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Speakers suggestion for a 2x10" cab "5-strings bass" oriented

W

washburn_it

Sep 18, 2010
123
2
Pistoia, Italy
#1
Hi,
I would like to build a 2x10" bass cab (total impedance 8 ohm) to use in conjunction with my Parsek 1x15" (Parsek is the previous brand name of MarkBass).
I have a little experience in loudspeakers building so this would be my first "serious" cab building.
I'm asking to the experienced users for the speakers (and building tips) that I may use for a 2x10" specifically "tuned" to be used with a 5 strings bass (Yamaha TRB5-II).
As simulation software I'm using BassBox PRO and I have made several simulations using long XMax drivers (>6 mm) such as B&C 10NW64 (16 ohm version wired in parallel), Faital 10HP1020 (8 ohm version wired in parallel since I don't have T/S parameters of the 16 ohm version), Eminence Legend BP-102 (4 ohm version wired in series).
The actual amp head that I'm using is a Parsek BS4000 (250 Watt RMS @ 8 ohm, 400 Watt RMS @ 4 ohm).
Now the problem:
I would like to use the 2x10" also as standalone unit (thus not connected with the 1x15") in case of small gigs then, playing a 5 strings bass, I would like to have a good response also around at 30 Hz (the Low B freq.)
Simulations results show that I can reach about 98/100 dB @ 250 Watt @ 30 Hz but the excursion of the cone is equal (if not slightly above) to the XMax value (for the Legend BP-102 I should limit the power more) thus without any "safe threshold" with the risk to damage the speakers.
I've considered (and obtained) these parameters:
Fb= 52 Hz
Vb= 90 liters (rounded)
F3= 50 Hz
No. of vents= 2 (Dv=120 mm, Lv= 148 mm, round shape)

When used in conjunction with the 1x15" I could also build a subsonic filter to protect the 2x10" filtering all frequencies below 40 Hz, but the problem is when the small cab is used alone.
So...do someone know a 10" speaker that has a low Fs (around 40 Hz or below) and a XMax > 7/8 mm?
Is there a way to lower the Fb without having a box as big as the 1x15"?
Any suggestion will be appreciated, thank you.

Regards,

Roberto


PS: I apologize for the long thread !
 
#2
Low fs, long xmax speakers like that would likely need to be crossed to a mid-driver to have much for clarity/upper harmonics. More suited to a true subwoofer. For a "regular" 210 cab I'd look at stuff with a bit higher fs and higher SPL. Something that could get you an f3 closer to 50hz without ending up with a giant box. That'll make for a full sound with a 5string. Don't worry so much about 30hz and look for something that'll play strong to 60 (1st harmonic) as that's where a lot of the power/volume is. A pair of bp102's crossed to a single alpha6 will make for a deep/full/clear studio monitorish tone for bass guitar. Finding good 4 or 16ohm 10's may be the biggest challenge.
 
#3
I can speak for the Eminence Legend BP102's. I have the 102-4's in an SWR Goliath II 4x10 (series/parallel for 4-ohms total) and I have the 8-ohm BP-102's in a Goliath II Jr. (8-ohms wired in parallel for 4-ohms total)

I have to say that with these in the 4x10, the bottom is huge and tight. As much (if not more) low-end than the Carvin 1x15 I had. Low B usage is extremely tight and focused.

For use in the 2x10, the low end isn't as big...I mean, it is a smaller cabinet and really isn't designed for big-bottom like the 4x10 is. But for a small room and not too loud. It's nice.

However, I'd recommend an HF horn with L-pad. Without a horn, the speakers can sound a bit muddy; in a sort of vintage sort of way. Their high end does roll off at 2kHz. I like a bit of high end in my sound, so I keep my HF horns at about -7dB. Nothing too crazy, but it does the job.
 
