Search found 2452 matches

by chris661
Fri Oct 08, 2021 9:43 pm
Forum: Speakers
Topic: Purifi-based monitor - options
Replies: 34
Views: 4326

Re: Purifi-based monitor - options

IIRC, Hornresp can model it if you morph it into an offset-driver alignment.

Chris
by chris661
Thu Oct 07, 2021 6:49 pm
Forum: Speakers
Topic: Purifi-based monitor - options
Replies: 34
Views: 4326

Re: Purifi-based monitor - options

A peak before rolloff will tend to ring.

Make the port longer to drop the tuning. The result should be a smoother frequency response, and I'd also expect the group delay to improve and/or push issues down in frequency.

Another option would be to go sealed, and EQ the speaker + room result.

Chris
by chris661
Thu Sep 30, 2021 7:50 pm
Forum: Assorted Stuff
Topic: Owston ‘21: What Are You Bringing?
Replies: 16
Views: 730

Re: Owston ‘21: What Are You Bringing?

Think it'll be the 8" 2.5-way speakers this year, likely powered by something reasonably meaty and solid-state. Happy to mix-and-match things, and I have a couple of things I could bring that might come in handy: - Measurement setup (SPL and impedance) - Powersoft amps (active crossovers etc) -...
by chris661
Thu Sep 30, 2021 7:38 pm
Forum: Assorted Stuff
Topic: Owston meet 27+28 Nov 21-add your name here
Replies: 18
Views: 729

Re: Owston meet 27+28 Nov 21-add your name here

Saturday and probably Sunday for me, Steve.
Really looking forward to it.

Chris
by chris661
Wed Sep 22, 2021 8:44 am
Forum: Assorted Stuff
Topic: Owston 21 ???
Replies: 37
Views: 1435

Re: Owston 21 ???

Happy with either, Steve. Have a few things I could bring.

Chris
by chris661
Sat Sep 11, 2021 3:53 pm
Forum: Speakers
Topic: PERSPEX QUASAR ver 2.0 prototype build
Replies: 195
Views: 38372

Re: PERSPEX QUASAR ver 2.0 prototype build

Thinking about it a little more, intuitively the above-mentioned inductor-only filter makes some sense: starting with the (large) assumption that each driver is approximately flat on an infinite baffle, we'd expect a -6dB/octave rolloff towards the bass in the region above Fs on the Lowther. In orde...
by chris661
Sat Sep 11, 2021 7:00 am
Forum: Speakers
Topic: PERSPEX QUASAR ver 2.0 prototype build
Replies: 195
Views: 38372

Re: PERSPEX QUASAR ver 2.0 prototype build

The fact that the lower mids improved with polarity swap of the Lowther just tells me that something else is wrong. Mark, I went back to XSim, which was the tool that helped me realise that inverted polarity improved the summation, and tried out every permutation of the crossover components that ha...
by chris661
Thu Sep 09, 2021 7:01 pm
Forum: Speakers
Topic: PERSPEX QUASAR ver 2.0 prototype build
Replies: 195
Views: 38372

Re: PERSPEX QUASAR ver 2.0 prototype build

As will I Chris. When last we had my mini meet and measured the test baffles, we now have 3 different OX'ers to play with: James original 1st Order series XO* 2nd order series OX based on actual measured speakers on test baffles and ESP research of series filters 2nd order conventional parallel fil...
by chris661
Sat Sep 04, 2021 8:57 am
Forum: Speakers
Topic: Speaker Update
Replies: 1
Views: 306

Speaker Update

Thought I'd do a bit of a write-up. It's been a while since I posted here, and I think I've finally figured out some speakers that will keep me happy for a long time. I've had these speakers for a few years now, and they've been pretty much unchanged for most of that time. When I first built them, t...
by chris661
Fri Sep 03, 2021 6:54 pm
Forum: Speakers
Topic: PERSPEX QUASAR ver 2.0 prototype build
Replies: 195
Views: 38372

Re: PERSPEX QUASAR ver 2.0 prototype build

Cool!
Interested to see which crossover you go with.

Chris
by chris661
Sat Aug 07, 2021 6:19 pm
Forum: Speakers
Topic: Something Stirs in the Workshop
Replies: 78
Views: 35472

Re: Something Stirs in the Workshop

Very nice work.

A question, if I may: if I brought you a horn made of a different material, could you replicate it in wood?
It would be okay if the original was destroyed.

TIA,
Chris
by chris661
Mon Jul 19, 2021 7:48 pm
Forum: Speakers
Topic: Purifi-based monitor - options
Replies: 34
Views: 4326

Re: Purifi-based monitor - options

Making the port longer & wider will maintain the tuning frequency while lowering the air velocity. However, the port itself can also exhibit resonances, so the hundreds-of-Hz range may end up bumpy. That's one of the tradeoffs. For example, the 15" subwoofers I use for PA stuff are only rea...
by chris661
Sun Jul 18, 2021 5:31 pm
Forum: Speakers
Topic: Purifi-based monitor - options
Replies: 34
Views: 4326

Re: Purifi-based monitor - options

Hi Mark, I'm a bit surprised that the group delay is changing - I'm assuming you're keeping the tuning frequency the same..? Personally, I'd prioritise linearity (in terms of output at higher power levels) over group delay, on the grounds that the room is likely to swamp small differences. I do reco...
by chris661
Sat Jun 26, 2021 8:36 am
Forum: Speakers
Topic: Purifi-based monitor - options
Replies: 34
Views: 4326

Re: Purifi-based monitor - options

Here it is for 1W ... seems a bit high ... but I have no background on this. PuriMLTL_4ohm_Velocity.JPG For HiFi designs, I try to keep below 17m/s at maximum expected power. Above that, compression starts to kick in, where the port won't "keep up" with the driver as levels increase. NB -...
by chris661
Mon Jun 14, 2021 6:24 pm
Forum: Assorted Stuff
Topic: Day out in Hull Friday 11th June.
Replies: 64
Views: 5540

Re: Day out in Hull Friday 11th June.

it actually sounded quite normal on its little speakers But if you listen to it on anything like good headphones the bass is playing more of a tune than we could hear in the room. Might be a room effect. I've measured +15dB peaks and near-perfect cancellations. I'm pretty lucky with my room - there...