Back story:
So I'm thinking either a sealed or ported cab with a pair of pro 15" or 18" drivers. Budget is under $300 per driver since I have to buy 12 or 14 of them
. Maybe I should consider singles for the surrounds?
The Onken W cabs look interesting, but they also look like a bit of a headache to design.
At fist glance, the B&C 15TBW100 (B&C SPEAKERS) looks good in a simple bass reflex cab. Two of them together should give me around 97db/w/m with 3000 watts rms.
Their 18", 18 TBW100 (B&C SPEAKERS) offering looks good too. Higher sensitivity and a stated bandwidth of 35-1Khz.
(Q 1) Will using these 18's compromise sound quality in the 200-500hz range as compared to the 15" drivers?
(Q 2) With the active x-overs it will be easy to time align., but do I have to pay much attention to matching dispersion patterns at 400-500hz crossover. The horns will have around 90 deg dispersion at the x-over where the cones will be omni???
(Q 3) And finally center to center spacing - is it supposed to be under 1/2 or 1/4 wavelength?
Any and all suggestions welcome. This system will be overkill, but it is a big room and I want it to be loafing along at reference level for movies.
So I'm thinking either a sealed or ported cab with a pair of pro 15" or 18" drivers. Budget is under $300 per driver since I have to buy 12 or 14 of them
. Maybe I should consider singles for the surrounds?The Onken W cabs look interesting, but they also look like a bit of a headache to design.
At fist glance, the B&C 15TBW100 (B&C SPEAKERS) looks good in a simple bass reflex cab. Two of them together should give me around 97db/w/m with 3000 watts rms.
Their 18", 18 TBW100 (B&C SPEAKERS) offering looks good too. Higher sensitivity and a stated bandwidth of 35-1Khz.
(Q 1) Will using these 18's compromise sound quality in the 200-500hz range as compared to the 15" drivers?
(Q 2) With the active x-overs it will be easy to time align., but do I have to pay much attention to matching dispersion patterns at 400-500hz crossover. The horns will have around 90 deg dispersion at the x-over where the cones will be omni???
(Q 3) And finally center to center spacing - is it supposed to be under 1/2 or 1/4 wavelength?
Any and all suggestions welcome. This system will be overkill, but it is a big room and I want it to be loafing along at reference level for movies.
Four Gjallerhorns will be able to do structural damage in a room only 28x38x10.5ft.So I'm thinking either a sealed or ported cab with a pair of pro 15" or 18" drivers. Budget is under $300 per driver since I have to buy 12 or 14 of them
At fist glance, the B&C 15TBW100 looks good in a simple bass reflex cab. Two of them together should give me around 97db/w/m with 3000 watts rms.
Their 18", 18 TBW100 offering looks good too. Higher sensitivity and a stated bandwidth of 35-1Khz.
Will using these 18's compromise sound quality in the 200-500hz range as compared to the 15" drivers?
(Q 2) With the active x-overs it will be easy to time align., but do I have to pay much attention to matching dispersion patterns at 400-500hz crossover. The horns will have around 90 deg dispersion at the x-over where the cones will be omni???
(Q 3) And finally center to center spacing - is it supposed to be under 1/2 or 1/4 wavelength?[/COLOR]
Any and all suggestions welcome. This system will be overkill, but it is a big room and I want it to be loafing along at reference level for movies.
A pair of B&C 15TBW100 in a ported cabinet driven with 3000 watts will easily do 125 dB.
12 to 14 of them? With a low 500 Hz crossover, one will keep up with a 288.
The 15 will sound better than the 18 around the crossover region you suggest, and will be closer to 90 degree dispersion, the 18 would be slightly narrower.
If center to center spacing is more than 1/4 wavelength, comb filtering will result.
However, with the system you propose, you would soon be so deaf that you won't notice comb filtering
.Four Gjallerhorns will be able to do structural damage in a room only 28x38x10.5ft.
A pair of B&C 15TBW100 in a ported cabinet driven with 3000 watts will easily do 125 dB.
12 to 14 of them? With a low 500 Hz crossover, one will keep up with a 288.
