I am going to design myself a 3 way center channel. For the design it will have the tweeter over the mid, in the middle with 8" woofers on the sides. The box will be about 9" tall, 30 or so inches wide and as deep as it needs to be for the required volume. My fronts are Swan diy2.2's so I'll probably use a hivi Q1R for the tweeter with it's Fs of 1000htz, I have some flexibility with the crossover point. A planar tweeter would be interesting to use if its possible??, but I don't think it would match my Swan's Q1R. Anyway, given I haven't selected my drivers yet, what are the ideal crossover points for a center channel? Are there ranges of speech where the crossover points should be avoided because it would be distracting? With this information I could choose drivers that fit those specs. These will crossover to my sub at 60htz.
Thanks, Fosmo
Thanks, Fosmo
I can't answer your question directly because it seems rather non sequitur...why the presumption that "use" would dictate crossover alignment rather than the drivers in the system?
And while we're at it, a question that has me stumped for anyone listening...Why is it considered A-OK to use completely different speaker systems together in a home theater system while it is clearly not OK in a stereo system? Just asking questions.
Mike
And while we're at it, a question that has me stumped for anyone listening...Why is it considered A-OK to use completely different speaker systems together in a home theater system while it is clearly not OK in a stereo system? Just asking questions.
Mike
As a rule of thumb, a lot of the human speech range is between 300 and 3000 Hz.
It might work best to cross over to the Q1R at 3 or 4 kHz - or above - especially if using it in a 3-way.
https://www.parts-express.com/pedocs/specs/297-417-hivi-q1r-spec-sheet.pdf
It might work best to cross over to the Q1R at 3 or 4 kHz - or above - especially if using it in a 3-way.
https://www.parts-express.com/pedocs/specs/297-417-hivi-q1r-spec-sheet.pdf
Well, there's a number of acceptable ways, so a few starting with the musical BW it's 60 - 250 - 2000 - 6000 Hz or stretch it to the limits of the Q1R
The pioneer's octave spreads are 60 - 152 - 385 - 977 Hz (too low)
The pioneer's telephone speech BWs are 60 - 250 - 2500 - 12500 Hz (analog) or 60 - 300 - 3000 - 12500 Hz (digital), so use the Q1R to its limits and trade higher XO point for greater power handling/less harmonic distortion.
The pioneer's octave spreads are 60 - 152 - 385 - 977 Hz (too low)
The pioneer's telephone speech BWs are 60 - 250 - 2500 - 12500 Hz (analog) or 60 - 300 - 3000 - 12500 Hz (digital), so use the Q1R to its limits and trade higher XO point for greater power handling/less harmonic distortion.
Well, it's not really OK unless THX certified, but for consumers in general, the processors, room variables make it a waste of time to get too serious with speaker matching as long as the CC does a good job of the mono ~250 - 8 kHz female speech BW whereas in stereo both channels are comb filtering (blending) the entire BW, so obviously much more critical.
IOW the female's superior hearing is the key to an excellent audio system IME when there's one in the listening group. Like the old saying goes, 'when mama's happy, everybody's happy and when not, nobody's happy'
.-GM, what do you mean by the "pioneer octave spread"?
I have narrowed my choices down. It looks like 250htz and 3000htz XO points? For the woofers I will use 2 8" Hivi M8N-1B's (88Db) ($39ea). For the tweeter it will be the Hivi Q1R ($20).
I really just need a mid now. The 3 best options I found are:
1st:-4" Dayton RS100P-8 ($25), the only negative is the sensitivity is a couple Db's less than the M8N. (86.2 vs. 88Db's)
2nd:-5" HiVi M5N-b ($25), I like the look of this one as it matches the M8N but it would likely need to XO earlier than the other 2.(87Db)
3rd:-4" FaitalPRO 4FE35 ($33), this one has a higher sensitivity (91Db)than the M8N so the overall speaker would be more sensitive and this could XO high like the Dayton. I'm also not a fan of the look of the mounting ring but looks aren't a deal breaker. With this being a "Pro" type driver should I be concerned with the quality of the sound as a trade off for high sensitivity? I do value sound quality over sensitivity though.
What do you guys think?
I have narrowed my choices down. It looks like 250htz and 3000htz XO points? For the woofers I will use 2 8" Hivi M8N-1B's (88Db) ($39ea). For the tweeter it will be the Hivi Q1R ($20).
I really just need a mid now. The 3 best options I found are:
1st:-4" Dayton RS100P-8 ($25), the only negative is the sensitivity is a couple Db's less than the M8N. (86.2 vs. 88Db's)
2nd:-5" HiVi M5N-b ($25), I like the look of this one as it matches the M8N but it would likely need to XO earlier than the other 2.(87Db)
3rd:-4" FaitalPRO 4FE35 ($33), this one has a higher sensitivity (91Db)than the M8N so the overall speaker would be more sensitive and this could XO high like the Dayton. I'm also not a fan of the look of the mounting ring but looks aren't a deal breaker. With this being a "Pro" type driver should I be concerned with the quality of the sound as a trade off for high sensitivity? I do value sound quality over sensitivity though.
