Blue Shadow
Waiting for Vintage Gear from this century
Pic is a 1000, but the L100 and L110 would look similar, too.
BOSE 901, without BOSE EQ?
- Thread starter iloveitloud
- Start date
Blue Shadow
Waiting for Vintage Gear from this century
The 501s thank you for that.
GD70
Lunatic Member
I had a set of series III's with the series IV EQ. I recapped the EQ and it made a big difference using the EQ vs. with out. Once you get the correct EQ in the signal path, then you'll hear how they are meant to sound. The other thing not mentioned, is do you have them properly setup according the the user manual? That is key. I did not have a good space for mine and never got to hear their full potential, and eventually sold them. I also refoamed all 18 drivers!
Good luck, Glenn
Good luck, Glenn
Ibemiked
Active Member
I have them 20 inches from the ground, 14 inches from the wall and no obstructions on the sides, so per the manual they are setup as recommended. It's actually pretty amazing what a difference the proper placement makes.
Ibemiked
Active Member
Nice l
Can you walk a dog with no leash? I’d avoid any Bose speaker without the eq , they need it to not sound truly horrid.
Michael Chew
New Member
Hello. I have 4 Bose 901 series 2 speakers( walnut type). They are in incredibly good condition. I would like to use all 4 speakers. Do I need to have 2 Bose series 2 active equalizers ? I was told by a tech at Bose that I do but in the manual I down loaded it said I could connect in series parallel and connect to a 4 ohm circuit instead of using one pair and connecting each speaker to an 8 ohm circuit. I do not know anything about sound quality. I am going to buy one active eq to get started. What amp or stereo amp do I need to drive the Bose 901 series 2 speakers? I can buy today a Yamaha RX-930 with 2 channel amp front and back. 85 watt front and 25 watt back. They have the coupler bar shunting out the pre amp out to the main amp in. This is where I connect the active eq? Please lend me your wisdom! Thank you
NH-MAN
Addicted Member
to save people some time looking at other thread mentioned here
Ok, folks, there's some confusion over the 901 EQ thing, here, yet everyone is correct. I installed many, many 901s in the 70s both in residences and in discos, too, and was a warranty repair shop for Bose gear, among others back then.
Here's the scoop:
* The original 901 Series I and IIs were an inefficient speaker due to the cabinet being sealed a la KLH and AR speakers. The equalizers for these 2 models were different in the boost and cut curves. This means that the 2 equalizers are sufficiently different for one to want to locate the proper one.
* The Series III 901 is a completely different animal as it was a ported design in an attempt to overcome the large investment in amplification and grow the installed base of 901s. IMHO, it worked. The equalizer for this model was, again, completely different in cosmetics as well as in the boost/cut curves.
* The Series IV/V/VI series were pretty much tweeks on the same basic design of the IIIs. Although the equalizers changed in cosmetics and switch placement, the boost/cut curves changed very little, IIRC. These were mainly the result of changes in production of the drivers.
How many equalizers to use........
* One equalizer is a 2-channel device so you need only one equalizer when you're:
- Using a 2-channel power amp or receiver to drive one or two sets of 901s, assuming that you're paralleling the 2 sets of 901s
* Two equalizers will be required if 2 stereo power amps are used to drive 2 pairs of 901s.
- That is, one channel of the equalizer will be needed for the boost/cut for each of the 4 channels in this configuration.
On connection of the equalizer(s):
- The 901 equalizers were designed to be placed into the Tape Monitor loop of a receiver or integrated amp. You'll find a Tape Monitor on the equalizer itself to replace the one that was used up on the receiver.
- For a preamp/power amp configuration, the equalizer would be placed between the preamp and power amp that drives the 901s.
- Alternately, the equalizer _could_ be placed in the Tape Monitor loop of the preamp, just as with the receiver.
BTW, can you reproduce the same Bose boost/cut curves with a parametric equalizer? Possibly. I recall I once cascaded 2 SAE equalizers (one connected into the other to get as much as +/-24db of boost/cut) to try to get it to sound like the Bose EQ with a set of the then-new Series IIIs. It was difficult but costly to achieve. IMHO, its not worth the effort and expense. I can't believe I even had that much time to dink around back then.