#4
Legend BP102-4 was my first choice but since I need a 8 ohm cab I should connect them in series and that would affect the resultant SPL.
That's why I'm looking for 16 ohm speakers so that I can connect them in parallel and have a good resultant SPL (with B&C it's around at 102 dB vs 93 dB of the Eminence).
I found also the interesting Beyma 10MW/Nd, it has a flatter response than B&C and Faital.
In fact they have a kind of "saddle" (I don't know if it's the right term) between 50 Hz and 200 Hz that I would avoid if possible.
To make it clear these are some graphs of the simulations:

[Invalid or Expired Link Removed]

The yellow is the B&C, the green is the Faital and the purple is the Beyma.

Which one would you judge the best considering what I want to do?
Thanks
 
#5
washburn_it said:
Any suggestion will be appreciated, thank you.
Click to expand...
Decide whether you want a 2x10 that will compliment the 115 or work best alone. You can't have both from the same driver. Long xmax and low Fs results in reduced midrange response, and a better midrange is ostensibly the reason for adding a 2x10.
 
#6
Yes, you are right.
I'm conscious that I can't have a "full range" cab from deep low to high end closed into a 2x10", I'm looking for a compromise of course and if this is not possible, then it will be a "only" midrange cab, natural extension of the 1x15".
I'm still in the "experiment and study" phase so, as no decision is taken yet, I need the suggestion of the experienced to know how to arrive as closest as possible to the right compromise.
Then...I'm open to every solution.
(I forgot to write that the cab will be equipped with a tweeter).

Regards,

Roberto
 
#7
Looking at your charts the Beyma looks better to me because it doesn't have the "saddle" lowering response in the lowmids. The meat and potatoes range of a bass guitar. It's excursion shoots up faster than the others below the tuning freq. but with 8mm of xmax that's a non issue.

A big BUT here. I'd go back and look at the FR charts for these drivers looking for good mid response further up the scale. It should be lacking in something with the low freq. performance of these. These things would likely end up with 210 that out performs your 15 in the lows but doesn't add any mid response or "punch" to the overall package.
 
#8
I should add that a tweeter won't play low enough to make up the difference when using lowend oriented speakers like these. There could easily be a giant hole in response between where the woofers fall off and the tweet starts working. In this situation, that hole could be an octave wide or more.
 
#9
How does your 5string sound played through your 15 by itself? What does it have, what does it lack?

I know you're probably not going to be able to find specs or really reverse engineer it but just for comparative purposes, a lot of commercial 15 cabs like that don't play much below 60hz, definately not 40 or 50. Then they have a hump tuned into them around 100-200hz so they sound loud. The rest of the "tone" depends on it's mid response further up.

Kind of a "dead reckoning" or "semi-educated guess" as to what you need in the 210.
 
#10
How does your 5string sound played through your 15 by itself? What does it have, what does it lack?
Click to expand...

It's not so "clear and bright" when, for instance, you slap, you can "feel" the lack of mid-freq. if you play a song of the old '70s.
That's why I thought about a 2x10".

I know you're probably not going to be able to find specs or really reverse engineer...
Click to expand...

Well...the 1x15" uses a B&C 15PZ40 (8 ohm, 600 Watt RMS) with two reflex ports Dv=100 mm, Lv=115 mm, with Vb= about 105 liters so, according these data, the Fb= 44 Hz and F3= 45 Hz.

I should add that a tweeter...
Click to expand...

Do you recommend then to use a 6" driver instead of a tweeter?

These things would likely end up with 210 that out performs your 15 in the lows but doesn't add any mid response or "punch" to the overall package.
Click to expand...

How do you set then the Fb? Would you change completely the kind of drivers?
In this case, should I use a high-pass filter set to, for instance, 40 Hz to protect the speakers from over-excursion?

Thanks, regards.

Roberto
 
#11
billfitzmaurice said:
Decide whether you want a 2x10 that will compliment the 115 or work best alone. You can't have both from the same driver. Long xmax and low Fs results in reduced midrange response, and a better midrange is ostensibly the reason for adding a 2x10.
Click to expand...