What do you guys think?
'Pioneers' as in the folks that invented modern sound reproduction (Western Electric, Bell Labs) to the point initially that over the decades since the mid 1930s any major advances has only been through increasing materials, manufacturing technology, or as the inventor Tom Danley laments, 'the ancients keep stealing all my inventions'!
Sound expands exponentially, so in a driver's theoretical pistonic BW (driver Fs, VC coil's frequency) it can be expressed in octave spreads based on the mean between these two when calculating XO points, i.e. basically polar matching without (historically) having to use either factory polar plots (not normally available to the DIYer)/DIY them:
Fh = Fl*2^n
Fl = Fh/2^n
n = ln(Fh/Fl)/ln(2)
where:
Fh = upper frequency
Fl = lower frequency, or the XO point in this case
n = octave spread
ln(2) = 0.6931
Sound expands exponentially, so in a driver's theoretical pistonic BW (driver Fs, VC coil's frequency) it can be expressed in octave spreads based on the mean between these two when calculating XO points, i.e. basically polar matching without (historically) having to use either factory polar plots (not normally available to the DIYer)/DIY them:
Fh = Fl*2^n
Fl = Fh/2^n
n = ln(Fh/Fl)/ln(2)
where:
Fh = upper frequency
Fl = lower frequency, or the XO point in this case
n = octave spread
ln(2) = 0.6931
Well, obviously you can mix n' match XO points between those I listed, but lose basic polar matching that often equates to increased XO design time/complexity.
Again based on XO octave spread:
mean = sqrt(250*3000) = ~866 Hz
eff. dia. = ~13543/pi/866 = ~4.98"/12.64 cm, so 6" frame size if favoring an HF bias or 6.5" for LF bias; beyond this, I've 'no hands on' experience, so you/others will have to decide what's best overall.
Prosound high speech intelligibility has been the primary performance goal since day one, so is best overall for any speaker alignment IME, especially in the critical mids BW.
In short, there's no such thing as having too much efficiency, just a point of diminishing returns or from an acoustics POV: 'acoustic solutions to acoustic problems'.
I'm only weighing in because I was going to ask, "What are the ideal specifications for a centre speaker?" (Personally, I believe anything beyond stereo for a Hi-fi system is a waste of time).
Practically, home theatre systems are a different beast. A flat frequency response is not a suitable solution. Singing and talking are vastly different. My first observation is that nobody seems to all for the 'slope'. You may set your low-pass to 80Hz but at 85Hz output is only a few dB down. Dependent on the slope, In a home theatre I would limit the upper response of a ported sub to 70Hz. Blasphemy: @ 6dB per octave I'd set my centre-speaker low threshold to around 90Hz.
When a cranked-up sub catches the fundamental frequencies of a male voice the result is muffle and waffle. Don't cuss me for distorting truth, the claimed function of the centre speaker is to increase clarity.
There is a simple test: Don Lafontaine.
Practically, home theatre systems are a different beast. A flat frequency response is not a suitable solution. Singing and talking are vastly different. My first observation is that nobody seems to all for the 'slope'. You may set your low-pass to 80Hz but at 85Hz output is only a few dB down. Dependent on the slope, In a home theatre I would limit the upper response of a ported sub to 70Hz. Blasphemy: @ 6dB per octave I'd set my centre-speaker low threshold to around 90Hz.
When a cranked-up sub catches the fundamental frequencies of a male voice the result is muffle and waffle. Don't cuss me for distorting truth, the claimed function of the centre speaker is to increase clarity.
There is a simple test: Don Lafontaine.
Sideways MTMs as centres do not work well unless the midWoofer to tweeter XO is (ideally) less than a quarter wavelength. In your case the XO from woofers to mids should be approx at a quarter. wavelength of the distance between the centres of the 2 woofers. At that point the woofers act/look like a single woofer.
dave
dave
Surtsey- Good point about the center being more for speech, that music. On my reciever I have the options of 100,80,or 50htz. I would use 50htz.
Dave- My center will be a 3 way design with the tweeter over the 4 inch mid, in the middle, with the (2) 8" woofers on either side. I think the distance between them is close enough but I'm not sure on the calculation.
Dave- My center will be a 3 way design with the tweeter over the 4 inch mid, in the middle, with the (2) 8" woofers on either side. I think the distance between them is close enough but I'm not sure on the calculation.
Dolby specs for center channels are that they should in fact be fullrange; the receiver does the main orchestration otherwise.
I understand. I did this illustration in 2007 to illustrate the proper way to do a sideways multiway centre channle (ignore the second mid).
Note that even this fails the quarer wave at the mid-tweeter XO (i’d be doing a WAW with a 3” replacing the mid+tweeter), but the woofer to mid is more critical in my estimation. I usually like to cross mids <250-300Hz, which represents a separation of 25-35cm.
dave
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The pioneer's thought so, but have only used the analog one 1st order on a 15" co-ax woofer/mid, 2"? tweeter, which sounded great in the intended vintage mono corner cab.
Note that this was for a system that was by design at least -24 dB/40 Hz, so the fact that the 250 Hz = ~16 Hz Fs was moot.