO this is an awesome driver. I have used it in a large open baffle, with a horn tweeter, and it sounded great (my WAF-00 project). You might consider that type of arrangement, but do a lot of careful modeling. I would be happy to share what I know about that, if you want to PM me. The driver could be used down to 400Hz or so pretty easily. Lower is more difficult.

The one "bad" about this driver is the very, very low Qts. I think it is below 0.2, or around there. Luckily you can increase it very easily: add series resistance (must be a power resistor). The other option is to use a chip amp and teh the driver in a negative current feedback loop using a small "sense" resistor. I can also point you to some resources on this topic.

If you want to keep the high SPL capability, just cross high (400-500Hz) and use this with the Econowave driver and horn combination (search Econowave on this site for lots of details). The Pyle PH612 and Selenium D220Ti are a popular combination and provide good response down to 1.6kHz. You can always cross higher so slopes can be 12dB/oct.

I would not use a 10" for a midrange. It has inherent upper frequency limitations because of beaming issues. Even 8" is pushing it once you get over 2.5kHz.

-Charlie

[DougL]

voltcontrol,
Thank you. Sounds like I have options.

Charlie,
Great to know you use the 8PE21 and like it.
I agree about the driver Q. However it is what it is.
My thoughts are the 10" is going to push down my tweeter xo frequency and a 6 is going to push up the woofer xo.


Thanks again.

Doug

[ttan98]

For the mid-range there are more options:

1. PHL 1120(mid range)
2. PHL 2460(mid woofer, I am using now)
3. Audax PR170M0 or PR170N0

all these drivers have spl about 96dB and over at mid band. 1&2 are more expensive but the audax are well priced. All three will sound very good.

for compression driver I suggest DE250 it can go low, about 1.7kHz and DE10 above 2kz. The former is better worth the extra money, it has a dynamic and smooth sound. DE10 should be used more like super tweeter.

[doug20]

For the waveguide, you should consider the QSC 122i waveguide and the Celestion 1745 CD.

Total they are around $80 shipped. They are a great combo, great proformance for that price tag.

You can ordered the 10" round waveguide from here

http://www.qscaudio.com/support/reso...ts/HPR122i.htm

Just click on it and order it.

You can order the 1745 CD from here

http://www.qscaudio.com/support/reso...parts_list.htm

Click on the CD (Part 42) and order it...Its a 1" through, do not let the 1.75" description confuse you.


btw, I have the B&C 6MD38, PHL1120, 18sound 6ND410....I like the PHL1120 the best subjective sound to me but that should me a ton to you. The 6ND410 is super sensitive and easy to work with in XO sims. I was going to match the 410 to a very small waveguide/CD but I have not found the right project yet.

The 6MD38 is nice too for a lower cost option but it does have lower sensitivity. Its not 98dB but neither is the PHL1120. Only the 6ND410 is around 98dB (although a little less with a proper XO).

[doug20]

Originally Posted by ttan98

for compression driver I suggest DE250 it can go low, about 1.7kHz

The DE250 can definitely go lower on a bigger waveguide. Geddes runs the XO for his < 1K Hz.

Definitely a good driver considering Geddes uses it.

[ttan98]

Originally Posted by doug20

The DE250 can definitely go lower on a bigger waveguide. Geddes runs the XO for his < 1K Hz.

Definitely a good driver considering Geddes uses it.

I would not cross below 1kHz, lowest I would go is 1.5Khz.