Caution for any of the older Series I, II and III equalizers. These are getting to be 30 - 40 years old and will need to have some components replaced in order for them to remain reliable. I suspect there will be a deterioration in sound quality due to aging components, too.
Hope that helps.
Cheers,
David
dshoaf, Jan 6, 2008 Report
Ok, folks, there's some confusion over the 901 EQ thing, here, yet everyone is correct. I installed many, many 901s in the 70s both in residences and in discos, too, and was a warranty repair shop for Bose gear, among others back then.
Here's the scoop:
* The original 901 Series I and IIs were an inefficient speaker due to the cabinet being sealed a la KLH and AR speakers. The equalizers for these 2 models were different in the boost and cut curves. This means that the 2 equalizers are sufficiently different for one to want to locate the proper one.
* The Series III 901 is a completely different animal as it was a ported design in an attempt to overcome the large investment in amplification and grow the installed base of 901s. IMHO, it worked. The equalizer for this model was, again, completely different in cosmetics as well as in the boost/cut curves.
* The Series IV/V/VI series were pretty much tweeks on the same basic design of the IIIs. Although the equalizers changed in cosmetics and switch placement, the boost/cut curves changed very little, IIRC. These were mainly the result of changes in production of the drivers.
How many equalizers to use........
* One equalizer is a 2-channel device so you need only one equalizer when you're:
- Using a 2-channel power amp or receiver to drive one or two sets of 901s, assuming that you're paralleling the 2 sets of 901s
* Two equalizers will be required if 2 stereo power amps are used to drive 2 pairs of 901s.
- That is, one channel of the equalizer will be needed for the boost/cut for each of the 4 channels in this configuration.
On connection of the equalizer(s):
- The 901 equalizers were designed to be placed into the Tape Monitor loop of a receiver or integrated amp. You'll find a Tape Monitor on the equalizer itself to replace the one that was used up on the receiver.
- For a preamp/power amp configuration, the equalizer would be placed between the preamp and power amp that drives the 901s.
- Alternately, the equalizer _could_ be placed in the Tape Monitor loop of the preamp, just as with the receiver.
BTW, can you reproduce the same Bose boost/cut curves with a parametric equalizer? Possibly. I recall I once cascaded 2 SAE equalizers (one connected into the other to get as much as +/-24db of boost/cut) to try to get it to sound like the Bose EQ with a set of the then-new Series IIIs. It was difficult but costly to achieve. IMHO, its not worth the effort and expense. I can't believe I even had that much time to dink around back then.
Caution for any of the older Series I, II and III equalizers. These are getting to be 30 - 40 years old and will need to have some components replaced in order for them to remain reliable. I suspect there will be a deterioration in sound quality due to aging components, too.
Hope that helps.
Cheers,
David
dshoaf, Jan 6, 2008 Report
jdmccall
Super Member
You can drive two pairs of 901's with one eq, if you have the right equipment. I would recommend a receiver, integrated or preamp with a tape monitor circuit (sometimes called an "external processor loop" -effectively the same thing). The Yamaha receiver is probably not a good choice. Avoid multi-channel AVR's. The simplest way to go without getting something pretty old, would be to find a good used NAD integrated amp that has a tape monitor circuit and also A/B speaker connections and selection. Connect the Bose eq in the tape monitor loop and the speakers to the A and B speaker jacks and you're done.
Wow so Bose need there own eq? So vintage equalizer cannot replace these . So they do not produce full range without it correct ?
jdmccall
Super Member
Correct. Graphic EQ's are a lousy substitute. A very flexible parametric with enough bands and boost could probably come very close but I think it's best to stick with the Bose units.
Just the 901’s. The 501/301/201/etc don’t require a special external EQ.
