No ..I don't use a subwoofer.....I don't need that.
I have another setup only for home theater.
Martin King have the same woofers into open baffle and the active setup provide 97db on 35hz.He tryed first Dayton woofers but the personal taste was Alpha's.
About qts...in fact is a matter of personal taste.
You should try to listen first woofers with 0,4-0,7 and after that you should go to Alpha's 1,26....but do that quiqly.
Some have a good reports using 0,5-0,7 and have a personal taste because use so called "quality of the bass"....but loose that cream of music.
But...I myself,Martin and many others owners have tryed all these qts.
The Alpha's do the job stunning.Bass is clean,full,a little soft,(that I appreciate to Alpha's)avoiding interference with Supravox,the instruments in right in my face.....
You should try to listen to have a good impression.
I have another setup only for home theater.
Martin King have the same woofers into open baffle and the active setup provide 97db on 35hz.He tryed first Dayton woofers but the personal taste was Alpha's.
About qts...in fact is a matter of personal taste.
You should try to listen first woofers with 0,4-0,7 and after that you should go to Alpha's 1,26....but do that quiqly.
Some have a good reports using 0,5-0,7 and have a personal taste because use so called "quality of the bass"....but loose that cream of music.
But...I myself,Martin and many others owners have tryed all these qts.
The Alpha's do the job stunning.Bass is clean,full,a little soft,(that I appreciate to Alpha's)avoiding interference with Supravox,the instruments in right in my face.....
You should try to listen to have a good impression.
This is OT but related to felix's OB subwoofer so forgve me if I post this here.
Felix,
I have a 4 12" woofers handy.
Qts 0.44
Qms 5.1
BL 7.8Tm,
Fs 17Hz
Vas 380 liters
MMs: 73gms
Voice coil height: 30mm
Air gap Height: 10mm
Resistance: 3.1 ohms (4 ohm nominal).
Presently they are in large sealed boxes (about 65-70 liters each) and I was hoping to reconfgure them into smaller boxes. I was thinking Apreioic till I saw your OB speakers. I understand OB will drop the Max SPL I will get by about 6db bot the bass should have better definition.
Felix,
I have a 4 12" woofers handy.
Qts 0.44
Qms 5.1
BL 7.8Tm,
Fs 17Hz
Vas 380 liters
MMs: 73gms
Voice coil height: 30mm
Air gap Height: 10mm
Resistance: 3.1 ohms (4 ohm nominal).
Presently they are in large sealed boxes (about 65-70 liters each) and I was hoping to reconfgure them into smaller boxes. I was thinking Apreioic till I saw your OB speakers. I understand OB will drop the Max SPL I will get by about 6db bot the bass should have better definition.
4 pieces of 12" into (two) open baffle don't think it goes very well.
First I wanted to try Peerless 12" sls ....but I wanted to make a very short compromise....and that is really woofers.
Another option will be if you will use 4 piece 12" only into one open baffle or dipole sistem.That means 8 drivers only for bass.
First I wanted to try Peerless 12" sls ....but I wanted to make a very short compromise....and that is really woofers.
Another option will be if you will use 4 piece 12" only into one open baffle or dipole sistem.That means 8 drivers only for bass.
I think OB lets a driver play more or less as intended by the manufacturer (most drivers are measured in an OB). It just needs to be large enough and it works... I do have the impression that large bass drivers perform better in such small baffles (I tried several small drivers and even with eq. I didn't like the results...).
I just built one proto (lucky I got the wood for free...) and immediateley loved it. After that I measured and saw it also measures fine...
I would always recommend building some kind of proto first...
The drivers I use (JBL 2220A) have very very low QTS, so after all the stories I expected it to need lots of EQ. But it doesn't!
I don't know what to believe anymore, right now I think there are many drivers suitable for the job....(more than people claim...)
Also I think there are many ways to rome, if you have more from this you can have less from the other. It's the balance that counts.
