Not sure what you are saying, but I suppose ALL fullrange drivers are better OFF axis
If you have followed my posts of BR's, you know that I dislike QB3 alignments, and your 56 l box is even more so. The problem with flat to cut-off BR's is that with any reasonable room lift, you get boomy, one note bass. Your alignment actually has a bit of a peak just before cut-off. Take a look at 40 l tuned to 45Hz. This is the shape of roll-off that I like to see.
At 10w, you will not exceed Xmax until 38Hz or so. But as with any BR, this one will unload quickly after that. Be careful about the material you play at this power level.
Bob
Better? Different.
The 1772 is surprisingly good at the top for an 8"er. It actually produces some power above 10KHZ. I have a good deal of experience with the 1772 and I like it a lot. It does my music very well -- small band classical, jazz trio, girl-and-a-guitar. I am just starting with the 166En. Running on the HT with Sirius Music piped through Dish Network, the 166En's sound fine. reasonably well balanced and no obvious bad habits. Expect a couple of months before I get to serious listening in my proposed MLTL.
Bob
I had actually used your 40L/45hz recommendation as my starting point. I then started trying other configurations to see what I would get.
I compared your suggestion with my questioned enclosure and see what you're talking about. The rolloff is indeed a bit smoother. I was thinking that with my enclosure/tune that I could take advantage of the room gain to flatten out the overall response. But, now that I think about it, I realize I need to do a few subwoofer sweeps outside and then inside the room I plan to put it in to see what the transfer function of the room itself is.
Thanks for your feedback.
OTOH, a smooth roll off (EBS) alignment with this driver, while extending the actual low frequency response can give you anemic mid bass since the mid and high frequencies will overpower the low notes. This is why Bob prefers a BSC contouring filter to knock down the mid and high frequencies.
I, OTOH, don't like BSC filters (to each his own 🙂 ) so prefer a little amount of bass lift translating to "midbass punch". Its a fine balance, too much and you end up with the dreaded one-note bass. Still experimenting and will talk about my experiments when done, but so far I'm having better results (in the midbass) with small double bass reflexes (1 cu ft or thereabouts) compared to larger MLTLs or horns.
hi zobsky - re: DBR - are using the classic 2:1 volume ratio and 3 identical duct recipe? if so what's your tuning? -- with something like Super10, I'd never follow TS low-tuned alignment = pathetic - no use to have small signal graph but no usable real-world performance- I got Super10 singing in "X15" - low cone excursion, nice sound, no filters😀
BSC= Baffle Step Compensation?
I'll have to read up on this.
I've found that the most pleasing response to me is one that imitates the equal loudness curve up to about 4khz, with a slow decrease in FR from there down... roughly 1db/octave, give or take.
I'm used to working with the car environment where this is pretty easily achievable due to the car's transfer function. In fact, I find that I often need to use a notch filter around 45hz in most applications to keep the boominess down. Even still, I have a rise of about 15dB from 250hz down to 30hz.
I ran some tests with my 10" subwoofer to see what type of boost I achieve from my listening room vs. the driver outside in the open environment. To my surprise, the response curves are roughly the same for the best case (corner loaded), yet the overall output is 5dB higher overall; the largest difference being at 40hz (1/3 octave scale) where the output is 10dB higher.
In the test that shows me more applicable results for towers sitting about 2' from the wall, I get a pretty nasty suckout at 40hz. This test kept all parameters the same and only the subwoofer location changed (mic was always 36" away in front of cone). Interesting to say the least. I'll have to do more testing to see what I can do about this.
At this point, I'm just going to have to start trying things. I'm a pretty avid tinkerer. I'm not as knowledgeable on the more complex enclosure designs, but I'll definately start my research. I don't plan to build a full range set for at least another month, and likely not until mid-July (after the PE tent sale 😉).
Thanks again, guys.
- Erin
ah, thanks bob.
When I said the 166e should be better off axis, I'm talking about highs dispersion.
Sort of the way a small dome tweeter has a larger sound than a 1.5" (less off axis dispersion).
I'm betting the TB is better overall (10g underhung cone vs 6.8g 166en)
But the $67 fostex can be hard to ignore too.
Norman
When I said the 166e should be better off axis, I'm talking about highs dispersion.
Sort of the way a small dome tweeter has a larger sound than a 1.5" (less off axis dispersion).
I'm betting the TB is better overall (10g underhung cone vs 6.8g 166en)
But the $67 fostex can be hard to ignore too.
Norman
Nope, I have both (albeit the original Fe-166E). The tangband1772 treble is superior in dispersion and extension, and broadly speaking, a nicer sounding driver. Not sure how they achieved this in an 8" driver.