The 15 will sound better than the 18 around the crossover region you suggest, and will be closer to 90 degree dispersion, the 18 would be slightly narrower.
If center to center spacing is more than 1/4 wavelength, comb filtering will result.
However, with the system you propose, you would soon be so deaf that you won't notice comb filtering
The building is constructed of steel beams & metal foom, so I don't think I have to worry about structural damage, but I could be wrong? The drywall could be another story
. I could do two GH's, but four would even out the in room response, no? The idea of 6 or 7 speakers is only for surround sound for movies. For music, it will just be the LR speakers playing. And I'll be sitting 24-28ft back from the speakers. The building is pretty leaky when it comes to bass I think... it's just drywall insulation and plywood. There will also be lots of room treatments.
1/4 wave length @ 500hz is only 16.5cm. No way to avoid comb filtering then...
In my control room I have heard the walls flapping at the resonant frequency with only around 105 dB output at 16 Hz.The building is constructed of steel beams & metal foom, so I don't think I have to worry about structural damage, but I could be wrong? The drywall could be another story
The idea of 6 or 7 speakers is only for surround sound for movies. For music, it will just be the LR speakers playing. And I'll be sitting 24-28ft back from the speakers.
1/4 wave length @ 500hz is only 16.5cm. No way to avoid comb filtering then...
Four Gjallerhorns are capable of 136.3 dB at 16 Hz at one meter. That could separate drywall from stud rather quickly.
Advocates of multiple subs for evening out room response speak in terms of small rooms, where the wavelengths are much longer than room dimensions.
Your room is not small, 35 feet is a 32 Hz wavelength, almost the length of a low B on a bass guitar.
Tom Danley's Synergy type speakers have all the drivers combined on a single constant directivity horn, each within 1/4 wavelength of the adjacent frequency band. No comb filtering, excellent phase, frequency and polar response.
The SH-50 has response low enough to use with the Gjallerhorn. With output capability of around 130 dB, a pair would suffice for a room your size.
Jason Cave has a used pair advertised for $4500 per pair plus shipping, available for pick up or audition in Luray, VA. 540-860-1099.
Art
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Surely that's not a regular 4 string?
The lowest note on those would be the open E string at 41Hz.
The bass player for the Red Elvises only uses three strings, but most electric basses are now 5 string.
The change seemed to start happening in the 90s, by the start of this century it seemed about 50%, now I see a lot more 5 strings than 4 strings.
40 Hz response used to be fine for pop, now 30 Hz will get most of it done, though there is plenty of music below that.
Yeah I noticed that around the same time.
Lots of reggae bass players use 5 strings but mostly so that they can fret the low E since playing an open string sounds very different to a fretted one.
On the other hand I used to work at the opera and all their contra basses were 5 stringed.
That was back in around '87.
Lots of reggae bass players use 5 strings but mostly so that they can fret the low E since playing an open string sounds very different to a fretted one.
On the other hand I used to work at the opera and all their contra basses were 5 stringed.
That was back in around '87.
Check out this link in regards to placing your subs vs. the room.
Boundary Cancellation and Room Modes
Have you considered a folded front loaded horn of some sort? This seemed like it was kind of close to meeting your needs, maybe redesign a bit smaller with a 15"...?
http://forum.speakerplans.com/topic11659_post369161.html#369161
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OP wanted to cross Altec 288 mid drivers at around 500 Hz, too low for the folded horn you suggested.
For sure, it doesn't take much if you happen to find out the resonant frequency of the drywall.
I'm always in awe of what Tom has achieved with the synergy horn. I'd love to hear them one day. But for now, working with what I have, there is no way around the 1/4 wavelength rule given the size of the Altec horns. I guess this is something you just have to accept as a compromise. There seem to be a fair amount of praise for the Onken and the Altec a7 etc and they all break the 1/4 wavelength rule.
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I missed that part the first time around. Very tempting, are they the active or passive version? At that price, I guess passive. I really wanted to have identical speakers (or very close) all the way round. Does Danley's smaller horns play down at low as the SH-50?
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