Hi,
i built my first pair of speakers and when making the crossover I noticed that the compression drivers are not 100% identical in frequency response. At around 2,2kHz there is a difference of about 4db. We are talking about the HF10AK measured without horn in about 1m distance. In the final speaker with the horn I needed to EQ this part heavier plus one driver is 1dB louder than the other. Would you say this is normal? Are they in tolerance and matched close enough? Or should they be closer together?
With the DSP I can get a flat FR. But let's say you want to build a passive speaker from Humble made hifi and you buy this pair of drivers. You would have a 4dB dip in one speaker. Not cool...
i built my first pair of speakers and when making the crossover I noticed that the compression drivers are not 100% identical in frequency response. At around 2,2kHz there is a difference of about 4db. We are talking about the HF10AK measured without horn in about 1m distance. In the final speaker with the horn I needed to EQ this part heavier plus one driver is 1dB louder than the other. Would you say this is normal? Are they in tolerance and matched close enough? Or should they be closer together?
With the DSP I can get a flat FR. But let's say you want to build a passive speaker from Humble made hifi and you buy this pair of drivers. You would have a 4dB dip in one speaker. Not cool...
Attachments
Is there a chance one or the other was opened or used before you got it? I’m thinking perhaps one is more broken in with use. I’ve bought stuff before which obviously was returned by others and resold. It’s not a good feeling and a bad business policy opened and used stuff should be rated b stock. Which shop was this?
Could you measure again at 3m and louder level slightly off axis? Just curious. Could also be room modes.
They were brand new and not opened before. Only thing I noticed is that the rubber foam on the front was slightly off. So it is not 100% in the right position. I doubt that it makes a 4dB difference in that specific frequency.
@fabricadetabaco The measurement above was done in the exact same place. I did it after I noticed they were not exactly the same. I can measure them with horn in my room at my listening position. But with even more reflexions. The difference is still visible.
I just want to know if this is normal? If it's not normal I can contact the shop.
@fabricadetabaco The measurement above was done in the exact same place. I did it after I noticed they were not exactly the same. I can measure them with horn in my room at my listening position. But with even more reflexions. The difference is still visible.
I just want to know if this is normal? If it's not normal I can contact the shop.
I read that. But it looks like his drivers were a little bit more extreme. He is talking about 2-3dB sensitivity loss. Mine is 1db and 4dB at that specific frequency. As it's my first speaker I don't know if this is tolerance or not.
I would take the back cap off both of them, put them back on and tighten the screws as evenly as possible.
Your measurements are probably within tolerance. Some batches are better matched than others.
Your measurements are probably within tolerance. Some batches are better matched than others.
@GM, attached measurement was without horn.
When I measure several times without mic or speaker moves, I get different curves. Besides that, you have 2db increments, it's too revealing maybe.
It's not easy to get reflection free measurements in a room, I figured that out the hard way, standing too close when setting crossover...
When I measure several times without mic or speaker moves, I get different curves. Besides that, you have 2db increments, it's too revealing maybe.
It's not easy to get reflection free measurements in a room, I figured that out the hard way, standing too close when setting crossover...
Right, I can still understand most of what I read [in English only 🙁] and from experience agreed with Ernie's assessment [leaky sealed rear cover, AKA 'loading cap'] to account for the differences, so not sure why your response is relevant unless you were there and/or did the measurements.
I don't want to play around myself as long they are under warranty. Beside the difference in FR they work great. Before I make things worse...
And I'm happy to be listening to music. Took me a while to finish everything 😀 Now it's time to enjoy.
It is possible with time gating. 4 ms gate should be possible, which results in a resolution of 250 Hz. Arta supports it.
Swapping the voice coil and diaphragm assembly and measuring again will tell something about the source of the differences.