Still experimenting. Yes, the 2:1 DBR and identical ports Weems recipe
Built 2 rough prototypes (one around 0.9 cu ft with two 2" DIA x 3.75 " ports, and the other 1.3 cu ft with two 2" DIA x 1.9" ports ). Both are tuned to around 60 Hz. The smaller box is a little peakier sounding in the midrange, has a bit more midbass hit between 100 Hz and 200 Hz and the larger one is more laid back and in practice could probably work without a sub with a single ended amp (high output impedance) and small scale / jazz music. One of my test amps is a 1.5 watt amp. OTOH, the smaller cab sounds punchy with either tube or solid state amps, though a bit boomy.
Both do okay as far as mid bass go. Real bass below 60 hz is more or less missing. Either sound louder than the W8-1772 in the karlson K12 (though I fancy that the reason is the K-slot dispersing sound across a wider area) , though I have no doubt that power handling in the K12 would probably be superior.
Given a choice, I'd like to integrate a smooth hi-eff sub with the larger cab, .. which is what I'm planning out. I'll talk more about it on my other thread when I'm done experimenting. I don't want to hijack this thread.
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thanks zob, I've replaced my compression driver / horn (as my avatar picture) with a dual 4" tang band bamboo.
The system was developing a ground loop somewhere that the +110db 1w/1m horn is making quite annoying.
It has lost some dynamics (some realism) but gained intelligibility.
The tang bands sit on top of my dual 15's.
Crossing 24db at 400hz to the full rangers, it is very loud and great impactful bass. Voices are more intelligible now than the horn crossed at either 1khz or 750hz. I'd prefer a 200hz 24db crossover point for the full rangers, but baffle step is quite real, especially backing up against a window (-3db @ 500hz and -6db @ 250hz), comfirmed using an equalizer.
I've been debating betwen the alpair 10, a fostex fe166e (of some sort), and the 1772 8" tang band.
In the past, I've run my dual 4" wide open with an 80hz f-mod on the 15's.
If I had ran it that way yesterday, I would have blown them in the opening scenes of "Valkarie". A WW2 German group was suprise attacked. Very, very loud compared to dialog (running off stereo outputs from dvd player).
Norman
The system was developing a ground loop somewhere that the +110db 1w/1m horn is making quite annoying.
It has lost some dynamics (some realism) but gained intelligibility.
The tang bands sit on top of my dual 15's.
Crossing 24db at 400hz to the full rangers, it is very loud and great impactful bass. Voices are more intelligible now than the horn crossed at either 1khz or 750hz. I'd prefer a 200hz 24db crossover point for the full rangers, but baffle step is quite real, especially backing up against a window (-3db @ 500hz and -6db @ 250hz), comfirmed using an equalizer.
I've been debating betwen the alpair 10, a fostex fe166e (of some sort), and the 1772 8" tang band.
In the past, I've run my dual 4" wide open with an 80hz f-mod on the 15's.
If I had ran it that way yesterday, I would have blown them in the opening scenes of "Valkarie". A WW2 German group was suprise attacked. Very, very loud compared to dialog (running off stereo outputs from dvd player).
Norman
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Go back and look at the plots in post #253. At 15* off axis the 1772's are putting out at 15KHz the same SPL as at 2KHz. Same at 30*! The dip in the 15* trace centered at 7.5KHz is right in the middle of the sibilance range. This smooths out those spitty vocals.
Looking at the factory plots for the 166, you may get something similar, but the all important 15* plot is missing.
Bob
>>> I've been debating betwen the alpair 10, a fostex fe166e (of some sort), and the 1772 8" tang band.
These are all good choices with their own flavors of goodness... including the cute little TB bamboo drivers which are also great. I have the 4" TB bamboos in my home theater setup as well as fostex 168s and 165k. I want to hear the alpairs!
>>> Built 2 rough prototypes (one around 0.9 cu ft with two 2" DIA x 3.75 " ports, and the other 1.3 cu ft with two 2" DIA x 1.9" ports ). Both are tuned to around 60 Hz. The smaller box is a little peakier sounding in the midrange, has a bit more midbass hit between 100 Hz and 200 Hz
Simmed a few small cabs for the TB 1808 (the 1772's brother) over the weekend. Seems my results are similar to your comments above Zobsky. I will punch in the specs for the 1772 and compare. I bet these drivers sound similar (all of the TBs i've heard have a family sound from 3" to 8") and even tho max flat bass doesn't look so good the way the drivers sound in simple sealed cabs produces great real world results that have detail and tone rivaling quality two ways. They are not perfect but do so much really well. I am considering just sealing them up in small boxes and sitting them on top of subs... or 15" woofers... which once heard, are addictive! In larger ported cabs the 1808s look like they produce great bass... just not sure from a power handling standpoint if this is the way to go but from what i 'see' these TBs have the potential to offer true full range sound all by themselves.