For instance if you have a smaller baffle, use larger drivers or eq. If your driver has high Qts it can be a smaller driver/less eq.
I'm starting to think if you just build something on a good hunch you're close enough to get it right anyway.
I must add that I presume most of the above (and a bit of experience) but I didn't try everything yet, and certainly don't claim to be some kind of OB guru....
I just built one proto (lucky I got the wood for free...) and immediateley loved it. After that I measured and saw it also measures fine...
I would always recommend building some kind of proto first...
The drivers I use (JBL 2220A) have very very low QTS, so after all the stories I expected it to need lots of EQ. But it doesn't!
I don't know what to believe anymore, right now I think there are many drivers suitable for the job....(more than people claim...)
Also I think there are many ways to rome, if you have more from this you can have less from the other. It's the balance that counts.
For instance if you have a smaller baffle, use larger drivers or eq. If your driver has high Qts it can be a smaller driver/less eq.
I'm starting to think if you just build something on a good hunch you're close enough to get it right anyway.
I must add that I presume most of the above (and a bit of experience) but I didn't try everything yet, and certainly don't claim to be some kind of OB guru....
felixx said:
I was surprised about this myself!
I bought 30 year old, but recently reconed drivers for 50EUR./each. containing the ingredient 'alnico' I started with the baffle only, than added 15cm sides to make a small u-frame, than made the real thing larger than necessary and it turned out precisely right My woofers have Qts somewere way under 0.30, effieciency about 100dB (if I was well informed...) So I expected shallow bass response. I figured since the top end is only 85db it could be well filtered. And since they are sort-of PA drivers they could handle serious power. Boy was I surprised Offcourse the fact that the baffle touches the floor makes a lot of difference. It completely eliminates the acoustic shortcut on the path to the listener, but even outside the socalled 'beam' (way off-axis) they appeared to show pretty good tonal balance, only less loud.felixx said:
I have another setup only for home theater.
Martin King have the same woofers into open baffle and the active setup provide 97db on 35hz.He tryed first Dayton woofers but the personal taste was Alpha's.
About qts...in fact is a matter of personal taste.
You should try to listen first woofers with 0,4-0,7 and after that you should go to Alpha's 1,26....but do that quiqly.
Some have a good reports using 0,5-0,7 and have a personal taste because use so called "quality of the bass"....but loose that cream of music.
But...I myself,Martin and many others owners have tryed all these qts.
The Alpha's do the job stunning.Bass is clean,full,a little soft,(that I appreciate to Alpha's)avoiding interference with Supravox,the instruments in right in my face.....
You should try to listen to have a good impression.
You sure have more experience than I have with OB, your speakers are quite compact for an OB. But I don't even doubt they sound like heaven...anymore....
Be building more of 'em, much much more
next with a really high Qts driver 
navin said:
Well from the measurements and from the experience I have nothing to complain about. I think a higher Q driver could have been smaller size and lower sensitivity. I just thought I'd start with overkill to create the necessary headroom to clean it up afterwards. But I don't feel I should change anything, like I said I'm totally satisfied! I don't even feel like using eq to boost the lowest freqs up. The driver has 40hz Fs and the system goes well below 50hz, which I find deep enough...
Bottom line is that the balance here seems quite allright, eventhough I think some adaptations are needed with low Qts drivers. But I see no problem in using low Qts drivers. High Qts will perhaps only give slight benefits...
I can only speculate on this for the moment, perhaps someone can explain it better or give a few nice examples? Pictures or measurements...or a link to....
Attachments
v-bro said:
you give me hope. With a Qts of 0.44 and a sens of about 90db though I am not hoping for somehting nice in a OB config. Presently my subwoofers (130 liters per side) are nice but WAF dictates a smaller box. Hence I figured isobarik (box size would be about 40 liters) untill I saw that beautiful OB picture.