I agree.

Also, I'm not usually one to talk someone out of a DIY project, but in this case I think I'm going to have to say something - the speaker you're trying to build sounds exactly like an Acme B2. Andy Lewis has already solved all your design problems, including the ones you haven't even thought of yet.
 
#13
washburn_it said:
Well...the 1x15" uses a B&C 15PZ40 (8 ohm, 600 Watt RMS) with two reflex ports Dv=100 mm, Lv=115 mm, with Vb= about 105 liters so, according these data, the Fb= 44 Hz and F3= 45 Hz.
Click to expand...


In your case, you know what your 15 is doing. It plays plenty deep enough and lacks uppermids/highs whatever. The 10's you're looking at will likely have the same type of character. I'd look at 10's that have good middle and upper response in exchange for deep bass. Your 15 is already providing that.

Another option would be to add a crossover and 6" mid to your existing 15.

Putting a mid with the 10's you're now looking at would be sort of like the Acme cab. Full sound all around. I guess you could do that and make it your cab you play all the time. Throw your 15 under to put out more bottom/lowmids to fill out the room when you need to.

More ideas to model anyway.
 
#16
I play a fiver, and I designed and built a 2-10" cab based on BP102's. I also incorporated an Alpha 6 midrange. The downside of this project is the fact its a 5 cu.ft. box. Since tone trumps weight/portability in my world, its a tradeoff I'll accept. I have yet to test it in a band setting, but playing along to recorded music I like the way it "cuts through".. Very clean..
 
#18
I've made other simulations with BP102-4 but: (Vb=90 liters)
1) if I set the Fb=60 Hz (F3=54,71 Hz) with input power @ 250 Watt I can use it safely (I mean without speakers over-excursion) if they reproduce from 46 Hz on, then I think I should use it always in conjunction with the 1x15" unless the input power is within 60 Watt;
2) if I set the Fb below 60 Hz the excursion, of course, increases "touching" the XMax around at 40 Hz and around at 70/80 Hz;
3) if I set the Fb=Fs I would have 107 dB @ 30 Hz but the input power should be limited @ 170 Watt max;

Since you (dhomer and will33) already used those speakers, how did you deal with these problems?
What's your Fb, Vb etc.?

As for the Beyma and Faital speakers, Faital replied me that they don't have 4 ohms or 16 ohms version for the 10HP1020 then this driver is "discarded", Beyma never replied (so far) to my request of info about 4 ohms or 16 ohms version for their 10MW/Nd, so B&C remains the other alternative to the BP102-4.
Considering to use the mid Alpha6 in conjunction with B&C 10NW64-16, what frequency would be the best cut for the Alpha6? (B&C declares a frequency range of FS to 3000 Hz, so 59 to 3000 Hz).
Thank you.

Regards,

Roberto


PS: I attached the B&C 10NW64-16 datasheet
 

Attachments

#19
billfitzmaurice said:
Decide whether you want a 2x10 that will compliment the 115 or work best alone. You can't have both from the same driver.
Click to expand...

I think this is good advice. I agree with whomever suggested adding a 6 inch mid to your 15- that's one possibility if you're able to put a crossover together.

My other suggestion would be to sell your 15 and build or buy a pair of matching cabs that provide the sound you want.
 
#20
Selling my 1x15" is not a solution since I don't want to sell it.
I like that "box" so I have no reason to give it away.
As I stated before, I would like to arrive to a compromise, if possible.
If this is not possible that's good, I will go for a "pure" mid-bass box but before taking this decision I want to try everything that is possible to have something that's not certainly an Acme Low B2 but something that I can use ALSO as standalone in small gigs when high volume is not required, if high volume is required then I would use the 2x10"+1x15".
I live on the 3rd floor without a lift so a 2x10" is certainly more "portable" than a 1x15" if I have to perform in a small pub.
As always...any suggestion (in that direction) is appreciated.

Regards,

Roberto
 

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