Godzilla
These are all good choices with their own flavors of goodness... including the cute little TB bamboo drivers which are also great. I have the 4" TB bamboos in my home theater setup as well as fostex 168s and 165k. I want to hear the alpairs!
>>> Built 2 rough prototypes (one around 0.9 cu ft with two 2" DIA x 3.75 " ports, and the other 1.3 cu ft with two 2" DIA x 1.9" ports ). Both are tuned to around 60 Hz. The smaller box is a little peakier sounding in the midrange, has a bit more midbass hit between 100 Hz and 200 Hz
Simmed a few small cabs for the TB 1808 (the 1772's brother) over the weekend. Seems my results are similar to your comments above Zobsky. I will punch in the specs for the 1772 and compare. I bet these drivers sound similar (all of the TBs i've heard have a family sound from 3" to 8") and even tho max flat bass doesn't look so good the way the drivers sound in simple sealed cabs produces great real world results that have detail and tone rivaling quality two ways. They are not perfect but do so much really well. I am considering just sealing them up in small boxes and sitting them on top of subs... or 15" woofers... which once heard, are addictive! In larger ported cabs the 1808s look like they produce great bass... just not sure from a power handling standpoint if this is the way to go but from what i 'see' these TBs have the potential to offer true full range sound all by themselves.
Godzilla
hey Bob - what do you think is the safe and effective amplifier upper power limit to make the most of 1772's dynamic range and not snap its coil? (I'm on 25w/channel) - 1772's high end is helped by what's apparently a good whizzer and phase plug design
Looking forward to hearing about other builds apart from mine. There's only so much sawdust I can create per weekend 🙂
I'm currently trying to decide on a set of full rangers for an open baffle supplemented by 2 X 10" bass reflex enclosures (the OB would sit on top of the BR enclosures) and crossed over kinda high. The full range would run without any additional EQ (I plan to biamp using an active crossover and run without any passive components between speakers and amps except wire). I'm attracted to the Fostex 166EN partly due to cost and decreased beaming, but the Qts is fairly low and the power handling will be marginal for my room. The TB 1808 might be the best choice overall, although I wish the price were lower. I won't need it to produce any bass below about 250 Hz. Any advice from the gurus? Any other speaker that would be better for my application?
Yes, the 1808 is a great full range driver but for less money the Wild Burro Betsy works great on open baffle and does not need a tweeter. It has a similar sound to the Fostex drivers (somewhat forward) and is very dynamic and detailed. If you like detail the Betsy's are worth considering for sure. Nearly every full range driver i try on OB sounds good as long as bass duty is done by something else.
Since i have the hole already cut, i am going to purchase the Eminence Alpha 8 and see how it sounds on OB with Alpha 15's below just for kicks. I have to dial in the tweeters but expect working on a crossover might provide a fun distraction to the excellent full rangers i've been listening too and enjoying for several years.
The attached chart are simmed drivers on a 24" wide x 48" tall open baffle. All make it to 250hz and all are capable drivers worth considering. What's interesting to me is how their responses converge almost leading one to believe they will sound similar... but they don't so something must be happening higher up in frequency that gives each driver its character.
Godzilla
Since i have the hole already cut, i am going to purchase the Eminence Alpha 8 and see how it sounds on OB with Alpha 15's below just for kicks. I have to dial in the tweeters but expect working on a crossover might provide a fun distraction to the excellent full rangers i've been listening too and enjoying for several years.
The attached chart are simmed drivers on a 24" wide x 48" tall open baffle. All make it to 250hz and all are capable drivers worth considering. What's interesting to me is how their responses converge almost leading one to believe they will sound similar... but they don't so something must be happening higher up in frequency that gives each driver its character.
Godzilla
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actually I was looking closely at the measured response of a jamo dual 12" open baffle (reference 907 in feb 2009).
The dipole dip is higher than expected. I assume that it is because eventhough the mid is a 5.5", the baffle looks smaller than 17.3" for the dip that should have been at 800hz if the baffle was 17.3" wide. The driver width makes the baffle look smaller (shorter distance to the rear).
But what is interesting is that spacially averaged in JA's room, there was no suckout at 1khz (page 108). But you see on the graphs of the individual drivers that the mid dips at 1.1khz, the feq boost (feq or where rear wave is 90 degrees out of phase, thus adding) near 500-600hz, then it rolls off (but not too much).
Norman
The dipole dip is higher than expected. I assume that it is because eventhough the mid is a 5.5", the baffle looks smaller than 17.3" for the dip that should have been at 800hz if the baffle was 17.3" wide. The driver width makes the baffle look smaller (shorter distance to the rear).
But what is interesting is that spacially averaged in JA's room, there was no suckout at 1khz (page 108). But you see on the graphs of the individual drivers that the mid dips at 1.1khz, the feq boost (feq or where rear wave is 90 degrees out of phase, thus adding) near 500-600hz, then it rolls off (but not too much).
Norman