Isobaric is nice to save space and still have very low roll-off, but OB scores a lot better on low distortion. Note that my OB is helped a lot by the floor (by putting the baffle in contact with the floor it also becomes part of the baffle, I also placed the woofer pretty near the floor. This will raise distortion a littlebit, but still waaay better than conventional enclosures) So bass response is very very good IMHO.
I think since you allready have the 12" drivers you should just try it out. Build one baffle first and see (hear ) what happens... Just use some cheapo fibreboard or an old (but massive) door like I did.... it might still lead to satisfaction....depends much on the top-end as well offcourse. And whether you have separate level control to match the volume....
My drivers were less ideal than yours if you ask me, and I'm VERY satisfied with the result. I don't care that they are big...
Bassdrum hits my stomach without being boomy, and I can follow very exactly what the bassquitar does in songs where I didn't even notice the bassplayer much on my previous subs.....
I think since you allready have the 12" drivers you should just try it out. Build one baffle first and see (hear
) what happens... Just use some cheapo fibreboard or an old (but massive) door like I did.... it might still lead to satisfaction....depends much on the top-end as well offcourse. And whether you have separate level control to match the volume....My drivers were less ideal than yours if you ask me, and I'm VERY satisfied with the result. I don't care that they are big...
Bassdrum hits my stomach without being boomy, and I can follow very exactly what the bassquitar does in songs where I didn't even notice the bassplayer much on my previous subs.....
Uhmm...I'm very sorry felixx
Perhaps this conversation should be moved to another thread, we are drifting much OT (OB....
) here...but that's what a forum is for isn't it? To teach and learn.
For some I'll be stating the obvious, but for rookies sake I wanted another thing off my chest. Just too many people are staring blind into striving for perfection. Well I think perfection is never reached, even with the most expensive systems there's allways some kind of compromise.
And striving for perfection isn't always fun, neither does it have anything to do with enjoying music more. There is nothing wrong though with experimenting a lot and learning what changes make the greatest difference. But you'll learn that creating very enjoyable sound can have much wider margins than many people make you believe...
The trick is in the discovery of what you like most in the sound. After many projects you might even find your nirvana. I've come to this point many times, than someone would drop by to 'have a listen' and not like my sound. Most of the times I didn't like what they had created (or just installed ) either....
The same thing can be said about speakers from the assembly line, they all sound very different, so there will allways be a few that suit your taste and some don't. Visiting hifishops with 'listening rooms' (with switchpanels to do A/B testing) helps a lot to discover what you like best.
Actually if you ask me, most people like ****** sound Even I do!
As a matter of fact I think even REAL sound suffers from distortion, the same orchestra for instance sounds entirely different at different locations....
The funniest part is that years ago I wanted to try all the latest findings and equipment (still have that urge, but I find out if I like it better a lot faster now...) I never had a set of speakers longer than a few months, sometimes only days. I use two ESL panels (from the fifties!) right now that I will never want to get rid of for sure, or at least it will have to take a hifi revolution The OB bass system came only lately, but gives me that same sense of THIS IS IT!
Hard for me to tell whether the woofer can be improved on at this point, but sure am not going for baby step improvements....
OK I admit, I'm a freak! But for you Navin, if you just want to enjoy and not keep on building stuff (and spending the whole sallery) I'd just try the four 12".....
Perhaps this conversation should be moved to another thread, we are drifting much OT (OB....
) here...but that's what a forum is for isn't it? To teach and learn.For some I'll be stating the obvious, but for rookies sake I wanted another thing off my chest. Just too many people are staring blind into striving for perfection. Well I think perfection is never reached, even with the most expensive systems there's allways some kind of compromise.
And striving for perfection isn't always fun, neither does it have anything to do with enjoying music more. There is nothing wrong though with experimenting a lot and learning what changes make the greatest difference. But you'll learn that creating very enjoyable sound can have much wider margins than many people make you believe...
