So I had a pair of the pictured pioneers laying around and was disappointed with the performance in the lower frequencies. I thought I could improve on it and make a good set for a SET tube amp. I chose the bose full range driver based on the TS parameters found at parts express. The problem I'm having however is that the sound is horribly shrill between 2-4khz. I have not installed a low pass filter since I'm awaiting the tweeters; however the crossover point for the high pass (lowest recommended being 1800hz) is going to leave a big gap in that range.
I opted to get genuine bose drivers (from a car) since they were way cheap and didn't have to wait (unlike P-E). Perhaps the characteristics of the bose are worse than the P-E replacements?
Parts Express Parts Express Replacement Speaker Driver for Bose 901 4-1/2" 1 Ohm : Questions, Answers, How To, FAQs, Tips, Advice, Answers, Buying Guide
I opted to get genuine bose drivers (from a car) since they were way cheap and didn't have to wait (unlike P-E). Perhaps the characteristics of the bose are worse than the P-E replacements?
Parts Express Parts Express Replacement Speaker Driver for Bose 901 4-1/2" 1 Ohm : Questions, Answers, How To, FAQs, Tips, Advice, Answers, Buying Guide
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May need a shallow notch between 2 - 4kHz to make these sound right..
Do this with a parallel LRC network in series with the "full range driver."
Edit: Bose makes a lot of different 4" drivers, not sure that you can safely assume that the car drivers are anything like the ones being sold by Parts Express. Variants I am aware of include ones with 1,2,4, and 8 ohm voice coils, with and without magnetic shunts, different cone material formulations, and different spiders.
Do this with a parallel LRC network in series with the "full range driver."
Edit: Bose makes a lot of different 4" drivers, not sure that you can safely assume that the car drivers are anything like the ones being sold by Parts Express. Variants I am aware of include ones with 1,2,4, and 8 ohm voice coils, with and without magnetic shunts, different cone material formulations, and different spiders.
this is a 1 ohm driver w/a cloth surround (unlike the foam surround of the 901's and PE's). Paper cone w/o doping (unlike the 151's)
I've heard of impedance mismatch affecting tone (although I am not sure how); my test amp is a ss rated to run 4-16 ohm loads. I figure since the drivers are relatively efficient and am only cracking the vol. 1/4 of the way, it wouldn't hurt anything.
I've heard of impedance mismatch affecting tone (although I am not sure how); my test amp is a ss rated to run 4-16 ohm loads. I figure since the drivers are relatively efficient and am only cracking the vol. 1/4 of the way, it wouldn't hurt anything.
I've tried two different crossovers (left overs from something) and did see an improvement. Granted these are not sized for the application.
One was a car crossover (what looks like a 2nd order Linkwitz-Riley)...I think it was sized for 4 ohm loads; 2x10uF caps, a big ceramic resistor and two identical inductors of unknown value.
The other one came from a home speaker, looks like a 2nd order xover....10&12uF caps, different sized inductors sharing a single ferrite core and big resistor like the other one.
The 1st one had less bass than the 2nd one, but the 2nd one's bass was too boomy. I guess i'll salvage the car xovers' circuit boards to fit my application; but I'm still affraid of the tweeter's Fo being so close to the xover point. Any advice?
I was initially hoping to just have a high pass filter (cap on tweeter) and that's it.
Thanks; for posterity:
Car Audio - Parallel Notch Filter Circuit for Speaker Design
Now i just need to take some frequency response measurements. Any recommendations for quick and dirty freeware?
can you use any run of the mill microphone? I'm having a hard time finding calibration procedures for something other than certain units.
parallel nine of those and you would get 0.11 ohms. There is no ordinary amplifier that will drive 1 ohm, let alone 0.11 ohms. You mean series, 9 x 1ohm is obviously 9 ohms.
check the impedance, there is no way a Luxman will drive a 1 ohm drive unit for long.
If I am reading you correctly, you got the drive units from a car. Then they won't be 1 ohm, 4 ohms seems more probable.
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Any of the Bose full range drivers intended for use with automotive switching amps (class D) will likely be 1 ohm, and do not have a magnetic shunt - they're intended for use with with a dedicated amp and EQ. (Which may be integrated with the driver or in a separate module.)
Note that these drivers really aren't that efficient and you are asking your lux to produce 4X the current it was designed to furnish at all volume settings and I would not be surprised if the SOA of the output devices is exceeded at relatively modest volumes. You need to insert a 3 ohm resistor in series with each driver to make them a safe load for your amp. Note that your amplifier at a given volume setting is asked to produce 6dB more output power than with a 4 ohm speaker. You'll soon kill your amp if these are actually 1 ohm speakers - easily checked with an ohm meter - the 1 ohm driver with a meter good for low ohms will measure about 0.8 ohms dcr..
Edit: Don't hold it against me, but I worked for the particular company referenced for nine years, and did work on some OEM (automotive) as well as the Lifestyle line. (product development/R&D)
yes; series like you said. The drivers are indeed 1 ohm (checked w/multimeter).
My logic was telling me that even at 1 watt I'd get decent volume (if the driver was indeed 91+db/w like the PE one). Basically I'd be dumping 4x the current but still be within the safe parameters of the amp.
Amp rated at 55wpc; @ 8ohms. It was plenty loud at 1/4 volume and amp blinking at 1 watt
any way to sort this out using joule's or ohm's laws?
I'm obviously pretty noobish at this but do like to experiment with unusual setups if the math says it's ok. I ultimately want to use the speakers with a 7-15 wpc amp; but if I can't get away with it; i'll look for better suited drivers or play w/impedance matching trafos.
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No, not really. I would add those resistors I mentioned in order to keep your amplifier operating comfortably within the SOA of the output devices. We would need to know the devices in question, the instantaneous current delivered to the load and the instantaneous voltage across the transistors to know whether they are operating within acceptable limits. Note that this also affects the power transformer and rectifiers as well.
Bad idea on a whole lot of levels. (I spent a lot of time deliberately exploding amps like yours..)
These aren't the right drivers for your project, you ought to get the ones you originally looked at.
the ones I originally looked at are also 1 ohm
; just the T-S parameters are the correct ones. I've read putting a resistor just screws up the sound big time...is this true? I mean, they also make the driver in 4 and 8 ohm load, just not the P-E one (which is what I originally designed this thing around).- Status
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