I dived into the world of Bose 901 Series 1 last year buy buying two electrically perfect but water damaged cabinets which I'd sanded down and refinished with custom made black acrylic panels. I tried using Audyessy XT32 and it worked...sort of. Highs were soft and Bass was non existent below 100Hz. I bought an EQ off of eBay for $100 n put another $200 in Audiophile parts. The results are incredible. sweet high, beautiful mid's, and deep Bass below 40Hz. I just bought another single 901 for the center channel and temporarily an running my Sony's DSP correction which gives me better highs than Audyessy did but Bass below 100Hz is severely attenuated.
Graphic Equalizers won't work because you need 18dB of boost at both 10kHz and above and 100Hz and below. There is Deer Creek custom mini DSP boxes. But I've never tried them and personally don't think they'd be as good as the analog active Bose Bose EQ boxes.
YOU NEED THE EQ !
Graphic Equalizers won't work because you need 18dB of boost at both 10kHz and above and 100Hz and below. There is Deer Creek custom mini DSP boxes. But I've never tried them and personally don't think they'd be as good as the analog active Bose Bose EQ boxes.
YOU NEED THE EQ !
Hi guys. I Know alot about 901's.. Davids comments above are all accurate. I got mine several years ago, series II. the cones on series Ii are almost always NOT foam so they don't rot like series 3,4,5,6...I got them due to unique design and unique sound. Lemme boil it down in lamans terms. You need to equalize the signal, place them correctly in the room and have a high wattage amp. If you have all 3 they sound spectacular.
Equalize - rebuild Bose factory series specific eq. Run two multi band eq's in series ( one into another), or get a digital signal processor with the eq curve programmed in it (deer Creek audio) has them. I have done all 3.
Bose eq's are old equipment. You will need to get it rebuilt. Two eq's..You will drive yourself insane adjusting both... But it can be done ( I used two for years). I currently use the dsp from deer Creek.. best solution. Sounds the best.
Placement... Place them correctly in the room.. this is critical. Google it.
High wattage amp. A all in one receiver, like 100 wpc will run them, but play too loud it will fry your amp (not the speakers) due to the huge equalization levels at low and high frequency required by the eq's. I have fried amps. High db's at such frequencies is hard on low power amps (fyi)
Get a crown pa amp.. cheap power get at least 250 wpc.. digital is ok, class A analog is better. a few hundred bucks. Play them loud with power and they sing. I have the original 901 paperwork.. it reccomends an amp with minimum 200 wpc.. I have an Adcom- gfa 555se amp which works fantastic but its spendy.
Lastly... Get a bbe Sonic maximizer for fine tuning. Put it before the eq. Use treble / base controls AT LAST OPTION, it messes up the frequency curve..
Hope this helps! hi I am
Hope this helps
Equalize - rebuild Bose factory series specific eq. Run two multi band eq's in series ( one into another), or get a digital signal processor with the eq curve programmed in it (deer Creek audio) has them. I have done all 3.
Bose eq's are old equipment. You will need to get it rebuilt. Two eq's..You will drive yourself insane adjusting both... But it can be done ( I used two for years). I currently use the dsp from deer Creek.. best solution. Sounds the best.
Placement... Place them correctly in the room.. this is critical. Google it.
High wattage amp. A all in one receiver, like 100 wpc will run them, but play too loud it will fry your amp (not the speakers) due to the huge equalization levels at low and high frequency required by the eq's. I have fried amps. High db's at such frequencies is hard on low power amps (fyi)
Get a crown pa amp.. cheap power get at least 250 wpc.. digital is ok, class A analog is better. a few hundred bucks. Play them loud with power and they sing. I have the original 901 paperwork.. it reccomends an amp with minimum 200 wpc.. I have an Adcom- gfa 555se amp which works fantastic but its spendy.
Lastly... Get a bbe Sonic maximizer for fine tuning. Put it before the eq. Use treble / base controls AT LAST OPTION, it messes up the frequency curve..
Hope this helps! hi I am
Hope this helps
bigx5murf
Super Member
Yes, I removed my pair from the ceiling of a house I was renovating. New owner let me have them.
tanker 200
Super Member
There used to be a pizza place on Long Island that had 901's hanging from the ceiling powered by a Pioneer SX-1250, it sounded nice from what I remember.