The trick is in the discovery of what you like most in the sound. After many projects you might even find your nirvana. I've come to this point many times, than someone would drop by to 'have a listen' and not like my sound. Most of the times I didn't like what they had created (or just installed
) either.... The same thing can be said about speakers from the assembly line, they all sound very different, so there will allways be a few that suit your taste and some don't. Visiting hifishops with 'listening rooms' (with switchpanels to do A/B testing) helps a lot to discover what you like best.
Actually if you ask me, most people like ****** sound
Even I do! As a matter of fact I think even REAL sound suffers from distortion, the same orchestra for instance sounds entirely different at different locations....The funniest part is that years ago I wanted to try all the latest findings and equipment (still have that urge, but I find out if I like it better a lot faster now...) I never had a set of speakers longer than a few months, sometimes only days. I use two ESL panels (from the fifties!) right now that I will never want to get rid of for sure, or at least it will have to take a hifi revolution
The OB bass system came only lately, but gives me that same sense of THIS IS IT! Hard for me to tell whether the woofer can be improved on at this point, but sure am not going for baby step improvements....
OK I admit, I'm a freak!
But for you Navin, if you just want to enjoy and not keep on building stuff (and spending the whole sallery) I'd just try the four 12".....
v-bro said:
I am not afraid of building speakers. Why i once had a TL in my car (yes 3 10" woofers that took up the whole trunk of my sedan, an Indian version of a 70's Vauxhall).
In my younger single days (pre internet) I have built several pairs starting from 3,4 and 5 way systems using Philips drivers (the only drivers avalilable in India) to Dynaudio, Focal, Morel, Scanspeak etc when I lived in the US. The problems I face today is a severe lack of time besides the import procedure in India is so poor that getting drivers into India is a pain in the neck (leave aside the higher duties/taxes).
Given this I am trying to make do with the drivers I have (besides what do I do with my current system if I build a new one with new drivers, no one will take my monstrocities even if free!
The other problem is as my family is expanding (we are now 4) is lack of space and WAF. So my speakers have gotten smaller (which is fine becuase my needs for SPLs have also drastically reduced). I used to use 2 JBL B460 woofer (using JBL 2245 woofers) for my bass. Those gave way to my current set of 12" (130 liters sealed boxes) now I would like to build something smaller. Some years back I think it was at a show in Neu Isenberg in Gemany I had seen a pair of OBs using a pair of 21" woofers or 24" wide baffles. They really sang. So I have lofty ideals of OBs.
BTW felix do you have any pic of the rear with the grill off? and v-bro do you have any other pics that can "motivate" me? After it was felix's pic on the Systems thead that got me all "hot and bothered" about OB in the first place.
FYI my OB would be XOed to a push-pull ScanSpeak 18W8546 and 9900. Amplification will be SS ( 3 x 2SJ50 / 3 x 2SK135) for the OB and EL34 for the mid (UL) and hf (Triode).
If this works I could simple relace the 12" I have for the Eminence 15A (if I make sure I have a large enough baffle).
v-bro said:
Would this be more true to say that it lets the driver play as measured by the manufacturer - if it's measured open baffle.
I'd suggest that driver makers design their drivers specifically for applications - I know that when Neil McKinney (of Lambda Acoustics) was designing his, he had designs for sealed (SB), ported (PB) and open baffle (the prefix escapes me).
And also that most measurements are generally done using a sealed box of known volume.
But, I could be out of touch...
?
I like this one:
All the deadrooms I visited had an 'IEC' baffle installed with rings to fit all kinds of driver sizes. Every driver was measured in this same baffle....
I've seen about five or six deadrooms in my life....
An externally hosted image should be here but it was not working when we last tested it.
Cloth Ears said:
All the deadrooms I visited had an 'IEC' baffle installed with rings to fit all kinds of driver sizes. Every driver was measured in this same baffle....
I've seen about five or six deadrooms in my life....
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